diff options
Diffstat (limited to 'Documentation')
188 files changed, 12323 insertions, 4309 deletions
diff --git a/Documentation/00-INDEX b/Documentation/00-INDEX index 2a39aeba1464..d05737aaa84b 100644 --- a/Documentation/00-INDEX +++ b/Documentation/00-INDEX @@ -86,6 +86,8 @@ cachetlb.txt - describes the cache/TLB flushing interfaces Linux uses. cdrom/ - directory with information on the CD-ROM drivers that Linux has. +cgroups/ + - cgroups features, including cpusets and memory controller. connector/ - docs on the netlink based userspace<->kernel space communication mod. console/ @@ -98,8 +100,6 @@ cpu-load.txt - document describing how CPU load statistics are collected. cpuidle/ - info on CPU_IDLE, CPU idle state management subsystem. -cpusets.txt - - documents the cpusets feature; assign CPUs and Mem to a set of tasks. cputopology.txt - documentation on how CPU topology info is exported via sysfs. cris/ diff --git a/Documentation/ABI/testing/debugfs-kmemtrace b/Documentation/ABI/testing/debugfs-kmemtrace new file mode 100644 index 000000000000..5e6a92a02d85 --- /dev/null +++ b/Documentation/ABI/testing/debugfs-kmemtrace @@ -0,0 +1,71 @@ +What: /sys/kernel/debug/kmemtrace/ +Date: July 2008 +Contact: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> +Description: + +In kmemtrace-enabled kernels, the following files are created: + +/sys/kernel/debug/kmemtrace/ + cpu<n> (0400) Per-CPU tracing data, see below. (binary) + total_overruns (0400) Total number of bytes which were dropped from + cpu<n> files because of full buffer condition, + non-binary. (text) + abi_version (0400) Kernel's kmemtrace ABI version. (text) + +Each per-CPU file should be read according to the relay interface. That is, +the reader should set affinity to that specific CPU and, as currently done by +the userspace application (though there are other methods), use poll() with +an infinite timeout before every read(). Otherwise, erroneous data may be +read. The binary data has the following _core_ format: + + Event ID (1 byte) Unsigned integer, one of: + 0 - represents an allocation (KMEMTRACE_EVENT_ALLOC) + 1 - represents a freeing of previously allocated memory + (KMEMTRACE_EVENT_FREE) + Type ID (1 byte) Unsigned integer, one of: + 0 - this is a kmalloc() / kfree() + 1 - this is a kmem_cache_alloc() / kmem_cache_free() + 2 - this is a __get_free_pages() et al. + Event size (2 bytes) Unsigned integer representing the + size of this event. Used to extend + kmemtrace. Discard the bytes you + don't know about. + Sequence number (4 bytes) Signed integer used to reorder data + logged on SMP machines. Wraparound + must be taken into account, although + it is unlikely. + Caller address (8 bytes) Return address to the caller. + Pointer to mem (8 bytes) Pointer to target memory area. Can be + NULL, but not all such calls might be + recorded. + +In case of KMEMTRACE_EVENT_ALLOC events, the next fields follow: + + Requested bytes (8 bytes) Total number of requested bytes, + unsigned, must not be zero. + Allocated bytes (8 bytes) Total number of actually allocated + bytes, unsigned, must not be lower + than requested bytes. + Requested flags (4 bytes) GFP flags supplied by the caller. + Target CPU (4 bytes) Signed integer, valid for event id 1. + If equal to -1, target CPU is the same + as origin CPU, but the reverse might + not be true. + +The data is made available in the same endianness the machine has. + +Other event ids and type ids may be defined and added. Other fields may be +added by increasing event size, but see below for details. +Every modification to the ABI, including new id definitions, are followed +by bumping the ABI version by one. + +Adding new data to the packet (features) is done at the end of the mandatory +data: + Feature size (2 byte) + Feature ID (1 byte) + Feature data (Feature size - 3 bytes) + + +Users: + kmemtrace-user - git://repo.or.cz/kmemtrace-user.git + diff --git a/Documentation/ABI/testing/debugfs-pktcdvd b/Documentation/ABI/testing/debugfs-pktcdvd index bf9c16b64c34..cf11736acb76 100644 --- a/Documentation/ABI/testing/debugfs-pktcdvd +++ b/Documentation/ABI/testing/debugfs-pktcdvd @@ -1,4 +1,4 @@ -What: /debug/pktcdvd/pktcdvd[0-7] +What: /sys/kernel/debug/pktcdvd/pktcdvd[0-7] Date: Oct. 2006 KernelVersion: 2.6.20 Contact: Thomas Maier <balagi@justmail.de> @@ -10,10 +10,10 @@ debugfs interface The pktcdvd module (packet writing driver) creates these files in debugfs: -/debug/pktcdvd/pktcdvd[0-7]/ +/sys/kernel/debug/pktcdvd/pktcdvd[0-7]/ info (0444) Lots of driver statistics and infos. Example: ------- -cat /debug/pktcdvd/pktcdvd0/info +cat /sys/kernel/debug/pktcdvd/pktcdvd0/info diff --git a/Documentation/ABI/testing/ima_policy b/Documentation/ABI/testing/ima_policy new file mode 100644 index 000000000000..6434f0df012e --- /dev/null +++ b/Documentation/ABI/testing/ima_policy @@ -0,0 +1,61 @@ +What: security/ima/policy +Date: May 2008 +Contact: Mimi Zohar <zohar@us.ibm.com> +Description: + The Trusted Computing Group(TCG) runtime Integrity + Measurement Architecture(IMA) maintains a list of hash + values of executables and other sensitive system files + loaded into the run-time of this system. At runtime, + the policy can be constrained based on LSM specific data. + Policies are loaded into the securityfs file ima/policy + by opening the file, writing the rules one at a time and + then closing the file. The new policy takes effect after + the file ima/policy is closed. + + rule format: action [condition ...] + + action: measure | dont_measure + condition:= base | lsm + base: [[func=] [mask=] [fsmagic=] [uid=]] + lsm: [[subj_user=] [subj_role=] [subj_type=] + [obj_user=] [obj_role=] [obj_type=]] + + base: func:= [BPRM_CHECK][FILE_MMAP][INODE_PERMISSION] + mask:= [MAY_READ] [MAY_WRITE] [MAY_APPEND] [MAY_EXEC] + fsmagic:= hex value + uid:= decimal value + lsm: are LSM specific + + default policy: + # PROC_SUPER_MAGIC + dont_measure fsmagic=0x9fa0 + # SYSFS_MAGIC + dont_measure fsmagic=0x62656572 + # DEBUGFS_MAGIC + dont_measure fsmagic=0x64626720 + # TMPFS_MAGIC + dont_measure fsmagic=0x01021994 + # SECURITYFS_MAGIC + dont_measure fsmagic=0x73636673 + + measure func=BPRM_CHECK + measure func=FILE_MMAP mask=MAY_EXEC + measure func=INODE_PERM mask=MAY_READ uid=0 + + The default policy measures all executables in bprm_check, + all files mmapped executable in file_mmap, and all files + open for read by root in inode_permission. + + Examples of LSM specific definitions: + + SELinux: + # SELINUX_MAGIC + dont_measure fsmagic=0xF97CFF8C + + dont_measure obj_type=var_log_t + dont_measure obj_type=auditd_log_t + measure subj_user=system_u func=INODE_PERM mask=MAY_READ + measure subj_role=system_r func=INODE_PERM mask=MAY_READ + + Smack: + measure subj_user=_ func=INODE_PERM mask=MAY_READ diff --git a/Documentation/ABI/testing/sysfs-bus-pci b/Documentation/ABI/testing/sysfs-bus-pci index e638e15a8895..97ad190e13af 100644 --- a/Documentation/ABI/testing/sysfs-bus-pci +++ b/Documentation/ABI/testing/sysfs-bus-pci @@ -41,6 +41,49 @@ Description: for the device and attempt to bind to it. For example: # echo "8086 10f5" > /sys/bus/pci/drivers/foo/new_id +What: /sys/bus/pci/drivers/.../remove_id +Date: February 2009 +Contact: Chris Wright <chrisw@sous-sol.org> +Description: + Writing a device ID to this file will remove an ID + that was dynamically added via the new_id sysfs entry. + The format for the device ID is: + VVVV DDDD SVVV SDDD CCCC MMMM. That is Vendor ID, Device + ID, Subsystem Vendor ID, Subsystem Device ID, Class, + and Class Mask. The Vendor ID and Device ID fields are + required, the rest are optional. After successfully + removing an ID, the driver will no longer support the + device. This is useful to ensure auto probing won't + match the driver to the device. For example: + # echo "8086 10f5" > /sys/bus/pci/drivers/foo/remove_id + +What: /sys/bus/pci/rescan +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of all PCI buses in the system, and + re-discover previously removed devices. + Depends on CONFIG_HOTPLUG. + +What: /sys/bus/pci/devices/.../remove +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + hot-remove the PCI device and any of its children. + Depends on CONFIG_HOTPLUG. + +What: /sys/bus/pci/devices/.../rescan +Date: January 2009 +Contact: Linux PCI developers <linux-pci@vger.kernel.org> +Description: + Writing a non-zero value to this attribute will + force a rescan of the device's parent bus and all + child buses, and re-discover devices removed earlier + from this part of the device tree. + Depends on CONFIG_HOTPLUG. + What: /sys/bus/pci/devices/.../vpd Date: February 2008 Contact: Ben Hutchings <bhutchings@solarflare.com> @@ -52,3 +95,30 @@ Description: that some devices may have malformatted data. If the underlying VPD has a writable section then the corresponding section of this file will be writable. + +What: /sys/bus/pci/devices/.../virtfnN +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when hardware supports the SR-IOV + capability and the Physical Function driver has enabled it. + The symbolic link points to the PCI device sysfs entry of the + Virtual Function whose index is N (0...MaxVFs-1). + +What: /sys/bus/pci/devices/.../dep_link +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when hardware supports the SR-IOV + capability and the Physical Function driver has enabled it, + and this device has vendor specific dependencies with others. + The symbolic link points to the PCI device sysfs entry of + Physical Function this device depends on. + +What: /sys/bus/pci/devices/.../physfn +Date: March 2009 +Contact: Yu Zhao <yu.zhao@intel.com> +Description: + This symbolic link appears when a device is a Virtual Function. + The symbolic link points to the PCI device sysfs entry of the + Physical Function this device associates with. diff --git a/Documentation/ABI/testing/sysfs-class-regulator b/Documentation/ABI/testing/sysfs-class-regulator index 873ef1fc1569..e091fa873792 100644 --- a/Documentation/ABI/testing/sysfs-class-regulator +++ b/Documentation/ABI/testing/sysfs-class-regulator @@ -4,8 +4,8 @@ KernelVersion: 2.6.26 Contact: Liam Girdwood <lrg@slimlogic.co.uk> Description: Some regulator directories will contain a field called - state. This reports the regulator enable status, for - regulators which can report that value. + state. This reports the regulator enable control, for + regulators which can report that input value. This will be one of the following strings: @@ -14,16 +14,54 @@ Description: 'unknown' 'enabled' means the regulator output is ON and is supplying - power to the system. + power to the system (assuming no error prevents it). 'disabled' means the regulator output is OFF and is not - supplying power to the system.. + supplying power to the system (unless some non-Linux + control has enabled it). 'unknown' means software cannot determine the state, or the reported state is invalid. NOTE: this field can be used in conjunction with microvolts - and microamps to determine regulator output levels. + or microamps to determine configured regulator output levels. + + +What: /sys/class/regulator/.../status +Description: + Some regulator directories will contain a field called + "status". This reports the current regulator status, for + regulators which can report that output value. + + This will be one of the following strings: + + off + on + error + fast + normal + idle + standby + + "off" means the regulator is not supplying power to the + system. + + "on" means the regulator is supplying power to the system, + and the regulator can't report a detailed operation mode. + + "error" indicates an out-of-regulation status such as being + disabled due to thermal shutdown, or voltage being unstable + because of problems with the input power supply. + + "fast", "normal", "idle", and "standby" are all detailed + regulator operation modes (described elsewhere). They + imply "on", but provide more detail. + + Note that regulator status is a function of many inputs, + not limited to control inputs from Linux. For example, + the actual load presented may trigger "error" status; or + a regulator may be enabled by another user, even though + Linux did not enable it. What: /sys/class/regulator/.../type @@ -58,7 +96,7 @@ Description: Some regulator directories will contain a field called microvolts. This holds the regulator output voltage setting measured in microvolts (i.e. E-6 Volts), for regulators - which can report that voltage. + which can report the control input for voltage. NOTE: This value should not be used to determine the regulator output voltage level as this value is the same regardless of @@ -73,7 +111,7 @@ Description: Some regulator directories will contain a field called microamps. This holds the regulator output current limit setting measured in microamps (i.e. E-6 Amps), for regulators - which can report that current. + which can report the control input for a current limit. NOTE: This value should not be used to determine the regulator output current level as this value is the same regardless of @@ -87,7 +125,7 @@ Contact: Liam Girdwood <lrg@slimlogic.co.uk> Description: Some regulator directories will contain a field called opmode. This holds the current regulator operating mode, - for regulators which can report it. + for regulators which can report that control input value. The opmode value can be one of the following strings: @@ -101,7 +139,8 @@ Description: NOTE: This value should not be used to determine the regulator output operating mode as this value is the same regardless of - whether the regulator is enabled or disabled. + whether the regulator is enabled or disabled. A "status" + attribute may be available to determine the actual mode. What: /sys/class/regulator/.../min_microvolts diff --git a/Documentation/ABI/testing/sysfs-firmware-acpi b/Documentation/ABI/testing/sysfs-firmware-acpi index e8ffc70ffe12..4f9ba3c2fca7 100644 --- a/Documentation/ABI/testing/sysfs-firmware-acpi +++ b/Documentation/ABI/testing/sysfs-firmware-acpi @@ -69,9 +69,13 @@ Description: gpe1F: 0 invalid gpe_all: 1192 sci: 1194 + sci_not: 0 - sci - The total number of times the ACPI SCI - has claimed an interrupt. + sci - The number of times the ACPI SCI + has been called and claimed an interrupt. + + sci_not - The number of times the ACPI SCI + has been called and NOT claimed an interrupt. gpe_all - count of SCI caused by GPEs. diff --git a/Documentation/ABI/testing/sysfs-fs-ext4 b/Documentation/ABI/testing/sysfs-fs-ext4 new file mode 100644 index 000000000000..4e79074de282 --- /dev/null +++ b/Documentation/ABI/testing/sysfs-fs-ext4 @@ -0,0 +1,81 @@ +What: /sys/fs/ext4/<disk>/mb_stats +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Controls whether the multiblock allocator should + collect statistics, which are shown during the unmount. + 1 means to collect statistics, 0 means not to collect + statistics + +What: /sys/fs/ext4/<disk>/mb_group_prealloc +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The multiblock allocator will round up allocation + requests to a multiple of this tuning parameter if the + stripe size is not set in the ext4 superblock + +What: /sys/fs/ext4/<disk>/mb_max_to_scan +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The maximum number of extents the multiblock allocator + will search to find the best extent + +What: /sys/fs/ext4/<disk>/mb_min_to_scan +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + The minimum number of extents the multiblock allocator + will search to find the best extent + +What: /sys/fs/ext4/<disk>/mb_order2_req +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Tuning parameter which controls the minimum size for + requests (as a power of 2) where the buddy cache is + used + +What: /sys/fs/ext4/<disk>/mb_stream_req +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Files which have fewer blocks than this tunable + parameter will have their blocks allocated out of a + block group specific preallocation pool, so that small + files are packed closely together. Each large file + will have its blocks allocated out of its own unique + preallocation pool. + +What: /sys/fs/ext4/<disk>/inode_readahead +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + Tuning parameter which controls the maximum number of + inode table blocks that ext4's inode table readahead + algorithm will pre-read into the buffer cache + +What: /sys/fs/ext4/<disk>/delayed_allocation_blocks +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of blocks + that are dirty in the page cache, but which do not + have their location in the filesystem allocated yet. + +What: /sys/fs/ext4/<disk>/lifetime_write_kbytes +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of kilobytes + of data that have been written to this filesystem since it was + created. + +What: /sys/fs/ext4/<disk>/session_write_kbytes +Date: March 2008 +Contact: "Theodore Ts'o" <tytso@mit.edu> +Description: + This file is read-only and shows the number of + kilobytes of data that have been written to this + filesystem since it was mounted. diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 2a3fcc55e981..d9aa43d78bcc 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -609,3 +609,109 @@ size is the size (and should be a page-sized multiple). The return value will be either a pointer to the processor virtual address of the memory, or an error (via PTR_ERR()) if any part of the region is occupied. + +Part III - Debug drivers use of the DMA-API +------------------------------------------- + +The DMA-API as described above as some constraints. DMA addresses must be +released with the corresponding function with the same size for example. With +the advent of hardware IOMMUs it becomes more and more important that drivers +do not violate those constraints. In the worst case such a violation can +result in data corruption up to destroyed filesystems. + +To debug drivers and find bugs in the usage of the DMA-API checking code can +be compiled into the kernel which will tell the developer about those +violations. If your architecture supports it you can select the "Enable +debugging of DMA-API usage" option in your kernel configuration. Enabling this +option has a performance impact. Do not enable it in production kernels. + +If you boot the resulting kernel will contain code which does some bookkeeping +about what DMA memory was allocated for which device. If this code detects an +error it prints a warning message with some details into your kernel log. An +example warning message may look like this: + +------------[ cut here ]------------ +WARNING: at /data2/repos/linux-2.6-iommu/lib/dma-debug.c:448 + check_unmap+0x203/0x490() +Hardware name: +forcedeth 0000:00:08.0: DMA-API: device driver frees DMA memory with wrong + function [device address=0x00000000640444be] [size=66 bytes] [mapped as +single] [unmapped as page] +Modules linked in: nfsd exportfs bridge stp llc r8169 +Pid: 0, comm: swapper Tainted: G W 2.6.28-dmatest-09289-g8bb99c0 #1 +Call Trace: + <IRQ> [<ffffffff80240b22>] warn_slowpath+0xf2/0x130 + [<ffffffff80647b70>] _spin_unlock+0x10/0x30 + [<ffffffff80537e75>] usb_hcd_link_urb_to_ep+0x75/0xc0 + [<ffffffff80647c22>] _spin_unlock_irqrestore+0x12/0x40 + [<ffffffff8055347f>] ohci_urb_enqueue+0x19f/0x7c0 + [<ffffffff80252f96>] queue_work+0x56/0x60 + [<ffffffff80237e10>] enqueue_task_fair+0x20/0x50 + [<ffffffff80539279>] usb_hcd_submit_urb+0x379/0xbc0 + [<ffffffff803b78c3>] cpumask_next_and+0x23/0x40 + [<ffffffff80235177>] find_busiest_group+0x207/0x8a0 + [<ffffffff8064784f>] _spin_lock_irqsave+0x1f/0x50 + [<ffffffff803c7ea3>] check_unmap+0x203/0x490 + [<ffffffff803c8259>] debug_dma_unmap_page+0x49/0x50 + [<ffffffff80485f26>] nv_tx_done_optimized+0xc6/0x2c0 + [<ffffffff80486c13>] nv_nic_irq_optimized+0x73/0x2b0 + [<ffffffff8026df84>] handle_IRQ_event+0x34/0x70 + [<ffffffff8026ffe9>] handle_edge_irq+0xc9/0x150 + [<ffffffff8020e3ab>] do_IRQ+0xcb/0x1c0 + [<ffffffff8020c093>] ret_from_intr+0x0/0xa + <EOI> <4>---[ end trace f6435a98e2a38c0e ]--- + +The driver developer can find the driver and the device including a stacktrace +of the DMA-API call which caused this warning. + +Per default only the first error will result in a warning message. All other +errors will only silently counted. This limitation exist to prevent the code +from flooding your kernel log. To support debugging a device driver this can +be disabled via debugfs. See the debugfs interface documentation below for +details. + +The debugfs directory for the DMA-API debugging code is called dma-api/. In +this directory the following files can currently be found: + + dma-api/all_errors This file contains a numeric value. If this + value is not equal to zero the debugging code + will print a warning for every error it finds + into the kernel log. Be carefull with this + option. It can easily flood your logs. + + dma-api/disabled This read-only file contains the character 'Y' + if the debugging code is disabled. This can + happen when it runs out of memory or if it was + disabled at boot time + + dma-api/error_count This file is read-only and shows the total + numbers of errors found. + + dma-api/num_errors The number in this file shows how many + warnings will be printed to the kernel log + before it stops. This number is initialized to + one at system boot and be set by writing into + this file + + dma-api/min_free_entries + This read-only file can be read to get the + minimum number of free dma_debug_entries the + allocator has ever seen. If this value goes + down to zero the code will disable itself + because it is not longer reliable. + + dma-api/num_free_entries + The current number of free dma_debug_entries + in the allocator. + +If you have this code compiled into your kernel it will be enabled by default. +If you want to boot without the bookkeeping anyway you can provide +'dma_debug=off' as a boot parameter. This will disable DMA-API debugging. +Notice that you can not enable it again at runtime. You have to reboot to do +so. + +When the code disables itself at runtime this is most likely because it ran +out of dma_debug_entries. These entries are preallocated at boot. The number +of preallocated entries is defined per architecture. If it is too low for you +boot with 'dma_debug_entries=<your_desired_number>' to overwrite the +architectural default. diff --git a/Documentation/DMA-mapping.txt b/Documentation/DMA-mapping.txt index b2a4d6d244d9..01f24e94bdb6 100644 --- a/Documentation/DMA-mapping.txt +++ b/Documentation/DMA-mapping.txt @@ -136,7 +136,7 @@ exactly why. The standard 32-bit addressing PCI device would do something like this: - if (pci_set_dma_mask(pdev, DMA_32BIT_MASK)) { + if (pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { printk(KERN_WARNING "mydev: No suitable DMA available.\n"); goto ignore_this_device; @@ -155,9 +155,9 @@ all 64-bits when accessing streaming DMA: int using_dac; - if (!pci_set_dma_mask(pdev, DMA_64BIT_MASK)) { + if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { using_dac = 1; - } else if (!pci_set_dma_mask(pdev, DMA_32BIT_MASK)) { + } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { using_dac = 0; } else { printk(KERN_WARNING @@ -170,14 +170,14 @@ the case would look like this: int using_dac, consistent_using_dac; - if (!pci_set_dma_mask(pdev, DMA_64BIT_MASK)) { + if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(64))) { using_dac = 1; consistent_using_dac = 1; - pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK); - } else if (!pci_set_dma_mask(pdev, DMA_32BIT_MASK)) { + pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(64)); + } else if (!pci_set_dma_mask(pdev, DMA_BIT_MASK(32))) { using_dac = 0; consistent_using_dac = 0; - pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK); + pci_set_consistent_dma_mask(pdev, DMA_BIT_MASK(32)); } else { printk(KERN_WARNING "mydev: No suitable DMA available.\n"); @@ -192,7 +192,7 @@ check the return value from pci_set_consistent_dma_mask(). Finally, if your device can only drive the low 24-bits of address during PCI bus mastering you might do something like: - if (pci_set_dma_mask(pdev, DMA_24BIT_MASK)) { + if (pci_set_dma_mask(pdev, DMA_BIT_MASK(24))) { printk(KERN_WARNING "mydev: 24-bit DMA addressing not available.\n"); goto ignore_this_device; @@ -213,7 +213,7 @@ most specific mask. Here is pseudo-code showing how this might be done: - #define PLAYBACK_ADDRESS_BITS DMA_32BIT_MASK + #define PLAYBACK_ADDRESS_BITS DMA_BIT_MASK(32) #define RECORD_ADDRESS_BITS 0x00ffffff struct my_sound_card *card; diff --git a/Documentation/DocBook/.gitignore b/Documentation/DocBook/.gitignore index c102c02ecf89..c6def352fe39 100644 --- a/Documentation/DocBook/.gitignore +++ b/Documentation/DocBook/.gitignore @@ -4,3 +4,7 @@ *.html *.9.gz *.9 +*.aux +*.dvi +*.log +*.out diff --git a/Documentation/DocBook/Makefile b/Documentation/DocBook/Makefile index 1462ed86d40a..b1eb661e6302 100644 --- a/Documentation/DocBook/Makefile +++ b/Documentation/DocBook/Makefile @@ -12,7 +12,8 @@ DOCBOOKS := z8530book.xml mcabook.xml device-drivers.xml \ kernel-api.xml filesystems.xml lsm.xml usb.xml kgdb.xml \ gadget.xml libata.xml mtdnand.xml librs.xml rapidio.xml \ genericirq.xml s390-drivers.xml uio-howto.xml scsi.xml \ - mac80211.xml debugobjects.xml sh.xml regulator.xml + mac80211.xml debugobjects.xml sh.xml regulator.xml \ + alsa-driver-api.xml writing-an-alsa-driver.xml ### # The build process is as follows (targets): @@ -30,7 +31,7 @@ PS_METHOD = $(prefer-db2x) ### # The targets that may be used. -PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs +PHONY += xmldocs sgmldocs psdocs pdfdocs htmldocs mandocs installmandocs cleandocs BOOKS := $(addprefix $(obj)/,$(DOCBOOKS)) xmldocs: $(BOOKS) @@ -142,7 +143,8 @@ quiet_cmd_db2pdf = PDF $@ $(call cmd,db2pdf) -main_idx = Documentation/DocBook/index.html +index = index.html +main_idx = Documentation/DocBook/$(index) build_main_index = rm -rf $(main_idx) && \ echo '<h1>Linux Kernel HTML Documentation</h1>' >> $(main_idx) && \ echo '<h2>Kernel Version: $(KERNELVERSION)</h2>' >> $(main_idx) && \ @@ -212,11 +214,12 @@ silent_gen_xml = : dochelp: @echo ' Linux kernel internal documentation in different formats:' @echo ' htmldocs - HTML' - @echo ' installmandocs - install man pages generated by mandocs' - @echo ' mandocs - man pages' @echo ' pdfdocs - PDF' @echo ' psdocs - Postscript' @echo ' xmldocs - XML DocBook' + @echo ' mandocs - man pages' + @echo ' installmandocs - install man pages generated by mandocs' + @echo ' cleandocs - clean all generated DocBook files' ### # Temporary files left by various tools @@ -230,10 +233,14 @@ clean-files := $(DOCBOOKS) \ $(patsubst %.xml, %.pdf, $(DOCBOOKS)) \ $(patsubst %.xml, %.html, $(DOCBOOKS)) \ $(patsubst %.xml, %.9, $(DOCBOOKS)) \ - $(C-procfs-example) + $(C-procfs-example) $(index) clean-dirs := $(patsubst %.xml,%,$(DOCBOOKS)) man +cleandocs: + $(Q)rm -f $(call objectify, $(clean-files)) + $(Q)rm -rf $(call objectify, $(clean-dirs)) + # Declare the contents of the .PHONY variable as phony. We keep that # information in a variable se we can use it in if_changed and friends. diff --git a/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl b/Documentation/DocBook/alsa-driver-api.tmpl index 9d644f7e241e..0230a96f0564 100644 --- a/Documentation/sound/alsa/DocBook/alsa-driver-api.tmpl +++ b/Documentation/DocBook/alsa-driver-api.tmpl @@ -1,11 +1,11 @@ -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V4.1//EN"> - -<book> -<?dbhtml filename="index.html"> +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" + "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> <!-- ****************************************************** --> <!-- Header --> <!-- ****************************************************** --> +<book id="ALSA-Driver-API"> <bookinfo> <title>The ALSA Driver API</title> @@ -35,6 +35,8 @@ </bookinfo> +<toc></toc> + <chapter><title>Management of Cards and Devices</title> <sect1><title>Card Management</title> !Esound/core/init.c @@ -71,6 +73,10 @@ !Esound/pci/ac97/ac97_codec.c !Esound/pci/ac97/ac97_pcm.c </sect1> + <sect1><title>Virtual Master Control API</title> +!Esound/core/vmaster.c +!Iinclude/sound/control.h + </sect1> </chapter> <chapter><title>MIDI API</title> <sect1><title>Raw MIDI API</title> @@ -89,6 +95,9 @@ <sect1><title>Hardware-Dependent Devices API</title> !Esound/core/hwdep.c </sect1> + <sect1><title>Jack Abstraction Layer API</title> +!Esound/core/jack.c + </sect1> <sect1><title>ISA DMA Helpers</title> !Esound/core/isadma.c </sect1> diff --git a/Documentation/DocBook/genericirq.tmpl b/Documentation/DocBook/genericirq.tmpl index 3a882d9a90a9..c671a0168096 100644 --- a/Documentation/DocBook/genericirq.tmpl +++ b/Documentation/DocBook/genericirq.tmpl @@ -440,6 +440,7 @@ desc->chip->end(); used in the generic IRQ layer. </para> !Iinclude/linux/irq.h +!Iinclude/linux/interrupt.h </chapter> <chapter id="pubfunctions"> diff --git a/Documentation/DocBook/kernel-api.tmpl b/Documentation/DocBook/kernel-api.tmpl index bc962cda6504..44b3def961a2 100644 --- a/Documentation/DocBook/kernel-api.tmpl +++ b/Documentation/DocBook/kernel-api.tmpl @@ -190,15 +190,20 @@ X!Ekernel/module.c !Edrivers/pci/pci.c !Edrivers/pci/pci-driver.c !Edrivers/pci/remove.c -!Edrivers/pci/pci-acpi.c !Edrivers/pci/search.c !Edrivers/pci/msi.c !Edrivers/pci/bus.c +!Edrivers/pci/access.c +!Edrivers/pci/irq.c +!Edrivers/pci/htirq.c <!-- FIXME: Removed for now since no structured comments in source X!Edrivers/pci/hotplug.c --> !Edrivers/pci/probe.c +!Edrivers/pci/slot.c !Edrivers/pci/rom.c +!Edrivers/pci/iov.c +!Idrivers/pci/pci-sysfs.c </sect1> <sect1><title>PCI Hotplug Support Library</title> !Edrivers/pci/hotplug/pci_hotplug_core.c @@ -258,7 +263,7 @@ X!Earch/x86/kernel/mca_32.c !Eblock/blk-tag.c !Iblock/blk-tag.c !Eblock/blk-integrity.c -!Iblock/blktrace.c +!Ikernel/trace/blktrace.c !Iblock/genhd.c !Eblock/genhd.c </chapter> diff --git a/Documentation/DocBook/mac80211.tmpl b/Documentation/DocBook/mac80211.tmpl index 77c3c202991b..fbeaffc1dcc3 100644 --- a/Documentation/DocBook/mac80211.tmpl +++ b/Documentation/DocBook/mac80211.tmpl @@ -17,8 +17,7 @@ </authorgroup> <copyright> - <year>2007</year> - <year>2008</year> + <year>2007-2009</year> <holder>Johannes Berg</holder> </copyright> @@ -165,8 +164,8 @@ usage should require reading the full document. !Pinclude/net/mac80211.h Frame format </sect1> <sect1> - <title>Alignment issues</title> - <para>TBD</para> + <title>Packet alignment</title> +!Pnet/mac80211/rx.c Packet alignment </sect1> <sect1> <title>Calling into mac80211 from interrupts</title> @@ -223,6 +222,17 @@ usage should require reading the full document. !Finclude/net/mac80211.h ieee80211_key_flags </chapter> + <chapter id="powersave"> + <title>Powersave support</title> +!Pinclude/net/mac80211.h Powersave support + </chapter> + + <chapter id="beacon-filter"> + <title>Beacon filter support</title> +!Pinclude/net/mac80211.h Beacon filter support +!Finclude/net/mac80211.h ieee80211_beacon_loss + </chapter> + <chapter id="qos"> <title>Multiple queues and QoS support</title> <para>TBD</para> diff --git a/Documentation/DocBook/procfs_example.c b/Documentation/DocBook/procfs_example.c index 8c6396e4bf31..a5b11793b1e0 100644 --- a/Documentation/DocBook/procfs_example.c +++ b/Documentation/DocBook/procfs_example.c @@ -117,9 +117,6 @@ static int __init init_procfs_example(void) rv = -ENOMEM; goto out; } - - example_dir->owner = THIS_MODULE; - /* create jiffies using convenience function */ jiffies_file = create_proc_read_entry("jiffies", 0444, example_dir, @@ -130,8 +127,6 @@ static int __init init_procfs_example(void) goto no_jiffies; } - jiffies_file->owner = THIS_MODULE; - /* create foo and bar files using same callback * functions */ @@ -146,7 +141,6 @@ static int __init init_procfs_example(void) foo_file->data = &foo_data; foo_file->read_proc = proc_read_foobar; foo_file->write_proc = proc_write_foobar; - foo_file->owner = THIS_MODULE; bar_file = create_proc_entry("bar", 0644, example_dir); if(bar_file == NULL) { @@ -159,7 +153,6 @@ static int __init init_procfs_example(void) bar_file->data = &bar_data; bar_file->read_proc = proc_read_foobar; bar_file->write_proc = proc_write_foobar; - bar_file->owner = THIS_MODULE; /* create symlink */ symlink = proc_symlink("jiffies_too", example_dir, @@ -169,8 +162,6 @@ static int __init init_procfs_example(void) goto no_symlink; } - symlink->owner = THIS_MODULE; - /* everything OK */ printk(KERN_INFO "%s %s initialised\n", MODULE_NAME, MODULE_VERS); diff --git a/Documentation/DocBook/uio-howto.tmpl b/Documentation/DocBook/uio-howto.tmpl index 52e1b79ce0e6..8f6e3b2403c7 100644 --- a/Documentation/DocBook/uio-howto.tmpl +++ b/Documentation/DocBook/uio-howto.tmpl @@ -42,6 +42,13 @@ GPL version 2. <revhistory> <revision> + <revnumber>0.8</revnumber> + <date>2008-12-24</date> + <authorinitials>hjk</authorinitials> + <revremark>Added name attributes in mem and portio sysfs directories. + </revremark> + </revision> + <revision> <revnumber>0.7</revnumber> <date>2008-12-23</date> <authorinitials>hjk</authorinitials> @@ -303,12 +310,19 @@ interested in translating it, please email me appear if the size of the mapping is not 0. </para> <para> - Each <filename>mapX/</filename> directory contains two read-only files - that show start address and size of the memory: + Each <filename>mapX/</filename> directory contains four read-only files + that show attributes of the memory: </para> <itemizedlist> <listitem> <para> + <filename>name</filename>: A string identifier for this mapping. This + is optional, the string can be empty. Drivers can set this to make it + easier for userspace to find the correct mapping. + </para> +</listitem> +<listitem> + <para> <filename>addr</filename>: The address of memory that can be mapped. </para> </listitem> @@ -366,12 +380,19 @@ offset = N * getpagesize(); <filename>/sys/class/uio/uioX/portio/</filename>. </para> <para> - Each <filename>portX/</filename> directory contains three read-only - files that show start, size, and type of the port region: + Each <filename>portX/</filename> directory contains four read-only + files that show name, start, size, and type of the port region: </para> <itemizedlist> <listitem> <para> + <filename>name</filename>: A string identifier for this port region. + The string is optional and can be empty. Drivers can set it to make it + easier for userspace to find a certain port region. + </para> +</listitem> +<listitem> + <para> <filename>start</filename>: The first port of this region. </para> </listitem> diff --git a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl b/Documentation/DocBook/writing-an-alsa-driver.tmpl index 87a7c07ab658..7a2e0e98986a 100644 --- a/Documentation/sound/alsa/DocBook/writing-an-alsa-driver.tmpl +++ b/Documentation/DocBook/writing-an-alsa-driver.tmpl @@ -1,11 +1,11 @@ -<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook V4.1//EN"> - -<book> -<?dbhtml filename="index.html"> +<?xml version="1.0" encoding="UTF-8"?> +<!DOCTYPE book PUBLIC "-//OASIS//DTD DocBook XML V4.1.2//EN" + "http://www.oasis-open.org/docbook/xml/4.1.2/docbookx.dtd" []> <!-- ****************************************************** --> <!-- Header --> <!-- ****************************************************** --> +<book id="Writing-an-ALSA-Driver"> <bookinfo> <title>Writing an ALSA Driver</title> <author> @@ -492,9 +492,9 @@ } /* (2) */ - card = snd_card_new(index[dev], id[dev], THIS_MODULE, 0); - if (card == NULL) - return -ENOMEM; + err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card); + if (err < 0) + return err; /* (3) */ err = snd_mychip_create(card, pci, &chip); @@ -590,8 +590,9 @@ <programlisting> <![CDATA[ struct snd_card *card; + int err; .... - card = snd_card_new(index[dev], id[dev], THIS_MODULE, 0); + err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card); ]]> </programlisting> </informalexample> @@ -809,26 +810,28 @@ <para> As mentioned above, to create a card instance, call - <function>snd_card_new()</function>. + <function>snd_card_create()</function>. <informalexample> <programlisting> <![CDATA[ struct snd_card *card; - card = snd_card_new(index, id, module, extra_size); + int err; + err = snd_card_create(index, id, module, extra_size, &card); ]]> </programlisting> </informalexample> </para> <para> - The function takes four arguments, the card-index number, the + The function takes five arguments, the card-index number, the id string, the module pointer (usually <constant>THIS_MODULE</constant>), - and the size of extra-data space. The last argument is used to + the size of extra-data space, and the pointer to return the + card instance. The extra_size argument is used to allocate card->private_data for the chip-specific data. Note that these data - are allocated by <function>snd_card_new()</function>. + are allocated by <function>snd_card_create()</function>. </para> </section> @@ -915,15 +918,16 @@ </para> <section id="card-management-chip-specific-snd-card-new"> - <title>1. Allocating via <function>snd_card_new()</function>.</title> + <title>1. Allocating via <function>snd_card_create()</function>.</title> <para> As mentioned above, you can pass the extra-data-length - to the 4th argument of <function>snd_card_new()</function>, i.e. + to the 4th argument of <function>snd_card_create()</function>, i.e. <informalexample> <programlisting> <![CDATA[ - card = snd_card_new(index[dev], id[dev], THIS_MODULE, sizeof(struct mychip)); + err = snd_card_create(index[dev], id[dev], THIS_MODULE, + sizeof(struct mychip), &card); ]]> </programlisting> </informalexample> @@ -952,8 +956,8 @@ <para> After allocating a card instance via - <function>snd_card_new()</function> (with - <constant>NULL</constant> on the 4th arg), call + <function>snd_card_create()</function> (with + <constant>0</constant> on the 4th arg), call <function>kzalloc()</function>. <informalexample> @@ -961,7 +965,7 @@ <![CDATA[ struct snd_card *card; struct mychip *chip; - card = snd_card_new(index[dev], id[dev], THIS_MODULE, NULL); + err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card); ..... chip = kzalloc(sizeof(*chip), GFP_KERNEL); ]]> @@ -1133,8 +1137,8 @@ if (err < 0) return err; /* check PCI availability (28bit DMA) */ - if (pci_set_dma_mask(pci, DMA_28BIT_MASK) < 0 || - pci_set_consistent_dma_mask(pci, DMA_28BIT_MASK) < 0) { + if (pci_set_dma_mask(pci, DMA_BIT_MASK(28)) < 0 || + pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(28)) < 0) { printk(KERN_ERR "error to set 28bit mask DMA\n"); pci_disable_device(pci); return -ENXIO; @@ -1248,8 +1252,8 @@ err = pci_enable_device(pci); if (err < 0) return err; - if (pci_set_dma_mask(pci, DMA_28BIT_MASK) < 0 || - pci_set_consistent_dma_mask(pci, DMA_28BIT_MASK) < 0) { + if (pci_set_dma_mask(pci, DMA_BIT_MASK(28)) < 0 || + pci_set_consistent_dma_mask(pci, DMA_BIT_MASK(28)) < 0) { printk(KERN_ERR "error to set 28bit mask DMA\n"); pci_disable_device(pci); return -ENXIO; @@ -5750,8 +5754,9 @@ struct _snd_pcm_runtime { .... struct snd_card *card; struct mychip *chip; + int err; .... - card = snd_card_new(index[dev], id[dev], THIS_MODULE, NULL); + err = snd_card_create(index[dev], id[dev], THIS_MODULE, 0, &card); .... chip = kzalloc(sizeof(*chip), GFP_KERNEL); .... @@ -5763,7 +5768,7 @@ struct _snd_pcm_runtime { </informalexample> When you created the chip data with - <function>snd_card_new()</function>, it's anyway accessible + <function>snd_card_create()</function>, it's anyway accessible via <structfield>private_data</structfield> field. <informalexample> @@ -5775,9 +5780,10 @@ struct _snd_pcm_runtime { .... struct snd_card *card; struct mychip *chip; + int err; .... - card = snd_card_new(index[dev], id[dev], THIS_MODULE, - sizeof(struct mychip)); + err = snd_card_create(index[dev], id[dev], THIS_MODULE, + sizeof(struct mychip), &card); .... chip = card->private_data; .... diff --git a/Documentation/PCI/MSI-HOWTO.txt b/Documentation/PCI/MSI-HOWTO.txt index 256defd7e174..dcf7acc720e1 100644 --- a/Documentation/PCI/MSI-HOWTO.txt +++ b/Documentation/PCI/MSI-HOWTO.txt @@ -4,506 +4,356 @@ Revised Feb 12, 2004 by Martine Silbermann email: Martine.Silbermann@hp.com Revised Jun 25, 2004 by Tom L Nguyen + Revised Jul 9, 2008 by Matthew Wilcox <willy@linux.intel.com> + Copyright 2003, 2008 Intel Corporation 1. About this guide -This guide describes the basics of Message Signaled Interrupts (MSI), -the advantages of using MSI over traditional interrupt mechanisms, -and how to enable your driver to use MSI or MSI-X. Also included is -a Frequently Asked Questions (FAQ) section. - -1.1 Terminology - -PCI devices can be single-function or multi-function. In either case, -when this text talks about enabling or disabling MSI on a "device -function," it is referring to one specific PCI device and function and -not to all functions on a PCI device (unless the PCI device has only -one function). - -2. Copyright 2003 Intel Corporation - -3. What is MSI/MSI-X? - -Message Signaled Interrupt (MSI), as described in the PCI Local Bus -Specification Revision 2.3 or later, is an optional feature, and a -required feature for PCI Express devices. MSI enables a device function -to request service by sending an Inbound Memory Write on its PCI bus to -the FSB as a Message Signal Interrupt transaction. Because MSI is -generated in the form of a Memory Write, all transaction conditions, -such as a Retry, Master-Abort, Target-Abort or normal completion, are -supported. - -A PCI device that supports MSI must also support pin IRQ assertion -interrupt mechanism to provide backward compatibility for systems that -do not support MSI. In systems which support MSI, the bus driver is -responsible for initializing the message address and message data of -the device function's MSI/MSI-X capability structure during device -initial configuration. - -An MSI capable device function indicates MSI support by implementing -the MSI/MSI-X capability structure in its PCI capability list. The -device function may implement both the MSI capability structure and -the MSI-X capability structure; however, the bus driver should not -enable both. - -The MSI capability structure contains Message Control register, -Message Address register and Message Data register. These registers -provide the bus driver control over MSI. The Message Control register -indicates the MSI capability supported by the device. The Message -Address register specifies the target address and the Message Data -register specifies the characteristics of the message. To request -service, the device function writes the content of the Message Data -register to the target address. The device and its software driver -are prohibited from writing to these registers. - -The MSI-X capability structure is an optional extension to MSI. It -uses an independent and separate capability structure. There are -some key advantages to implementing the MSI-X capability structure -over the MSI capability structure as described below. - - - Support a larger maximum number of vectors per function. - - - Provide the ability for system software to configure - each vector with an independent message address and message - data, specified by a table that resides in Memory Space. - - - MSI and MSI-X both support per-vector masking. Per-vector - masking is an optional extension of MSI but a required - feature for MSI-X. Per-vector masking provides the kernel the - ability to mask/unmask a single MSI while running its - interrupt service routine. If per-vector masking is - not supported, then the device driver should provide the - hardware/software synchronization to ensure that the device - generates MSI when the driver wants it to do so. - -4. Why use MSI? - -As a benefit to the simplification of board design, MSI allows board -designers to remove out-of-band interrupt routing. MSI is another -step towards a legacy-free environment. - -Due to increasing pressure on chipset and processor packages to -reduce pin count, the need for interrupt pins is expected to -diminish over time. Devices, due to pin constraints, may implement -messages to increase performance. - -PCI Express endpoints uses INTx emulation (in-band messages) instead -of IRQ pin assertion. Using INTx emulation requires interrupt -sharing among devices connected to the same node (PCI bridge) while -MSI is unique (non-shared) and does not require BIOS configuration -support. As a result, the PCI Express technology requires MSI -support for better interrupt performance. - -Using MSI enables the device functions to support two or more -vectors, which can be configured to target different CPUs to -increase scalability. - -5. Configuring a driver to use MSI/MSI-X - -By default, the kernel will not enable MSI/MSI-X on all devices that -support this capability. The CONFIG_PCI_MSI kernel option -must be selected to enable MSI/MSI-X support. - -5.1 Including MSI/MSI-X support into the kernel - -To allow MSI/MSI-X capable device drivers to selectively enable -MSI/MSI-X (using pci_enable_msi()/pci_enable_msix() as described -below), the VECTOR based scheme needs to be enabled by setting -CONFIG_PCI_MSI during kernel config. - -Since the target of the inbound message is the local APIC, providing -CONFIG_X86_LOCAL_APIC must be enabled as well as CONFIG_PCI_MSI. - -5.2 Configuring for MSI support - -Due to the non-contiguous fashion in vector assignment of the -existing Linux kernel, this version does not support multiple -messages regardless of a device function is capable of supporting -more than one vector. To enable MSI on a device function's MSI -capability structure requires a device driver to call the function -pci_enable_msi() explicitly. - -5.2.1 API pci_enable_msi +This guide describes the basics of Message Signaled Interrupts (MSIs), +the advantages of using MSI over traditional interrupt mechanisms, how +to change your driver to use MSI or MSI-X and some basic diagnostics to +try if a device doesn't support MSIs. -int pci_enable_msi(struct pci_dev *dev) -With this new API, a device driver that wants to have MSI -enabled on its device function must call this API to enable MSI. -A successful call will initialize the MSI capability structure -with ONE vector, regardless of whether a device function is -capable of supporting multiple messages. This vector replaces the -pre-assigned dev->irq with a new MSI vector. To avoid a conflict -of the new assigned vector with existing pre-assigned vector requires -a device driver to call this API before calling request_irq(). +2. What are MSIs? -5.2.2 API pci_disable_msi +A Message Signaled Interrupt is a write from the device to a special +address which causes an interrupt to be received by the CPU. -void pci_disable_msi(struct pci_dev *dev) +The MSI capability was first specified in PCI 2.2 and was later enhanced +in PCI 3.0 to allow each interrupt to be masked individually. The MSI-X +capability was also introduced with PCI 3.0. It supports more interrupts +per device than MSI and allows interrupts to be independently configured. -This API should always be used to undo the effect of pci_enable_msi() -when a device driver is unloading. This API restores dev->irq with -the pre-assigned IOAPIC vector and switches a device's interrupt -mode to PCI pin-irq assertion/INTx emulation mode. - -Note that a device driver should always call free_irq() on the MSI vector -that it has done request_irq() on before calling this API. Failure to do -so results in a BUG_ON() and a device will be left with MSI enabled and -leaks its vector. - -5.2.3 MSI mode vs. legacy mode diagram - -The below diagram shows the events which switch the interrupt -mode on the MSI-capable device function between MSI mode and -PIN-IRQ assertion mode. - - ------------ pci_enable_msi ------------------------ - | | <=============== | | - | MSI MODE | | PIN-IRQ ASSERTION MODE | - | | ===============> | | - ------------ pci_disable_msi ------------------------ - - -Figure 1. MSI Mode vs. Legacy Mode - -In Figure 1, a device operates by default in legacy mode. Legacy -in this context means PCI pin-irq assertion or PCI-Express INTx -emulation. A successful MSI request (using pci_enable_msi()) switches -a device's interrupt mode to MSI mode. A pre-assigned IOAPIC vector -stored in dev->irq will be saved by the PCI subsystem and a new -assigned MSI vector will replace dev->irq. - -To return back to its default mode, a device driver should always call -pci_disable_msi() to undo the effect of pci_enable_msi(). Note that a -device driver should always call free_irq() on the MSI vector it has -done request_irq() on before calling pci_disable_msi(). Failure to do -so results in a BUG_ON() and a device will be left with MSI enabled and -leaks its vector. Otherwise, the PCI subsystem restores a device's -dev->irq with a pre-assigned IOAPIC vector and marks the released -MSI vector as unused. - -Once being marked as unused, there is no guarantee that the PCI -subsystem will reserve this MSI vector for a device. Depending on -the availability of current PCI vector resources and the number of -MSI/MSI-X requests from other drivers, this MSI may be re-assigned. - -For the case where the PCI subsystem re-assigns this MSI vector to -another driver, a request to switch back to MSI mode may result -in being assigned a different MSI vector or a failure if no more -vectors are available. - -5.3 Configuring for MSI-X support - -Due to the ability of the system software to configure each vector of -the MSI-X capability structure with an independent message address -and message data, the non-contiguous fashion in vector assignment of -the existing Linux kernel has no impact on supporting multiple -messages on an MSI-X capable device functions. To enable MSI-X on -a device function's MSI-X capability structure requires its device -driver to call the function pci_enable_msix() explicitly. - -The function pci_enable_msix(), once invoked, enables either -all or nothing, depending on the current availability of PCI vector -resources. If the PCI vector resources are available for the number -of vectors requested by a device driver, this function will configure -the MSI-X table of the MSI-X capability structure of a device with -requested messages. To emphasize this reason, for example, a device -may be capable for supporting the maximum of 32 vectors while its -software driver usually may request 4 vectors. It is recommended -that the device driver should call this function once during the -initialization phase of the device driver. - -Unlike the function pci_enable_msi(), the function pci_enable_msix() -does not replace the pre-assigned IOAPIC dev->irq with a new MSI -vector because the PCI subsystem writes the 1:1 vector-to-entry mapping -into the field vector of each element contained in a second argument. -Note that the pre-assigned IOAPIC dev->irq is valid only if the device -operates in PIN-IRQ assertion mode. In MSI-X mode, any attempt at -using dev->irq by the device driver to request for interrupt service -may result in unpredictable behavior. - -For each MSI-X vector granted, a device driver is responsible for calling -other functions like request_irq(), enable_irq(), etc. to enable -this vector with its corresponding interrupt service handler. It is -a device driver's choice to assign all vectors with the same -interrupt service handler or each vector with a unique interrupt -service handler. - -5.3.1 Handling MMIO address space of MSI-X Table - -The PCI 3.0 specification has implementation notes that MMIO address -space for a device's MSI-X structure should be isolated so that the -software system can set different pages for controlling accesses to the -MSI-X structure. The implementation of MSI support requires the PCI -subsystem, not a device driver, to maintain full control of the MSI-X -table/MSI-X PBA (Pending Bit Array) and MMIO address space of the MSI-X -table/MSI-X PBA. A device driver should not access the MMIO address -space of the MSI-X table/MSI-X PBA. - -5.3.2 API pci_enable_msix +Devices may support both MSI and MSI-X, but only one can be enabled at +a time. -int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) -This API enables a device driver to request the PCI subsystem -to enable MSI-X messages on its hardware device. Depending on -the availability of PCI vectors resources, the PCI subsystem enables -either all or none of the requested vectors. +3. Why use MSIs? + +There are three reasons why using MSIs can give an advantage over +traditional pin-based interrupts. + +Pin-based PCI interrupts are often shared amongst several devices. +To support this, the kernel must call each interrupt handler associated +with an interrupt, which leads to reduced performance for the system as +a whole. MSIs are never shared, so this problem cannot arise. + +When a device writes data to memory, then raises a pin-based interrupt, +it is possible that the interrupt may arrive before all the data has +arrived in memory (this becomes more likely with devices behind PCI-PCI +bridges). In order to ensure that all the data has arrived in memory, +the interrupt handler must read a register on the device which raised +the interrupt. PCI transaction ordering rules require that all the data +arrives in memory before the value can be returned from the register. +Using MSIs avoids this problem as the interrupt-generating write cannot +pass the data writes, so by the time the interrupt is raised, the driver +knows that all the data has arrived in memory. + +PCI devices can only support a single pin-based interrupt per function. +Often drivers have to query the device to find out what event has +occurred, slowing down interrupt handling for the common case. With +MSIs, a device can support more interrupts, allowing each interrupt +to be specialised to a different purpose. One possible design gives +infrequent conditions (such as errors) their own interrupt which allows +the driver to handle the normal interrupt handling path more efficiently. +Other possible designs include giving one interrupt to each packet queue +in a network card or each port in a storage controller. + + +4. How to use MSIs + +PCI devices are initialised to use pin-based interrupts. The device +driver has to set up the device to use MSI or MSI-X. Not all machines +support MSIs correctly, and for those machines, the APIs described below +will simply fail and the device will continue to use pin-based interrupts. + +4.1 Include kernel support for MSIs + +To support MSI or MSI-X, the kernel must be built with the CONFIG_PCI_MSI +option enabled. This option is only available on some architectures, +and it may depend on some other options also being set. For example, +on x86, you must also enable X86_UP_APIC or SMP in order to see the +CONFIG_PCI_MSI option. + +4.2 Using MSI + +Most of the hard work is done for the driver in the PCI layer. It simply +has to request that the PCI layer set up the MSI capability for this +device. + +4.2.1 pci_enable_msi + +int pci_enable_msi(struct pci_dev *dev) + +A successful call will allocate ONE interrupt to the device, regardless +of how many MSIs the device supports. The device will be switched from +pin-based interrupt mode to MSI mode. The dev->irq number is changed +to a new number which represents the message signaled interrupt. +This function should be called before the driver calls request_irq() +since enabling MSIs disables the pin-based IRQ and the driver will not +receive interrupts on the old interrupt. + +4.2.2 pci_enable_msi_block + +int pci_enable_msi_block(struct pci_dev *dev, int count) + +This variation on the above call allows a device driver to request multiple +MSIs. The MSI specification only allows interrupts to be allocated in +powers of two, up to a maximum of 2^5 (32). + +If this function returns 0, it has succeeded in allocating at least as many +interrupts as the driver requested (it may have allocated more in order +to satisfy the power-of-two requirement). In this case, the function +enables MSI on this device and updates dev->irq to be the lowest of +the new interrupts assigned to it. The other interrupts assigned to +the device are in the range dev->irq to dev->irq + count - 1. + +If this function returns a negative number, it indicates an error and +the driver should not attempt to request any more MSI interrupts for +this device. If this function returns a positive number, it will be +less than 'count' and indicate the number of interrupts that could have +been allocated. In neither case will the irq value have been +updated, nor will the device have been switched into MSI mode. + +The device driver must decide what action to take if +pci_enable_msi_block() returns a value less than the number asked for. +Some devices can make use of fewer interrupts than the maximum they +request; in this case the driver should call pci_enable_msi_block() +again. Note that it is not guaranteed to succeed, even when the +'count' has been reduced to the value returned from a previous call to +pci_enable_msi_block(). This is because there are multiple constraints +on the number of vectors that can be allocated; pci_enable_msi_block() +will return as soon as it finds any constraint that doesn't allow the +call to succeed. + +4.2.3 pci_disable_msi + +void pci_disable_msi(struct pci_dev *dev) -Argument 'dev' points to the device (pci_dev) structure. +This function should be used to undo the effect of pci_enable_msi() or +pci_enable_msi_block(). Calling it restores dev->irq to the pin-based +interrupt number and frees the previously allocated message signaled +interrupt(s). The interrupt may subsequently be assigned to another +device, so drivers should not cache the value of dev->irq. -Argument 'entries' is a pointer to an array of msix_entry structs. -The number of entries is indicated in argument 'nvec'. -struct msix_entry is defined in /driver/pci/msi.h: +A device driver must always call free_irq() on the interrupt(s) +for which it has called request_irq() before calling this function. +Failure to do so will result in a BUG_ON(), the device will be left with +MSI enabled and will leak its vector. + +4.3 Using MSI-X + +The MSI-X capability is much more flexible than the MSI capability. +It supports up to 2048 interrupts, each of which can be controlled +independently. To support this flexibility, drivers must use an array of +`struct msix_entry': struct msix_entry { u16 vector; /* kernel uses to write alloc vector */ u16 entry; /* driver uses to specify entry */ }; -A device driver is responsible for initializing the field 'entry' of -each element with a unique entry supported by MSI-X table. Otherwise, --EINVAL will be returned as a result. A successful return of zero -indicates the PCI subsystem completed initializing each of the requested -entries of the MSI-X table with message address and message data. -Last but not least, the PCI subsystem will write the 1:1 -vector-to-entry mapping into the field 'vector' of each element. A -device driver is responsible for keeping track of allocated MSI-X -vectors in its internal data structure. - -A return of zero indicates that the number of MSI-X vectors was -successfully allocated. A return of greater than zero indicates -MSI-X vector shortage. Or a return of less than zero indicates -a failure. This failure may be a result of duplicate entries -specified in second argument, or a result of no available vector, -or a result of failing to initialize MSI-X table entries. - -5.3.3 API pci_disable_msix +This allows for the device to use these interrupts in a sparse fashion; +for example it could use interrupts 3 and 1027 and allocate only a +two-element array. The driver is expected to fill in the 'entry' value +in each element of the array to indicate which entries it wants the kernel +to assign interrupts for. It is invalid to fill in two entries with the +same number. + +4.3.1 pci_enable_msix + +int pci_enable_msix(struct pci_dev *dev, struct msix_entry *entries, int nvec) + +Calling this function asks the PCI subsystem to allocate 'nvec' MSIs. +The 'entries' argument is a pointer to an array of msix_entry structs +which should be at least 'nvec' entries in size. On success, the +function will return 0 and the device will have been switched into +MSI-X interrupt mode. The 'vector' elements in each entry will have +been filled in with the interrupt number. The driver should then call +request_irq() for each 'vector' that it decides to use. + +If this function returns a negative number, it indicates an error and +the driver should not attempt to allocate any more MSI-X interrupts for +this device. If it returns a positive number, it indicates the maximum +number of interrupt vectors that could have been allocated. See example +below. + +This function, in contrast with pci_enable_msi(), does not adjust +dev->irq. The device will not generate interrupts for this interrupt +number once MSI-X is enabled. The device driver is responsible for +keeping track of the interrupts assigned to the MSI-X vectors so it can +free them again later. + +Device drivers should normally call this function once per device +during the initialization phase. + +It is ideal if drivers can cope with a variable number of MSI-X interrupts, +there are many reasons why the platform may not be able to provide the +exact number a driver asks for. + +A request loop to achieve that might look like: + +static int foo_driver_enable_msix(struct foo_adapter *adapter, int nvec) +{ + while (nvec >= FOO_DRIVER_MINIMUM_NVEC) { + rc = pci_enable_msix(adapter->pdev, + adapter->msix_entries, nvec); + if (rc > 0) + nvec = rc; + else + return rc; + } + + return -ENOSPC; +} + +4.3.2 pci_disable_msix void pci_disable_msix(struct pci_dev *dev) -This API should always be used to undo the effect of pci_enable_msix() -when a device driver is unloading. Note that a device driver should -always call free_irq() on all MSI-X vectors it has done request_irq() -on before calling this API. Failure to do so results in a BUG_ON() and -a device will be left with MSI-X enabled and leaks its vectors. - -5.3.4 MSI-X mode vs. legacy mode diagram - -The below diagram shows the events which switch the interrupt -mode on the MSI-X capable device function between MSI-X mode and -PIN-IRQ assertion mode (legacy). - - ------------ pci_enable_msix(,,n) ------------------------ - | | <=============== | | - | MSI-X MODE | | PIN-IRQ ASSERTION MODE | - | | ===============> | | - ------------ pci_disable_msix ------------------------ - -Figure 2. MSI-X Mode vs. Legacy Mode - -In Figure 2, a device operates by default in legacy mode. A -successful MSI-X request (using pci_enable_msix()) switches a -device's interrupt mode to MSI-X mode. A pre-assigned IOAPIC vector -stored in dev->irq will be saved by the PCI subsystem; however, -unlike MSI mode, the PCI subsystem will not replace dev->irq with -assigned MSI-X vector because the PCI subsystem already writes the 1:1 -vector-to-entry mapping into the field 'vector' of each element -specified in second argument. - -To return back to its default mode, a device driver should always call -pci_disable_msix() to undo the effect of pci_enable_msix(). Note that -a device driver should always call free_irq() on all MSI-X vectors it -has done request_irq() on before calling pci_disable_msix(). Failure -to do so results in a BUG_ON() and a device will be left with MSI-X -enabled and leaks its vectors. Otherwise, the PCI subsystem switches a -device function's interrupt mode from MSI-X mode to legacy mode and -marks all allocated MSI-X vectors as unused. - -Once being marked as unused, there is no guarantee that the PCI -subsystem will reserve these MSI-X vectors for a device. Depending on -the availability of current PCI vector resources and the number of -MSI/MSI-X requests from other drivers, these MSI-X vectors may be -re-assigned. - -For the case where the PCI subsystem re-assigned these MSI-X vectors -to other drivers, a request to switch back to MSI-X mode may result -being assigned with another set of MSI-X vectors or a failure if no -more vectors are available. - -5.4 Handling function implementing both MSI and MSI-X capabilities - -For the case where a function implements both MSI and MSI-X -capabilities, the PCI subsystem enables a device to run either in MSI -mode or MSI-X mode but not both. A device driver determines whether it -wants MSI or MSI-X enabled on its hardware device. Once a device -driver requests for MSI, for example, it is prohibited from requesting -MSI-X; in other words, a device driver is not permitted to ping-pong -between MSI mod MSI-X mode during a run-time. - -5.5 Hardware requirements for MSI/MSI-X support - -MSI/MSI-X support requires support from both system hardware and -individual hardware device functions. - -5.5.1 Required x86 hardware support - -Since the target of MSI address is the local APIC CPU, enabling -MSI/MSI-X support in the Linux kernel is dependent on whether existing -system hardware supports local APIC. Users should verify that their -system supports local APIC operation by testing that it runs when -CONFIG_X86_LOCAL_APIC=y. - -In SMP environment, CONFIG_X86_LOCAL_APIC is automatically set; -however, in UP environment, users must manually set -CONFIG_X86_LOCAL_APIC. Once CONFIG_X86_LOCAL_APIC=y, setting -CONFIG_PCI_MSI enables the VECTOR based scheme and the option for -MSI-capable device drivers to selectively enable MSI/MSI-X. - -Note that CONFIG_X86_IO_APIC setting is irrelevant because MSI/MSI-X -vector is allocated new during runtime and MSI/MSI-X support does not -depend on BIOS support. This key independency enables MSI/MSI-X -support on future IOxAPIC free platforms. - -5.5.2 Device hardware support - -The hardware device function supports MSI by indicating the -MSI/MSI-X capability structure on its PCI capability list. By -default, this capability structure will not be initialized by -the kernel to enable MSI during the system boot. In other words, -the device function is running on its default pin assertion mode. -Note that in many cases the hardware supporting MSI have bugs, -which may result in system hangs. The software driver of specific -MSI-capable hardware is responsible for deciding whether to call -pci_enable_msi or not. A return of zero indicates the kernel -successfully initialized the MSI/MSI-X capability structure of the -device function. The device function is now running on MSI/MSI-X mode. - -5.6 How to tell whether MSI/MSI-X is enabled on device function - -At the driver level, a return of zero from the function call of -pci_enable_msi()/pci_enable_msix() indicates to a device driver that -its device function is initialized successfully and ready to run in -MSI/MSI-X mode. - -At the user level, users can use the command 'cat /proc/interrupts' -to display the vectors allocated for devices and their interrupt -MSI/MSI-X modes ("PCI-MSI"/"PCI-MSI-X"). Below shows MSI mode is -enabled on a SCSI Adaptec 39320D Ultra320 controller. - - CPU0 CPU1 - 0: 324639 0 IO-APIC-edge timer - 1: 1186 0 IO-APIC-edge i8042 - 2: 0 0 XT-PIC cascade - 12: 2797 0 IO-APIC-edge i8042 - 14: 6543 0 IO-APIC-edge ide0 - 15: 1 0 IO-APIC-edge ide1 -169: 0 0 IO-APIC-level uhci-hcd -185: 0 0 IO-APIC-level uhci-hcd -193: 138 10 PCI-MSI aic79xx -201: 30 0 PCI-MSI aic79xx -225: 30 0 IO-APIC-level aic7xxx -233: 30 0 IO-APIC-level aic7xxx -NMI: 0 0 -LOC: 324553 325068 -ERR: 0 -MIS: 0 - -6. MSI quirks - -Several PCI chipsets or devices are known to not support MSI. -The PCI stack provides 3 possible levels of MSI disabling: -* on a single device -* on all devices behind a specific bridge -* globally - -6.1. Disabling MSI on a single device - -Under some circumstances it might be required to disable MSI on a -single device. This may be achieved by either not calling pci_enable_msi() -or all, or setting the pci_dev->no_msi flag before (most of the time -in a quirk). - -6.2. Disabling MSI below a bridge - -The vast majority of MSI quirks are required by PCI bridges not -being able to route MSI between busses. In this case, MSI have to be -disabled on all devices behind this bridge. It is achieves by setting -the PCI_BUS_FLAGS_NO_MSI flag in the pci_bus->bus_flags of the bridge -subordinate bus. There is no need to set the same flag on bridges that -are below the broken bridge. When pci_enable_msi() is called to enable -MSI on a device, pci_msi_supported() takes care of checking the NO_MSI -flag in all parent busses of the device. - -Some bridges actually support dynamic MSI support enabling/disabling -by changing some bits in their PCI configuration space (especially -the Hypertransport chipsets such as the nVidia nForce and Serverworks -HT2000). It may then be required to update the NO_MSI flag on the -corresponding devices in the sysfs hierarchy. To enable MSI support -on device "0000:00:0e", do: - - echo 1 > /sys/bus/pci/devices/0000:00:0e/msi_bus - -To disable MSI support, echo 0 instead of 1. Note that it should be -used with caution since changing this value might break interrupts. - -6.3. Disabling MSI globally - -Some extreme cases may require to disable MSI globally on the system. -For now, the only known case is a Serverworks PCI-X chipsets (MSI are -not supported on several busses that are not all connected to the -chipset in the Linux PCI hierarchy). In the vast majority of other -cases, disabling only behind a specific bridge is enough. - -For debugging purpose, the user may also pass pci=nomsi on the kernel -command-line to explicitly disable MSI globally. But, once the appro- -priate quirks are added to the kernel, this option should not be -required anymore. - -6.4. Finding why MSI cannot be enabled on a device - -Assuming that MSI are not enabled on a device, you should look at -dmesg to find messages that quirks may output when disabling MSI -on some devices, some bridges or even globally. -Then, lspci -t gives the list of bridges above a device. Reading -/sys/bus/pci/devices/0000:00:0e/msi_bus will tell you whether MSI -are enabled (1) or disabled (0). In 0 is found in a single bridge -msi_bus file above the device, MSI cannot be enabled. - -7. FAQ - -Q1. Are there any limitations on using the MSI? - -A1. If the PCI device supports MSI and conforms to the -specification and the platform supports the APIC local bus, -then using MSI should work. - -Q2. Will it work on all the Pentium processors (P3, P4, Xeon, -AMD processors)? In P3 IPI's are transmitted on the APIC local -bus and in P4 and Xeon they are transmitted on the system -bus. Are there any implications with this? - -A2. MSI support enables a PCI device sending an inbound -memory write (0xfeexxxxx as target address) on its PCI bus -directly to the FSB. Since the message address has a -redirection hint bit cleared, it should work. - -Q3. The target address 0xfeexxxxx will be translated by the -Host Bridge into an interrupt message. Are there any -limitations on the chipsets such as Intel 8xx, Intel e7xxx, -or VIA? - -A3. If these chipsets support an inbound memory write with -target address set as 0xfeexxxxx, as conformed to PCI -specification 2.3 or latest, then it should work. - -Q4. From the driver point of view, if the MSI is lost because -of errors occurring during inbound memory write, then it may -wait forever. Is there a mechanism for it to recover? - -A4. Since the target of the transaction is an inbound memory -write, all transaction termination conditions (Retry, -Master-Abort, Target-Abort, or normal completion) are -supported. A device sending an MSI must abide by all the PCI -rules and conditions regarding that inbound memory write. So, -if a retry is signaled it must retry, etc... We believe that -the recommendation for Abort is also a retry (refer to PCI -specification 2.3 or latest). +This API should be used to undo the effect of pci_enable_msix(). It frees +the previously allocated message signaled interrupts. The interrupts may +subsequently be assigned to another device, so drivers should not cache +the value of the 'vector' elements over a call to pci_disable_msix(). + +A device driver must always call free_irq() on the interrupt(s) +for which it has called request_irq() before calling this function. +Failure to do so will result in a BUG_ON(), the device will be left with +MSI enabled and will leak its vector. + +4.3.3 The MSI-X Table + +The MSI-X capability specifies a BAR and offset within that BAR for the +MSI-X Table. This address is mapped by the PCI subsystem, and should not +be accessed directly by the device driver. If the driver wishes to +mask or unmask an interrupt, it should call disable_irq() / enable_irq(). + +4.4 Handling devices implementing both MSI and MSI-X capabilities + +If a device implements both MSI and MSI-X capabilities, it can +run in either MSI mode or MSI-X mode but not both simultaneously. +This is a requirement of the PCI spec, and it is enforced by the +PCI layer. Calling pci_enable_msi() when MSI-X is already enabled or +pci_enable_msix() when MSI is already enabled will result in an error. +If a device driver wishes to switch between MSI and MSI-X at runtime, +it must first quiesce the device, then switch it back to pin-interrupt +mode, before calling pci_enable_msi() or pci_enable_msix() and resuming +operation. This is not expected to be a common operation but may be +useful for debugging or testing during development. + +4.5 Considerations when using MSIs + +4.5.1 Choosing between MSI-X and MSI + +If your device supports both MSI-X and MSI capabilities, you should use +the MSI-X facilities in preference to the MSI facilities. As mentioned +above, MSI-X supports any number of interrupts between 1 and 2048. +In constrast, MSI is restricted to a maximum of 32 interrupts (and +must be a power of two). In addition, the MSI interrupt vectors must +be allocated consecutively, so the system may not be able to allocate +as many vectors for MSI as it could for MSI-X. On some platforms, MSI +interrupts must all be targetted at the same set of CPUs whereas MSI-X +interrupts can all be targetted at different CPUs. + +4.5.2 Spinlocks + +Most device drivers have a per-device spinlock which is taken in the +interrupt handler. With pin-based interrupts or a single MSI, it is not +necessary to disable interrupts (Linux guarantees the same interrupt will +not be re-entered). If a device uses multiple interrupts, the driver +must disable interrupts while the lock is held. If the device sends +a different interrupt, the driver will deadlock trying to recursively +acquire the spinlock. + +There are two solutions. The first is to take the lock with +spin_lock_irqsave() or spin_lock_irq() (see +Documentation/DocBook/kernel-locking). The second is to specify +IRQF_DISABLED to request_irq() so that the kernel runs the entire +interrupt routine with interrupts disabled. + +If your MSI interrupt routine does not hold the lock for the whole time +it is running, the first solution may be best. The second solution is +normally preferred as it avoids making two transitions from interrupt +disabled to enabled and back again. + +4.6 How to tell whether MSI/MSI-X is enabled on a device + +Using 'lspci -v' (as root) may show some devices with "MSI", "Message +Signalled Interrupts" or "MSI-X" capabilities. Each of these capabilities +has an 'Enable' flag which will be followed with either "+" (enabled) +or "-" (disabled). + + +5. MSI quirks + +Several PCI chipsets or devices are known not to support MSIs. +The PCI stack provides three ways to disable MSIs: + +1. globally +2. on all devices behind a specific bridge +3. on a single device + +5.1. Disabling MSIs globally + +Some host chipsets simply don't support MSIs properly. If we're +lucky, the manufacturer knows this and has indicated it in the ACPI +FADT table. In this case, Linux will automatically disable MSIs. +Some boards don't include this information in the table and so we have +to detect them ourselves. The complete list of these is found near the +quirk_disable_all_msi() function in drivers/pci/quirks.c. + +If you have a board which has problems with MSIs, you can pass pci=nomsi +on the kernel command line to disable MSIs on all devices. It would be +in your best interests to report the problem to linux-pci@vger.kernel.org +including a full 'lspci -v' so we can add the quirks to the kernel. + +5.2. Disabling MSIs below a bridge + +Some PCI bridges are not able to route MSIs between busses properly. +In this case, MSIs must be disabled on all devices behind the bridge. + +Some bridges allow you to enable MSIs by changing some bits in their +PCI configuration space (especially the Hypertransport chipsets such +as the nVidia nForce and Serverworks HT2000). As with host chipsets, +Linux mostly knows about them and automatically enables MSIs if it can. +If you have a bridge which Linux doesn't yet know about, you can enable +MSIs in configuration space using whatever method you know works, then +enable MSIs on that bridge by doing: + + echo 1 > /sys/bus/pci/devices/$bridge/msi_bus + +where $bridge is the PCI address of the bridge you've enabled (eg +0000:00:0e.0). + +To disable MSIs, echo 0 instead of 1. Changing this value should be +done with caution as it can break interrupt handling for all devices +below this bridge. + +Again, please notify linux-pci@vger.kernel.org of any bridges that need +special handling. + +5.3. Disabling MSIs on a single device + +Some devices are known to have faulty MSI implementations. Usually this +is handled in the individual device driver but occasionally it's necessary +to handle this with a quirk. Some drivers have an option to disable use +of MSI. While this is a convenient workaround for the driver author, +it is not good practise, and should not be emulated. + +5.4. Finding why MSIs are disabled on a device + +From the above three sections, you can see that there are many reasons +why MSIs may not be enabled for a given device. Your first step should +be to examine your dmesg carefully to determine whether MSIs are enabled +for your machine. You should also check your .config to be sure you +have enabled CONFIG_PCI_MSI. + +Then, 'lspci -t' gives the list of bridges above a device. Reading +/sys/bus/pci/devices/*/msi_bus will tell you whether MSI are enabled (1) +or disabled (0). If 0 is found in any of the msi_bus files belonging +to bridges between the PCI root and the device, MSIs are disabled. + +It is also worth checking the device driver to see whether it supports MSIs. +For example, it may contain calls to pci_enable_msi(), pci_enable_msix() or +pci_enable_msi_block(). diff --git a/Documentation/PCI/pci-iov-howto.txt b/Documentation/PCI/pci-iov-howto.txt new file mode 100644 index 000000000000..fc73ef5d65b8 --- /dev/null +++ b/Documentation/PCI/pci-iov-howto.txt @@ -0,0 +1,99 @@ + PCI Express I/O Virtualization Howto + Copyright (C) 2009 Intel Corporation + Yu Zhao <yu.zhao@intel.com> + + +1. Overview + +1.1 What is SR-IOV + +Single Root I/O Virtualization (SR-IOV) is a PCI Express Extended +capability which makes one physical device appear as multiple virtual +devices. The physical device is referred to as Physical Function (PF) +while the virtual devices are referred to as Virtual Functions (VF). +Allocation of the VF can be dynamically controlled by the PF via +registers encapsulated in the capability. By default, this feature is +not enabled and the PF behaves as traditional PCIe device. Once it's +turned on, each VF's PCI configuration space can be accessed by its own +Bus, Device and Function Number (Routing ID). And each VF also has PCI +Memory Space, which is used to map its register set. VF device driver +operates on the register set so it can be functional and appear as a +real existing PCI device. + +2. User Guide + +2.1 How can I enable SR-IOV capability + +The device driver (PF driver) will control the enabling and disabling +of the capability via API provided by SR-IOV core. If the hardware +has SR-IOV capability, loading its PF driver would enable it and all +VFs associated with the PF. + +2.2 How can I use the Virtual Functions + +The VF is treated as hot-plugged PCI devices in the kernel, so they +should be able to work in the same way as real PCI devices. The VF +requires device driver that is same as a normal PCI device's. + +3. Developer Guide + +3.1 SR-IOV API + +To enable SR-IOV capability: + int pci_enable_sriov(struct pci_dev *dev, int nr_virtfn); + 'nr_virtfn' is number of VFs to be enabled. + +To disable SR-IOV capability: + void pci_disable_sriov(struct pci_dev *dev); + +To notify SR-IOV core of Virtual Function Migration: + irqreturn_t pci_sriov_migration(struct pci_dev *dev); + +3.2 Usage example + +Following piece of code illustrates the usage of the SR-IOV API. + +static int __devinit dev_probe(struct pci_dev *dev, const struct pci_device_id *id) +{ + pci_enable_sriov(dev, NR_VIRTFN); + + ... + + return 0; +} + +static void __devexit dev_remove(struct pci_dev *dev) +{ + pci_disable_sriov(dev); + + ... +} + +static int dev_suspend(struct pci_dev *dev, pm_message_t state) +{ + ... + + return 0; +} + +static int dev_resume(struct pci_dev *dev) +{ + ... + + return 0; +} + +static void dev_shutdown(struct pci_dev *dev) +{ + ... +} + +static struct pci_driver dev_driver = { + .name = "SR-IOV Physical Function driver", + .id_table = dev_id_table, + .probe = dev_probe, + .remove = __devexit_p(dev_remove), + .suspend = dev_suspend, + .resume = dev_resume, + .shutdown = dev_shutdown, +}; diff --git a/Documentation/RCU/checklist.txt b/Documentation/RCU/checklist.txt index 6e253407b3dc..accfe2f5247d 100644 --- a/Documentation/RCU/checklist.txt +++ b/Documentation/RCU/checklist.txt @@ -298,3 +298,15 @@ over a rather long period of time, but improvements are always welcome! Note that, rcu_assign_pointer() and rcu_dereference() relate to SRCU just as they do to other forms of RCU. + +15. The whole point of call_rcu(), synchronize_rcu(), and friends + is to wait until all pre-existing readers have finished before + carrying out some otherwise-destructive operation. It is + therefore critically important to -first- remove any path + that readers can follow that could be affected by the + destructive operation, and -only- -then- invoke call_rcu(), + synchronize_rcu(), or friends. + + Because these primitives only wait for pre-existing readers, + it is the caller's responsibility to guarantee safety to + any subsequent readers. diff --git a/Documentation/RCU/listRCU.txt b/Documentation/RCU/listRCU.txt index 1fd175368a87..4349c1487e91 100644 --- a/Documentation/RCU/listRCU.txt +++ b/Documentation/RCU/listRCU.txt @@ -118,7 +118,7 @@ Following are the RCU equivalents for these two functions: list_for_each_entry(e, list, list) { if (!audit_compare_rule(rule, &e->rule)) { list_del_rcu(&e->list); - call_rcu(&e->rcu, audit_free_rule, e); + call_rcu(&e->rcu, audit_free_rule); return 0; } } @@ -206,7 +206,7 @@ RCU ("read-copy update") its name. The RCU code is as follows: ne->rule.action = newaction; ne->rule.file_count = newfield_count; list_replace_rcu(e, ne); - call_rcu(&e->rcu, audit_free_rule, e); + call_rcu(&e->rcu, audit_free_rule); return 0; } } @@ -283,7 +283,7 @@ flag under the spinlock as follows: list_del_rcu(&e->list); e->deleted = 1; spin_unlock(&e->lock); - call_rcu(&e->rcu, audit_free_rule, e); + call_rcu(&e->rcu, audit_free_rule); return 0; } } diff --git a/Documentation/RCU/rcu.txt b/Documentation/RCU/rcu.txt index 95821a29ae41..7aa2002ade77 100644 --- a/Documentation/RCU/rcu.txt +++ b/Documentation/RCU/rcu.txt @@ -81,7 +81,7 @@ o I hear that RCU needs work in order to support realtime kernels? This work is largely completed. Realtime-friendly RCU can be enabled via the CONFIG_PREEMPT_RCU kernel configuration parameter. However, work is in progress for enabling priority boosting of - preempted RCU read-side critical sections.This is needed if you + preempted RCU read-side critical sections. This is needed if you have CPU-bound realtime threads. o Where can I find more information on RCU? diff --git a/Documentation/RCU/rculist_nulls.txt b/Documentation/RCU/rculist_nulls.txt index 239f542d48ba..6389dec33459 100644 --- a/Documentation/RCU/rculist_nulls.txt +++ b/Documentation/RCU/rculist_nulls.txt @@ -21,7 +21,7 @@ if (obj) { /* * Because a writer could delete object, and a writer could * reuse these object before the RCU grace period, we - * must check key after geting the reference on object + * must check key after getting the reference on object */ if (obj->key != key) { // not the object we expected put_ref(obj); @@ -117,7 +117,7 @@ a race (some writer did a delete and/or a move of an object to another chain) checking the final 'nulls' value if the lookup met the end of chain. If final 'nulls' value is not the slot number, then we must restart the lookup at -the begining. If the object was moved to same chain, +the beginning. If the object was moved to the same chain, then the reader doesnt care : It might eventually scan the list again without harm. diff --git a/Documentation/Smack.txt b/Documentation/Smack.txt index 989c2fcd8111..629c92e99783 100644 --- a/Documentation/Smack.txt +++ b/Documentation/Smack.txt @@ -184,14 +184,16 @@ length. Single character labels using special characters, that being anything other than a letter or digit, are reserved for use by the Smack development team. Smack labels are unstructured, case sensitive, and the only operation ever performed on them is comparison for equality. Smack labels cannot -contain unprintable characters or the "/" (slash) character. +contain unprintable characters or the "/" (slash) character. Smack labels +cannot begin with a '-', which is reserved for special options. There are some predefined labels: - _ Pronounced "floor", a single underscore character. - ^ Pronounced "hat", a single circumflex character. - * Pronounced "star", a single asterisk character. - ? Pronounced "huh", a single question mark character. + _ Pronounced "floor", a single underscore character. + ^ Pronounced "hat", a single circumflex character. + * Pronounced "star", a single asterisk character. + ? Pronounced "huh", a single question mark character. + @ Pronounced "Internet", a single at sign character. Every task on a Smack system is assigned a label. System tasks, such as init(8) and systems daemons, are run with the floor ("_") label. User tasks @@ -412,6 +414,36 @@ sockets. A privileged program may set this to match the label of another task with which it hopes to communicate. +Smack Netlabel Exceptions + +You will often find that your labeled application has to talk to the outside, +unlabeled world. To do this there's a special file /smack/netlabel where you can +add some exceptions in the form of : +@IP1 LABEL1 or +@IP2/MASK LABEL2 + +It means that your application will have unlabeled access to @IP1 if it has +write access on LABEL1, and access to the subnet @IP2/MASK if it has write +access on LABEL2. + +Entries in the /smack/netlabel file are matched by longest mask first, like in +classless IPv4 routing. + +A special label '@' and an option '-CIPSO' can be used there : +@ means Internet, any application with any label has access to it +-CIPSO means standard CIPSO networking + +If you don't know what CIPSO is and don't plan to use it, you can just do : +echo 127.0.0.1 -CIPSO > /smack/netlabel +echo 0.0.0.0/0 @ > /smack/netlabel + +If you use CIPSO on your 192.168.0.0/16 local network and need also unlabeled +Internet access, you can have : +echo 127.0.0.1 -CIPSO > /smack/netlabel +echo 192.168.0.0/16 -CIPSO > /smack/netlabel +echo 0.0.0.0/0 @ > /smack/netlabel + + Writing Applications for Smack There are three sorts of applications that will run on a Smack system. How an diff --git a/Documentation/arm/Samsung-S3C24XX/Suspend.txt b/Documentation/arm/Samsung-S3C24XX/Suspend.txt index 0dab6e32c130..a30fe510572b 100644 --- a/Documentation/arm/Samsung-S3C24XX/Suspend.txt +++ b/Documentation/arm/Samsung-S3C24XX/Suspend.txt @@ -40,13 +40,13 @@ Resuming Machine Support --------------- - The machine specific functions must call the s3c2410_pm_init() function + The machine specific functions must call the s3c_pm_init() function to say that its bootloader is capable of resuming. This can be as simple as adding the following to the machine's definition: - INITMACHINE(s3c2410_pm_init) + INITMACHINE(s3c_pm_init) - A board can do its own setup before calling s3c2410_pm_init, if it + A board can do its own setup before calling s3c_pm_init, if it needs to setup anything else for power management support. There is currently no support for over-riding the default method of @@ -74,7 +74,7 @@ statuc void __init machine_init(void) enable_irq_wake(IRQ_EINT0); - s3c2410_pm_init(); + s3c_pm_init(); } diff --git a/Documentation/arm/memory.txt b/Documentation/arm/memory.txt index dc6045577a8b..43cb1004d35f 100644 --- a/Documentation/arm/memory.txt +++ b/Documentation/arm/memory.txt @@ -29,7 +29,14 @@ ffff0000 ffff0fff CPU vector page. CPU supports vector relocation (control register V bit.) -ffc00000 fffeffff DMA memory mapping region. Memory returned +fffe0000 fffeffff XScale cache flush area. This is used + in proc-xscale.S to flush the whole data + cache. Free for other usage on non-XScale. + +fff00000 fffdffff Fixmap mapping region. Addresses provided + by fix_to_virt() will be located here. + +ffc00000 ffefffff DMA memory mapping region. Memory returned by the dma_alloc_xxx functions will be dynamically mapped here. diff --git a/Documentation/block/biodoc.txt b/Documentation/block/biodoc.txt index ecad6ee75705..6fab97ea7e6b 100644 --- a/Documentation/block/biodoc.txt +++ b/Documentation/block/biodoc.txt @@ -1040,23 +1040,21 @@ Front merges are handled by the binary trees in AS and deadline schedulers. iii. Plugging the queue to batch requests in anticipation of opportunities for merge/sort optimizations -This is just the same as in 2.4 so far, though per-device unplugging -support is anticipated for 2.5. Also with a priority-based i/o scheduler, -such decisions could be based on request priorities. - Plugging is an approach that the current i/o scheduling algorithm resorts to so that it collects up enough requests in the queue to be able to take advantage of the sorting/merging logic in the elevator. If the queue is empty when a request comes in, then it plugs the request queue -(sort of like plugging the bottom of a vessel to get fluid to build up) +(sort of like plugging the bath tub of a vessel to get fluid to build up) till it fills up with a few more requests, before starting to service the requests. This provides an opportunity to merge/sort the requests before passing them down to the device. There are various conditions when the queue is unplugged (to open up the flow again), either through a scheduled task or could be on demand. For example wait_on_buffer sets the unplugging going -(by running tq_disk) so the read gets satisfied soon. So in the read case, -the queue gets explicitly unplugged as part of waiting for completion, -in fact all queues get unplugged as a side-effect. +through sync_buffer() running blk_run_address_space(mapping). Or the caller +can do it explicity through blk_unplug(bdev). So in the read case, +the queue gets explicitly unplugged as part of waiting for completion on that +buffer. For page driven IO, the address space ->sync_page() takes care of +doing the blk_run_address_space(). Aside: This is kind of controversial territory, as it's not clear if plugging is @@ -1067,11 +1065,6 @@ Aside: multi-page bios being queued in one shot, we may not need to wait to merge a big request from the broken up pieces coming by. - Per-queue granularity unplugging (still a Todo) may help reduce some of the - concerns with just a single tq_disk flush approach. Something like - blk_kick_queue() to unplug a specific queue (right away ?) - or optionally, all queues, is in the plan. - 4.4 I/O contexts I/O contexts provide a dynamically allocated per process data area. They may be used in I/O schedulers, and in the block layer (could be used for IO statis, diff --git a/Documentation/block/switching-sched.txt b/Documentation/block/switching-sched.txt index 634c952e1964..d5af3f630814 100644 --- a/Documentation/block/switching-sched.txt +++ b/Documentation/block/switching-sched.txt @@ -35,9 +35,3 @@ noop anticipatory deadline [cfq] # echo anticipatory > /sys/block/hda/queue/scheduler # cat /sys/block/hda/queue/scheduler noop [anticipatory] deadline cfq - -Each io queue has a set of io scheduler tunables associated with it. These -tunables control how the io scheduler works. You can find these entries -in: - -/sys/block/<device>/queue/iosched diff --git a/Documentation/blockdev/00-INDEX b/Documentation/blockdev/00-INDEX index 86f054c47013..c08df56dd91b 100644 --- a/Documentation/blockdev/00-INDEX +++ b/Documentation/blockdev/00-INDEX @@ -8,6 +8,8 @@ cpqarray.txt - info on using Compaq's SMART2 Intelligent Disk Array Controllers. floppy.txt - notes and driver options for the floppy disk driver. +mflash.txt + - info on mGine m(g)flash driver for linux. nbd.txt - info on a TCP implementation of a network block device. paride.txt diff --git a/Documentation/blockdev/mflash.txt b/Documentation/blockdev/mflash.txt new file mode 100644 index 000000000000..1f610ecf698a --- /dev/null +++ b/Documentation/blockdev/mflash.txt @@ -0,0 +1,84 @@ +This document describes m[g]flash support in linux. + +Contents + 1. Overview + 2. Reserved area configuration + 3. Example of mflash platform driver registration + +1. Overview + +Mflash and gflash are embedded flash drive. The only difference is mflash is +MCP(Multi Chip Package) device. These two device operate exactly same way. +So the rest mflash repersents mflash and gflash altogether. + +Internally, mflash has nand flash and other hardware logics and supports +2 different operation (ATA, IO) modes. ATA mode doesn't need any new +driver and currently works well under standard IDE subsystem. Actually it's +one chip SSD. IO mode is ATA-like custom mode for the host that doesn't have +IDE interface. + +Followings are brief descriptions about IO mode. +A. IO mode based on ATA protocol and uses some custom command. (read confirm, +write confirm) +B. IO mode uses SRAM bus interface. +C. IO mode supports 4kB boot area, so host can boot from mflash. + +2. Reserved area configuration +If host boot from mflash, usually needs raw area for boot loader image. All of +the mflash's block device operation will be taken this value as start offset. +Note that boot loader's size of reserved area and kernel configuration value +must be same. + +3. Example of mflash platform driver registration +Working mflash is very straight forward. Adding platform device stuff to board +configuration file is all. Here is some pseudo example. + +static struct mg_drv_data mflash_drv_data = { + /* If you want to polling driver set to 1 */ + .use_polling = 0, + /* device attribution */ + .dev_attr = MG_BOOT_DEV +}; + +static struct resource mg_mflash_rsc[] = { + /* Base address of mflash */ + [0] = { + .start = 0x08000000, + .end = 0x08000000 + SZ_64K - 1, + .flags = IORESOURCE_MEM + }, + /* mflash interrupt pin */ + [1] = { + .start = IRQ_GPIO(84), + .end = IRQ_GPIO(84), + .flags = IORESOURCE_IRQ + }, + /* mflash reset pin */ + [2] = { + .start = 43, + .end = 43, + .name = MG_RST_PIN, + .flags = IORESOURCE_IO + }, + /* mflash reset-out pin + * If you use mflash as storage device (i.e. other than MG_BOOT_DEV), + * should assign this */ + [3] = { + .start = 51, + .end = 51, + .name = MG_RSTOUT_PIN, + .flags = IORESOURCE_IO + } +}; + +static struct platform_device mflash_dev = { + .name = MG_DEV_NAME, + .id = -1, + .dev = { + .platform_data = &mflash_drv_data, + }, + .num_resources = ARRAY_SIZE(mg_mflash_rsc), + .resource = mg_mflash_rsc +}; + +platform_device_register(&mflash_dev); diff --git a/Documentation/cgroups/00-INDEX b/Documentation/cgroups/00-INDEX new file mode 100644 index 000000000000..3f58fa3d6d00 --- /dev/null +++ b/Documentation/cgroups/00-INDEX @@ -0,0 +1,18 @@ +00-INDEX + - this file +cgroups.txt + - Control Groups definition, implementation details, examples and API. +cpuacct.txt + - CPU Accounting Controller; account CPU usage for groups of tasks. +cpusets.txt + - documents the cpusets feature; assign CPUs and Mem to a set of tasks. +devices.txt + - Device Whitelist Controller; description, interface and security. +freezer-subsystem.txt + - checkpointing; rationale to not use signals, interface. +memcg_test.txt + - Memory Resource Controller; implementation details. +memory.txt + - Memory Resource Controller; design, accounting, interface, testing. +resource_counter.txt + - Resource Counter API. diff --git a/Documentation/cgroups/cgroups.txt b/Documentation/cgroups/cgroups.txt index 93feb8444489..6eb1a97e88ce 100644 --- a/Documentation/cgroups/cgroups.txt +++ b/Documentation/cgroups/cgroups.txt @@ -56,7 +56,7 @@ hierarchy, and a set of subsystems; each subsystem has system-specific state attached to each cgroup in the hierarchy. Each hierarchy has an instance of the cgroup virtual filesystem associated with it. -At any one time there may be multiple active hierachies of task +At any one time there may be multiple active hierarchies of task cgroups. Each hierarchy is a partition of all tasks in the system. User level code may create and destroy cgroups by name in an @@ -124,10 +124,10 @@ following lines: / \ Prof (15%) students (5%) -Browsers like firefox/lynx go into the WWW network class, while (k)nfsd go +Browsers like Firefox/Lynx go into the WWW network class, while (k)nfsd go into NFS network class. -At the same time firefox/lynx will share an appropriate CPU/Memory class +At the same time Firefox/Lynx will share an appropriate CPU/Memory class depending on who launched it (prof/student). With the ability to classify tasks differently for different resources @@ -325,7 +325,7 @@ and then start a subshell 'sh' in that cgroup: Creating, modifying, using the cgroups can be done through the cgroup virtual filesystem. -To mount a cgroup hierarchy will all available subsystems, type: +To mount a cgroup hierarchy with all available subsystems, type: # mount -t cgroup xxx /dev/cgroup The "xxx" is not interpreted by the cgroup code, but will appear in @@ -333,12 +333,23 @@ The "xxx" is not interpreted by the cgroup code, but will appear in To mount a cgroup hierarchy with just the cpuset and numtasks subsystems, type: -# mount -t cgroup -o cpuset,numtasks hier1 /dev/cgroup +# mount -t cgroup -o cpuset,memory hier1 /dev/cgroup To change the set of subsystems bound to a mounted hierarchy, just remount with different options: +# mount -o remount,cpuset,ns hier1 /dev/cgroup -# mount -o remount,cpuset,ns /dev/cgroup +Now memory is removed from the hierarchy and ns is added. + +Note this will add ns to the hierarchy but won't remove memory or +cpuset, because the new options are appended to the old ones: +# mount -o remount,ns /dev/cgroup + +To Specify a hierarchy's release_agent: +# mount -t cgroup -o cpuset,release_agent="/sbin/cpuset_release_agent" \ + xxx /dev/cgroup + +Note that specifying 'release_agent' more than once will return failure. Note that changing the set of subsystems is currently only supported when the hierarchy consists of a single (root) cgroup. Supporting @@ -349,6 +360,11 @@ Then under /dev/cgroup you can find a tree that corresponds to the tree of the cgroups in the system. For instance, /dev/cgroup is the cgroup that holds the whole system. +If you want to change the value of release_agent: +# echo "/sbin/new_release_agent" > /dev/cgroup/release_agent + +It can also be changed via remount. + If you want to create a new cgroup under /dev/cgroup: # cd /dev/cgroup # mkdir my_cgroup @@ -476,11 +492,13 @@ cgroup->parent is still valid. (Note - can also be called for a newly-created cgroup if an error occurs after this subsystem's create() method has been called for the new cgroup). -void pre_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp); +int pre_destroy(struct cgroup_subsys *ss, struct cgroup *cgrp); Called before checking the reference count on each subsystem. This may be useful for subsystems which have some extra references even if -there are not tasks in the cgroup. +there are not tasks in the cgroup. If pre_destroy() returns error code, +rmdir() will fail with it. From this behavior, pre_destroy() can be +called multiple times against a cgroup. int can_attach(struct cgroup_subsys *ss, struct cgroup *cgrp, struct task_struct *task) @@ -521,7 +539,7 @@ always handled well. void post_clone(struct cgroup_subsys *ss, struct cgroup *cgrp) (cgroup_mutex held by caller) -Called at the end of cgroup_clone() to do any paramater +Called at the end of cgroup_clone() to do any parameter initialization which might be required before a task could attach. For example in cpusets, no task may attach before 'cpus' and 'mems' are set up. diff --git a/Documentation/cgroups/cpuacct.txt b/Documentation/cgroups/cpuacct.txt index bb775fbe43d7..8b930946c52a 100644 --- a/Documentation/cgroups/cpuacct.txt +++ b/Documentation/cgroups/cpuacct.txt @@ -30,3 +30,21 @@ The above steps create a new group g1 and move the current shell process (bash) into it. CPU time consumed by this bash and its children can be obtained from g1/cpuacct.usage and the same is accumulated in /cgroups/cpuacct.usage also. + +cpuacct.stat file lists a few statistics which further divide the +CPU time obtained by the cgroup into user and system times. Currently +the following statistics are supported: + +user: Time spent by tasks of the cgroup in user mode. +system: Time spent by tasks of the cgroup in kernel mode. + +user and system are in USER_HZ unit. + +cpuacct controller uses percpu_counter interface to collect user and +system times. This has two side effects: + +- It is theoretically possible to see wrong values for user and system times. + This is because percpu_counter_read() on 32bit systems isn't safe + against concurrent writes. +- It is possible to see slightly outdated values for user and system times + due to the batch processing nature of percpu_counter. diff --git a/Documentation/cgroups/cpusets.txt b/Documentation/cgroups/cpusets.txt index 0611e9528c7c..f9ca389dddf4 100644 --- a/Documentation/cgroups/cpusets.txt +++ b/Documentation/cgroups/cpusets.txt @@ -131,7 +131,7 @@ Cpusets extends these two mechanisms as follows: - The hierarchy of cpusets can be mounted at /dev/cpuset, for browsing and manipulation from user space. - A cpuset may be marked exclusive, which ensures that no other - cpuset (except direct ancestors and descendents) may contain + cpuset (except direct ancestors and descendants) may contain any overlapping CPUs or Memory Nodes. - You can list all the tasks (by pid) attached to any cpuset. @@ -226,7 +226,7 @@ nodes with memory--using the cpuset_track_online_nodes() hook. -------------------------------- If a cpuset is cpu or mem exclusive, no other cpuset, other than -a direct ancestor or descendent, may share any of the same CPUs or +a direct ancestor or descendant, may share any of the same CPUs or Memory Nodes. A cpuset that is mem_exclusive *or* mem_hardwall is "hardwalled", @@ -427,7 +427,7 @@ child cpusets have this flag enabled. When doing this, you don't usually want to leave any unpinned tasks in the top cpuset that might use non-trivial amounts of CPU, as such tasks may be artificially constrained to some subset of CPUs, depending on -the particulars of this flag setting in descendent cpusets. Even if +the particulars of this flag setting in descendant cpusets. Even if such a task could use spare CPU cycles in some other CPUs, the kernel scheduler might not consider the possibility of load balancing that task to that underused CPU. @@ -531,9 +531,9 @@ be idle. Of course it takes some searching cost to find movable tasks and/or idle CPUs, the scheduler might not search all CPUs in the domain -everytime. In fact, in some architectures, the searching ranges on +every time. In fact, in some architectures, the searching ranges on events are limited in the same socket or node where the CPU locates, -while the load balance on tick searchs all. +while the load balance on tick searches all. For example, assume CPU Z is relatively far from CPU X. Even if CPU Z is idle while CPU X and the siblings are busy, scheduler can't migrate @@ -601,7 +601,7 @@ its new cpuset, then the task will continue to use whatever subset of MPOL_BIND nodes are still allowed in the new cpuset. If the task was using MPOL_BIND and now none of its MPOL_BIND nodes are allowed in the new cpuset, then the task will be essentially treated as if it -was MPOL_BIND bound to the new cpuset (even though its numa placement, +was MPOL_BIND bound to the new cpuset (even though its NUMA placement, as queried by get_mempolicy(), doesn't change). If a task is moved from one cpuset to another, then the kernel will adjust the tasks memory placement, as above, the next time that the kernel attempts diff --git a/Documentation/cgroups/devices.txt b/Documentation/cgroups/devices.txt index 7cc6e6a60672..57ca4c89fe5c 100644 --- a/Documentation/cgroups/devices.txt +++ b/Documentation/cgroups/devices.txt @@ -42,7 +42,7 @@ suffice, but we can decide the best way to adequately restrict movement as people get some experience with this. We may just want to require CAP_SYS_ADMIN, which at least is a separate bit from CAP_MKNOD. We may want to just refuse moving to a cgroup which -isn't a descendent of the current one. Or we may want to use +isn't a descendant of the current one. Or we may want to use CAP_MAC_ADMIN, since we really are trying to lock down root. CAP_SYS_ADMIN is needed to modify the whitelist or move another diff --git a/Documentation/cgroups/memcg_test.txt b/Documentation/cgroups/memcg_test.txt index 523a9c16c400..72db89ed0609 100644 --- a/Documentation/cgroups/memcg_test.txt +++ b/Documentation/cgroups/memcg_test.txt @@ -1,5 +1,5 @@ Memory Resource Controller(Memcg) Implementation Memo. -Last Updated: 2009/1/19 +Last Updated: 2009/1/20 Base Kernel Version: based on 2.6.29-rc2. Because VM is getting complex (one of reasons is memcg...), memcg's behavior @@ -356,7 +356,25 @@ Under below explanation, we assume CONFIG_MEM_RES_CTRL_SWAP=y. (Shell-B) # move all tasks in /cgroup/test to /cgroup # /sbin/swapoff -a - # rmdir /test/cgroup + # rmdir /cgroup/test # kill malloc task. Of course, tmpfs v.s. swapoff test should be tested, too. + + 9.8 OOM-Killer + Out-of-memory caused by memcg's limit will kill tasks under + the memcg. When hierarchy is used, a task under hierarchy + will be killed by the kernel. + In this case, panic_on_oom shouldn't be invoked and tasks + in other groups shouldn't be killed. + + It's not difficult to cause OOM under memcg as following. + Case A) when you can swapoff + #swapoff -a + #echo 50M > /memory.limit_in_bytes + run 51M of malloc + + Case B) when you use mem+swap limitation. + #echo 50M > memory.limit_in_bytes + #echo 50M > memory.memsw.limit_in_bytes + run 51M of malloc diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt index e1501964df1e..1a608877b14e 100644 --- a/Documentation/cgroups/memory.txt +++ b/Documentation/cgroups/memory.txt @@ -6,15 +6,14 @@ used here with the memory controller that is used in hardware. Salient features -a. Enable control of both RSS (mapped) and Page Cache (unmapped) pages +a. Enable control of Anonymous, Page Cache (mapped and unmapped) and + Swap Cache memory pages. b. The infrastructure allows easy addition of other types of memory to control c. Provides *zero overhead* for non memory controller users d. Provides a double LRU: global memory pressure causes reclaim from the global LRU; a cgroup on hitting a limit, reclaims from the per cgroup LRU -NOTE: Swap Cache (unmapped) is not accounted now. - Benefits and Purpose of the memory controller The memory controller isolates the memory behaviour of a group of tasks @@ -290,34 +289,44 @@ will be charged as a new owner of it. moved to the parent. If you want to avoid that, force_empty will be useful. 5.2 stat file - memory.stat file includes following statistics (now) - cache - # of pages from page-cache and shmem. - rss - # of pages from anonymous memory. - pgpgin - # of event of charging - pgpgout - # of event of uncharging - active_anon - # of pages on active lru of anon, shmem. - inactive_anon - # of pages on active lru of anon, shmem - active_file - # of pages on active lru of file-cache - inactive_file - # of pages on inactive lru of file cache - unevictable - # of pages cannot be reclaimed.(mlocked etc) - - Below is depend on CONFIG_DEBUG_VM. - inactive_ratio - VM inernal parameter. (see mm/page_alloc.c) - recent_rotated_anon - VM internal parameter. (see mm/vmscan.c) - recent_rotated_file - VM internal parameter. (see mm/vmscan.c) - recent_scanned_anon - VM internal parameter. (see mm/vmscan.c) - recent_scanned_file - VM internal parameter. (see mm/vmscan.c) - - Memo: + +memory.stat file includes following statistics + +cache - # of bytes of page cache memory. +rss - # of bytes of anonymous and swap cache memory. +pgpgin - # of pages paged in (equivalent to # of charging events). +pgpgout - # of pages paged out (equivalent to # of uncharging events). +active_anon - # of bytes of anonymous and swap cache memory on active + lru list. +inactive_anon - # of bytes of anonymous memory and swap cache memory on + inactive lru list. +active_file - # of bytes of file-backed memory on active lru list. +inactive_file - # of bytes of file-backed memory on inactive lru list. +unevictable - # of bytes of memory that cannot be reclaimed (mlocked etc). + +The following additional stats are dependent on CONFIG_DEBUG_VM. + +inactive_ratio - VM internal parameter. (see mm/page_alloc.c) +recent_rotated_anon - VM internal parameter. (see mm/vmscan.c) +recent_rotated_file - VM internal parameter. (see mm/vmscan.c) +recent_scanned_anon - VM internal parameter. (see mm/vmscan.c) +recent_scanned_file - VM internal parameter. (see mm/vmscan.c) + +Memo: recent_rotated means recent frequency of lru rotation. recent_scanned means recent # of scans to lru. showing for better debug please see the code for meanings. +Note: + Only anonymous and swap cache memory is listed as part of 'rss' stat. + This should not be confused with the true 'resident set size' or the + amount of physical memory used by the cgroup. Per-cgroup rss + accounting is not done yet. 5.3 swappiness Similar to /proc/sys/vm/swappiness, but affecting a hierarchy of groups only. - Following cgroup's swapiness can't be changed. + Following cgroups' swapiness can't be changed. - root cgroup (uses /proc/sys/vm/swappiness). - a cgroup which uses hierarchy and it has child cgroup. - a cgroup which uses hierarchy and not the root of hierarchy. diff --git a/Documentation/cgroups/resource_counter.txt b/Documentation/cgroups/resource_counter.txt index f196ac1d7d25..95b24d766eab 100644 --- a/Documentation/cgroups/resource_counter.txt +++ b/Documentation/cgroups/resource_counter.txt @@ -47,13 +47,18 @@ to work with it. 2. Basic accounting routines - a. void res_counter_init(struct res_counter *rc) + a. void res_counter_init(struct res_counter *rc, + struct res_counter *rc_parent) Initializes the resource counter. As usual, should be the first routine called for a new counter. - b. int res_counter_charge[_locked] - (struct res_counter *rc, unsigned long val) + The struct res_counter *parent can be used to define a hierarchical + child -> parent relationship directly in the res_counter structure, + NULL can be used to define no relationship. + + c. int res_counter_charge(struct res_counter *rc, unsigned long val, + struct res_counter **limit_fail_at) When a resource is about to be allocated it has to be accounted with the appropriate resource counter (controller should determine @@ -67,15 +72,25 @@ to work with it. * if the charging is performed first, then it should be uncharged on error path (if the one is called). - c. void res_counter_uncharge[_locked] + If the charging fails and a hierarchical dependency exists, the + limit_fail_at parameter is set to the particular res_counter element + where the charging failed. + + d. int res_counter_charge_locked + (struct res_counter *rc, unsigned long val) + + The same as res_counter_charge(), but it must not acquire/release the + res_counter->lock internally (it must be called with res_counter->lock + held). + + e. void res_counter_uncharge[_locked] (struct res_counter *rc, unsigned long val) When a resource is released (freed) it should be de-accounted from the resource counter it was accounted to. This is called "uncharging". - The _locked routines imply that the res_counter->lock is taken. - + The _locked routines imply that the res_counter->lock is taken. 2.1 Other accounting routines diff --git a/Documentation/cpu-freq/governors.txt b/Documentation/cpu-freq/governors.txt index 5b0cfa67aff9..ce73f3eb5ddb 100644 --- a/Documentation/cpu-freq/governors.txt +++ b/Documentation/cpu-freq/governors.txt @@ -117,10 +117,28 @@ accessible parameters: sampling_rate: measured in uS (10^-6 seconds), this is how often you want the kernel to look at the CPU usage and to make decisions on what to do about the frequency. Typically this is set to values of -around '10000' or more. - -show_sampling_rate_(min|max): the minimum and maximum sampling rates -available that you may set 'sampling_rate' to. +around '10000' or more. It's default value is (cmp. with users-guide.txt): +transition_latency * 1000 +The lowest value you can set is: +transition_latency * 100 or it may get restricted to a value where it +makes not sense for the kernel anymore to poll that often which depends +on your HZ config variable (HZ=1000: max=20000us, HZ=250: max=5000). +Be aware that transition latency is in ns and sampling_rate is in us, so you +get the same sysfs value by default. +Sampling rate should always get adjusted considering the transition latency +To set the sampling rate 750 times as high as the transition latency +in the bash (as said, 1000 is default), do: +echo `$(($(cat cpuinfo_transition_latency) * 750 / 1000)) \ + >ondemand/sampling_rate + +show_sampling_rate_(min|max): THIS INTERFACE IS DEPRECATED, DON'T USE IT. +You can use wider ranges now and the general +cpuinfo_transition_latency variable (cmp. with user-guide.txt) can be +used to obtain exactly the same info: +show_sampling_rate_min = transtition_latency * 500 / 1000 +show_sampling_rate_max = transtition_latency * 500000 / 1000 +(divided by 1000 is to illustrate that sampling rate is in us and +transition latency is exported ns). up_threshold: defines what the average CPU usage between the samplings of 'sampling_rate' needs to be for the kernel to make a decision on diff --git a/Documentation/cpu-freq/user-guide.txt b/Documentation/cpu-freq/user-guide.txt index 917918f84fc7..75f41193f3e1 100644 --- a/Documentation/cpu-freq/user-guide.txt +++ b/Documentation/cpu-freq/user-guide.txt @@ -152,6 +152,18 @@ cpuinfo_min_freq : this file shows the minimum operating frequency the processor can run at(in kHz) cpuinfo_max_freq : this file shows the maximum operating frequency the processor can run at(in kHz) +cpuinfo_transition_latency The time it takes on this CPU to + switch between two frequencies in nano + seconds. If unknown or known to be + that high that the driver does not + work with the ondemand governor, -1 + (CPUFREQ_ETERNAL) will be returned. + Using this information can be useful + to choose an appropriate polling + frequency for a kernel governor or + userspace daemon. Make sure to not + switch the frequency too often + resulting in performance loss. scaling_driver : this file shows what cpufreq driver is used to set the frequency on this CPU diff --git a/Documentation/cputopology.txt b/Documentation/cputopology.txt index 45932ec21cee..b41f3e58aefa 100644 --- a/Documentation/cputopology.txt +++ b/Documentation/cputopology.txt @@ -18,11 +18,11 @@ For an architecture to support this feature, it must define some of these macros in include/asm-XXX/topology.h: #define topology_physical_package_id(cpu) #define topology_core_id(cpu) -#define topology_thread_siblings(cpu) -#define topology_core_siblings(cpu) +#define topology_thread_cpumask(cpu) +#define topology_core_cpumask(cpu) The type of **_id is int. -The type of siblings is cpumask_t. +The type of siblings is (const) struct cpumask *. To be consistent on all architectures, include/linux/topology.h provides default definitions for any of the above macros that are diff --git a/Documentation/devices.txt b/Documentation/devices.txt index 2be08240ee80..53d64d382343 100644 --- a/Documentation/devices.txt +++ b/Documentation/devices.txt @@ -1,9 +1,9 @@ LINUX ALLOCATED DEVICES (2.6+ version) - Maintained by Torben Mathiasen <device@lanana.org> + Maintained by Alan Cox <device@lanana.org> - Last revised: 29 November 2006 + Last revised: 6th April 2009 This list is the Linux Device List, the official registry of allocated device numbers and /dev directory nodes for the Linux operating @@ -67,6 +67,11 @@ up to date. Due to the number of registrations I have to maintain it in "batch mode", so there is likely additional registrations that haven't been listed yet. +Fourth, remember that Linux now has extensive support for dynamic allocation +of device numbering and can use sysfs and udev to handle the naming needs. +There are still some exceptions in the serial and boot device area. Before +asking for a device number make sure you actually need one. + Finally, sometimes I have to play "namespace police." Please don't be offended. I often get submissions for /dev names that would be bound to cause conflicts down the road. I am trying to avoid getting in a @@ -101,7 +106,7 @@ Your cooperation is appreciated. 0 = /dev/ram0 First RAM disk 1 = /dev/ram1 Second RAM disk ... - 250 = /dev/initrd Initial RAM disk {2.6} + 250 = /dev/initrd Initial RAM disk Older kernels had /dev/ramdisk (1, 1) here. /dev/initrd refers to a RAM disk which was preloaded @@ -340,7 +345,7 @@ Your cooperation is appreciated. 14 = /dev/touchscreen/ucb1x00 UCB 1x00 touchscreen 15 = /dev/touchscreen/mk712 MK712 touchscreen 128 = /dev/beep Fancy beep device - 129 = /dev/modreq Kernel module load request {2.6} + 129 = 130 = /dev/watchdog Watchdog timer port 131 = /dev/temperature Machine internal temperature 132 = /dev/hwtrap Hardware fault trap @@ -350,10 +355,10 @@ Your cooperation is appreciated. 139 = /dev/openprom SPARC OpenBoot PROM 140 = /dev/relay8 Berkshire Products Octal relay card 141 = /dev/relay16 Berkshire Products ISO-16 relay card - 142 = /dev/msr x86 model-specific registers {2.6} + 142 = 143 = /dev/pciconf PCI configuration space 144 = /dev/nvram Non-volatile configuration RAM - 145 = /dev/hfmodem Soundcard shortwave modem control {2.6} + 145 = /dev/hfmodem Soundcard shortwave modem control 146 = /dev/graphics Linux/SGI graphics device 147 = /dev/opengl Linux/SGI OpenGL pipe 148 = /dev/gfx Linux/SGI graphics effects device @@ -435,6 +440,9 @@ Your cooperation is appreciated. 228 = /dev/hpet HPET driver 229 = /dev/fuse Fuse (virtual filesystem in user-space) 230 = /dev/midishare MidiShare driver + 231 = /dev/snapshot System memory snapshot device + 232 = /dev/kvm Kernel-based virtual machine (hardware virtualization extensions) + 233 = /dev/kmview View-OS A process with a view 240-254 Reserved for local use 255 Reserved for MISC_DYNAMIC_MINOR @@ -466,10 +474,7 @@ Your cooperation is appreciated. The device names specified are proposed -- if there are "standard" names for these devices, please let me know. - 12 block MSCDEX CD-ROM callback support {2.6} - 0 = /dev/dos_cd0 First MSCDEX CD-ROM - 1 = /dev/dos_cd1 Second MSCDEX CD-ROM - ... + 12 block 13 char Input core 0 = /dev/input/js0 First joystick @@ -498,7 +503,7 @@ Your cooperation is appreciated. 2 = /dev/midi00 First MIDI port 3 = /dev/dsp Digital audio 4 = /dev/audio Sun-compatible digital audio - 6 = /dev/sndstat Sound card status information {2.6} + 6 = 7 = /dev/audioctl SPARC audio control device 8 = /dev/sequencer2 Sequencer -- alternate device 16 = /dev/mixer1 Second soundcard mixer control @@ -510,14 +515,7 @@ Your cooperation is appreciated. 34 = /dev/midi02 Third MIDI port 50 = /dev/midi03 Fourth MIDI port - 14 block BIOS harddrive callback support {2.6} - 0 = /dev/dos_hda First BIOS harddrive whole disk - 64 = /dev/dos_hdb Second BIOS harddrive whole disk - 128 = /dev/dos_hdc Third BIOS harddrive whole disk - 192 = /dev/dos_hdd Fourth BIOS harddrive whole disk - - Partitions are handled in the same way as IDE disks - (see major number 3). + 14 block 15 char Joystick 0 = /dev/js0 First analog joystick @@ -535,14 +533,14 @@ Your cooperation is appreciated. 16 block GoldStar CD-ROM 0 = /dev/gscd GoldStar CD-ROM - 17 char Chase serial card + 17 char OBSOLETE (was Chase serial card) 0 = /dev/ttyH0 First Chase port 1 = /dev/ttyH1 Second Chase port ... 17 block Optics Storage CD-ROM 0 = /dev/optcd Optics Storage CD-ROM - 18 char Chase serial card - alternate devices + 18 char OBSOLETE (was Chase serial card - alternate devices) 0 = /dev/cuh0 Callout device for ttyH0 1 = /dev/cuh1 Callout device for ttyH1 ... @@ -644,8 +642,7 @@ Your cooperation is appreciated. 2 = /dev/sbpcd2 Panasonic CD-ROM controller 0 unit 2 3 = /dev/sbpcd3 Panasonic CD-ROM controller 0 unit 3 - 26 char Quanta WinVision frame grabber {2.6} - 0 = /dev/wvisfgrab Quanta WinVision frame grabber + 26 char 26 block Second Matsushita (Panasonic/SoundBlaster) CD-ROM 0 = /dev/sbpcd4 Panasonic CD-ROM controller 1 unit 0 @@ -872,7 +869,7 @@ Your cooperation is appreciated. and "user level packet I/O." This board is also accessible as a standard networking "eth" device. - 38 block Reserved for Linux/AP+ + 38 block OBSOLETE (was Linux/AP+) 39 char ML-16P experimental I/O board 0 = /dev/ml16pa-a0 First card, first analog channel @@ -892,29 +889,16 @@ Your cooperation is appreciated. 50 = /dev/ml16pb-c1 Second card, second counter/timer 51 = /dev/ml16pb-c2 Second card, third counter/timer ... - 39 block Reserved for Linux/AP+ + 39 block - 40 char Matrox Meteor frame grabber {2.6} - 0 = /dev/mmetfgrab Matrox Meteor frame grabber + 40 char - 40 block Syquest EZ135 parallel port removable drive - 0 = /dev/eza Parallel EZ135 drive, whole disk - - This device is obsolete and will be removed in a - future version of Linux. It has been replaced with - the parallel port IDE disk driver at major number 45. - Partitions are handled in the same way as IDE disks - (see major number 3). + 40 block 41 char Yet Another Micro Monitor 0 = /dev/yamm Yet Another Micro Monitor - 41 block MicroSolutions BackPack parallel port CD-ROM - 0 = /dev/bpcd BackPack CD-ROM - - This device is obsolete and will be removed in a - future version of Linux. It has been replaced with - the parallel port ATAPI CD-ROM driver at major number 46. + 41 block 42 char Demo/sample use @@ -1681,13 +1665,7 @@ Your cooperation is appreciated. disks (see major number 3) except that the limit on partitions is 15. - 93 char IBM Smart Capture Card frame grabber {2.6} - 0 = /dev/iscc0 First Smart Capture Card - 1 = /dev/iscc1 Second Smart Capture Card - ... - 128 = /dev/isccctl0 First Smart Capture Card control - 129 = /dev/isccctl1 Second Smart Capture Card control - ... + 93 char 93 block NAND Flash Translation Layer filesystem 0 = /dev/nftla First NFTL layer @@ -1695,10 +1673,7 @@ Your cooperation is appreciated. ... 240 = /dev/nftlp 16th NTFL layer - 94 char miroVIDEO DC10/30 capture/playback device {2.6} - 0 = /dev/dcxx0 First capture card - 1 = /dev/dcxx1 Second capture card - ... + 94 char 94 block IBM S/390 DASD block storage 0 = /dev/dasda First DASD device, major @@ -1791,11 +1766,7 @@ Your cooperation is appreciated. ... 15 = /dev/amiraid/ar?p15 15th partition -102 char Philips SAA5249 Teletext signal decoder {2.6} - 0 = /dev/tlk0 First Teletext decoder - 1 = /dev/tlk1 Second Teletext decoder - 2 = /dev/tlk2 Third Teletext decoder - 3 = /dev/tlk3 Fourth Teletext decoder +102 char 102 block Compressed block device 0 = /dev/cbd/a First compressed block device, whole device @@ -1916,10 +1887,7 @@ Your cooperation is appreciated. DAC960 (see major number 48) except that the limit on partitions is 15. -111 char Philips SAA7146-based audio/video card {2.6} - 0 = /dev/av0 First A/V card - 1 = /dev/av1 Second A/V card - ... +111 char 111 block Compaq Next Generation Drive Array, eighth controller 0 = /dev/cciss/c7d0 First logical drive, whole disk @@ -2079,8 +2047,8 @@ Your cooperation is appreciated. ... 119 char VMware virtual network control - 0 = /dev/vmnet0 1st virtual network - 1 = /dev/vmnet1 2nd virtual network + 0 = /dev/vnet0 1st virtual network + 1 = /dev/vnet1 2nd virtual network ... 120-127 char LOCAL/EXPERIMENTAL USE @@ -2450,7 +2418,7 @@ Your cooperation is appreciated. 2 = /dev/raw/raw2 Second raw I/O device ... -163 char UNASSIGNED (was Radio Tech BIM-XXX-RS232 radio modem - see 51) +163 char 164 char Chase Research AT/PCI-Fast serial card 0 = /dev/ttyCH0 AT/PCI-Fast board 0, port 0 @@ -2542,6 +2510,12 @@ Your cooperation is appreciated. 1 = /dev/clanvi1 Second cLAN adapter ... +179 block MMC block devices + 0 = /dev/mmcblk0 First SD/MMC card + 1 = /dev/mmcblk0p1 First partition on first MMC card + 8 = /dev/mmcblk1 Second SD/MMC card + ... + 179 char CCube DVXChip-based PCI products 0 = /dev/dvxirq0 First DVX device 1 = /dev/dvxirq1 Second DVX device @@ -2560,6 +2534,9 @@ Your cooperation is appreciated. 96 = /dev/usb/hiddev0 1st USB HID device ... 111 = /dev/usb/hiddev15 16th USB HID device + 112 = /dev/usb/auer0 1st auerswald ISDN device + ... + 127 = /dev/usb/auer15 16th auerswald ISDN device 128 = /dev/usb/brlvgr0 First Braille Voyager device ... 131 = /dev/usb/brlvgr3 Fourth Braille Voyager device @@ -2810,6 +2787,20 @@ Your cooperation is appreciated. ... 190 = /dev/ttyUL3 Xilinx uartlite - port 3 191 = /dev/xvc0 Xen virtual console - port 0 + 192 = /dev/ttyPZ0 pmac_zilog - port 0 + ... + 195 = /dev/ttyPZ3 pmac_zilog - port 3 + 196 = /dev/ttyTX0 TX39/49 serial port 0 + ... + 204 = /dev/ttyTX7 TX39/49 serial port 7 + 205 = /dev/ttySC0 SC26xx serial port 0 + 206 = /dev/ttySC1 SC26xx serial port 1 + 207 = /dev/ttySC2 SC26xx serial port 2 + 208 = /dev/ttySC3 SC26xx serial port 3 + 209 = /dev/ttyMAX0 MAX3100 serial port 0 + 210 = /dev/ttyMAX1 MAX3100 serial port 1 + 211 = /dev/ttyMAX2 MAX3100 serial port 2 + 212 = /dev/ttyMAX3 MAX3100 serial port 3 205 char Low-density serial ports (alternate device) 0 = /dev/culu0 Callout device for ttyLU0 @@ -3145,6 +3136,20 @@ Your cooperation is appreciated. 1 = /dev/blockrom1 Second ROM card's translation layer interface ... +259 block Block Extended Major + Used dynamically to hold additional partition minor + numbers and allow large numbers of partitions per device + +259 char FPGA configuration interfaces + 0 = /dev/icap0 First Xilinx internal configuration + 1 = /dev/icap1 Second Xilinx internal configuration + +260 char OSD (Object-based-device) SCSI Device + 0 = /dev/osd0 First OSD Device + 1 = /dev/osd1 Second OSD Device + ... + 255 = /dev/osd255 256th OSD Device + **** ADDITIONAL /dev DIRECTORY ENTRIES This section details additional entries that should or may exist in diff --git a/Documentation/dontdiff b/Documentation/dontdiff index 1e89a51ea49b..88519daab6e9 100644 --- a/Documentation/dontdiff +++ b/Documentation/dontdiff @@ -62,7 +62,6 @@ aic7*reg_print.c* aic7*seq.h* aicasm aicdb.h* -asm asm-offsets.h asm_offsets.h autoconf.h* diff --git a/Documentation/driver-model/platform.txt b/Documentation/driver-model/platform.txt index 83009fdcbbc8..2e2c2ea90ceb 100644 --- a/Documentation/driver-model/platform.txt +++ b/Documentation/driver-model/platform.txt @@ -169,3 +169,62 @@ three different ways to find such a match: be probed later if another device registers. (Which is OK, since this interface is only for use with non-hotpluggable devices.) + +Early Platform Devices and Drivers +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The early platform interfaces provide platform data to platform device +drivers early on during the system boot. The code is built on top of the +early_param() command line parsing and can be executed very early on. + +Example: "earlyprintk" class early serial console in 6 steps + +1. Registering early platform device data +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The architecture code registers platform device data using the function +early_platform_add_devices(). In the case of early serial console this +should be hardware configuration for the serial port. Devices registered +at this point will later on be matched against early platform drivers. + +2. Parsing kernel command line +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The architecture code calls parse_early_param() to parse the kernel +command line. This will execute all matching early_param() callbacks. +User specified early platform devices will be registered at this point. +For the early serial console case the user can specify port on the +kernel command line as "earlyprintk=serial.0" where "earlyprintk" is +the class string, "serial" is the name of the platfrom driver and +0 is the platform device id. If the id is -1 then the dot and the +id can be omitted. + +3. Installing early platform drivers belonging to a certain class +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The architecture code may optionally force registration of all early +platform drivers belonging to a certain class using the function +early_platform_driver_register_all(). User specified devices from +step 2 have priority over these. This step is omitted by the serial +driver example since the early serial driver code should be disabled +unless the user has specified port on the kernel command line. + +4. Early platform driver registration +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +Compiled-in platform drivers making use of early_platform_init() are +automatically registered during step 2 or 3. The serial driver example +should use early_platform_init("earlyprintk", &platform_driver). + +5. Probing of early platform drivers belonging to a certain class +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The architecture code calls early_platform_driver_probe() to match +registered early platform devices associated with a certain class with +registered early platform drivers. Matched devices will get probed(). +This step can be executed at any point during the early boot. As soon +as possible may be good for the serial port case. + +6. Inside the early platform driver probe() +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ +The driver code needs to take special care during early boot, especially +when it comes to memory allocation and interrupt registration. The code +in the probe() function can use is_early_platform_device() to check if +it is called at early platform device or at the regular platform device +time. The early serial driver performs register_console() at this point. + +For further information, see <linux/platform_device.h>. diff --git a/Documentation/dvb/get_dvb_firmware b/Documentation/dvb/get_dvb_firmware index f2e908d7f90d..2f21ecd4c205 100644 --- a/Documentation/dvb/get_dvb_firmware +++ b/Documentation/dvb/get_dvb_firmware @@ -25,7 +25,7 @@ use IO::Handle; "tda10046lifeview", "av7110", "dec2000t", "dec2540t", "dec3000s", "vp7041", "dibusb", "nxt2002", "nxt2004", "or51211", "or51132_qam", "or51132_vsb", "bluebird", - "opera1"); + "opera1", "cx231xx", "cx18", "cx23885", "pvrusb2" ); # Check args syntax() if (scalar(@ARGV) != 1); @@ -37,8 +37,8 @@ for ($i=0; $i < scalar(@components); $i++) { $outfile = eval($cid); die $@ if $@; print STDERR <<EOF; -Firmware $outfile extracted successfully. -Now copy it to either /usr/lib/hotplug/firmware or /lib/firmware +Firmware(s) $outfile extracted successfully. +Now copy it(they) to either /usr/lib/hotplug/firmware or /lib/firmware (depending on configuration of firmware hotplug). EOF exit(0); @@ -345,6 +345,85 @@ sub or51211 { $fwfile; } +sub cx231xx { + my $fwfile = "v4l-cx231xx-avcore-01.fw"; + my $url = "http://linuxtv.org/downloads/firmware/$fwfile"; + my $hash = "7d3bb956dc9df0eafded2b56ba57cc42"; + + checkstandard(); + + wgetfile($fwfile, $url); + verify($fwfile, $hash); + + $fwfile; +} + +sub cx18 { + my $url = "http://linuxtv.org/downloads/firmware/"; + + my %files = ( + 'v4l-cx23418-apu.fw' => '588f081b562f5c653a3db1ad8f65939a', + 'v4l-cx23418-cpu.fw' => 'b6c7ed64bc44b1a6e0840adaeac39d79', + 'v4l-cx23418-dig.fw' => '95bc688d3e7599fd5800161e9971cc55', + ); + + checkstandard(); + + my $allfiles; + foreach my $fwfile (keys %files) { + wgetfile($fwfile, "$url/$fwfile"); + verify($fwfile, $files{$fwfile}); + $allfiles .= " $fwfile"; + } + + $allfiles =~ s/^\s//; + + $allfiles; +} + +sub cx23885 { + my $url = "http://linuxtv.org/downloads/firmware/"; + + my %files = ( + 'v4l-cx23885-avcore-01.fw' => 'a9f8f5d901a7fb42f552e1ee6384f3bb', + 'v4l-cx23885-enc.fw' => 'a9f8f5d901a7fb42f552e1ee6384f3bb', + ); + + checkstandard(); + + my $allfiles; + foreach my $fwfile (keys %files) { + wgetfile($fwfile, "$url/$fwfile"); + verify($fwfile, $files{$fwfile}); + $allfiles .= " $fwfile"; + } + + $allfiles =~ s/^\s//; + + $allfiles; +} + +sub pvrusb2 { + my $url = "http://linuxtv.org/downloads/firmware/"; + + my %files = ( + 'v4l-cx25840.fw' => 'dadb79e9904fc8af96e8111d9cb59320', + ); + + checkstandard(); + + my $allfiles; + foreach my $fwfile (keys %files) { + wgetfile($fwfile, "$url/$fwfile"); + verify($fwfile, $files{$fwfile}); + $allfiles .= " $fwfile"; + } + + $allfiles =~ s/^\s//; + + $allfiles; +} + sub or51132_qam { my $fwfile = "dvb-fe-or51132-qam.fw"; my $url = "http://linuxtv.org/downloads/firmware/$fwfile"; diff --git a/Documentation/dynamic-debug-howto.txt b/Documentation/dynamic-debug-howto.txt new file mode 100644 index 000000000000..674c5663d346 --- /dev/null +++ b/Documentation/dynamic-debug-howto.txt @@ -0,0 +1,240 @@ + +Introduction +============ + +This document describes how to use the dynamic debug (ddebug) feature. + +Dynamic debug is designed to allow you to dynamically enable/disable kernel +code to obtain additional kernel information. Currently, if +CONFIG_DYNAMIC_DEBUG is set, then all pr_debug()/dev_debug() calls can be +dynamically enabled per-callsite. + +Dynamic debug has even more useful features: + + * Simple query language allows turning on and off debugging statements by + matching any combination of: + + - source filename + - function name + - line number (including ranges of line numbers) + - module name + - format string + + * Provides a debugfs control file: <debugfs>/dynamic_debug/control which can be + read to display the complete list of known debug statements, to help guide you + +Controlling dynamic debug Behaviour +=============================== + +The behaviour of pr_debug()/dev_debug()s are controlled via writing to a +control file in the 'debugfs' filesystem. Thus, you must first mount the debugfs +filesystem, in order to make use of this feature. Subsequently, we refer to the +control file as: <debugfs>/dynamic_debug/control. For example, if you want to +enable printing from source file 'svcsock.c', line 1603 you simply do: + +nullarbor:~ # echo 'file svcsock.c line 1603 +p' > + <debugfs>/dynamic_debug/control + +If you make a mistake with the syntax, the write will fail thus: + +nullarbor:~ # echo 'file svcsock.c wtf 1 +p' > + <debugfs>/dynamic_debug/control +-bash: echo: write error: Invalid argument + +Viewing Dynamic Debug Behaviour +=========================== + +You can view the currently configured behaviour of all the debug statements +via: + +nullarbor:~ # cat <debugfs>/dynamic_debug/control +# filename:lineno [module]function flags format +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:323 [svcxprt_rdma]svc_rdma_cleanup - "SVCRDMA Module Removed, deregister RPC RDMA transport\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:341 [svcxprt_rdma]svc_rdma_init - "\011max_inline : %d\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:340 [svcxprt_rdma]svc_rdma_init - "\011sq_depth : %d\012" +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svc_rdma.c:338 [svcxprt_rdma]svc_rdma_init - "\011max_requests : %d\012" +... + + +You can also apply standard Unix text manipulation filters to this +data, e.g. + +nullarbor:~ # grep -i rdma <debugfs>/dynamic_debug/control | wc -l +62 + +nullarbor:~ # grep -i tcp <debugfs>/dynamic_debug/control | wc -l +42 + +Note in particular that the third column shows the enabled behaviour +flags for each debug statement callsite (see below for definitions of the +flags). The default value, no extra behaviour enabled, is "-". So +you can view all the debug statement callsites with any non-default flags: + +nullarbor:~ # awk '$3 != "-"' <debugfs>/dynamic_debug/control +# filename:lineno [module]function flags format +/usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c:1603 [sunrpc]svc_send p "svc_process: st_sendto returned %d\012" + + +Command Language Reference +========================== + +At the lexical level, a command comprises a sequence of words separated +by whitespace characters. Note that newlines are treated as word +separators and do *not* end a command or allow multiple commands to +be done together. So these are all equivalent: + +nullarbor:~ # echo -c 'file svcsock.c line 1603 +p' > + <debugfs>/dynamic_debug/control +nullarbor:~ # echo -c ' file svcsock.c line 1603 +p ' > + <debugfs>/dynamic_debug/control +nullarbor:~ # echo -c 'file svcsock.c\nline 1603 +p' > + <debugfs>/dynamic_debug/control +nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + <debugfs>/dynamic_debug/control + +Commands are bounded by a write() system call. If you want to do +multiple commands you need to do a separate "echo" for each, like: + +nullarbor:~ # echo 'file svcsock.c line 1603 +p' > /proc/dprintk ;\ +> echo 'file svcsock.c line 1563 +p' > /proc/dprintk + +or even like: + +nullarbor:~ # ( +> echo 'file svcsock.c line 1603 +p' ;\ +> echo 'file svcsock.c line 1563 +p' ;\ +> ) > /proc/dprintk + +At the syntactical level, a command comprises a sequence of match +specifications, followed by a flags change specification. + +command ::= match-spec* flags-spec + +The match-spec's are used to choose a subset of the known dprintk() +callsites to which to apply the flags-spec. Think of them as a query +with implicit ANDs between each pair. Note that an empty list of +match-specs is possible, but is not very useful because it will not +match any debug statement callsites. + +A match specification comprises a keyword, which controls the attribute +of the callsite to be compared, and a value to compare against. Possible +keywords are: + +match-spec ::= 'func' string | + 'file' string | + 'module' string | + 'format' string | + 'line' line-range + +line-range ::= lineno | + '-'lineno | + lineno'-' | + lineno'-'lineno +// Note: line-range cannot contain space, e.g. +// "1-30" is valid range but "1 - 30" is not. + +lineno ::= unsigned-int + +The meanings of each keyword are: + +func + The given string is compared against the function name + of each callsite. Example: + + func svc_tcp_accept + +file + The given string is compared against either the full + pathname or the basename of the source file of each + callsite. Examples: + + file svcsock.c + file /usr/src/packages/BUILD/sgi-enhancednfs-1.4/default/net/sunrpc/svcsock.c + +module + The given string is compared against the module name + of each callsite. The module name is the string as + seen in "lsmod", i.e. without the directory or the .ko + suffix and with '-' changed to '_'. Examples: + + module sunrpc + module nfsd + +format + The given string is searched for in the dynamic debug format + string. Note that the string does not need to match the + entire format, only some part. Whitespace and other + special characters can be escaped using C octal character + escape \ooo notation, e.g. the space character is \040. + Alternatively, the string can be enclosed in double quote + characters (") or single quote characters ('). + Examples: + + format svcrdma: // many of the NFS/RDMA server dprintks + format readahead // some dprintks in the readahead cache + format nfsd:\040SETATTR // one way to match a format with whitespace + format "nfsd: SETATTR" // a neater way to match a format with whitespace + format 'nfsd: SETATTR' // yet another way to match a format with whitespace + +line + The given line number or range of line numbers is compared + against the line number of each dprintk() callsite. A single + line number matches the callsite line number exactly. A + range of line numbers matches any callsite between the first + and last line number inclusive. An empty first number means + the first line in the file, an empty line number means the + last number in the file. Examples: + + line 1603 // exactly line 1603 + line 1600-1605 // the six lines from line 1600 to line 1605 + line -1605 // the 1605 lines from line 1 to line 1605 + line 1600- // all lines from line 1600 to the end of the file + +The flags specification comprises a change operation followed +by one or more flag characters. The change operation is one +of the characters: + +- + remove the given flags + ++ + add the given flags + += + set the flags to the given flags + +The flags are: + +p + Causes a printk() message to be emitted to dmesg + +Note the regexp ^[-+=][scp]+$ matches a flags specification. +Note also that there is no convenient syntax to remove all +the flags at once, you need to use "-psc". + +Examples +======== + +// enable the message at line 1603 of file svcsock.c +nullarbor:~ # echo -n 'file svcsock.c line 1603 +p' > + <debugfs>/dynamic_debug/control + +// enable all the messages in file svcsock.c +nullarbor:~ # echo -n 'file svcsock.c +p' > + <debugfs>/dynamic_debug/control + +// enable all the messages in the NFS server module +nullarbor:~ # echo -n 'module nfsd +p' > + <debugfs>/dynamic_debug/control + +// enable all 12 messages in the function svc_process() +nullarbor:~ # echo -n 'func svc_process +p' > + <debugfs>/dynamic_debug/control + +// disable all 12 messages in the function svc_process() +nullarbor:~ # echo -n 'func svc_process -p' > + <debugfs>/dynamic_debug/control + +// enable messages for NFS calls READ, READLINK, READDIR and READDIR+. +nullarbor:~ # echo -n 'format "nfsd: READ" +p' > + <debugfs>/dynamic_debug/control diff --git a/Documentation/fb/00-INDEX b/Documentation/fb/00-INDEX index caabbd395e61..a618fd99c9f0 100644 --- a/Documentation/fb/00-INDEX +++ b/Documentation/fb/00-INDEX @@ -11,8 +11,6 @@ aty128fb.txt - info on the ATI Rage128 frame buffer driver. cirrusfb.txt - info on the driver for Cirrus Logic chipsets. -cyblafb/ - - directory with documentation files related to the cyblafb driver. deferred_io.txt - an introduction to deferred IO. fbcon.txt diff --git a/Documentation/fb/cyblafb/bugs b/Documentation/fb/cyblafb/bugs deleted file mode 100644 index 9443a6d72cdd..000000000000 --- a/Documentation/fb/cyblafb/bugs +++ /dev/null @@ -1,13 +0,0 @@ -Bugs -==== - -I currently don't know of any bug. Please do send reports to: - - linux-fbdev-devel@lists.sourceforge.net - - Knut_Petersen@t-online.de. - - -Untested features -================= - -All LCD stuff is untested. If it worked in tridentfb, it should work in -cyblafb. Please test and report the results to Knut_Petersen@t-online.de. diff --git a/Documentation/fb/cyblafb/credits b/Documentation/fb/cyblafb/credits deleted file mode 100644 index 0eb3b443dc2b..000000000000 --- a/Documentation/fb/cyblafb/credits +++ /dev/null @@ -1,7 +0,0 @@ -Thanks to -========= - * Alan Hourihane, for writing the X trident driver - * Jani Monoses, for writing the tridentfb driver - * Antonino A. Daplas, for review of the first published - version of cyblafb and some code - * Jochen Hein, for testing and a helpfull bug report diff --git a/Documentation/fb/cyblafb/documentation b/Documentation/fb/cyblafb/documentation deleted file mode 100644 index bb1aac048425..000000000000 --- a/Documentation/fb/cyblafb/documentation +++ /dev/null @@ -1,17 +0,0 @@ -Available Documentation -======================= - -Apollo PLE 133 Chipset VT8601A North Bridge Datasheet, Rev. 1.82, October 22, -2001, available from VIA: - - http://www.viavpsd.com/product/6/15/DS8601A182.pdf - -The datasheet is incomplete, some registers that need to be programmed are not -explained at all and important bits are listed as "reserved". But you really -need the datasheet to understand the code. "p. xxx" comments refer to page -numbers of this document. - -XFree/XOrg drivers are available and of good quality, looking at the code -there is a good idea if the datasheet does not provide enough information -or if the datasheet seems to be wrong. - diff --git a/Documentation/fb/cyblafb/fb.modes b/Documentation/fb/cyblafb/fb.modes deleted file mode 100644 index fe0e5223ba86..000000000000 --- a/Documentation/fb/cyblafb/fb.modes +++ /dev/null @@ -1,154 +0,0 @@ -# -# Sample fb.modes file -# -# Provides an incomplete list of working modes for -# the cyberblade/i1 graphics core. -# -# The value 4294967256 is used instead of -40. Of course, -40 is not -# a really reasonable value, but chip design does not always follow -# logic. Believe me, it's ok, and it's the way the BIOS does it. -# -# fbset requires 4294967256 in fb.modes and -40 as an argument to -# the -t parameter. That's also not too reasonable, and it might change -# in the future or might even be differt for your current version. -# - -mode "640x480-50" - geometry 640 480 2048 4096 8 - timings 47619 4294967256 24 17 0 216 3 -endmode - -mode "640x480-60" - geometry 640 480 2048 4096 8 - timings 39682 4294967256 24 17 0 216 3 -endmode - -mode "640x480-70" - geometry 640 480 2048 4096 8 - timings 34013 4294967256 24 17 0 216 3 -endmode - -mode "640x480-72" - geometry 640 480 2048 4096 8 - timings 33068 4294967256 24 17 0 216 3 -endmode - -mode "640x480-75" - geometry 640 480 2048 4096 8 - timings 31746 4294967256 24 17 0 216 3 -endmode - -mode "640x480-80" - geometry 640 480 2048 4096 8 - timings 29761 4294967256 24 17 0 216 3 -endmode - -mode "640x480-85" - geometry 640 480 2048 4096 8 - timings 28011 4294967256 24 17 0 216 3 -endmode - -mode "800x600-50" - geometry 800 600 2048 4096 8 - timings 30303 96 24 14 0 136 11 -endmode - -mode "800x600-60" - geometry 800 600 2048 4096 8 - timings 25252 96 24 14 0 136 11 -endmode - -mode "800x600-70" - geometry 800 600 2048 4096 8 - timings 21645 96 24 14 0 136 11 -endmode - -mode "800x600-72" - geometry 800 600 2048 4096 8 - timings 21043 96 24 14 0 136 11 -endmode - -mode "800x600-75" - geometry 800 600 2048 4096 8 - timings 20202 96 24 14 0 136 11 -endmode - -mode "800x600-80" - geometry 800 600 2048 4096 8 - timings 18939 96 24 14 0 136 11 -endmode - -mode "800x600-85" - geometry 800 600 2048 4096 8 - timings 17825 96 24 14 0 136 11 -endmode - -mode "1024x768-50" - geometry 1024 768 2048 4096 8 - timings 19054 144 24 29 0 120 3 -endmode - -mode "1024x768-60" - geometry 1024 768 2048 4096 8 - timings 15880 144 24 29 0 120 3 -endmode - -mode "1024x768-70" - geometry 1024 768 2048 4096 8 - timings 13610 144 24 29 0 120 3 -endmode - -mode "1024x768-72" - geometry 1024 768 2048 4096 8 - timings 13232 144 24 29 0 120 3 -endmode - -mode "1024x768-75" - geometry 1024 768 2048 4096 8 - timings 12703 144 24 29 0 120 3 -endmode - -mode "1024x768-80" - geometry 1024 768 2048 4096 8 - timings 11910 144 24 29 0 120 3 -endmode - -mode "1024x768-85" - geometry 1024 768 2048 4096 8 - timings 11209 144 24 29 0 120 3 -endmode - -mode "1280x1024-50" - geometry 1280 1024 2048 4096 8 - timings 11114 232 16 39 0 160 3 -endmode - -mode "1280x1024-60" - geometry 1280 1024 2048 4096 8 - timings 9262 232 16 39 0 160 3 -endmode - -mode "1280x1024-70" - geometry 1280 1024 2048 4096 8 - timings 7939 232 16 39 0 160 3 -endmode - -mode "1280x1024-72" - geometry 1280 1024 2048 4096 8 - timings 7719 232 16 39 0 160 3 -endmode - -mode "1280x1024-75" - geometry 1280 1024 2048 4096 8 - timings 7410 232 16 39 0 160 3 -endmode - -mode "1280x1024-80" - geometry 1280 1024 2048 4096 8 - timings 6946 232 16 39 0 160 3 -endmode - -mode "1280x1024-85" - geometry 1280 1024 2048 4096 8 - timings 6538 232 16 39 0 160 3 -endmode diff --git a/Documentation/fb/cyblafb/performance b/Documentation/fb/cyblafb/performance deleted file mode 100644 index 8d15d5dfc6b3..000000000000 --- a/Documentation/fb/cyblafb/performance +++ /dev/null @@ -1,79 +0,0 @@ -Speed -===== - -CyBlaFB is much faster than tridentfb and vesafb. Compare the performance data -for mode 1280x1024-[8,16,32]@61 Hz. - -Test 1: Cat a file with 2000 lines of 0 characters. -Test 2: Cat a file with 2000 lines of 80 characters. -Test 3: Cat a file with 2000 lines of 160 characters. - -All values show system time use in seconds, kernel 2.6.12 was used for -the measurements. 2.6.13 is a bit slower, 2.6.14 hopefully will include a -patch that speeds up kernel bitblitting a lot ( > 20%). - -+-----------+-----------------------------------------------------+ -| | not accelerated | -| TRIDENTFB +-----------------+-----------------+-----------------+ -| of 2.6.12 | 8 bpp | 16 bpp | 32 bpp | -| | noypan | ypan | noypan | ypan | noypan | ypan | -+-----------+--------+--------+--------+--------+--------+--------+ -| Test 1 | 4.31 | 4.33 | 6.05 | 12.81 | ---- | ---- | -| Test 2 | 67.94 | 5.44 | 123.16 | 14.79 | ---- | ---- | -| Test 3 | 131.36 | 6.55 | 240.12 | 16.76 | ---- | ---- | -+-----------+--------+--------+--------+--------+--------+--------+ -| Comments | | | completely bro- | -| | | | ken, monitor | -| | | | switches off | -+-----------+-----------------+-----------------+-----------------+ - - -+-----------+-----------------------------------------------------+ -| | accelerated | -| TRIDENTFB +-----------------+-----------------+-----------------+ -| of 2.6.12 | 8 bpp | 16 bpp | 32 bpp | -| | noypan | ypan | noypan | ypan | noypan | ypan | -+-----------+--------+--------+--------+--------+--------+--------+ -| Test 1 | ---- | ---- | 20.62 | 1.22 | ---- | ---- | -| Test 2 | ---- | ---- | 22.61 | 3.19 | ---- | ---- | -| Test 3 | ---- | ---- | 24.59 | 5.16 | ---- | ---- | -+-----------+--------+--------+--------+--------+--------+--------+ -| Comments | broken, writing | broken, ok only | completely bro- | -| | to wrong places | if bgcolor is | ken, monitor | -| | on screen + bug | black, bug in | switches off | -| | in fillrect() | fillrect() | | -+-----------+-----------------+-----------------+-----------------+ - - -+-----------+-----------------------------------------------------+ -| | not accelerated | -| VESAFB +-----------------+-----------------+-----------------+ -| of 2.6.12 | 8 bpp | 16 bpp | 32 bpp | -| | noypan | ypan | noypan | ypan | noypan | ypan | -+-----------+--------+--------+--------+--------+--------+--------+ -| Test 1 | 4.26 | 3.76 | 5.99 | 7.23 | ---- | ---- | -| Test 2 | 65.65 | 4.89 | 120.88 | 9.08 | ---- | ---- | -| Test 3 | 126.91 | 5.94 | 235.77 | 11.03 | ---- | ---- | -+-----------+--------+--------+--------+--------+--------+--------+ -| Comments | vga=0x307 | vga=0x31a | vga=0x31b not | -| | fh=80kHz | fh=80kHz | supported by | -| | fv=75kHz | fv=75kHz | video BIOS and | -| | | | hardware | -+-----------+-----------------+-----------------+-----------------+ - - -+-----------+-----------------------------------------------------+ -| | accelerated | -| CYBLAFB +-----------------+-----------------+-----------------+ -| | 8 bpp | 16 bpp | 32 bpp | -| | noypan | ypan | noypan | ypan | noypan | ypan | -+-----------+--------+--------+--------+--------+--------+--------+ -| Test 1 | 8.02 | 0.23 | 19.04 | 0.61 | 57.12 | 2.74 | -| Test 2 | 8.38 | 0.55 | 19.39 | 0.92 | 57.54 | 3.13 | -| Test 3 | 8.73 | 0.86 | 19.74 | 1.24 | 57.95 | 3.51 | -+-----------+--------+--------+--------+--------+--------+--------+ -| Comments | | | | -| | | | | -| | | | | -| | | | | -+-----------+-----------------+-----------------+-----------------+ diff --git a/Documentation/fb/cyblafb/todo b/Documentation/fb/cyblafb/todo deleted file mode 100644 index c5f6d0eae545..000000000000 --- a/Documentation/fb/cyblafb/todo +++ /dev/null @@ -1,31 +0,0 @@ -TODO / Missing features -======================= - -Verify LCD stuff "stretch" and "center" options are - completely untested ... this code needs to be - verified. As I don't have access to such - hardware, please contact me if you are - willing run some tests. - -Interlaced video modes The reason that interleaved - modes are disabled is that I do not know - the meaning of the vertical interlace - parameter. Also the datasheet mentions a - bit d8 of a horizontal interlace parameter, - but nowhere the lower 8 bits. Please help - if you can. - -low-res double scan modes Who needs it? - -accelerated color blitting Who needs it? The console driver does use color - blitting for nothing but drawing the penguine, - everything else is done using color expanding - blitting of 1bpp character bitmaps. - -ioctls Who needs it? - -TV-out Will be done later. Use "vga= " at boot time - to set a suitable video mode. - -??? Feel free to contact me if you have any - feature requests diff --git a/Documentation/fb/cyblafb/usage b/Documentation/fb/cyblafb/usage deleted file mode 100644 index a39bb3d402a2..000000000000 --- a/Documentation/fb/cyblafb/usage +++ /dev/null @@ -1,217 +0,0 @@ -CyBlaFB is a framebuffer driver for the Cyberblade/i1 graphics core integrated -into the VIA Apollo PLE133 (aka vt8601) south bridge. It is developed and -tested using a VIA EPIA 5000 board. - -Cyblafb - compiled into the kernel or as a module? -================================================== - -You might compile cyblafb either as a module or compile it permanently into the -kernel. - -Unless you have a real reason to do so you should not compile both vesafb and -cyblafb permanently into the kernel. It's possible and it helps during the -developement cycle, but it's useless and will at least block some otherwise -usefull memory for ordinary users. - -Selecting Modes -=============== - - Startup Mode - ============ - - First of all, you might use the "vga=???" boot parameter as it is - documented in vesafb.txt and svga.txt. Cyblafb will detect the video - mode selected and will use the geometry and timings found by - inspecting the hardware registers. - - video=cyblafb vga=0x317 - - Alternatively you might use a combination of the mode, ref and bpp - parameters. If you compiled the driver into the kernel, add something - like this to the kernel command line: - - video=cyblafb:1280x1024,bpp=16,ref=50 ... - - If you compiled the driver as a module, the same mode would be - selected by the following command: - - modprobe cyblafb mode=1280x1024 bpp=16 ref=50 ... - - None of the modes possible to select as startup modes are affected by - the problems described at the end of the next subsection. - - For all startup modes cyblafb chooses a virtual x resolution of 2048, - the only exception is mode 1280x1024 in combination with 32 bpp. This - allows ywrap scrolling for all those modes if rotation is 0 or 2, and - also fast scrolling if rotation is 1 or 3. The default virtual y reso- - lution is 4096 for bpp == 8, 2048 for bpp==16 and 1024 for bpp == 32, - again with the only exception of 1280x1024 at 32 bpp. - - Please do set your video memory size to 8 Mb in the Bios setup. Other - values will work, but performace is decreased for a lot of modes. - - Mode changes using fbset - ======================== - - You might use fbset to change the video mode, see "man fbset". Cyblafb - generally does assume that you know what you are doing. But it does - some checks, especially those that are needed to prevent you from - damaging your hardware. - - - only 8, 16, 24 and 32 bpp video modes are accepted - - interlaced video modes are not accepted - - double scan video modes are not accepted - - if a flat panel is found, cyblafb does not allow you - to program a resolution higher than the physical - resolution of the flat panel monitor - - cyblafb does not allow vclk to exceed 230 MHz. As 32 bpp - and (currently) 24 bit modes use a doubled vclk internally, - the dotclock limit as seen by fbset is 115 MHz for those - modes and 230 MHz for 8 and 16 bpp modes. - - cyblafb will allow you to select very high resolutions as - long as the hardware can be programmed to these modes. The - documented limit 1600x1200 is not enforced, but don't expect - perfect signal quality. - - Any request that violates the rules given above will be either changed - to something the hardware supports or an error value will be returned. - - If you program a virtual y resolution higher than the hardware limit, - cyblafb will silently decrease that value to the highest possible - value. The same is true for a virtual x resolution that is not - supported by the hardware. Cyblafb tries to adapt vyres first because - vxres decides if ywrap scrolling is possible or not. - - Attempts to disable acceleration are ignored, I believe that this is - safe. - - Some video modes that should work do not work as expected. If you use - the standard fb.modes, fbset 640x480-60 will program that mode, but - you will see a vertical area, about two characters wide, with only - much darker characters than the other characters on the screen. - Cyblafb does allow that mode to be set, as it does not violate the - official specifications. It would need a lot of code to reliably sort - out all invalid modes, playing around with the margin values will - give a valid mode quickly. And if cyblafb would detect such an invalid - mode, should it silently alter the requested values or should it - report an error? Both options have some pros and cons. As stated - above, none of the startup modes are affected, and if you set - verbosity to 1 or higher, cyblafb will print the fbset command that - would be needed to program that mode using fbset. - - -Other Parameters -================ - - -crt don't autodetect, assume monitor connected to - standard VGA connector - -fp don't autodetect, assume flat panel display - connected to flat panel monitor interface - -nativex inform driver about native x resolution of - flat panel monitor connected to special - interface (should be autodetected) - -stretch stretch image to adapt low resolution modes to - higer resolutions of flat panel monitors - connected to special interface - -center center image to adapt low resolution modes to - higer resolutions of flat panel monitors - connected to special interface - -memsize use if autodetected memsize is wrong ... - should never be necessary - -nopcirr disable PCI read retry -nopciwr disable PCI write retry -nopcirb disable PCI read bursts -nopciwb disable PCI write bursts - -bpp bpp for specified modes - valid values: 8 || 16 || 24 || 32 - -ref refresh rate for specified mode - valid values: 50 <= ref <= 85 - -mode 640x480 or 800x600 or 1024x768 or 1280x1024 - if not specified, the startup mode will be detected - and used, so you might also use the vga=??? parameter - described in vesafb.txt. If you do not specify a mode, - bpp and ref parameters are ignored. - -verbosity 0 is the default, increase to at least 2 for every - bug report! - -Development hints -================= - -It's much faster do compile a module and to load the new version after -unloading the old module than to compile a new kernel and to reboot. So if you -try to work on cyblafb, it might be a good idea to use cyblafb as a module. -In real life, fast often means dangerous, and that's also the case here. If -you introduce a serious bug when cyblafb is compiled into the kernel, the -kernel will lock or oops with a high probability before the file system is -mounted, and the danger for your data is low. If you load a broken own version -of cyblafb on a running system, the danger for the integrity of the file -system is much higher as you might need a hard reset afterwards. Decide -yourself. - -Module unloading, the vfb method -================================ - -If you want to unload/reload cyblafb using the virtual framebuffer, you need -to enable vfb support in the kernel first. After that, load the modules as -shown below: - - modprobe vfb vfb_enable=1 - modprobe fbcon - modprobe cyblafb - fbset -fb /dev/fb1 1280x1024-60 -vyres 2662 - con2fb /dev/fb1 /dev/tty1 - ... - -If you now made some changes to cyblafb and want to reload it, you might do it -as show below: - - con2fb /dev/fb0 /dev/tty1 - ... - rmmod cyblafb - modprobe cyblafb - con2fb /dev/fb1 /dev/tty1 - ... - -Of course, you might choose another mode, and most certainly you also want to -map some other /dev/tty* to the real framebuffer device. You might also choose -to compile fbcon as a kernel module or place it permanently in the kernel. - -I do not know of any way to unload fbcon, and fbcon will prevent the -framebuffer device loaded first from unloading. [If there is a way, then -please add a description here!] - -Module unloading, the vesafb method -=================================== - -Configure the kernel: - - <*> Support for frame buffer devices - [*] VESA VGA graphics support - <M> Cyberblade/i1 support - -Add e.g. "video=vesafb:ypan vga=0x307" to the kernel parameters. The ypan -parameter is important, choose any vga parameter you like as long as it is -a graphics mode. - -After booting, load cyblafb without any mode and bpp parameter and assign -cyblafb to individual ttys using con2fb, e.g.: - - modprobe cyblafb - con2fb /dev/fb1 /dev/tty1 - -Unloading cyblafb works without problems after you assign vesafb to all -ttys again, e.g.: - - con2fb /dev/fb0 /dev/tty1 - rmmod cyblafb diff --git a/Documentation/fb/cyblafb/whatsnew b/Documentation/fb/cyblafb/whatsnew deleted file mode 100644 index 76c07a26e044..000000000000 --- a/Documentation/fb/cyblafb/whatsnew +++ /dev/null @@ -1,29 +0,0 @@ -0.62 -==== - - - the vesafb parameter has been removed as I decided to allow the - feature without any special parameter. - - - Cyblafb does not use the vga style of panning any longer, now the - "right view" register in the graphics engine IO space is used. Without - that change it was impossible to use all available memory, and without - access to all available memory it is impossible to ywrap. - - - The imageblit function now uses hardware acceleration for all font - widths. Hardware blitting across pixel column 2048 is broken in the - cyberblade/i1 graphics core, but we work around that hardware bug. - - - modes with vxres != xres are supported now. - - - ywrap scrolling is supported now and the default. This is a big - performance gain. - - - default video modes use vyres > yres and vxres > xres to allow - almost optimal scrolling speed for normal and rotated screens - - - some features mainly usefull for debugging the upper layers of the - framebuffer system have been added, have a look at the code - - - fixed: Oops after unloading cyblafb when reading /proc/io* - - - we work around some bugs of the higher framebuffer layers. diff --git a/Documentation/fb/cyblafb/whycyblafb b/Documentation/fb/cyblafb/whycyblafb deleted file mode 100644 index a123bc11e698..000000000000 --- a/Documentation/fb/cyblafb/whycyblafb +++ /dev/null @@ -1,85 +0,0 @@ -I tried the following framebuffer drivers: - - - TRIDENTFB is full of bugs. Acceleration is broken for Blade3D - graphics cores like the cyberblade/i1. It claims to support a great - number of devices, but documentation for most of these devices is - unfortunately not available. There is _no_ reason to use tridentfb - for cyberblade/i1 + CRT users. VESAFB is faster, and the one - advantage, mode switching, is broken in tridentfb. - - - VESAFB is used by many distributions as a standard. Vesafb does - not support mode switching. VESAFB is a bit faster than the working - configurations of TRIDENTFB, but it is still too slow, even if you - use ypan. - - - EPIAFB (you'll find it on sourceforge) supports the Cyberblade/i1 - graphics core, but it still has serious bugs and developement seems - to have stopped. This is the one driver with TV-out support. If you - do need this feature, try epiafb. - -None of these drivers was a real option for me. - -I believe that is unreasonable to change code that announces to support 20 -devices if I only have more or less sufficient documentation for exactly one -of these. The risk of breaking device foo while fixing device bar is too high. - -So I decided to start CyBlaFB as a stripped down tridentfb. - -All code specific to other Trident chips has been removed. After that there -were a lot of cosmetic changes to increase the readability of the code. All -register names were changed to those mnemonics used in the datasheet. Function -and macro names were changed if they hindered easy understanding of the code. - -After that I debugged the code and implemented some new features. I'll try to -give a little summary of the main changes: - - - calculation of vertical and horizontal timings was fixed - - - video signal quality has been improved dramatically - - - acceleration: - - - fillrect and copyarea were fixed and reenabled - - - color expanding imageblit was newly implemented, color - imageblit (only used to draw the penguine) still uses the - generic code. - - - init of the acceleration engine was improved and moved to a - place where it really works ... - - - sync function has a timeout now and tries to reset and - reinit the accel engine if necessary - - - fewer slow copyarea calls when doing ypan scrolling by using - undocumented bit d21 of screen start address stored in - CR2B[5]. BIOS does use it also, so this should be safe. - - - cyblafb rejects any attempt to set modes that would cause vclk - values above reasonable 230 MHz. 32bit modes use a clock - multiplicator of 2, so fbset does show the correct values for - pixclock but not for vclk in this case. The fbset limit is 115 MHz - for 32 bpp modes. - - - cyblafb rejects modes known to be broken or unimplemented (all - interlaced modes, all doublescan modes for now) - - - cyblafb now works independant of the video mode in effect at startup - time (tridentfb does not init all needed registers to reasonable - values) - - - switching between video modes does work reliably now - - - the first video mode now is the one selected on startup using the - vga=???? mechanism or any of - - 640x480, 800x600, 1024x768, 1280x1024 - - 8, 16, 24 or 32 bpp - - refresh between 50 Hz and 85 Hz, 1 Hz steps (1280x1024-32 - is limited to 63Hz) - - - pci retry and pci burst mode are settable (try to disable if you - experience latency problems) - - - built as a module cyblafb might be unloaded and reloaded using - the vfb module and con2vt or might be used together with vesafb - diff --git a/Documentation/fb/uvesafb.txt b/Documentation/fb/uvesafb.txt index 7ac3c4078ff9..eefdd91d298a 100644 --- a/Documentation/fb/uvesafb.txt +++ b/Documentation/fb/uvesafb.txt @@ -59,7 +59,8 @@ Accepted options: ypan Enable display panning using the VESA protected mode interface. The visible screen is just a window of the video memory, console scrolling is done by changing the - start of the window. Available on x86 only. + start of the window. This option is available on x86 + only and is the default option on that architecture. ywrap Same as ypan, but assumes your gfx board can wrap-around the video memory (i.e. starts reading from top if it @@ -67,7 +68,7 @@ ywrap Same as ypan, but assumes your gfx board can wrap-around Available on x86 only. redraw Scroll by redrawing the affected part of the screen, this - is the safe (and slow) default. + is the default on non-x86. (If you're using uvesafb as a module, the above three options are used a parameter of the scroll option, e.g. scroll=ypan.) @@ -182,7 +183,7 @@ from the Video BIOS if you set pixclock to 0 in fb_var_screeninfo. -- Michal Januszewski <spock@gentoo.org> - Last updated: 2007-06-16 + Last updated: 2009-03-30 Documentation of the uvesafb options is loosely based on vesafb.txt. diff --git a/Documentation/feature-removal-schedule.txt b/Documentation/feature-removal-schedule.txt index 5ddbe350487a..de491a3e2313 100644 --- a/Documentation/feature-removal-schedule.txt +++ b/Documentation/feature-removal-schedule.txt @@ -6,20 +6,47 @@ be removed from this file. --------------------------- -What: old static regulatory information and ieee80211_regdom module parameter -When: 2.6.29 +What: The ieee80211_regdom module parameter +When: March 2010 / desktop catchup + +Why: This was inherited by the CONFIG_WIRELESS_OLD_REGULATORY code, + and currently serves as an option for users to define an + ISO / IEC 3166 alpha2 code for the country they are currently + present in. Although there are userspace API replacements for this + through nl80211 distributions haven't yet caught up with implementing + decent alternatives through standard GUIs. Although available as an + option through iw or wpa_supplicant its just a matter of time before + distributions pick up good GUI options for this. The ideal solution + would actually consist of intelligent designs which would do this for + the user automatically even when travelling through different countries. + Until then we leave this module parameter as a compromise. + + When userspace improves with reasonable widely-available alternatives for + this we will no longer need this module parameter. This entry hopes that + by the super-futuristically looking date of "March 2010" we will have + such replacements widely available. + +Who: Luis R. Rodriguez <lrodriguez@atheros.com> + +--------------------------- + +What: CONFIG_WIRELESS_OLD_REGULATORY - old static regulatory information +When: March 2010 / desktop catchup + Why: The old regulatory infrastructure has been replaced with a new one which does not require statically defined regulatory domains. We do not want to keep static regulatory domains in the kernel due to the the dynamic nature of regulatory law and localization. We kept around the old static definitions for the regulatory domains of: + * US * JP * EU + and used by default the US when CONFIG_WIRELESS_OLD_REGULATORY was - set. We also kept around the ieee80211_regdom module parameter in case - some applications were relying on it. Changing regulatory domains - can now be done instead by using nl80211, as is done with iw. + set. We will remove this option once the standard Linux desktop catches + up with the new userspace APIs we have implemented. + Who: Luis R. Rodriguez <lrodriguez@atheros.com> --------------------------- @@ -37,10 +64,10 @@ Who: Pavel Machek <pavel@suse.cz> --------------------------- -What: Video4Linux API 1 ioctls and video_decoder.h from Video devices. -When: December 2008 -Files: include/linux/video_decoder.h include/linux/videodev.h -Check: include/linux/video_decoder.h include/linux/videodev.h +What: Video4Linux API 1 ioctls and from Video devices. +When: July 2009 +Files: include/linux/videodev.h +Check: include/linux/videodev.h Why: V4L1 AP1 was replaced by V4L2 API during migration from 2.4 to 2.6 series. The old API have lots of drawbacks and don't provide enough means to work with all video and audio standards. The newer API is @@ -228,8 +255,20 @@ Who: Jan Engelhardt <jengelh@computergmbh.de> --------------------------- +What: GPIO autorequest on gpio_direction_{input,output}() in gpiolib +When: February 2010 +Why: All callers should use explicit gpio_request()/gpio_free(). + The autorequest mechanism in gpiolib was provided mostly as a + migration aid for legacy GPIO interfaces (for SOC based GPIOs). + Those users have now largely migrated. Platforms implementing + the GPIO interfaces without using gpiolib will see no changes. +Who: David Brownell <dbrownell@users.sourceforge.net> +--------------------------- + What: b43 support for firmware revision < 410 -When: July 2008 +When: The schedule was July 2008, but it was decided that we are going to keep the + code as long as there are no major maintanance headaches. + So it _could_ be removed _any_ time now, if it conflicts with something new. Why: The support code for the old firmware hurts code readability/maintainability and slightly hurts runtime performance. Bugfixes for the old firmware are not provided by Broadcom anymore. @@ -244,13 +283,6 @@ Who: Glauber Costa <gcosta@redhat.com> --------------------------- -What: remove HID compat support -When: 2.6.29 -Why: needed only as a temporary solution until distros fix themselves up -Who: Jiri Slaby <jirislaby@gmail.com> - ---------------------------- - What: print_fn_descriptor_symbol() When: October 2009 Why: The %pF vsprintf format provides the same functionality in a @@ -282,6 +314,18 @@ Who: Vlad Yasevich <vladislav.yasevich@hp.com> --------------------------- +What: Ability for non root users to shm_get hugetlb pages based on mlock + resource limits +When: 2.6.31 +Why: Non root users need to be part of /proc/sys/vm/hugetlb_shm_group or + have CAP_IPC_LOCK to be able to allocate shm segments backed by + huge pages. The mlock based rlimit check to allow shm hugetlb is + inconsistent with mmap based allocations. Hence it is being + deprecated. +Who: Ravikiran Thirumalai <kiran@scalex86.org> + +--------------------------- + What: CONFIG_THERMAL_HWMON When: January 2009 Why: This option was introduced just to allow older lm-sensors userspace @@ -310,8 +354,10 @@ Who: Krzysztof Piotr Oledzki <ole@ans.pl> --------------------------- -What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client() -When: 2.6.29 (ideally) or 2.6.30 (more likely) +What: i2c_attach_client(), i2c_detach_client(), i2c_driver->detach_client(), + i2c_adapter->client_register(), i2c_adapter->client_unregister +When: 2.6.30 +Check: i2c_attach_client i2c_detach_client Why: Deprecated by the new (standard) device driver binding model. Use i2c_driver->probe() and ->remove() instead. Who: Jean Delvare <khali@linux-fr.org> @@ -326,12 +372,68 @@ Who: Hans de Goede <hdegoede@redhat.com> --------------------------- -What: SELinux "compat_net" functionality -When: 2.6.30 at the earliest -Why: In 2.6.18 the Secmark concept was introduced to replace the "compat_net" - network access control functionality of SELinux. Secmark offers both - better performance and greater flexibility than the "compat_net" - mechanism. Now that the major Linux distributions have moved to - Secmark, it is time to deprecate the older mechanism and start the - process of removing the old code. -Who: Paul Moore <paul.moore@hp.com> +What: sysfs ui for changing p4-clockmod parameters +When: September 2009 +Why: See commits 129f8ae9b1b5be94517da76009ea956e89104ce8 and + e088e4c9cdb618675874becb91b2fd581ee707e6. + Removal is subject to fixing any remaining bugs in ACPI which may + cause the thermal throttling not to happen at the right time. +Who: Dave Jones <davej@redhat.com>, Matthew Garrett <mjg@redhat.com> + +----------------------------- + +What: __do_IRQ all in one fits nothing interrupt handler +When: 2.6.32 +Why: __do_IRQ was kept for easy migration to the type flow handlers. + More than two years of migration time is enough. +Who: Thomas Gleixner <tglx@linutronix.de> + +----------------------------- + +What: obsolete generic irq defines and typedefs +When: 2.6.30 +Why: The defines and typedefs (hw_interrupt_type, no_irq_type, irq_desc_t) + have been kept around for migration reasons. After more than two years + it's time to remove them finally +Who: Thomas Gleixner <tglx@linutronix.de> + +--------------------------- + +What: fakephp and associated sysfs files in /sys/bus/pci/slots/ +When: 2011 +Why: In 2.6.27, the semantics of /sys/bus/pci/slots was redefined to + represent a machine's physical PCI slots. The change in semantics + had userspace implications, as the hotplug core no longer allowed + drivers to create multiple sysfs files per physical slot (required + for multi-function devices, e.g.). fakephp was seen as a developer's + tool only, and its interface changed. Too late, we learned that + there were some users of the fakephp interface. + + In 2.6.30, the original fakephp interface was restored. At the same + time, the PCI core gained the ability that fakephp provided, namely + function-level hot-remove and hot-add. + + Since the PCI core now provides the same functionality, exposed in: + + /sys/bus/pci/rescan + /sys/bus/pci/devices/.../remove + /sys/bus/pci/devices/.../rescan + + there is no functional reason to maintain fakephp as well. + + We will keep the existing module so that 'modprobe fakephp' will + present the old /sys/bus/pci/slots/... interface for compatibility, + but users are urged to migrate their applications to the API above. + + After a reasonable transition period, we will remove the legacy + fakephp interface. +Who: Alex Chiang <achiang@hp.com> + +--------------------------- + +What: i2c-voodoo3 driver +When: October 2009 +Why: Superseded by tdfxfb. I2C/DDC support used to live in a separate + driver but this caused driver conflicts. +Who: Jean Delvare <khali@linux-fr.org> + Krzysztof Helt <krzysztof.h1@wp.pl> diff --git a/Documentation/filesystems/00-INDEX b/Documentation/filesystems/00-INDEX index 52cd611277a3..8dd6db76171d 100644 --- a/Documentation/filesystems/00-INDEX +++ b/Documentation/filesystems/00-INDEX @@ -68,6 +68,8 @@ ncpfs.txt - info on Novell Netware(tm) filesystem using NCP protocol. nfsroot.txt - short guide on setting up a diskless box with NFS root filesystem. +nilfs2.txt + - info and mount options for the NILFS2 filesystem. ntfs.txt - info and mount options for the NTFS filesystem (Windows NT). ocfs2.txt diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index ec6a9392a173..3120f8dd2c31 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -437,8 +437,11 @@ grab BKL for cases when we close a file that had been opened r/w, but that can and should be done using the internal locking with smaller critical areas). Current worst offender is ext2_get_block()... -->fasync() is a mess. This area needs a big cleanup and that will probably -affect locking. +->fasync() is called without BKL protection, and is responsible for +maintaining the FASYNC bit in filp->f_flags. Most instances call +fasync_helper(), which does that maintenance, so it's not normally +something one needs to worry about. Return values > 0 will be mapped to +zero in the VFS layer. ->readdir() and ->ioctl() on directories must be changed. Ideally we would move ->readdir() to inode_operations and use a separate method for directory @@ -502,23 +505,31 @@ prototypes: void (*open)(struct vm_area_struct*); void (*close)(struct vm_area_struct*); int (*fault)(struct vm_area_struct*, struct vm_fault *); - int (*page_mkwrite)(struct vm_area_struct *, struct page *); + int (*page_mkwrite)(struct vm_area_struct *, struct vm_fault *); int (*access)(struct vm_area_struct *, unsigned long, void*, int, int); locking rules: BKL mmap_sem PageLocked(page) open: no yes close: no yes -fault: no yes -page_mkwrite: no yes no +fault: no yes can return with page locked +page_mkwrite: no yes can return with page locked access: no yes - ->page_mkwrite() is called when a previously read-only page is -about to become writeable. The file system is responsible for -protecting against truncate races. Once appropriate action has been -taking to lock out truncate, the page range should be verified to be -within i_size. The page mapping should also be checked that it is not -NULL. + ->fault() is called when a previously not present pte is about +to be faulted in. The filesystem must find and return the page associated +with the passed in "pgoff" in the vm_fault structure. If it is possible that +the page may be truncated and/or invalidated, then the filesystem must lock +the page, then ensure it is not already truncated (the page lock will block +subsequent truncate), and then return with VM_FAULT_LOCKED, and the page +locked. The VM will unlock the page. + + ->page_mkwrite() is called when a previously read-only pte is +about to become writeable. The filesystem again must ensure that there are +no truncate/invalidate races, and then return with the page locked. If +the page has been truncated, the filesystem should not look up a new page +like the ->fault() handler, but simply return with VM_FAULT_NOPAGE, which +will cause the VM to retry the fault. ->access() is called when get_user_pages() fails in acces_process_vm(), typically used to debug a process through diff --git a/Documentation/filesystems/caching/backend-api.txt b/Documentation/filesystems/caching/backend-api.txt new file mode 100644 index 000000000000..382d52cdaf2d --- /dev/null +++ b/Documentation/filesystems/caching/backend-api.txt @@ -0,0 +1,658 @@ + ========================== + FS-CACHE CACHE BACKEND API + ========================== + +The FS-Cache system provides an API by which actual caches can be supplied to +FS-Cache for it to then serve out to network filesystems and other interested +parties. + +This API is declared in <linux/fscache-cache.h>. + + +==================================== +INITIALISING AND REGISTERING A CACHE +==================================== + +To start off, a cache definition must be initialised and registered for each +cache the backend wants to make available. For instance, CacheFS does this in +the fill_super() operation on mounting. + +The cache definition (struct fscache_cache) should be initialised by calling: + + void fscache_init_cache(struct fscache_cache *cache, + struct fscache_cache_ops *ops, + const char *idfmt, + ...); + +Where: + + (*) "cache" is a pointer to the cache definition; + + (*) "ops" is a pointer to the table of operations that the backend supports on + this cache; and + + (*) "idfmt" is a format and printf-style arguments for constructing a label + for the cache. + + +The cache should then be registered with FS-Cache by passing a pointer to the +previously initialised cache definition to: + + int fscache_add_cache(struct fscache_cache *cache, + struct fscache_object *fsdef, + const char *tagname); + +Two extra arguments should also be supplied: + + (*) "fsdef" which should point to the object representation for the FS-Cache + master index in this cache. Netfs primary index entries will be created + here. FS-Cache keeps the caller's reference to the index object if + successful and will release it upon withdrawal of the cache. + + (*) "tagname" which, if given, should be a text string naming this cache. If + this is NULL, the identifier will be used instead. For CacheFS, the + identifier is set to name the underlying block device and the tag can be + supplied by mount. + +This function may return -ENOMEM if it ran out of memory or -EEXIST if the tag +is already in use. 0 will be returned on success. + + +===================== +UNREGISTERING A CACHE +===================== + +A cache can be withdrawn from the system by calling this function with a +pointer to the cache definition: + + void fscache_withdraw_cache(struct fscache_cache *cache); + +In CacheFS's case, this is called by put_super(). + + +======== +SECURITY +======== + +The cache methods are executed one of two contexts: + + (1) that of the userspace process that issued the netfs operation that caused + the cache method to be invoked, or + + (2) that of one of the processes in the FS-Cache thread pool. + +In either case, this may not be an appropriate context in which to access the +cache. + +The calling process's fsuid, fsgid and SELinux security identities may need to +be masqueraded for the duration of the cache driver's access to the cache. +This is left to the cache to handle; FS-Cache makes no effort in this regard. + + +=================================== +CONTROL AND STATISTICS PRESENTATION +=================================== + +The cache may present data to the outside world through FS-Cache's interfaces +in sysfs and procfs - the former for control and the latter for statistics. + +A sysfs directory called /sys/fs/fscache/<cachetag>/ is created if CONFIG_SYSFS +is enabled. This is accessible through the kobject struct fscache_cache::kobj +and is for use by the cache as it sees fit. + + +======================== +RELEVANT DATA STRUCTURES +======================== + + (*) Index/Data file FS-Cache representation cookie: + + struct fscache_cookie { + struct fscache_object_def *def; + struct fscache_netfs *netfs; + void *netfs_data; + ... + }; + + The fields that might be of use to the backend describe the object + definition, the netfs definition and the netfs's data for this cookie. + The object definition contain functions supplied by the netfs for loading + and matching index entries; these are required to provide some of the + cache operations. + + + (*) In-cache object representation: + + struct fscache_object { + int debug_id; + enum { + FSCACHE_OBJECT_RECYCLING, + ... + } state; + spinlock_t lock + struct fscache_cache *cache; + struct fscache_cookie *cookie; + ... + }; + + Structures of this type should be allocated by the cache backend and + passed to FS-Cache when requested by the appropriate cache operation. In + the case of CacheFS, they're embedded in CacheFS's internal object + structures. + + The debug_id is a simple integer that can be used in debugging messages + that refer to a particular object. In such a case it should be printed + using "OBJ%x" to be consistent with FS-Cache. + + Each object contains a pointer to the cookie that represents the object it + is backing. An object should retired when put_object() is called if it is + in state FSCACHE_OBJECT_RECYCLING. The fscache_object struct should be + initialised by calling fscache_object_init(object). + + + (*) FS-Cache operation record: + + struct fscache_operation { + atomic_t usage; + struct fscache_object *object; + unsigned long flags; + #define FSCACHE_OP_EXCLUSIVE + void (*processor)(struct fscache_operation *op); + void (*release)(struct fscache_operation *op); + ... + }; + + FS-Cache has a pool of threads that it uses to give CPU time to the + various asynchronous operations that need to be done as part of driving + the cache. These are represented by the above structure. The processor + method is called to give the op CPU time, and the release method to get + rid of it when its usage count reaches 0. + + An operation can be made exclusive upon an object by setting the + appropriate flag before enqueuing it with fscache_enqueue_operation(). If + an operation needs more processing time, it should be enqueued again. + + + (*) FS-Cache retrieval operation record: + + struct fscache_retrieval { + struct fscache_operation op; + struct address_space *mapping; + struct list_head *to_do; + ... + }; + + A structure of this type is allocated by FS-Cache to record retrieval and + allocation requests made by the netfs. This struct is then passed to the + backend to do the operation. The backend may get extra refs to it by + calling fscache_get_retrieval() and refs may be discarded by calling + fscache_put_retrieval(). + + A retrieval operation can be used by the backend to do retrieval work. To + do this, the retrieval->op.processor method pointer should be set + appropriately by the backend and fscache_enqueue_retrieval() called to + submit it to the thread pool. CacheFiles, for example, uses this to queue + page examination when it detects PG_lock being cleared. + + The to_do field is an empty list available for the cache backend to use as + it sees fit. + + + (*) FS-Cache storage operation record: + + struct fscache_storage { + struct fscache_operation op; + pgoff_t store_limit; + ... + }; + + A structure of this type is allocated by FS-Cache to record outstanding + writes to be made. FS-Cache itself enqueues this operation and invokes + the write_page() method on the object at appropriate times to effect + storage. + + +================ +CACHE OPERATIONS +================ + +The cache backend provides FS-Cache with a table of operations that can be +performed on the denizens of the cache. These are held in a structure of type: + + struct fscache_cache_ops + + (*) Name of cache provider [mandatory]: + + const char *name + + This isn't strictly an operation, but should be pointed at a string naming + the backend. + + + (*) Allocate a new object [mandatory]: + + struct fscache_object *(*alloc_object)(struct fscache_cache *cache, + struct fscache_cookie *cookie) + + This method is used to allocate a cache object representation to back a + cookie in a particular cache. fscache_object_init() should be called on + the object to initialise it prior to returning. + + This function may also be used to parse the index key to be used for + multiple lookup calls to turn it into a more convenient form. FS-Cache + will call the lookup_complete() method to allow the cache to release the + form once lookup is complete or aborted. + + + (*) Look up and create object [mandatory]: + + void (*lookup_object)(struct fscache_object *object) + + This method is used to look up an object, given that the object is already + allocated and attached to the cookie. This should instantiate that object + in the cache if it can. + + The method should call fscache_object_lookup_negative() as soon as + possible if it determines the object doesn't exist in the cache. If the + object is found to exist and the netfs indicates that it is valid then + fscache_obtained_object() should be called once the object is in a + position to have data stored in it. Similarly, fscache_obtained_object() + should also be called once a non-present object has been created. + + If a lookup error occurs, fscache_object_lookup_error() should be called + to abort the lookup of that object. + + + (*) Release lookup data [mandatory]: + + void (*lookup_complete)(struct fscache_object *object) + + This method is called to ask the cache to release any resources it was + using to perform a lookup. + + + (*) Increment object refcount [mandatory]: + + struct fscache_object *(*grab_object)(struct fscache_object *object) + + This method is called to increment the reference count on an object. It + may fail (for instance if the cache is being withdrawn) by returning NULL. + It should return the object pointer if successful. + + + (*) Lock/Unlock object [mandatory]: + + void (*lock_object)(struct fscache_object *object) + void (*unlock_object)(struct fscache_object *object) + + These methods are used to exclusively lock an object. It must be possible + to schedule with the lock held, so a spinlock isn't sufficient. + + + (*) Pin/Unpin object [optional]: + + int (*pin_object)(struct fscache_object *object) + void (*unpin_object)(struct fscache_object *object) + + These methods are used to pin an object into the cache. Once pinned an + object cannot be reclaimed to make space. Return -ENOSPC if there's not + enough space in the cache to permit this. + + + (*) Update object [mandatory]: + + int (*update_object)(struct fscache_object *object) + + This is called to update the index entry for the specified object. The + new information should be in object->cookie->netfs_data. This can be + obtained by calling object->cookie->def->get_aux()/get_attr(). + + + (*) Discard object [mandatory]: + + void (*drop_object)(struct fscache_object *object) + + This method is called to indicate that an object has been unbound from its + cookie, and that the cache should release the object's resources and + retire it if it's in state FSCACHE_OBJECT_RECYCLING. + + This method should not attempt to release any references held by the + caller. The caller will invoke the put_object() method as appropriate. + + + (*) Release object reference [mandatory]: + + void (*put_object)(struct fscache_object *object) + + This method is used to discard a reference to an object. The object may + be freed when all the references to it are released. + + + (*) Synchronise a cache [mandatory]: + + void (*sync)(struct fscache_cache *cache) + + This is called to ask the backend to synchronise a cache with its backing + device. + + + (*) Dissociate a cache [mandatory]: + + void (*dissociate_pages)(struct fscache_cache *cache) + + This is called to ask a cache to perform any page dissociations as part of + cache withdrawal. + + + (*) Notification that the attributes on a netfs file changed [mandatory]: + + int (*attr_changed)(struct fscache_object *object); + + This is called to indicate to the cache that certain attributes on a netfs + file have changed (for example the maximum size a file may reach). The + cache can read these from the netfs by calling the cookie's get_attr() + method. + + The cache may use the file size information to reserve space on the cache. + It should also call fscache_set_store_limit() to indicate to FS-Cache the + highest byte it's willing to store for an object. + + This method may return -ve if an error occurred or the cache object cannot + be expanded. In such a case, the object will be withdrawn from service. + + This operation is run asynchronously from FS-Cache's thread pool, and + storage and retrieval operations from the netfs are excluded during the + execution of this operation. + + + (*) Reserve cache space for an object's data [optional]: + + int (*reserve_space)(struct fscache_object *object, loff_t size); + + This is called to request that cache space be reserved to hold the data + for an object and the metadata used to track it. Zero size should be + taken as request to cancel a reservation. + + This should return 0 if successful, -ENOSPC if there isn't enough space + available, or -ENOMEM or -EIO on other errors. + + The reservation may exceed the current size of the object, thus permitting + future expansion. If the amount of space consumed by an object would + exceed the reservation, it's permitted to refuse requests to allocate + pages, but not required. An object may be pruned down to its reservation + size if larger than that already. + + + (*) Request page be read from cache [mandatory]: + + int (*read_or_alloc_page)(struct fscache_retrieval *op, + struct page *page, + gfp_t gfp) + + This is called to attempt to read a netfs page from the cache, or to + reserve a backing block if not. FS-Cache will have done as much checking + as it can before calling, but most of the work belongs to the backend. + + If there's no page in the cache, then -ENODATA should be returned if the + backend managed to reserve a backing block; -ENOBUFS or -ENOMEM if it + didn't. + + If there is suitable data in the cache, then a read operation should be + queued and 0 returned. When the read finishes, fscache_end_io() should be + called. + + The fscache_mark_pages_cached() should be called for the page if any cache + metadata is retained. This will indicate to the netfs that the page needs + explicit uncaching. This operation takes a pagevec, thus allowing several + pages to be marked at once. + + The retrieval record pointed to by op should be retained for each page + queued and released when I/O on the page has been formally ended. + fscache_get/put_retrieval() are available for this purpose. + + The retrieval record may be used to get CPU time via the FS-Cache thread + pool. If this is desired, the op->op.processor should be set to point to + the appropriate processing routine, and fscache_enqueue_retrieval() should + be called at an appropriate point to request CPU time. For instance, the + retrieval routine could be enqueued upon the completion of a disk read. + The to_do field in the retrieval record is provided to aid in this. + + If an I/O error occurs, fscache_io_error() should be called and -ENOBUFS + returned if possible or fscache_end_io() called with a suitable error + code.. + + + (*) Request pages be read from cache [mandatory]: + + int (*read_or_alloc_pages)(struct fscache_retrieval *op, + struct list_head *pages, + unsigned *nr_pages, + gfp_t gfp) + + This is like the read_or_alloc_page() method, except it is handed a list + of pages instead of one page. Any pages on which a read operation is + started must be added to the page cache for the specified mapping and also + to the LRU. Such pages must also be removed from the pages list and + *nr_pages decremented per page. + + If there was an error such as -ENOMEM, then that should be returned; else + if one or more pages couldn't be read or allocated, then -ENOBUFS should + be returned; else if one or more pages couldn't be read, then -ENODATA + should be returned. If all the pages are dispatched then 0 should be + returned. + + + (*) Request page be allocated in the cache [mandatory]: + + int (*allocate_page)(struct fscache_retrieval *op, + struct page *page, + gfp_t gfp) + + This is like the read_or_alloc_page() method, except that it shouldn't + read from the cache, even if there's data there that could be retrieved. + It should, however, set up any internal metadata required such that + the write_page() method can write to the cache. + + If there's no backing block available, then -ENOBUFS should be returned + (or -ENOMEM if there were other problems). If a block is successfully + allocated, then the netfs page should be marked and 0 returned. + + + (*) Request pages be allocated in the cache [mandatory]: + + int (*allocate_pages)(struct fscache_retrieval *op, + struct list_head *pages, + unsigned *nr_pages, + gfp_t gfp) + + This is an multiple page version of the allocate_page() method. pages and + nr_pages should be treated as for the read_or_alloc_pages() method. + + + (*) Request page be written to cache [mandatory]: + + int (*write_page)(struct fscache_storage *op, + struct page *page); + + This is called to write from a page on which there was a previously + successful read_or_alloc_page() call or similar. FS-Cache filters out + pages that don't have mappings. + + This method is called asynchronously from the FS-Cache thread pool. It is + not required to actually store anything, provided -ENODATA is then + returned to the next read of this page. + + If an error occurred, then a negative error code should be returned, + otherwise zero should be returned. FS-Cache will take appropriate action + in response to an error, such as withdrawing this object. + + If this method returns success then FS-Cache will inform the netfs + appropriately. + + + (*) Discard retained per-page metadata [mandatory]: + + void (*uncache_page)(struct fscache_object *object, struct page *page) + + This is called when a netfs page is being evicted from the pagecache. The + cache backend should tear down any internal representation or tracking it + maintains for this page. + + +================== +FS-CACHE UTILITIES +================== + +FS-Cache provides some utilities that a cache backend may make use of: + + (*) Note occurrence of an I/O error in a cache: + + void fscache_io_error(struct fscache_cache *cache) + + This tells FS-Cache that an I/O error occurred in the cache. After this + has been called, only resource dissociation operations (object and page + release) will be passed from the netfs to the cache backend for the + specified cache. + + This does not actually withdraw the cache. That must be done separately. + + + (*) Invoke the retrieval I/O completion function: + + void fscache_end_io(struct fscache_retrieval *op, struct page *page, + int error); + + This is called to note the end of an attempt to retrieve a page. The + error value should be 0 if successful and an error otherwise. + + + (*) Set highest store limit: + + void fscache_set_store_limit(struct fscache_object *object, + loff_t i_size); + + This sets the limit FS-Cache imposes on the highest byte it's willing to + try and store for a netfs. Any page over this limit is automatically + rejected by fscache_read_alloc_page() and co with -ENOBUFS. + + + (*) Mark pages as being cached: + + void fscache_mark_pages_cached(struct fscache_retrieval *op, + struct pagevec *pagevec); + + This marks a set of pages as being cached. After this has been called, + the netfs must call fscache_uncache_page() to unmark the pages. + + + (*) Perform coherency check on an object: + + enum fscache_checkaux fscache_check_aux(struct fscache_object *object, + const void *data, + uint16_t datalen); + + This asks the netfs to perform a coherency check on an object that has + just been looked up. The cookie attached to the object will determine the + netfs to use. data and datalen should specify where the auxiliary data + retrieved from the cache can be found. + + One of three values will be returned: + + (*) FSCACHE_CHECKAUX_OKAY + + The coherency data indicates the object is valid as is. + + (*) FSCACHE_CHECKAUX_NEEDS_UPDATE + + The coherency data needs updating, but otherwise the object is + valid. + + (*) FSCACHE_CHECKAUX_OBSOLETE + + The coherency data indicates that the object is obsolete and should + be discarded. + + + (*) Initialise a freshly allocated object: + + void fscache_object_init(struct fscache_object *object); + + This initialises all the fields in an object representation. + + + (*) Indicate the destruction of an object: + + void fscache_object_destroyed(struct fscache_cache *cache); + + This must be called to inform FS-Cache that an object that belonged to a + cache has been destroyed and deallocated. This will allow continuation + of the cache withdrawal process when it is stopped pending destruction of + all the objects. + + + (*) Indicate negative lookup on an object: + + void fscache_object_lookup_negative(struct fscache_object *object); + + This is called to indicate to FS-Cache that a lookup process for an object + found a negative result. + + This changes the state of an object to permit reads pending on lookup + completion to go off and start fetching data from the netfs server as it's + known at this point that there can't be any data in the cache. + + This may be called multiple times on an object. Only the first call is + significant - all subsequent calls are ignored. + + + (*) Indicate an object has been obtained: + + void fscache_obtained_object(struct fscache_object *object); + + This is called to indicate to FS-Cache that a lookup process for an object + produced a positive result, or that an object was created. This should + only be called once for any particular object. + + This changes the state of an object to indicate: + + (1) if no call to fscache_object_lookup_negative() has been made on + this object, that there may be data available, and that reads can + now go and look for it; and + + (2) that writes may now proceed against this object. + + + (*) Indicate that object lookup failed: + + void fscache_object_lookup_error(struct fscache_object *object); + + This marks an object as having encountered a fatal error (usually EIO) + and causes it to move into a state whereby it will be withdrawn as soon + as possible. + + + (*) Get and release references on a retrieval record: + + void fscache_get_retrieval(struct fscache_retrieval *op); + void fscache_put_retrieval(struct fscache_retrieval *op); + + These two functions are used to retain a retrieval record whilst doing + asynchronous data retrieval and block allocation. + + + (*) Enqueue a retrieval record for processing. + + void fscache_enqueue_retrieval(struct fscache_retrieval *op); + + This enqueues a retrieval record for processing by the FS-Cache thread + pool. One of the threads in the pool will invoke the retrieval record's + op->op.processor callback function. This function may be called from + within the callback function. + + + (*) List of object state names: + + const char *fscache_object_states[]; + + For debugging purposes, this may be used to turn the state that an object + is in into a text string for display purposes. diff --git a/Documentation/filesystems/caching/cachefiles.txt b/Documentation/filesystems/caching/cachefiles.txt new file mode 100644 index 000000000000..748a1ae49e12 --- /dev/null +++ b/Documentation/filesystems/caching/cachefiles.txt @@ -0,0 +1,501 @@ + =============================================== + CacheFiles: CACHE ON ALREADY MOUNTED FILESYSTEM + =============================================== + +Contents: + + (*) Overview. + + (*) Requirements. + + (*) Configuration. + + (*) Starting the cache. + + (*) Things to avoid. + + (*) Cache culling. + + (*) Cache structure. + + (*) Security model and SELinux. + + (*) A note on security. + + (*) Statistical information. + + (*) Debugging. + + +======== +OVERVIEW +======== + +CacheFiles is a caching backend that's meant to use as a cache a directory on +an already mounted filesystem of a local type (such as Ext3). + +CacheFiles uses a userspace daemon to do some of the cache management - such as +reaping stale nodes and culling. This is called cachefilesd and lives in +/sbin. + +The filesystem and data integrity of the cache are only as good as those of the +filesystem providing the backing services. Note that CacheFiles does not +attempt to journal anything since the journalling interfaces of the various +filesystems are very specific in nature. + +CacheFiles creates a misc character device - "/dev/cachefiles" - that is used +to communication with the daemon. Only one thing may have this open at once, +and whilst it is open, a cache is at least partially in existence. The daemon +opens this and sends commands down it to control the cache. + +CacheFiles is currently limited to a single cache. + +CacheFiles attempts to maintain at least a certain percentage of free space on +the filesystem, shrinking the cache by culling the objects it contains to make +space if necessary - see the "Cache Culling" section. This means it can be +placed on the same medium as a live set of data, and will expand to make use of +spare space and automatically contract when the set of data requires more +space. + + +============ +REQUIREMENTS +============ + +The use of CacheFiles and its daemon requires the following features to be +available in the system and in the cache filesystem: + + - dnotify. + + - extended attributes (xattrs). + + - openat() and friends. + + - bmap() support on files in the filesystem (FIBMAP ioctl). + + - The use of bmap() to detect a partial page at the end of the file. + +It is strongly recommended that the "dir_index" option is enabled on Ext3 +filesystems being used as a cache. + + +============= +CONFIGURATION +============= + +The cache is configured by a script in /etc/cachefilesd.conf. These commands +set up cache ready for use. The following script commands are available: + + (*) brun <N>% + (*) bcull <N>% + (*) bstop <N>% + (*) frun <N>% + (*) fcull <N>% + (*) fstop <N>% + + Configure the culling limits. Optional. See the section on culling + The defaults are 7% (run), 5% (cull) and 1% (stop) respectively. + + The commands beginning with a 'b' are file space (block) limits, those + beginning with an 'f' are file count limits. + + (*) dir <path> + + Specify the directory containing the root of the cache. Mandatory. + + (*) tag <name> + + Specify a tag to FS-Cache to use in distinguishing multiple caches. + Optional. The default is "CacheFiles". + + (*) debug <mask> + + Specify a numeric bitmask to control debugging in the kernel module. + Optional. The default is zero (all off). The following values can be + OR'd into the mask to collect various information: + + 1 Turn on trace of function entry (_enter() macros) + 2 Turn on trace of function exit (_leave() macros) + 4 Turn on trace of internal debug points (_debug()) + + This mask can also be set through sysfs, eg: + + echo 5 >/sys/modules/cachefiles/parameters/debug + + +================== +STARTING THE CACHE +================== + +The cache is started by running the daemon. The daemon opens the cache device, +configures the cache and tells it to begin caching. At that point the cache +binds to fscache and the cache becomes live. + +The daemon is run as follows: + + /sbin/cachefilesd [-d]* [-s] [-n] [-f <configfile>] + +The flags are: + + (*) -d + + Increase the debugging level. This can be specified multiple times and + is cumulative with itself. + + (*) -s + + Send messages to stderr instead of syslog. + + (*) -n + + Don't daemonise and go into background. + + (*) -f <configfile> + + Use an alternative configuration file rather than the default one. + + +=============== +THINGS TO AVOID +=============== + +Do not mount other things within the cache as this will cause problems. The +kernel module contains its own very cut-down path walking facility that ignores +mountpoints, but the daemon can't avoid them. + +Do not create, rename or unlink files and directories in the cache whilst the +cache is active, as this may cause the state to become uncertain. + +Renaming files in the cache might make objects appear to be other objects (the +filename is part of the lookup key). + +Do not change or remove the extended attributes attached to cache files by the +cache as this will cause the cache state management to get confused. + +Do not create files or directories in the cache, lest the cache get confused or +serve incorrect data. + +Do not chmod files in the cache. The module creates things with minimal +permissions to prevent random users being able to access them directly. + + +============= +CACHE CULLING +============= + +The cache may need culling occasionally to make space. This involves +discarding objects from the cache that have been used less recently than +anything else. Culling is based on the access time of data objects. Empty +directories are culled if not in use. + +Cache culling is done on the basis of the percentage of blocks and the +percentage of files available in the underlying filesystem. There are six +"limits": + + (*) brun + (*) frun + + If the amount of free space and the number of available files in the cache + rises above both these limits, then culling is turned off. + + (*) bcull + (*) fcull + + If the amount of available space or the number of available files in the + cache falls below either of these limits, then culling is started. + + (*) bstop + (*) fstop + + If the amount of available space or the number of available files in the + cache falls below either of these limits, then no further allocation of + disk space or files is permitted until culling has raised things above + these limits again. + +These must be configured thusly: + + 0 <= bstop < bcull < brun < 100 + 0 <= fstop < fcull < frun < 100 + +Note that these are percentages of available space and available files, and do +_not_ appear as 100 minus the percentage displayed by the "df" program. + +The userspace daemon scans the cache to build up a table of cullable objects. +These are then culled in least recently used order. A new scan of the cache is +started as soon as space is made in the table. Objects will be skipped if +their atimes have changed or if the kernel module says it is still using them. + + +=============== +CACHE STRUCTURE +=============== + +The CacheFiles module will create two directories in the directory it was +given: + + (*) cache/ + + (*) graveyard/ + +The active cache objects all reside in the first directory. The CacheFiles +kernel module moves any retired or culled objects that it can't simply unlink +to the graveyard from which the daemon will actually delete them. + +The daemon uses dnotify to monitor the graveyard directory, and will delete +anything that appears therein. + + +The module represents index objects as directories with the filename "I..." or +"J...". Note that the "cache/" directory is itself a special index. + +Data objects are represented as files if they have no children, or directories +if they do. Their filenames all begin "D..." or "E...". If represented as a +directory, data objects will have a file in the directory called "data" that +actually holds the data. + +Special objects are similar to data objects, except their filenames begin +"S..." or "T...". + + +If an object has children, then it will be represented as a directory. +Immediately in the representative directory are a collection of directories +named for hash values of the child object keys with an '@' prepended. Into +this directory, if possible, will be placed the representations of the child +objects: + + INDEX INDEX INDEX DATA FILES + ========= ========== ================================= ================ + cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400 + cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...DB1ry + cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...N22ry + cache/@4a/I03nfs/@30/Ji000000000000000--fHg8hi8400/@75/Es0g000w...FP1ry + + +If the key is so long that it exceeds NAME_MAX with the decorations added on to +it, then it will be cut into pieces, the first few of which will be used to +make a nest of directories, and the last one of which will be the objects +inside the last directory. The names of the intermediate directories will have +'+' prepended: + + J1223/@23/+xy...z/+kl...m/Epqr + + +Note that keys are raw data, and not only may they exceed NAME_MAX in size, +they may also contain things like '/' and NUL characters, and so they may not +be suitable for turning directly into a filename. + +To handle this, CacheFiles will use a suitably printable filename directly and +"base-64" encode ones that aren't directly suitable. The two versions of +object filenames indicate the encoding: + + OBJECT TYPE PRINTABLE ENCODED + =============== =============== =============== + Index "I..." "J..." + Data "D..." "E..." + Special "S..." "T..." + +Intermediate directories are always "@" or "+" as appropriate. + + +Each object in the cache has an extended attribute label that holds the object +type ID (required to distinguish special objects) and the auxiliary data from +the netfs. The latter is used to detect stale objects in the cache and update +or retire them. + + +Note that CacheFiles will erase from the cache any file it doesn't recognise or +any file of an incorrect type (such as a FIFO file or a device file). + + +========================== +SECURITY MODEL AND SELINUX +========================== + +CacheFiles is implemented to deal properly with the LSM security features of +the Linux kernel and the SELinux facility. + +One of the problems that CacheFiles faces is that it is generally acting on +behalf of a process, and running in that process's context, and that includes a +security context that is not appropriate for accessing the cache - either +because the files in the cache are inaccessible to that process, or because if +the process creates a file in the cache, that file may be inaccessible to other +processes. + +The way CacheFiles works is to temporarily change the security context (fsuid, +fsgid and actor security label) that the process acts as - without changing the +security context of the process when it the target of an operation performed by +some other process (so signalling and suchlike still work correctly). + + +When the CacheFiles module is asked to bind to its cache, it: + + (1) Finds the security label attached to the root cache directory and uses + that as the security label with which it will create files. By default, + this is: + + cachefiles_var_t + + (2) Finds the security label of the process which issued the bind request + (presumed to be the cachefilesd daemon), which by default will be: + + cachefilesd_t + + and asks LSM to supply a security ID as which it should act given the + daemon's label. By default, this will be: + + cachefiles_kernel_t + + SELinux transitions the daemon's security ID to the module's security ID + based on a rule of this form in the policy. + + type_transition <daemon's-ID> kernel_t : process <module's-ID>; + + For instance: + + type_transition cachefilesd_t kernel_t : process cachefiles_kernel_t; + + +The module's security ID gives it permission to create, move and remove files +and directories in the cache, to find and access directories and files in the +cache, to set and access extended attributes on cache objects, and to read and +write files in the cache. + +The daemon's security ID gives it only a very restricted set of permissions: it +may scan directories, stat files and erase files and directories. It may +not read or write files in the cache, and so it is precluded from accessing the +data cached therein; nor is it permitted to create new files in the cache. + + +There are policy source files available in: + + http://people.redhat.com/~dhowells/fscache/cachefilesd-0.8.tar.bz2 + +and later versions. In that tarball, see the files: + + cachefilesd.te + cachefilesd.fc + cachefilesd.if + +They are built and installed directly by the RPM. + +If a non-RPM based system is being used, then copy the above files to their own +directory and run: + + make -f /usr/share/selinux/devel/Makefile + semodule -i cachefilesd.pp + +You will need checkpolicy and selinux-policy-devel installed prior to the +build. + + +By default, the cache is located in /var/fscache, but if it is desirable that +it should be elsewhere, than either the above policy files must be altered, or +an auxiliary policy must be installed to label the alternate location of the +cache. + +For instructions on how to add an auxiliary policy to enable the cache to be +located elsewhere when SELinux is in enforcing mode, please see: + + /usr/share/doc/cachefilesd-*/move-cache.txt + +When the cachefilesd rpm is installed; alternatively, the document can be found +in the sources. + + +================== +A NOTE ON SECURITY +================== + +CacheFiles makes use of the split security in the task_struct. It allocates +its own task_security structure, and redirects current->cred to point to it +when it acts on behalf of another process, in that process's context. + +The reason it does this is that it calls vfs_mkdir() and suchlike rather than +bypassing security and calling inode ops directly. Therefore the VFS and LSM +may deny the CacheFiles access to the cache data because under some +circumstances the caching code is running in the security context of whatever +process issued the original syscall on the netfs. + +Furthermore, should CacheFiles create a file or directory, the security +parameters with that object is created (UID, GID, security label) would be +derived from that process that issued the system call, thus potentially +preventing other processes from accessing the cache - including CacheFiles's +cache management daemon (cachefilesd). + +What is required is to temporarily override the security of the process that +issued the system call. We can't, however, just do an in-place change of the +security data as that affects the process as an object, not just as a subject. +This means it may lose signals or ptrace events for example, and affects what +the process looks like in /proc. + +So CacheFiles makes use of a logical split in the security between the +objective security (task->real_cred) and the subjective security (task->cred). +The objective security holds the intrinsic security properties of a process and +is never overridden. This is what appears in /proc, and is what is used when a +process is the target of an operation by some other process (SIGKILL for +example). + +The subjective security holds the active security properties of a process, and +may be overridden. This is not seen externally, and is used whan a process +acts upon another object, for example SIGKILLing another process or opening a +file. + +LSM hooks exist that allow SELinux (or Smack or whatever) to reject a request +for CacheFiles to run in a context of a specific security label, or to create +files and directories with another security label. + + +======================= +STATISTICAL INFORMATION +======================= + +If FS-Cache is compiled with the following option enabled: + + CONFIG_CACHEFILES_HISTOGRAM=y + +then it will gather certain statistics and display them through a proc file. + + (*) /proc/fs/cachefiles/histogram + + cat /proc/fs/cachefiles/histogram + JIFS SECS LOOKUPS MKDIRS CREATES + ===== ===== ========= ========= ========= + + This shows the breakdown of the number of times each amount of time + between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The + columns are as follows: + + COLUMN TIME MEASUREMENT + ======= ======================================================= + LOOKUPS Length of time to perform a lookup on the backing fs + MKDIRS Length of time to perform a mkdir on the backing fs + CREATES Length of time to perform a create on the backing fs + + Each row shows the number of events that took a particular range of times. + Each step is 1 jiffy in size. The JIFS column indicates the particular + jiffy range covered, and the SECS field the equivalent number of seconds. + + +========= +DEBUGGING +========= + +If CONFIG_CACHEFILES_DEBUG is enabled, the CacheFiles facility can have runtime +debugging enabled by adjusting the value in: + + /sys/module/cachefiles/parameters/debug + +This is a bitmask of debugging streams to enable: + + BIT VALUE STREAM POINT + ======= ======= =============================== ======================= + 0 1 General Function entry trace + 1 2 Function exit trace + 2 4 General + +The appropriate set of values should be OR'd together and the result written to +the control file. For example: + + echo $((1|4|8)) >/sys/module/cachefiles/parameters/debug + +will turn on all function entry debugging. diff --git a/Documentation/filesystems/caching/fscache.txt b/Documentation/filesystems/caching/fscache.txt new file mode 100644 index 000000000000..9e94b9491d89 --- /dev/null +++ b/Documentation/filesystems/caching/fscache.txt @@ -0,0 +1,333 @@ + ========================== + General Filesystem Caching + ========================== + +======== +OVERVIEW +======== + +This facility is a general purpose cache for network filesystems, though it +could be used for caching other things such as ISO9660 filesystems too. + +FS-Cache mediates between cache backends (such as CacheFS) and network +filesystems: + + +---------+ + | | +--------------+ + | NFS |--+ | | + | | | +-->| CacheFS | + +---------+ | +----------+ | | /dev/hda5 | + | | | | +--------------+ + +---------+ +-->| | | + | | | |--+ + | AFS |----->| FS-Cache | + | | | |--+ + +---------+ +-->| | | + | | | | +--------------+ + +---------+ | +----------+ | | | + | | | +-->| CacheFiles | + | ISOFS |--+ | /var/cache | + | | +--------------+ + +---------+ + +Or to look at it another way, FS-Cache is a module that provides a caching +facility to a network filesystem such that the cache is transparent to the +user: + + +---------+ + | | + | Server | + | | + +---------+ + | NETWORK + ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + | + | +----------+ + V | | + +---------+ | | + | | | | + | NFS |----->| FS-Cache | + | | | |--+ + +---------+ | | | +--------------+ +--------------+ + | | | | | | | | + V +----------+ +-->| CacheFiles |-->| Ext3 | + +---------+ | /var/cache | | /dev/sda6 | + | | +--------------+ +--------------+ + | VFS | ^ ^ + | | | | + +---------+ +--------------+ | + | KERNEL SPACE | | + ~~~~~|~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~|~~~~~~|~~~~ + | USER SPACE | | + V | | + +---------+ +--------------+ + | | | | + | Process | | cachefilesd | + | | | | + +---------+ +--------------+ + + +FS-Cache does not follow the idea of completely loading every netfs file +opened in its entirety into a cache before permitting it to be accessed and +then serving the pages out of that cache rather than the netfs inode because: + + (1) It must be practical to operate without a cache. + + (2) The size of any accessible file must not be limited to the size of the + cache. + + (3) The combined size of all opened files (this includes mapped libraries) + must not be limited to the size of the cache. + + (4) The user should not be forced to download an entire file just to do a + one-off access of a small portion of it (such as might be done with the + "file" program). + +It instead serves the cache out in PAGE_SIZE chunks as and when requested by +the netfs('s) using it. + + +FS-Cache provides the following facilities: + + (1) More than one cache can be used at once. Caches can be selected + explicitly by use of tags. + + (2) Caches can be added / removed at any time. + + (3) The netfs is provided with an interface that allows either party to + withdraw caching facilities from a file (required for (2)). + + (4) The interface to the netfs returns as few errors as possible, preferring + rather to let the netfs remain oblivious. + + (5) Cookies are used to represent indices, files and other objects to the + netfs. The simplest cookie is just a NULL pointer - indicating nothing + cached there. + + (6) The netfs is allowed to propose - dynamically - any index hierarchy it + desires, though it must be aware that the index search function is + recursive, stack space is limited, and indices can only be children of + indices. + + (7) Data I/O is done direct to and from the netfs's pages. The netfs + indicates that page A is at index B of the data-file represented by cookie + C, and that it should be read or written. The cache backend may or may + not start I/O on that page, but if it does, a netfs callback will be + invoked to indicate completion. The I/O may be either synchronous or + asynchronous. + + (8) Cookies can be "retired" upon release. At this point FS-Cache will mark + them as obsolete and the index hierarchy rooted at that point will get + recycled. + + (9) The netfs provides a "match" function for index searches. In addition to + saying whether a match was made or not, this can also specify that an + entry should be updated or deleted. + +(10) As much as possible is done asynchronously. + + +FS-Cache maintains a virtual indexing tree in which all indices, files, objects +and pages are kept. Bits of this tree may actually reside in one or more +caches. + + FSDEF + | + +------------------------------------+ + | | + NFS AFS + | | + +--------------------------+ +-----------+ + | | | | + homedir mirror afs.org redhat.com + | | | + +------------+ +---------------+ +----------+ + | | | | | | + 00001 00002 00007 00125 vol00001 vol00002 + | | | | | + +---+---+ +-----+ +---+ +------+------+ +-----+----+ + | | | | | | | | | | | | | +PG0 PG1 PG2 PG0 XATTR PG0 PG1 DIRENT DIRENT DIRENT R/W R/O Bak + | | + PG0 +-------+ + | | + 00001 00003 + | + +---+---+ + | | | + PG0 PG1 PG2 + +In the example above, you can see two netfs's being backed: NFS and AFS. These +have different index hierarchies: + + (*) The NFS primary index contains per-server indices. Each server index is + indexed by NFS file handles to get data file objects. Each data file + objects can have an array of pages, but may also have further child + objects, such as extended attributes and directory entries. Extended + attribute objects themselves have page-array contents. + + (*) The AFS primary index contains per-cell indices. Each cell index contains + per-logical-volume indices. Each of volume index contains up to three + indices for the read-write, read-only and backup mirrors of those volumes. + Each of these contains vnode data file objects, each of which contains an + array of pages. + +The very top index is the FS-Cache master index in which individual netfs's +have entries. + +Any index object may reside in more than one cache, provided it only has index +children. Any index with non-index object children will be assumed to only +reside in one cache. + + +The netfs API to FS-Cache can be found in: + + Documentation/filesystems/caching/netfs-api.txt + +The cache backend API to FS-Cache can be found in: + + Documentation/filesystems/caching/backend-api.txt + +A description of the internal representations and object state machine can be +found in: + + Documentation/filesystems/caching/object.txt + + +======================= +STATISTICAL INFORMATION +======================= + +If FS-Cache is compiled with the following options enabled: + + CONFIG_FSCACHE_STATS=y + CONFIG_FSCACHE_HISTOGRAM=y + +then it will gather certain statistics and display them through a number of +proc files. + + (*) /proc/fs/fscache/stats + + This shows counts of a number of events that can happen in FS-Cache: + + CLASS EVENT MEANING + ======= ======= ======================================================= + Cookies idx=N Number of index cookies allocated + dat=N Number of data storage cookies allocated + spc=N Number of special cookies allocated + Objects alc=N Number of objects allocated + nal=N Number of object allocation failures + avl=N Number of objects that reached the available state + ded=N Number of objects that reached the dead state + ChkAux non=N Number of objects that didn't have a coherency check + ok=N Number of objects that passed a coherency check + upd=N Number of objects that needed a coherency data update + obs=N Number of objects that were declared obsolete + Pages mrk=N Number of pages marked as being cached + unc=N Number of uncache page requests seen + Acquire n=N Number of acquire cookie requests seen + nul=N Number of acq reqs given a NULL parent + noc=N Number of acq reqs rejected due to no cache available + ok=N Number of acq reqs succeeded + nbf=N Number of acq reqs rejected due to error + oom=N Number of acq reqs failed on ENOMEM + Lookups n=N Number of lookup calls made on cache backends + neg=N Number of negative lookups made + pos=N Number of positive lookups made + crt=N Number of objects created by lookup + Updates n=N Number of update cookie requests seen + nul=N Number of upd reqs given a NULL parent + run=N Number of upd reqs granted CPU time + Relinqs n=N Number of relinquish cookie requests seen + nul=N Number of rlq reqs given a NULL parent + wcr=N Number of rlq reqs waited on completion of creation + AttrChg n=N Number of attribute changed requests seen + ok=N Number of attr changed requests queued + nbf=N Number of attr changed rejected -ENOBUFS + oom=N Number of attr changed failed -ENOMEM + run=N Number of attr changed ops given CPU time + Allocs n=N Number of allocation requests seen + ok=N Number of successful alloc reqs + wt=N Number of alloc reqs that waited on lookup completion + nbf=N Number of alloc reqs rejected -ENOBUFS + ops=N Number of alloc reqs submitted + owt=N Number of alloc reqs waited for CPU time + Retrvls n=N Number of retrieval (read) requests seen + ok=N Number of successful retr reqs + wt=N Number of retr reqs that waited on lookup completion + nod=N Number of retr reqs returned -ENODATA + nbf=N Number of retr reqs rejected -ENOBUFS + int=N Number of retr reqs aborted -ERESTARTSYS + oom=N Number of retr reqs failed -ENOMEM + ops=N Number of retr reqs submitted + owt=N Number of retr reqs waited for CPU time + Stores n=N Number of storage (write) requests seen + ok=N Number of successful store reqs + agn=N Number of store reqs on a page already pending storage + nbf=N Number of store reqs rejected -ENOBUFS + oom=N Number of store reqs failed -ENOMEM + ops=N Number of store reqs submitted + run=N Number of store reqs granted CPU time + Ops pend=N Number of times async ops added to pending queues + run=N Number of times async ops given CPU time + enq=N Number of times async ops queued for processing + dfr=N Number of async ops queued for deferred release + rel=N Number of async ops released + gc=N Number of deferred-release async ops garbage collected + + + (*) /proc/fs/fscache/histogram + + cat /proc/fs/fscache/histogram + JIFS SECS OBJ INST OP RUNS OBJ RUNS RETRV DLY RETRIEVLS + ===== ===== ========= ========= ========= ========= ========= + + This shows the breakdown of the number of times each amount of time + between 0 jiffies and HZ-1 jiffies a variety of tasks took to run. The + columns are as follows: + + COLUMN TIME MEASUREMENT + ======= ======================================================= + OBJ INST Length of time to instantiate an object + OP RUNS Length of time a call to process an operation took + OBJ RUNS Length of time a call to process an object event took + RETRV DLY Time between an requesting a read and lookup completing + RETRIEVLS Time between beginning and end of a retrieval + + Each row shows the number of events that took a particular range of times. + Each step is 1 jiffy in size. The JIFS column indicates the particular + jiffy range covered, and the SECS field the equivalent number of seconds. + + +========= +DEBUGGING +========= + +If CONFIG_FSCACHE_DEBUG is enabled, the FS-Cache facility can have runtime +debugging enabled by adjusting the value in: + + /sys/module/fscache/parameters/debug + +This is a bitmask of debugging streams to enable: + + BIT VALUE STREAM POINT + ======= ======= =============================== ======================= + 0 1 Cache management Function entry trace + 1 2 Function exit trace + 2 4 General + 3 8 Cookie management Function entry trace + 4 16 Function exit trace + 5 32 General + 6 64 Page handling Function entry trace + 7 128 Function exit trace + 8 256 General + 9 512 Operation management Function entry trace + 10 1024 Function exit trace + 11 2048 General + +The appropriate set of values should be OR'd together and the result written to +the control file. For example: + + echo $((1|8|64)) >/sys/module/fscache/parameters/debug + +will turn on all function entry debugging. diff --git a/Documentation/filesystems/caching/netfs-api.txt b/Documentation/filesystems/caching/netfs-api.txt new file mode 100644 index 000000000000..4db125b3a5c6 --- /dev/null +++ b/Documentation/filesystems/caching/netfs-api.txt @@ -0,0 +1,778 @@ + =============================== + FS-CACHE NETWORK FILESYSTEM API + =============================== + +There's an API by which a network filesystem can make use of the FS-Cache +facilities. This is based around a number of principles: + + (1) Caches can store a number of different object types. There are two main + object types: indices and files. The first is a special type used by + FS-Cache to make finding objects faster and to make retiring of groups of + objects easier. + + (2) Every index, file or other object is represented by a cookie. This cookie + may or may not have anything associated with it, but the netfs doesn't + need to care. + + (3) Barring the top-level index (one entry per cached netfs), the index + hierarchy for each netfs is structured according the whim of the netfs. + +This API is declared in <linux/fscache.h>. + +This document contains the following sections: + + (1) Network filesystem definition + (2) Index definition + (3) Object definition + (4) Network filesystem (un)registration + (5) Cache tag lookup + (6) Index registration + (7) Data file registration + (8) Miscellaneous object registration + (9) Setting the data file size + (10) Page alloc/read/write + (11) Page uncaching + (12) Index and data file update + (13) Miscellaneous cookie operations + (14) Cookie unregistration + (15) Index and data file invalidation + (16) FS-Cache specific page flags. + + +============================= +NETWORK FILESYSTEM DEFINITION +============================= + +FS-Cache needs a description of the network filesystem. This is specified +using a record of the following structure: + + struct fscache_netfs { + uint32_t version; + const char *name; + struct fscache_cookie *primary_index; + ... + }; + +This first two fields should be filled in before registration, and the third +will be filled in by the registration function; any other fields should just be +ignored and are for internal use only. + +The fields are: + + (1) The name of the netfs (used as the key in the toplevel index). + + (2) The version of the netfs (if the name matches but the version doesn't, the + entire in-cache hierarchy for this netfs will be scrapped and begun + afresh). + + (3) The cookie representing the primary index will be allocated according to + another parameter passed into the registration function. + +For example, kAFS (linux/fs/afs/) uses the following definitions to describe +itself: + + struct fscache_netfs afs_cache_netfs = { + .version = 0, + .name = "afs", + }; + + +================ +INDEX DEFINITION +================ + +Indices are used for two purposes: + + (1) To aid the finding of a file based on a series of keys (such as AFS's + "cell", "volume ID", "vnode ID"). + + (2) To make it easier to discard a subset of all the files cached based around + a particular key - for instance to mirror the removal of an AFS volume. + +However, since it's unlikely that any two netfs's are going to want to define +their index hierarchies in quite the same way, FS-Cache tries to impose as few +restraints as possible on how an index is structured and where it is placed in +the tree. The netfs can even mix indices and data files at the same level, but +it's not recommended. + +Each index entry consists of a key of indeterminate length plus some auxilliary +data, also of indeterminate length. + +There are some limits on indices: + + (1) Any index containing non-index objects should be restricted to a single + cache. Any such objects created within an index will be created in the + first cache only. The cache in which an index is created can be + controlled by cache tags (see below). + + (2) The entry data must be atomically journallable, so it is limited to about + 400 bytes at present. At least 400 bytes will be available. + + (3) The depth of the index tree should be judged with care as the search + function is recursive. Too many layers will run the kernel out of stack. + + +================= +OBJECT DEFINITION +================= + +To define an object, a structure of the following type should be filled out: + + struct fscache_cookie_def + { + uint8_t name[16]; + uint8_t type; + + struct fscache_cache_tag *(*select_cache)( + const void *parent_netfs_data, + const void *cookie_netfs_data); + + uint16_t (*get_key)(const void *cookie_netfs_data, + void *buffer, + uint16_t bufmax); + + void (*get_attr)(const void *cookie_netfs_data, + uint64_t *size); + + uint16_t (*get_aux)(const void *cookie_netfs_data, + void *buffer, + uint16_t bufmax); + + enum fscache_checkaux (*check_aux)(void *cookie_netfs_data, + const void *data, + uint16_t datalen); + + void (*get_context)(void *cookie_netfs_data, void *context); + + void (*put_context)(void *cookie_netfs_data, void *context); + + void (*mark_pages_cached)(void *cookie_netfs_data, + struct address_space *mapping, + struct pagevec *cached_pvec); + + void (*now_uncached)(void *cookie_netfs_data); + }; + +This has the following fields: + + (1) The type of the object [mandatory]. + + This is one of the following values: + + (*) FSCACHE_COOKIE_TYPE_INDEX + + This defines an index, which is a special FS-Cache type. + + (*) FSCACHE_COOKIE_TYPE_DATAFILE + + This defines an ordinary data file. + + (*) Any other value between 2 and 255 + + This defines an extraordinary object such as an XATTR. + + (2) The name of the object type (NUL terminated unless all 16 chars are used) + [optional]. + + (3) A function to select the cache in which to store an index [optional]. + + This function is invoked when an index needs to be instantiated in a cache + during the instantiation of a non-index object. Only the immediate index + parent for the non-index object will be queried. Any indices above that + in the hierarchy may be stored in multiple caches. This function does not + need to be supplied for any non-index object or any index that will only + have index children. + + If this function is not supplied or if it returns NULL then the first + cache in the parent's list will be chosed, or failing that, the first + cache in the master list. + + (4) A function to retrieve an object's key from the netfs [mandatory]. + + This function will be called with the netfs data that was passed to the + cookie acquisition function and the maximum length of key data that it may + provide. It should write the required key data into the given buffer and + return the quantity it wrote. + + (5) A function to retrieve attribute data from the netfs [optional]. + + This function will be called with the netfs data that was passed to the + cookie acquisition function. It should return the size of the file if + this is a data file. The size may be used to govern how much cache must + be reserved for this file in the cache. + + If the function is absent, a file size of 0 is assumed. + + (6) A function to retrieve auxilliary data from the netfs [optional]. + + This function will be called with the netfs data that was passed to the + cookie acquisition function and the maximum length of auxilliary data that + it may provide. It should write the auxilliary data into the given buffer + and return the quantity it wrote. + + If this function is absent, the auxilliary data length will be set to 0. + + The length of the auxilliary data buffer may be dependent on the key + length. A netfs mustn't rely on being able to provide more than 400 bytes + for both. + + (7) A function to check the auxilliary data [optional]. + + This function will be called to check that a match found in the cache for + this object is valid. For instance with AFS it could check the auxilliary + data against the data version number returned by the server to determine + whether the index entry in a cache is still valid. + + If this function is absent, it will be assumed that matching objects in a + cache are always valid. + + If present, the function should return one of the following values: + + (*) FSCACHE_CHECKAUX_OKAY - the entry is okay as is + (*) FSCACHE_CHECKAUX_NEEDS_UPDATE - the entry requires update + (*) FSCACHE_CHECKAUX_OBSOLETE - the entry should be deleted + + This function can also be used to extract data from the auxilliary data in + the cache and copy it into the netfs's structures. + + (8) A pair of functions to manage contexts for the completion callback + [optional]. + + The cache read/write functions are passed a context which is then passed + to the I/O completion callback function. To ensure this context remains + valid until after the I/O completion is called, two functions may be + provided: one to get an extra reference on the context, and one to drop a + reference to it. + + If the context is not used or is a type of object that won't go out of + scope, then these functions are not required. These functions are not + required for indices as indices may not contain data. These functions may + be called in interrupt context and so may not sleep. + + (9) A function to mark a page as retaining cache metadata [optional]. + + This is called by the cache to indicate that it is retaining in-memory + information for this page and that the netfs should uncache the page when + it has finished. This does not indicate whether there's data on the disk + or not. Note that several pages at once may be presented for marking. + + The PG_fscache bit is set on the pages before this function would be + called, so the function need not be provided if this is sufficient. + + This function is not required for indices as they're not permitted data. + +(10) A function to unmark all the pages retaining cache metadata [mandatory]. + + This is called by FS-Cache to indicate that a backing store is being + unbound from a cookie and that all the marks on the pages should be + cleared to prevent confusion. Note that the cache will have torn down all + its tracking information so that the pages don't need to be explicitly + uncached. + + This function is not required for indices as they're not permitted data. + + +=================================== +NETWORK FILESYSTEM (UN)REGISTRATION +=================================== + +The first step is to declare the network filesystem to the cache. This also +involves specifying the layout of the primary index (for AFS, this would be the +"cell" level). + +The registration function is: + + int fscache_register_netfs(struct fscache_netfs *netfs); + +It just takes a pointer to the netfs definition. It returns 0 or an error as +appropriate. + +For kAFS, registration is done as follows: + + ret = fscache_register_netfs(&afs_cache_netfs); + +The last step is, of course, unregistration: + + void fscache_unregister_netfs(struct fscache_netfs *netfs); + + +================ +CACHE TAG LOOKUP +================ + +FS-Cache permits the use of more than one cache. To permit particular index +subtrees to be bound to particular caches, the second step is to look up cache +representation tags. This step is optional; it can be left entirely up to +FS-Cache as to which cache should be used. The problem with doing that is that +FS-Cache will always pick the first cache that was registered. + +To get the representation for a named tag: + + struct fscache_cache_tag *fscache_lookup_cache_tag(const char *name); + +This takes a text string as the name and returns a representation of a tag. It +will never return an error. It may return a dummy tag, however, if it runs out +of memory; this will inhibit caching with this tag. + +Any representation so obtained must be released by passing it to this function: + + void fscache_release_cache_tag(struct fscache_cache_tag *tag); + +The tag will be retrieved by FS-Cache when it calls the object definition +operation select_cache(). + + +================== +INDEX REGISTRATION +================== + +The third step is to inform FS-Cache about part of an index hierarchy that can +be used to locate files. This is done by requesting a cookie for each index in +the path to the file: + + struct fscache_cookie * + fscache_acquire_cookie(struct fscache_cookie *parent, + const struct fscache_object_def *def, + void *netfs_data); + +This function creates an index entry in the index represented by parent, +filling in the index entry by calling the operations pointed to by def. + +Note that this function never returns an error - all errors are handled +internally. It may, however, return NULL to indicate no cookie. It is quite +acceptable to pass this token back to this function as the parent to another +acquisition (or even to the relinquish cookie, read page and write page +functions - see below). + +Note also that no indices are actually created in a cache until a non-index +object needs to be created somewhere down the hierarchy. Furthermore, an index +may be created in several different caches independently at different times. +This is all handled transparently, and the netfs doesn't see any of it. + +For example, with AFS, a cell would be added to the primary index. This index +entry would have a dependent inode containing a volume location index for the +volume mappings within this cell: + + cell->cache = + fscache_acquire_cookie(afs_cache_netfs.primary_index, + &afs_cell_cache_index_def, + cell); + +Then when a volume location was accessed, it would be entered into the cell's +index and an inode would be allocated that acts as a volume type and hash chain +combination: + + vlocation->cache = + fscache_acquire_cookie(cell->cache, + &afs_vlocation_cache_index_def, + vlocation); + +And then a particular flavour of volume (R/O for example) could be added to +that index, creating another index for vnodes (AFS inode equivalents): + + volume->cache = + fscache_acquire_cookie(vlocation->cache, + &afs_volume_cache_index_def, + volume); + + +====================== +DATA FILE REGISTRATION +====================== + +The fourth step is to request a data file be created in the cache. This is +identical to index cookie acquisition. The only difference is that the type in +the object definition should be something other than index type. + + vnode->cache = + fscache_acquire_cookie(volume->cache, + &afs_vnode_cache_object_def, + vnode); + + +================================= +MISCELLANEOUS OBJECT REGISTRATION +================================= + +An optional step is to request an object of miscellaneous type be created in +the cache. This is almost identical to index cookie acquisition. The only +difference is that the type in the object definition should be something other +than index type. Whilst the parent object could be an index, it's more likely +it would be some other type of object such as a data file. + + xattr->cache = + fscache_acquire_cookie(vnode->cache, + &afs_xattr_cache_object_def, + xattr); + +Miscellaneous objects might be used to store extended attributes or directory +entries for example. + + +========================== +SETTING THE DATA FILE SIZE +========================== + +The fifth step is to set the physical attributes of the file, such as its size. +This doesn't automatically reserve any space in the cache, but permits the +cache to adjust its metadata for data tracking appropriately: + + int fscache_attr_changed(struct fscache_cookie *cookie); + +The cache will return -ENOBUFS if there is no backing cache or if there is no +space to allocate any extra metadata required in the cache. The attributes +will be accessed with the get_attr() cookie definition operation. + +Note that attempts to read or write data pages in the cache over this size may +be rebuffed with -ENOBUFS. + +This operation schedules an attribute adjustment to happen asynchronously at +some point in the future, and as such, it may happen after the function returns +to the caller. The attribute adjustment excludes read and write operations. + + +===================== +PAGE READ/ALLOC/WRITE +===================== + +And the sixth step is to store and retrieve pages in the cache. There are +three functions that are used to do this. + +Note: + + (1) A page should not be re-read or re-allocated without uncaching it first. + + (2) A read or allocated page must be uncached when the netfs page is released + from the pagecache. + + (3) A page should only be written to the cache if previous read or allocated. + +This permits the cache to maintain its page tracking in proper order. + + +PAGE READ +--------- + +Firstly, the netfs should ask FS-Cache to examine the caches and read the +contents cached for a particular page of a particular file if present, or else +allocate space to store the contents if not: + + typedef + void (*fscache_rw_complete_t)(struct page *page, + void *context, + int error); + + int fscache_read_or_alloc_page(struct fscache_cookie *cookie, + struct page *page, + fscache_rw_complete_t end_io_func, + void *context, + gfp_t gfp); + +The cookie argument must specify a cookie for an object that isn't an index, +the page specified will have the data loaded into it (and is also used to +specify the page number), and the gfp argument is used to control how any +memory allocations made are satisfied. + +If the cookie indicates the inode is not cached: + + (1) The function will return -ENOBUFS. + +Else if there's a copy of the page resident in the cache: + + (1) The mark_pages_cached() cookie operation will be called on that page. + + (2) The function will submit a request to read the data from the cache's + backing device directly into the page specified. + + (3) The function will return 0. + + (4) When the read is complete, end_io_func() will be invoked with: + + (*) The netfs data supplied when the cookie was created. + + (*) The page descriptor. + + (*) The context argument passed to the above function. This will be + maintained with the get_context/put_context functions mentioned above. + + (*) An argument that's 0 on success or negative for an error code. + + If an error occurs, it should be assumed that the page contains no usable + data. + + end_io_func() will be called in process context if the read is results in + an error, but it might be called in interrupt context if the read is + successful. + +Otherwise, if there's not a copy available in cache, but the cache may be able +to store the page: + + (1) The mark_pages_cached() cookie operation will be called on that page. + + (2) A block may be reserved in the cache and attached to the object at the + appropriate place. + + (3) The function will return -ENODATA. + +This function may also return -ENOMEM or -EINTR, in which case it won't have +read any data from the cache. + + +PAGE ALLOCATE +------------- + +Alternatively, if there's not expected to be any data in the cache for a page +because the file has been extended, a block can simply be allocated instead: + + int fscache_alloc_page(struct fscache_cookie *cookie, + struct page *page, + gfp_t gfp); + +This is similar to the fscache_read_or_alloc_page() function, except that it +never reads from the cache. It will return 0 if a block has been allocated, +rather than -ENODATA as the other would. One or the other must be performed +before writing to the cache. + +The mark_pages_cached() cookie operation will be called on the page if +successful. + + +PAGE WRITE +---------- + +Secondly, if the netfs changes the contents of the page (either due to an +initial download or if a user performs a write), then the page should be +written back to the cache: + + int fscache_write_page(struct fscache_cookie *cookie, + struct page *page, + gfp_t gfp); + +The cookie argument must specify a data file cookie, the page specified should +contain the data to be written (and is also used to specify the page number), +and the gfp argument is used to control how any memory allocations made are +satisfied. + +The page must have first been read or allocated successfully and must not have +been uncached before writing is performed. + +If the cookie indicates the inode is not cached then: + + (1) The function will return -ENOBUFS. + +Else if space can be allocated in the cache to hold this page: + + (1) PG_fscache_write will be set on the page. + + (2) The function will submit a request to write the data to cache's backing + device directly from the page specified. + + (3) The function will return 0. + + (4) When the write is complete PG_fscache_write is cleared on the page and + anyone waiting for that bit will be woken up. + +Else if there's no space available in the cache, -ENOBUFS will be returned. It +is also possible for the PG_fscache_write bit to be cleared when no write took +place if unforeseen circumstances arose (such as a disk error). + +Writing takes place asynchronously. + + +MULTIPLE PAGE READ +------------------ + +A facility is provided to read several pages at once, as requested by the +readpages() address space operation: + + int fscache_read_or_alloc_pages(struct fscache_cookie *cookie, + struct address_space *mapping, + struct list_head *pages, + int *nr_pages, + fscache_rw_complete_t end_io_func, + void *context, + gfp_t gfp); + +This works in a similar way to fscache_read_or_alloc_page(), except: + + (1) Any page it can retrieve data for is removed from pages and nr_pages and + dispatched for reading to the disk. Reads of adjacent pages on disk may + be merged for greater efficiency. + + (2) The mark_pages_cached() cookie operation will be called on several pages + at once if they're being read or allocated. + + (3) If there was an general error, then that error will be returned. + + Else if some pages couldn't be allocated or read, then -ENOBUFS will be + returned. + + Else if some pages couldn't be read but were allocated, then -ENODATA will + be returned. + + Otherwise, if all pages had reads dispatched, then 0 will be returned, the + list will be empty and *nr_pages will be 0. + + (4) end_io_func will be called once for each page being read as the reads + complete. It will be called in process context if error != 0, but it may + be called in interrupt context if there is no error. + +Note that a return of -ENODATA, -ENOBUFS or any other error does not preclude +some of the pages being read and some being allocated. Those pages will have +been marked appropriately and will need uncaching. + + +============== +PAGE UNCACHING +============== + +To uncache a page, this function should be called: + + void fscache_uncache_page(struct fscache_cookie *cookie, + struct page *page); + +This function permits the cache to release any in-memory representation it +might be holding for this netfs page. This function must be called once for +each page on which the read or write page functions above have been called to +make sure the cache's in-memory tracking information gets torn down. + +Note that pages can't be explicitly deleted from the a data file. The whole +data file must be retired (see the relinquish cookie function below). + +Furthermore, note that this does not cancel the asynchronous read or write +operation started by the read/alloc and write functions, so the page +invalidation and release functions must use: + + bool fscache_check_page_write(struct fscache_cookie *cookie, + struct page *page); + +to see if a page is being written to the cache, and: + + void fscache_wait_on_page_write(struct fscache_cookie *cookie, + struct page *page); + +to wait for it to finish if it is. + + +========================== +INDEX AND DATA FILE UPDATE +========================== + +To request an update of the index data for an index or other object, the +following function should be called: + + void fscache_update_cookie(struct fscache_cookie *cookie); + +This function will refer back to the netfs_data pointer stored in the cookie by +the acquisition function to obtain the data to write into each revised index +entry. The update method in the parent index definition will be called to +transfer the data. + +Note that partial updates may happen automatically at other times, such as when +data blocks are added to a data file object. + + +=============================== +MISCELLANEOUS COOKIE OPERATIONS +=============================== + +There are a number of operations that can be used to control cookies: + + (*) Cookie pinning: + + int fscache_pin_cookie(struct fscache_cookie *cookie); + void fscache_unpin_cookie(struct fscache_cookie *cookie); + + These operations permit data cookies to be pinned into the cache and to + have the pinning removed. They are not permitted on index cookies. + + The pinning function will return 0 if successful, -ENOBUFS in the cookie + isn't backed by a cache, -EOPNOTSUPP if the cache doesn't support pinning, + -ENOSPC if there isn't enough space to honour the operation, -ENOMEM or + -EIO if there's any other problem. + + (*) Data space reservation: + + int fscache_reserve_space(struct fscache_cookie *cookie, loff_t size); + + This permits a netfs to request cache space be reserved to store up to the + given amount of a file. It is permitted to ask for more than the current + size of the file to allow for future file expansion. + + If size is given as zero then the reservation will be cancelled. + + The function will return 0 if successful, -ENOBUFS in the cookie isn't + backed by a cache, -EOPNOTSUPP if the cache doesn't support reservations, + -ENOSPC if there isn't enough space to honour the operation, -ENOMEM or + -EIO if there's any other problem. + + Note that this doesn't pin an object in a cache; it can still be culled to + make space if it's not in use. + + +===================== +COOKIE UNREGISTRATION +===================== + +To get rid of a cookie, this function should be called. + + void fscache_relinquish_cookie(struct fscache_cookie *cookie, + int retire); + +If retire is non-zero, then the object will be marked for recycling, and all +copies of it will be removed from all active caches in which it is present. +Not only that but all child objects will also be retired. + +If retire is zero, then the object may be available again when next the +acquisition function is called. Retirement here will overrule the pinning on a +cookie. + +One very important note - relinquish must NOT be called for a cookie unless all +the cookies for "child" indices, objects and pages have been relinquished +first. + + +================================ +INDEX AND DATA FILE INVALIDATION +================================ + +There is no direct way to invalidate an index subtree or a data file. To do +this, the caller should relinquish and retire the cookie they have, and then +acquire a new one. + + +=========================== +FS-CACHE SPECIFIC PAGE FLAG +=========================== + +FS-Cache makes use of a page flag, PG_private_2, for its own purpose. This is +given the alternative name PG_fscache. + +PG_fscache is used to indicate that the page is known by the cache, and that +the cache must be informed if the page is going to go away. It's an indication +to the netfs that the cache has an interest in this page, where an interest may +be a pointer to it, resources allocated or reserved for it, or I/O in progress +upon it. + +The netfs can use this information in methods such as releasepage() to +determine whether it needs to uncache a page or update it. + +Furthermore, if this bit is set, releasepage() and invalidatepage() operations +will be called on a page to get rid of it, even if PG_private is not set. This +allows caching to attempted on a page before read_cache_pages() to be called +after fscache_read_or_alloc_pages() as the former will try and release pages it +was given under certain circumstances. + +This bit does not overlap with such as PG_private. This means that FS-Cache +can be used with a filesystem that uses the block buffering code. + +There are a number of operations defined on this flag: + + int PageFsCache(struct page *page); + void SetPageFsCache(struct page *page) + void ClearPageFsCache(struct page *page) + int TestSetPageFsCache(struct page *page) + int TestClearPageFsCache(struct page *page) + +These functions are bit test, bit set, bit clear, bit test and set and bit +test and clear operations on PG_fscache. diff --git a/Documentation/filesystems/caching/object.txt b/Documentation/filesystems/caching/object.txt new file mode 100644 index 000000000000..e8b0a35d8fe5 --- /dev/null +++ b/Documentation/filesystems/caching/object.txt @@ -0,0 +1,313 @@ + ==================================================== + IN-KERNEL CACHE OBJECT REPRESENTATION AND MANAGEMENT + ==================================================== + +By: David Howells <dhowells@redhat.com> + +Contents: + + (*) Representation + + (*) Object management state machine. + + - Provision of cpu time. + - Locking simplification. + + (*) The set of states. + + (*) The set of events. + + +============== +REPRESENTATION +============== + +FS-Cache maintains an in-kernel representation of each object that a netfs is +currently interested in. Such objects are represented by the fscache_cookie +struct and are referred to as cookies. + +FS-Cache also maintains a separate in-kernel representation of the objects that +a cache backend is currently actively caching. Such objects are represented by +the fscache_object struct. The cache backends allocate these upon request, and +are expected to embed them in their own representations. These are referred to +as objects. + +There is a 1:N relationship between cookies and objects. A cookie may be +represented by multiple objects - an index may exist in more than one cache - +or even by no objects (it may not be cached). + +Furthermore, both cookies and objects are hierarchical. The two hierarchies +correspond, but the cookies tree is a superset of the union of the object trees +of multiple caches: + + NETFS INDEX TREE : CACHE 1 : CACHE 2 + : : + : +-----------+ : + +----------->| IObject | : + +-----------+ | : +-----------+ : + | ICookie |-------+ : | : + +-----------+ | : | : +-----------+ + | +------------------------------>| IObject | + | : | : +-----------+ + | : V : | + | : +-----------+ : | + V +----------->| IObject | : | + +-----------+ | : +-----------+ : | + | ICookie |-------+ : | : V + +-----------+ | : | : +-----------+ + | +------------------------------>| IObject | + +-----+-----+ : | : +-----------+ + | | : | : | + V | : V : | + +-----------+ | : +-----------+ : | + | ICookie |------------------------->| IObject | : | + +-----------+ | : +-----------+ : | + | V : | : V + | +-----------+ : | : +-----------+ + | | ICookie |-------------------------------->| IObject | + | +-----------+ : | : +-----------+ + V | : V : | + +-----------+ | : +-----------+ : | + | DCookie |------------------------->| DObject | : | + +-----------+ | : +-----------+ : | + | : : | + +-------+-------+ : : | + | | : : | + V V : : V + +-----------+ +-----------+ : : +-----------+ + | DCookie | | DCookie |------------------------>| DObject | + +-----------+ +-----------+ : : +-----------+ + : : + +In the above illustration, ICookie and IObject represent indices and DCookie +and DObject represent data storage objects. Indices may have representation in +multiple caches, but currently, non-index objects may not. Objects of any type +may also be entirely unrepresented. + +As far as the netfs API goes, the netfs is only actually permitted to see +pointers to the cookies. The cookies themselves and any objects attached to +those cookies are hidden from it. + + +=============================== +OBJECT MANAGEMENT STATE MACHINE +=============================== + +Within FS-Cache, each active object is managed by its own individual state +machine. The state for an object is kept in the fscache_object struct, in +object->state. A cookie may point to a set of objects that are in different +states. + +Each state has an action associated with it that is invoked when the machine +wakes up in that state. There are four logical sets of states: + + (1) Preparation: states that wait for the parent objects to become ready. The + representations are hierarchical, and it is expected that an object must + be created or accessed with respect to its parent object. + + (2) Initialisation: states that perform lookups in the cache and validate + what's found and that create on disk any missing metadata. + + (3) Normal running: states that allow netfs operations on objects to proceed + and that update the state of objects. + + (4) Termination: states that detach objects from their netfs cookies, that + delete objects from disk, that handle disk and system errors and that free + up in-memory resources. + + +In most cases, transitioning between states is in response to signalled events. +When a state has finished processing, it will usually set the mask of events in +which it is interested (object->event_mask) and relinquish the worker thread. +Then when an event is raised (by calling fscache_raise_event()), if the event +is not masked, the object will be queued for processing (by calling +fscache_enqueue_object()). + + +PROVISION OF CPU TIME +--------------------- + +The work to be done by the various states is given CPU time by the threads of +the slow work facility (see Documentation/slow-work.txt). This is used in +preference to the workqueue facility because: + + (1) Threads may be completely occupied for very long periods of time by a + particular work item. These state actions may be doing sequences of + synchronous, journalled disk accesses (lookup, mkdir, create, setxattr, + getxattr, truncate, unlink, rmdir, rename). + + (2) Threads may do little actual work, but may rather spend a lot of time + sleeping on I/O. This means that single-threaded and 1-per-CPU-threaded + workqueues don't necessarily have the right numbers of threads. + + +LOCKING SIMPLIFICATION +---------------------- + +Because only one worker thread may be operating on any particular object's +state machine at once, this simplifies the locking, particularly with respect +to disconnecting the netfs's representation of a cache object (fscache_cookie) +from the cache backend's representation (fscache_object) - which may be +requested from either end. + + +================= +THE SET OF STATES +================= + +The object state machine has a set of states that it can be in. There are +preparation states in which the object sets itself up and waits for its parent +object to transit to a state that allows access to its children: + + (1) State FSCACHE_OBJECT_INIT. + + Initialise the object and wait for the parent object to become active. In + the cache, it is expected that it will not be possible to look an object + up from the parent object, until that parent object itself has been looked + up. + +There are initialisation states in which the object sets itself up and accesses +disk for the object metadata: + + (2) State FSCACHE_OBJECT_LOOKING_UP. + + Look up the object on disk, using the parent as a starting point. + FS-Cache expects the cache backend to probe the cache to see whether this + object is represented there, and if it is, to see if it's valid (coherency + management). + + The cache should call fscache_object_lookup_negative() to indicate lookup + failure for whatever reason, and should call fscache_obtained_object() to + indicate success. + + At the completion of lookup, FS-Cache will let the netfs go ahead with + read operations, no matter whether the file is yet cached. If not yet + cached, read operations will be immediately rejected with ENODATA until + the first known page is uncached - as to that point there can be no data + to be read out of the cache for that file that isn't currently also held + in the pagecache. + + (3) State FSCACHE_OBJECT_CREATING. + + Create an object on disk, using the parent as a starting point. This + happens if the lookup failed to find the object, or if the object's + coherency data indicated what's on disk is out of date. In this state, + FS-Cache expects the cache to create + + The cache should call fscache_obtained_object() if creation completes + successfully, fscache_object_lookup_negative() otherwise. + + At the completion of creation, FS-Cache will start processing write + operations the netfs has queued for an object. If creation failed, the + write ops will be transparently discarded, and nothing recorded in the + cache. + +There are some normal running states in which the object spends its time +servicing netfs requests: + + (4) State FSCACHE_OBJECT_AVAILABLE. + + A transient state in which pending operations are started, child objects + are permitted to advance from FSCACHE_OBJECT_INIT state, and temporary + lookup data is freed. + + (5) State FSCACHE_OBJECT_ACTIVE. + + The normal running state. In this state, requests the netfs makes will be + passed on to the cache. + + (6) State FSCACHE_OBJECT_UPDATING. + + The state machine comes here to update the object in the cache from the + netfs's records. This involves updating the auxiliary data that is used + to maintain coherency. + +And there are terminal states in which an object cleans itself up, deallocates +memory and potentially deletes stuff from disk: + + (7) State FSCACHE_OBJECT_LC_DYING. + + The object comes here if it is dying because of a lookup or creation + error. This would be due to a disk error or system error of some sort. + Temporary data is cleaned up, and the parent is released. + + (8) State FSCACHE_OBJECT_DYING. + + The object comes here if it is dying due to an error, because its parent + cookie has been relinquished by the netfs or because the cache is being + withdrawn. + + Any child objects waiting on this one are given CPU time so that they too + can destroy themselves. This object waits for all its children to go away + before advancing to the next state. + + (9) State FSCACHE_OBJECT_ABORT_INIT. + + The object comes to this state if it was waiting on its parent in + FSCACHE_OBJECT_INIT, but its parent died. The object will destroy itself + so that the parent may proceed from the FSCACHE_OBJECT_DYING state. + +(10) State FSCACHE_OBJECT_RELEASING. +(11) State FSCACHE_OBJECT_RECYCLING. + + The object comes to one of these two states when dying once it is rid of + all its children, if it is dying because the netfs relinquished its + cookie. In the first state, the cached data is expected to persist, and + in the second it will be deleted. + +(12) State FSCACHE_OBJECT_WITHDRAWING. + + The object transits to this state if the cache decides it wants to + withdraw the object from service, perhaps to make space, but also due to + error or just because the whole cache is being withdrawn. + +(13) State FSCACHE_OBJECT_DEAD. + + The object transits to this state when the in-memory object record is + ready to be deleted. The object processor shouldn't ever see an object in + this state. + + +THE SET OF EVENTS +----------------- + +There are a number of events that can be raised to an object state machine: + + (*) FSCACHE_OBJECT_EV_UPDATE + + The netfs requested that an object be updated. The state machine will ask + the cache backend to update the object, and the cache backend will ask the + netfs for details of the change through its cookie definition ops. + + (*) FSCACHE_OBJECT_EV_CLEARED + + This is signalled in two circumstances: + + (a) when an object's last child object is dropped and + + (b) when the last operation outstanding on an object is completed. + + This is used to proceed from the dying state. + + (*) FSCACHE_OBJECT_EV_ERROR + + This is signalled when an I/O error occurs during the processing of some + object. + + (*) FSCACHE_OBJECT_EV_RELEASE + (*) FSCACHE_OBJECT_EV_RETIRE + + These are signalled when the netfs relinquishes a cookie it was using. + The event selected depends on whether the netfs asks for the backing + object to be retired (deleted) or retained. + + (*) FSCACHE_OBJECT_EV_WITHDRAW + + This is signalled when the cache backend wants to withdraw an object. + This means that the object will have to be detached from the netfs's + cookie. + +Because the withdrawing releasing/retiring events are all handled by the object +state machine, it doesn't matter if there's a collision with both ends trying +to sever the connection at the same time. The state machine can just pick +which one it wants to honour, and that effects the other. diff --git a/Documentation/filesystems/caching/operations.txt b/Documentation/filesystems/caching/operations.txt new file mode 100644 index 000000000000..b6b070c57cbf --- /dev/null +++ b/Documentation/filesystems/caching/operations.txt @@ -0,0 +1,213 @@ + ================================ + ASYNCHRONOUS OPERATIONS HANDLING + ================================ + +By: David Howells <dhowells@redhat.com> + +Contents: + + (*) Overview. + + (*) Operation record initialisation. + + (*) Parameters. + + (*) Procedure. + + (*) Asynchronous callback. + + +======== +OVERVIEW +======== + +FS-Cache has an asynchronous operations handling facility that it uses for its +data storage and retrieval routines. Its operations are represented by +fscache_operation structs, though these are usually embedded into some other +structure. + +This facility is available to and expected to be be used by the cache backends, +and FS-Cache will create operations and pass them off to the appropriate cache +backend for completion. + +To make use of this facility, <linux/fscache-cache.h> should be #included. + + +=============================== +OPERATION RECORD INITIALISATION +=============================== + +An operation is recorded in an fscache_operation struct: + + struct fscache_operation { + union { + struct work_struct fast_work; + struct slow_work slow_work; + }; + unsigned long flags; + fscache_operation_processor_t processor; + ... + }; + +Someone wanting to issue an operation should allocate something with this +struct embedded in it. They should initialise it by calling: + + void fscache_operation_init(struct fscache_operation *op, + fscache_operation_release_t release); + +with the operation to be initialised and the release function to use. + +The op->flags parameter should be set to indicate the CPU time provision and +the exclusivity (see the Parameters section). + +The op->fast_work, op->slow_work and op->processor flags should be set as +appropriate for the CPU time provision (see the Parameters section). + +FSCACHE_OP_WAITING may be set in op->flags prior to each submission of the +operation and waited for afterwards. + + +========== +PARAMETERS +========== + +There are a number of parameters that can be set in the operation record's flag +parameter. There are three options for the provision of CPU time in these +operations: + + (1) The operation may be done synchronously (FSCACHE_OP_MYTHREAD). A thread + may decide it wants to handle an operation itself without deferring it to + another thread. + + This is, for example, used in read operations for calling readpages() on + the backing filesystem in CacheFiles. Although readpages() does an + asynchronous data fetch, the determination of whether pages exist is done + synchronously - and the netfs does not proceed until this has been + determined. + + If this option is to be used, FSCACHE_OP_WAITING must be set in op->flags + before submitting the operation, and the operating thread must wait for it + to be cleared before proceeding: + + wait_on_bit(&op->flags, FSCACHE_OP_WAITING, + fscache_wait_bit, TASK_UNINTERRUPTIBLE); + + + (2) The operation may be fast asynchronous (FSCACHE_OP_FAST), in which case it + will be given to keventd to process. Such an operation is not permitted + to sleep on I/O. + + This is, for example, used by CacheFiles to copy data from a backing fs + page to a netfs page after the backing fs has read the page in. + + If this option is used, op->fast_work and op->processor must be + initialised before submitting the operation: + + INIT_WORK(&op->fast_work, do_some_work); + + + (3) The operation may be slow asynchronous (FSCACHE_OP_SLOW), in which case it + will be given to the slow work facility to process. Such an operation is + permitted to sleep on I/O. + + This is, for example, used by FS-Cache to handle background writes of + pages that have just been fetched from a remote server. + + If this option is used, op->slow_work and op->processor must be + initialised before submitting the operation: + + fscache_operation_init_slow(op, processor) + + +Furthermore, operations may be one of two types: + + (1) Exclusive (FSCACHE_OP_EXCLUSIVE). Operations of this type may not run in + conjunction with any other operation on the object being operated upon. + + An example of this is the attribute change operation, in which the file + being written to may need truncation. + + (2) Shareable. Operations of this type may be running simultaneously. It's + up to the operation implementation to prevent interference between other + operations running at the same time. + + +========= +PROCEDURE +========= + +Operations are used through the following procedure: + + (1) The submitting thread must allocate the operation and initialise it + itself. Normally this would be part of a more specific structure with the + generic op embedded within. + + (2) The submitting thread must then submit the operation for processing using + one of the following two functions: + + int fscache_submit_op(struct fscache_object *object, + struct fscache_operation *op); + + int fscache_submit_exclusive_op(struct fscache_object *object, + struct fscache_operation *op); + + The first function should be used to submit non-exclusive ops and the + second to submit exclusive ones. The caller must still set the + FSCACHE_OP_EXCLUSIVE flag. + + If successful, both functions will assign the operation to the specified + object and return 0. -ENOBUFS will be returned if the object specified is + permanently unavailable. + + The operation manager will defer operations on an object that is still + undergoing lookup or creation. The operation will also be deferred if an + operation of conflicting exclusivity is in progress on the object. + + If the operation is asynchronous, the manager will retain a reference to + it, so the caller should put their reference to it by passing it to: + + void fscache_put_operation(struct fscache_operation *op); + + (3) If the submitting thread wants to do the work itself, and has marked the + operation with FSCACHE_OP_MYTHREAD, then it should monitor + FSCACHE_OP_WAITING as described above and check the state of the object if + necessary (the object might have died whilst the thread was waiting). + + When it has finished doing its processing, it should call + fscache_put_operation() on it. + + (4) The operation holds an effective lock upon the object, preventing other + exclusive ops conflicting until it is released. The operation can be + enqueued for further immediate asynchronous processing by adjusting the + CPU time provisioning option if necessary, eg: + + op->flags &= ~FSCACHE_OP_TYPE; + op->flags |= ~FSCACHE_OP_FAST; + + and calling: + + void fscache_enqueue_operation(struct fscache_operation *op) + + This can be used to allow other things to have use of the worker thread + pools. + + +===================== +ASYNCHRONOUS CALLBACK +===================== + +When used in asynchronous mode, the worker thread pool will invoke the +processor method with a pointer to the operation. This should then get at the +container struct by using container_of(): + + static void fscache_write_op(struct fscache_operation *_op) + { + struct fscache_storage *op = + container_of(_op, struct fscache_storage, op); + ... + } + +The caller holds a reference on the operation, and will invoke +fscache_put_operation() when the processor function returns. The processor +function is at liberty to call fscache_enqueue_operation() or to take extra +references. diff --git a/Documentation/filesystems/exofs.txt b/Documentation/filesystems/exofs.txt new file mode 100644 index 000000000000..0ced74c2f73c --- /dev/null +++ b/Documentation/filesystems/exofs.txt @@ -0,0 +1,176 @@ +=============================================================================== +WHAT IS EXOFS? +=============================================================================== + +exofs is a file system that uses an OSD and exports the API of a normal Linux +file system. Users access exofs like any other local file system, and exofs +will in turn issue commands to the local OSD initiator. + +OSD is a new T10 command set that views storage devices not as a large/flat +array of sectors but as a container of objects, each having a length, quota, +time attributes and more. Each object is addressed by a 64bit ID, and is +contained in a 64bit ID partition. Each object has associated attributes +attached to it, which are integral part of the object and provide metadata about +the object. The standard defines some common obligatory attributes, but user +attributes can be added as needed. + +=============================================================================== +ENVIRONMENT +=============================================================================== + +To use this file system, you need to have an object store to run it on. You +may download a target from: +http://open-osd.org + +See Documentation/scsi/osd.txt for how to setup a working osd environment. + +=============================================================================== +USAGE +=============================================================================== + +1. Download and compile exofs and open-osd initiator: + You need an external Kernel source tree or kernel headers from your + distribution. (anything based on 2.6.26 or later). + + a. download open-osd including exofs source using: + [parent-directory]$ git clone git://git.open-osd.org/open-osd.git + + b. Build the library module like this: + [parent-directory]$ make -C KSRC=$(KER_DIR) open-osd + + This will build both the open-osd initiator as well as the exofs kernel + module. Use whatever parameters you compiled your Kernel with and + $(KER_DIR) above pointing to the Kernel you compile against. See the file + open-osd/top-level-Makefile for an example. + +2. Get the OSD initiator and target set up properly, and login to the target. + See Documentation/scsi/osd.txt for farther instructions. Also see ./do-osd + for example script that does all these steps. + +3. Insmod the exofs.ko module: + [exofs]$ insmod exofs.ko + +4. Make sure the directory where you want to mount exists. If not, create it. + (For example, mkdir /mnt/exofs) + +5. At first run you will need to invoke the mkfs.exofs application + + As an example, this will create the file system on: + /dev/osd0 partition ID 65536 + + mkfs.exofs --pid=65536 --format /dev/osd0 + + The --format is optional if not specified no OSD_FORMAT will be + preformed and a clean file system will be created in the specified pid, + in the available space of the target. (Use --format=size_in_meg to limit + the total LUN space available) + + If pid already exist it will be deleted and a new one will be created in it's + place. Be careful. + + An exofs lives inside a single OSD partition. You can create multiple exofs + filesystems on the same device using multiple pids. + + (run mkfs.exofs without any parameters for usage help message) + +6. Mount the file system. + + For example, to mount /dev/osd0, partition ID 0x10000 on /mnt/exofs: + + mount -t exofs -o pid=65536 /dev/osd0 /mnt/exofs/ + +7. For reference (See do-exofs example script): + do-exofs start - an example of how to perform the above steps. + do-exofs stop - an example of how to unmount the file system. + do-exofs format - an example of how to format and mkfs a new exofs. + +8. Extra compilation flags (uncomment in fs/exofs/Kbuild): + CONFIG_EXOFS_DEBUG - for debug messages and extra checks. + +=============================================================================== +exofs mount options +=============================================================================== +Similar to any mount command: + mount -t exofs -o exofs_options /dev/osdX mount_exofs_directory + +Where: + -t exofs: specifies the exofs file system + + /dev/osdX: X is a decimal number. /dev/osdX was created after a successful + login into an OSD target. + + mount_exofs_directory: The directory to mount the file system on + + exofs specific options: Options are separated by commas (,) + pid=<integer> - The partition number to mount/create as + container of the filesystem. + This option is mandatory + to=<integer> - Timeout in ticks for a single command + default is (60 * HZ) [for debugging only] + +=============================================================================== +DESIGN +=============================================================================== + +* The file system control block (AKA on-disk superblock) resides in an object + with a special ID (defined in common.h). + Information included in the file system control block is used to fill the + in-memory superblock structure at mount time. This object is created before + the file system is used by mkexofs.c It contains information such as: + - The file system's magic number + - The next inode number to be allocated + +* Each file resides in its own object and contains the data (and it will be + possible to extend the file over multiple objects, though this has not been + implemented yet). + +* A directory is treated as a file, and essentially contains a list of <file + name, inode #> pairs for files that are found in that directory. The object + IDs correspond to the files' inode numbers and will be allocated according to + a bitmap (stored in a separate object). Now they are allocated using a + counter. + +* Each file's control block (AKA on-disk inode) is stored in its object's + attributes. This applies to both regular files and other types (directories, + device files, symlinks, etc.). + +* Credentials are generated per object (inode and superblock) when they is + created in memory (read off disk or created). The credential works for all + operations and is used as long as the object remains in memory. + +* Async OSD operations are used whenever possible, but the target may execute + them out of order. The operations that concern us are create, delete, + readpage, writepage, update_inode, and truncate. The following pairs of + operations should execute in the order written, and we need to prevent them + from executing in reverse order: + - The following are handled with the OBJ_CREATED and OBJ_2BCREATED + flags. OBJ_CREATED is set when we know the object exists on the OSD - + in create's callback function, and when we successfully do a read_inode. + OBJ_2BCREATED is set in the beginning of the create function, so we + know that we should wait. + - create/delete: delete should wait until the object is created + on the OSD. + - create/readpage: readpage should be able to return a page + full of zeroes in this case. If there was a write already + en-route (i.e. create, writepage, readpage) then the page + would be locked, and so it would really be the same as + create/writepage. + - create/writepage: if writepage is called for a sync write, it + should wait until the object is created on the OSD. + Otherwise, it should just return. + - create/truncate: truncate should wait until the object is + created on the OSD. + - create/update_inode: update_inode should wait until the + object is created on the OSD. + - Handled by VFS locks: + - readpage/delete: shouldn't happen because of page lock. + - writepage/delete: shouldn't happen because of page lock. + - readpage/writepage: shouldn't happen because of page lock. + +=============================================================================== +LICENSE/COPYRIGHT +=============================================================================== +The exofs file system is based on ext2 v0.5b (distributed with the Linux kernel +version 2.6.10). All files include the original copyrights, and the license +is GPL version 2 (only version 2, as is true for the Linux kernel). The +Linux kernel can be downloaded from www.kernel.org. diff --git a/Documentation/filesystems/ext2.txt b/Documentation/filesystems/ext2.txt index 4333e836c495..e055acb6b2d4 100644 --- a/Documentation/filesystems/ext2.txt +++ b/Documentation/filesystems/ext2.txt @@ -373,10 +373,11 @@ Filesystem Resizing http://ext2resize.sourceforge.net/ Compression (*) http://e2compr.sourceforge.net/ Implementations for: -Windows 95/98/NT/2000 http://uranus.it.swin.edu.au/~jn/linux/Explore2fs.htm -Windows 95 (*) http://www.yipton.demon.co.uk/content.html#FSDEXT2 +Windows 95/98/NT/2000 http://www.chrysocome.net/explore2fs +Windows 95 (*) http://www.yipton.net/content.html#FSDEXT2 DOS client (*) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/ -OS/2 http://perso.wanadoo.fr/matthieu.willm/ext2-os2/ -RISC OS client ftp://ftp.barnet.ac.uk/pub/acorn/armlinux/iscafs/ +OS/2 (+) ftp://metalab.unc.edu/pub/Linux/system/filesystems/ext2/ +RISC OS client http://www.esw-heim.tu-clausthal.de/~marco/smorbrod/IscaFS/ (*) no longer actively developed/supported (as of Apr 2001) +(+) no longer actively developed/supported (as of Mar 2009) diff --git a/Documentation/filesystems/ext3.txt b/Documentation/filesystems/ext3.txt index 9dd2a3bb2acc..570f9bd9be2b 100644 --- a/Documentation/filesystems/ext3.txt +++ b/Documentation/filesystems/ext3.txt @@ -14,6 +14,11 @@ Options When mounting an ext3 filesystem, the following option are accepted: (*) == default +ro Mount filesystem read only. Note that ext3 will replay + the journal (and thus write to the partition) even when + mounted "read only". Mount options "ro,noload" can be + used to prevent writes to the filesystem. + journal=update Update the ext3 file system's journal to the current format. @@ -27,7 +32,9 @@ journal_dev=devnum When the external journal device's major/minor numbers identified through its new major/minor numbers encoded in devnum. -noload Don't load the journal on mounting. +noload Don't load the journal on mounting. Note that this forces + mount of inconsistent filesystem, which can lead to + various problems. data=journal All data are committed into the journal prior to being written into the main file system. @@ -92,9 +99,12 @@ nocheck debug Extra debugging information is sent to syslog. -errors=remount-ro(*) Remount the filesystem read-only on an error. +errors=remount-ro Remount the filesystem read-only on an error. errors=continue Keep going on a filesystem error. errors=panic Panic and halt the machine if an error occurs. + (These mount options override the errors behavior + specified in the superblock, which can be + configured using tune2fs.) data_err=ignore(*) Just print an error message if an error occurs in a file data buffer in ordered mode. @@ -198,5 +208,5 @@ kernel source: <file:fs/ext3/> programs: http://e2fsprogs.sourceforge.net/ http://ext2resize.sourceforge.net -useful links: http://www-106.ibm.com/developerworks/linux/library/l-fs7/ - http://www-106.ibm.com/developerworks/linux/library/l-fs8/ +useful links: http://www.ibm.com/developerworks/library/l-fs7.html + http://www.ibm.com/developerworks/library/l-fs8.html diff --git a/Documentation/filesystems/ext4.txt b/Documentation/filesystems/ext4.txt index cec829bc7291..97882df04865 100644 --- a/Documentation/filesystems/ext4.txt +++ b/Documentation/filesystems/ext4.txt @@ -85,7 +85,7 @@ Note: More extensive information for getting started with ext4 can be * extent format more robust in face of on-disk corruption due to magics, * internal redundancy in tree * improved file allocation (multi-block alloc) -* fix 32000 subdirectory limit +* lift 32000 subdirectory limit imposed by i_links_count[1] * nsec timestamps for mtime, atime, ctime, create time * inode version field on disk (NFSv4, Lustre) * reduced e2fsck time via uninit_bg feature @@ -100,6 +100,9 @@ Note: More extensive information for getting started with ext4 can be * efficent new ordered mode in JBD2 and ext4(avoid using buffer head to force the ordering) +[1] Filesystems with a block size of 1k may see a limit imposed by the +directory hash tree having a maximum depth of two. + 2.2 Candidate features for future inclusion * Online defrag (patches available but not well tested) @@ -180,8 +183,8 @@ commit=nrsec (*) Ext4 can be told to sync all its data and metadata performance. barrier=<0|1(*)> This enables/disables the use of write barriers in - the jbd code. barrier=0 disables, barrier=1 enables. - This also requires an IO stack which can support +barrier(*) the jbd code. barrier=0 disables, barrier=1 enables. +nobarrier This also requires an IO stack which can support barriers, and if jbd gets an error on a barrier write, it will disable again with a warning. Write barriers enforce proper on-disk ordering @@ -189,6 +192,9 @@ barrier=<0|1(*)> This enables/disables the use of write barriers in safe to use, at some performance penalty. If your disks are battery-backed in one way or another, disabling barriers may safely improve performance. + The mount options "barrier" and "nobarrier" can + also be used to enable or disable barriers, for + consistency with other ext4 mount options. inode_readahead=n This tuning parameter controls the maximum number of inode table blocks that ext4's inode @@ -310,6 +316,24 @@ journal_ioprio=prio The I/O priority (from 0 to 7, where 0 is the a slightly higher priority than the default I/O priority. +auto_da_alloc(*) Many broken applications don't use fsync() when +noauto_da_alloc replacing existing files via patterns such as + fd = open("foo.new")/write(fd,..)/close(fd)/ + rename("foo.new", "foo"), or worse yet, + fd = open("foo", O_TRUNC)/write(fd,..)/close(fd). + If auto_da_alloc is enabled, ext4 will detect + the replace-via-rename and replace-via-truncate + patterns and force that any delayed allocation + blocks are allocated such that at the next + journal commit, in the default data=ordered + mode, the data blocks of the new file are forced + to disk before the rename() operation is + commited. This provides roughly the same level + of guarantees as ext3, and avoids the + "zero-length" problem that can happen when a + system crashes before the delayed allocation + blocks are forced to disk. + Data Mode ========= There are 3 different data modes: diff --git a/Documentation/filesystems/knfsd-stats.txt b/Documentation/filesystems/knfsd-stats.txt new file mode 100644 index 000000000000..64ced5149d37 --- /dev/null +++ b/Documentation/filesystems/knfsd-stats.txt @@ -0,0 +1,159 @@ + +Kernel NFS Server Statistics +============================ + +This document describes the format and semantics of the statistics +which the kernel NFS server makes available to userspace. These +statistics are available in several text form pseudo files, each of +which is described separately below. + +In most cases you don't need to know these formats, as the nfsstat(8) +program from the nfs-utils distribution provides a helpful command-line +interface for extracting and printing them. + +All the files described here are formatted as a sequence of text lines, +separated by newline '\n' characters. Lines beginning with a hash +'#' character are comments intended for humans and should be ignored +by parsing routines. All other lines contain a sequence of fields +separated by whitespace. + +/proc/fs/nfsd/pool_stats +------------------------ + +This file is available in kernels from 2.6.30 onwards, if the +/proc/fs/nfsd filesystem is mounted (it almost always should be). + +The first line is a comment which describes the fields present in +all the other lines. The other lines present the following data as +a sequence of unsigned decimal numeric fields. One line is shown +for each NFS thread pool. + +All counters are 64 bits wide and wrap naturally. There is no way +to zero these counters, instead applications should do their own +rate conversion. + +pool + The id number of the NFS thread pool to which this line applies. + This number does not change. + + Thread pool ids are a contiguous set of small integers starting + at zero. The maximum value depends on the thread pool mode, but + currently cannot be larger than the number of CPUs in the system. + Note that in the default case there will be a single thread pool + which contains all the nfsd threads and all the CPUs in the system, + and thus this file will have a single line with a pool id of "0". + +packets-arrived + Counts how many NFS packets have arrived. More precisely, this + is the number of times that the network stack has notified the + sunrpc server layer that new data may be available on a transport + (e.g. an NFS or UDP socket or an NFS/RDMA endpoint). + + Depending on the NFS workload patterns and various network stack + effects (such as Large Receive Offload) which can combine packets + on the wire, this may be either more or less than the number + of NFS calls received (which statistic is available elsewhere). + However this is a more accurate and less workload-dependent measure + of how much CPU load is being placed on the sunrpc server layer + due to NFS network traffic. + +sockets-enqueued + Counts how many times an NFS transport is enqueued to wait for + an nfsd thread to service it, i.e. no nfsd thread was considered + available. + + The circumstance this statistic tracks indicates that there was NFS + network-facing work to be done but it couldn't be done immediately, + thus introducing a small delay in servicing NFS calls. The ideal + rate of change for this counter is zero; significantly non-zero + values may indicate a performance limitation. + + This can happen either because there are too few nfsd threads in the + thread pool for the NFS workload (the workload is thread-limited), + or because the NFS workload needs more CPU time than is available in + the thread pool (the workload is CPU-limited). In the former case, + configuring more nfsd threads will probably improve the performance + of the NFS workload. In the latter case, the sunrpc server layer is + already choosing not to wake idle nfsd threads because there are too + many nfsd threads which want to run but cannot, so configuring more + nfsd threads will make no difference whatsoever. The overloads-avoided + statistic (see below) can be used to distinguish these cases. + +threads-woken + Counts how many times an idle nfsd thread is woken to try to + receive some data from an NFS transport. + + This statistic tracks the circumstance where incoming + network-facing NFS work is being handled quickly, which is a good + thing. The ideal rate of change for this counter will be close + to but less than the rate of change of the packets-arrived counter. + +overloads-avoided + Counts how many times the sunrpc server layer chose not to wake an + nfsd thread, despite the presence of idle nfsd threads, because + too many nfsd threads had been recently woken but could not get + enough CPU time to actually run. + + This statistic counts a circumstance where the sunrpc layer + heuristically avoids overloading the CPU scheduler with too many + runnable nfsd threads. The ideal rate of change for this counter + is zero. Significant non-zero values indicate that the workload + is CPU limited. Usually this is associated with heavy CPU usage + on all the CPUs in the nfsd thread pool. + + If a sustained large overloads-avoided rate is detected on a pool, + the top(1) utility should be used to check for the following + pattern of CPU usage on all the CPUs associated with the given + nfsd thread pool. + + - %us ~= 0 (as you're *NOT* running applications on your NFS server) + + - %wa ~= 0 + + - %id ~= 0 + + - %sy + %hi + %si ~= 100 + + If this pattern is seen, configuring more nfsd threads will *not* + improve the performance of the workload. If this patten is not + seen, then something more subtle is wrong. + +threads-timedout + Counts how many times an nfsd thread triggered an idle timeout, + i.e. was not woken to handle any incoming network packets for + some time. + + This statistic counts a circumstance where there are more nfsd + threads configured than can be used by the NFS workload. This is + a clue that the number of nfsd threads can be reduced without + affecting performance. Unfortunately, it's only a clue and not + a strong indication, for a couple of reasons: + + - Currently the rate at which the counter is incremented is quite + slow; the idle timeout is 60 minutes. Unless the NFS workload + remains constant for hours at a time, this counter is unlikely + to be providing information that is still useful. + + - It is usually a wise policy to provide some slack, + i.e. configure a few more nfsds than are currently needed, + to allow for future spikes in load. + + +Note that incoming packets on NFS transports will be dealt with in +one of three ways. An nfsd thread can be woken (threads-woken counts +this case), or the transport can be enqueued for later attention +(sockets-enqueued counts this case), or the packet can be temporarily +deferred because the transport is currently being used by an nfsd +thread. This last case is not very interesting and is not explicitly +counted, but can be inferred from the other counters thus: + +packets-deferred = packets-arrived - ( sockets-enqueued + threads-woken ) + + +More +---- +Descriptions of the other statistics file should go here. + + +Greg Banks <gnb@sgi.com> +26 Mar 2009 diff --git a/Documentation/filesystems/nfs41-server.txt b/Documentation/filesystems/nfs41-server.txt new file mode 100644 index 000000000000..05d81cbcb2e1 --- /dev/null +++ b/Documentation/filesystems/nfs41-server.txt @@ -0,0 +1,161 @@ +NFSv4.1 Server Implementation + +Server support for minorversion 1 can be controlled using the +/proc/fs/nfsd/versions control file. The string output returned +by reading this file will contain either "+4.1" or "-4.1" +correspondingly. + +Currently, server support for minorversion 1 is disabled by default. +It can be enabled at run time by writing the string "+4.1" to +the /proc/fs/nfsd/versions control file. Note that to write this +control file, the nfsd service must be taken down. Use your user-mode +nfs-utils to set this up; see rpc.nfsd(8) + +The NFSv4 minorversion 1 (NFSv4.1) implementation in nfsd is based +on the latest NFSv4.1 Internet Draft: +http://tools.ietf.org/html/draft-ietf-nfsv4-minorversion1-29 + +From the many new features in NFSv4.1 the current implementation +focuses on the mandatory-to-implement NFSv4.1 Sessions, providing +"exactly once" semantics and better control and throttling of the +resources allocated for each client. + +Other NFSv4.1 features, Parallel NFS operations in particular, +are still under development out of tree. +See http://wiki.linux-nfs.org/wiki/index.php/PNFS_prototype_design +for more information. + +The table below, taken from the NFSv4.1 document, lists +the operations that are mandatory to implement (REQ), optional +(OPT), and NFSv4.0 operations that are required not to implement (MNI) +in minor version 1. The first column indicates the operations that +are not supported yet by the linux server implementation. + +The OPTIONAL features identified and their abbreviations are as follows: + pNFS Parallel NFS + FDELG File Delegations + DDELG Directory Delegations + +The following abbreviations indicate the linux server implementation status. + I Implemented NFSv4.1 operations. + NS Not Supported. + NS* unimplemented optional feature. + P pNFS features implemented out of tree. + PNS pNFS features that are not supported yet (out of tree). + +Operations + + +----------------------+------------+--------------+----------------+ + | Operation | REQ, REC, | Feature | Definition | + | | OPT, or | (REQ, REC, | | + | | MNI | or OPT) | | + +----------------------+------------+--------------+----------------+ + | ACCESS | REQ | | Section 18.1 | +NS | BACKCHANNEL_CTL | REQ | | Section 18.33 | +NS | BIND_CONN_TO_SESSION | REQ | | Section 18.34 | + | CLOSE | REQ | | Section 18.2 | + | COMMIT | REQ | | Section 18.3 | + | CREATE | REQ | | Section 18.4 | +I | CREATE_SESSION | REQ | | Section 18.36 | +NS*| DELEGPURGE | OPT | FDELG (REQ) | Section 18.5 | + | DELEGRETURN | OPT | FDELG, | Section 18.6 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS | DESTROY_CLIENTID | REQ | | Section 18.50 | +I | DESTROY_SESSION | REQ | | Section 18.37 | +I | EXCHANGE_ID | REQ | | Section 18.35 | +NS | FREE_STATEID | REQ | | Section 18.38 | + | GETATTR | REQ | | Section 18.7 | +P | GETDEVICEINFO | OPT | pNFS (REQ) | Section 18.40 | +P | GETDEVICELIST | OPT | pNFS (OPT) | Section 18.41 | + | GETFH | REQ | | Section 18.8 | +NS*| GET_DIR_DELEGATION | OPT | DDELG (REQ) | Section 18.39 | +P | LAYOUTCOMMIT | OPT | pNFS (REQ) | Section 18.42 | +P | LAYOUTGET | OPT | pNFS (REQ) | Section 18.43 | +P | LAYOUTRETURN | OPT | pNFS (REQ) | Section 18.44 | + | LINK | OPT | | Section 18.9 | + | LOCK | REQ | | Section 18.10 | + | LOCKT | REQ | | Section 18.11 | + | LOCKU | REQ | | Section 18.12 | + | LOOKUP | REQ | | Section 18.13 | + | LOOKUPP | REQ | | Section 18.14 | + | NVERIFY | REQ | | Section 18.15 | + | OPEN | REQ | | Section 18.16 | +NS*| OPENATTR | OPT | | Section 18.17 | + | OPEN_CONFIRM | MNI | | N/A | + | OPEN_DOWNGRADE | REQ | | Section 18.18 | + | PUTFH | REQ | | Section 18.19 | + | PUTPUBFH | REQ | | Section 18.20 | + | PUTROOTFH | REQ | | Section 18.21 | + | READ | REQ | | Section 18.22 | + | READDIR | REQ | | Section 18.23 | + | READLINK | OPT | | Section 18.24 | +NS | RECLAIM_COMPLETE | REQ | | Section 18.51 | + | RELEASE_LOCKOWNER | MNI | | N/A | + | REMOVE | REQ | | Section 18.25 | + | RENAME | REQ | | Section 18.26 | + | RENEW | MNI | | N/A | + | RESTOREFH | REQ | | Section 18.27 | + | SAVEFH | REQ | | Section 18.28 | + | SECINFO | REQ | | Section 18.29 | +NS | SECINFO_NO_NAME | REC | pNFS files | Section 18.45, | + | | | layout (REQ) | Section 13.12 | +I | SEQUENCE | REQ | | Section 18.46 | + | SETATTR | REQ | | Section 18.30 | + | SETCLIENTID | MNI | | N/A | + | SETCLIENTID_CONFIRM | MNI | | N/A | +NS | SET_SSV | REQ | | Section 18.47 | +NS | TEST_STATEID | REQ | | Section 18.48 | + | VERIFY | REQ | | Section 18.31 | +NS*| WANT_DELEGATION | OPT | FDELG (OPT) | Section 18.49 | + | WRITE | REQ | | Section 18.32 | + +Callback Operations + + +-------------------------+-----------+-------------+---------------+ + | Operation | REQ, REC, | Feature | Definition | + | | OPT, or | (REQ, REC, | | + | | MNI | or OPT) | | + +-------------------------+-----------+-------------+---------------+ + | CB_GETATTR | OPT | FDELG (REQ) | Section 20.1 | +P | CB_LAYOUTRECALL | OPT | pNFS (REQ) | Section 20.3 | +NS*| CB_NOTIFY | OPT | DDELG (REQ) | Section 20.4 | +P | CB_NOTIFY_DEVICEID | OPT | pNFS (OPT) | Section 20.12 | +NS*| CB_NOTIFY_LOCK | OPT | | Section 20.11 | +NS*| CB_PUSH_DELEG | OPT | FDELG (OPT) | Section 20.5 | + | CB_RECALL | OPT | FDELG, | Section 20.2 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS*| CB_RECALL_ANY | OPT | FDELG, | Section 20.6 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS | CB_RECALL_SLOT | REQ | | Section 20.8 | +NS*| CB_RECALLABLE_OBJ_AVAIL | OPT | DDELG, pNFS | Section 20.7 | + | | | (REQ) | | +I | CB_SEQUENCE | OPT | FDELG, | Section 20.9 | + | | | DDELG, pNFS | | + | | | (REQ) | | +NS*| CB_WANTS_CANCELLED | OPT | FDELG, | Section 20.10 | + | | | DDELG, pNFS | | + | | | (REQ) | | + +-------------------------+-----------+-------------+---------------+ + +Implementation notes: + +EXCHANGE_ID: +* only SP4_NONE state protection supported +* implementation ids are ignored + +CREATE_SESSION: +* backchannel attributes are ignored +* backchannel security parameters are ignored + +SEQUENCE: +* no support for dynamic slot table renegotiation (optional) + +nfsv4.1 COMPOUND rules: +The following cases aren't supported yet: +* Enforcing of NFS4ERR_NOT_ONLY_OP for: BIND_CONN_TO_SESSION, CREATE_SESSION, + DESTROY_CLIENTID, DESTROY_SESSION, EXCHANGE_ID. +* DESTROY_SESSION MUST be the final operation in the COMPOUND request. + diff --git a/Documentation/filesystems/nilfs2.txt b/Documentation/filesystems/nilfs2.txt new file mode 100644 index 000000000000..55c4300abfcb --- /dev/null +++ b/Documentation/filesystems/nilfs2.txt @@ -0,0 +1,200 @@ +NILFS2 +------ + +NILFS2 is a log-structured file system (LFS) supporting continuous +snapshotting. In addition to versioning capability of the entire file +system, users can even restore files mistakenly overwritten or +destroyed just a few seconds ago. Since NILFS2 can keep consistency +like conventional LFS, it achieves quick recovery after system +crashes. + +NILFS2 creates a number of checkpoints every few seconds or per +synchronous write basis (unless there is no change). Users can select +significant versions among continuously created checkpoints, and can +change them into snapshots which will be preserved until they are +changed back to checkpoints. + +There is no limit on the number of snapshots until the volume gets +full. Each snapshot is mountable as a read-only file system +concurrently with its writable mount, and this feature is convenient +for online backup. + +The userland tools are included in nilfs-utils package, which is +available from the following download page. At least "mkfs.nilfs2", +"mount.nilfs2", "umount.nilfs2", and "nilfs_cleanerd" (so called +cleaner or garbage collector) are required. Details on the tools are +described in the man pages included in the package. + +Project web page: http://www.nilfs.org/en/ +Download page: http://www.nilfs.org/en/download.html +Git tree web page: http://www.nilfs.org/git/ +NILFS mailing lists: http://www.nilfs.org/mailman/listinfo/users + +Caveats +======= + +Features which NILFS2 does not support yet: + + - atime + - extended attributes + - POSIX ACLs + - quotas + - writable snapshots + - remote backup (CDP) + - data integrity + - defragmentation + +Mount options +============= + +NILFS2 supports the following mount options: +(*) == default + +barrier=on(*) This enables/disables barriers. barrier=off disables + it, barrier=on enables it. +errors=continue(*) Keep going on a filesystem error. +errors=remount-ro Remount the filesystem read-only on an error. +errors=panic Panic and halt the machine if an error occurs. +cp=n Specify the checkpoint-number of the snapshot to be + mounted. Checkpoints and snapshots are listed by lscp + user command. Only the checkpoints marked as snapshot + are mountable with this option. Snapshot is read-only, + so a read-only mount option must be specified together. +order=relaxed(*) Apply relaxed order semantics that allows modified data + blocks to be written to disk without making a + checkpoint if no metadata update is going. This mode + is equivalent to the ordered data mode of the ext3 + filesystem except for the updates on data blocks still + conserve atomicity. This will improve synchronous + write performance for overwriting. +order=strict Apply strict in-order semantics that preserves sequence + of all file operations including overwriting of data + blocks. That means, it is guaranteed that no + overtaking of events occurs in the recovered file + system after a crash. + +NILFS2 usage +============ + +To use nilfs2 as a local file system, simply: + + # mkfs -t nilfs2 /dev/block_device + # mount -t nilfs2 /dev/block_device /dir + +This will also invoke the cleaner through the mount helper program +(mount.nilfs2). + +Checkpoints and snapshots are managed by the following commands. +Their manpages are included in the nilfs-utils package above. + + lscp list checkpoints or snapshots. + mkcp make a checkpoint or a snapshot. + chcp change an existing checkpoint to a snapshot or vice versa. + rmcp invalidate specified checkpoint(s). + +To mount a snapshot, + + # mount -t nilfs2 -r -o cp=<cno> /dev/block_device /snap_dir + +where <cno> is the checkpoint number of the snapshot. + +To unmount the NILFS2 mount point or snapshot, simply: + + # umount /dir + +Then, the cleaner daemon is automatically shut down by the umount +helper program (umount.nilfs2). + +Disk format +=========== + +A nilfs2 volume is equally divided into a number of segments except +for the super block (SB) and segment #0. A segment is the container +of logs. Each log is composed of summary information blocks, payload +blocks, and an optional super root block (SR): + + ______________________________________________________ + | |SB| | Segment | Segment | Segment | ... | Segment | | + |_|__|_|____0____|____1____|____2____|_____|____N____|_| + 0 +1K +4K +8M +16M +24M +(8MB x N) + . . (Typical offsets for 4KB-block) + . . + .______________________. + | log | log |... | log | + |__1__|__2__|____|__m__| + . . + . . + . . + .______________________________. + | Summary | Payload blocks |SR| + |_blocks__|_________________|__| + +The payload blocks are organized per file, and each file consists of +data blocks and B-tree node blocks: + + |<--- File-A --->|<--- File-B --->| + _______________________________________________________________ + | Data blocks | B-tree blocks | Data blocks | B-tree blocks | ... + _|_____________|_______________|_____________|_______________|_ + + +Since only the modified blocks are written in the log, it may have +files without data blocks or B-tree node blocks. + +The organization of the blocks is recorded in the summary information +blocks, which contains a header structure (nilfs_segment_summary), per +file structures (nilfs_finfo), and per block structures (nilfs_binfo): + + _________________________________________________________________________ + | Summary | finfo | binfo | ... | binfo | finfo | binfo | ... | binfo |... + |_blocks__|___A___|_(A,1)_|_____|(A,Na)_|___B___|_(B,1)_|_____|(B,Nb)_|___ + + +The logs include regular files, directory files, symbolic link files +and several meta data files. The mata data files are the files used +to maintain file system meta data. The current version of NILFS2 uses +the following meta data files: + + 1) Inode file (ifile) -- Stores on-disk inodes + 2) Checkpoint file (cpfile) -- Stores checkpoints + 3) Segment usage file (sufile) -- Stores allocation state of segments + 4) Data address translation file -- Maps virtual block numbers to usual + (DAT) block numbers. This file serves to + make on-disk blocks relocatable. + +The following figure shows a typical organization of the logs: + + _________________________________________________________________________ + | Summary | regular file | file | ... | ifile | cpfile | sufile | DAT |SR| + |_blocks__|_or_directory_|_______|_____|_______|________|________|_____|__| + + +To stride over segment boundaries, this sequence of files may be split +into multiple logs. The sequence of logs that should be treated as +logically one log, is delimited with flags marked in the segment +summary. The recovery code of nilfs2 looks this boundary information +to ensure atomicity of updates. + +The super root block is inserted for every checkpoints. It includes +three special inodes, inodes for the DAT, cpfile, and sufile. Inodes +of regular files, directories, symlinks and other special files, are +included in the ifile. The inode of ifile itself is included in the +corresponding checkpoint entry in the cpfile. Thus, the hierarchy +among NILFS2 files can be depicted as follows: + + Super block (SB) + | + v + Super root block (the latest cno=xx) + |-- DAT + |-- sufile + `-- cpfile + |-- ifile (cno=c1) + |-- ifile (cno=c2) ---- file (ino=i1) + : : |-- file (ino=i2) + `-- ifile (cno=xx) |-- file (ino=i3) + : : + `-- file (ino=yy) + ( regular file, directory, or symlink ) + +For detail on the format of each file, please see include/linux/nilfs2_fs.h. diff --git a/Documentation/filesystems/pohmelfs/design_notes.txt b/Documentation/filesystems/pohmelfs/design_notes.txt new file mode 100644 index 000000000000..dcf833587162 --- /dev/null +++ b/Documentation/filesystems/pohmelfs/design_notes.txt @@ -0,0 +1,71 @@ +POHMELFS: Parallel Optimized Host Message Exchange Layered File System. + + Evgeniy Polyakov <zbr@ioremap.net> + +Homepage: http://www.ioremap.net/projects/pohmelfs + +POHMELFS first began as a network filesystem with coherent local data and +metadata caches but is now evolving into a parallel distributed filesystem. + +Main features of this FS include: + * Locally coherent cache for data and metadata with (potentially) byte-range locks. + Since all Linux filesystems lock the whole inode during writing, algorithm + is very simple and does not use byte-ranges, although they are sent in + locking messages. + * Completely async processing of all events except creation of hard and symbolic + links, and rename events. + Object creation and data reading and writing are processed asynchronously. + * Flexible object architecture optimized for network processing. + Ability to create long paths to objects and remove arbitrarily huge + directories with a single network command. + (like removing the whole kernel tree via a single network command). + * Very high performance. + * Fast and scalable multithreaded userspace server. Being in userspace it works + with any underlying filesystem and still is much faster than async in-kernel NFS one. + * Client is able to switch between different servers (if one goes down, client + automatically reconnects to second and so on). + * Transactions support. Full failover for all operations. + Resending transactions to different servers on timeout or error. + * Read request (data read, directory listing, lookup requests) balancing between multiple servers. + * Write requests are replicated to multiple servers and completed only when all of them are acked. + * Ability to add and/or remove servers from the working set at run-time. + * Strong authentification and possible data encryption in network channel. + * Extended attributes support. + +POHMELFS is based on transactions, which are potentially long-standing objects that live +in the client's memory. Each transaction contains all the information needed to process a given +command (or set of commands, which is frequently used during data writing: single transactions +can contain creation and data writing commands). Transactions are committed by all the servers +to which they are sent and, in case of failures, are eventually resent or dropped with an error. +For example, reading will return an error if no servers are available. + +POHMELFS uses a asynchronous approach to data processing. Courtesy of transactions, it is +possible to detach replies from requests and, if the command requires data to be received, the +caller sleeps waiting for it. Thus, it is possible to issue multiple read commands to different +servers and async threads will pick up replies in parallel, find appropriate transactions in the +system and put the data where it belongs (like the page or inode cache). + +The main feature of POHMELFS is writeback data and the metadata cache. +Only a few non-performance critical operations use the write-through cache and +are synchronous: hard and symbolic link creation, and object rename. Creation, +removal of objects and data writing are asynchronous and are sent to +the server during system writeback. Only one writer at a time is allowed for any +given inode, which is guarded by an appropriate locking protocol. +Because of this feature, POHMELFS is extremely fast at metadata intensive +workloads and can fully utilize the bandwidth to the servers when doing bulk +data transfers. + +POHMELFS clients operate with a working set of servers and are capable of balancing read-only +operations (like lookups or directory listings) between them according to IO priorities. +Administrators can add or remove servers from the set at run-time via special commands (described +in Documentation/pohmelfs/info.txt file). Writes are replicated to all servers, which are connected +with write permission turned on. IO priority and permissions can be changed in run-time. + +POHMELFS is capable of full data channel encryption and/or strong crypto hashing. +One can select any kernel supported cipher, encryption mode, hash type and operation mode +(hmac or digest). It is also possible to use both or neither (default). Crypto configuration +is checked during mount time and, if the server does not support it, appropriate capabilities +will be disabled or mount will fail (if 'crypto_fail_unsupported' mount option is specified). +Crypto performance heavily depends on the number of crypto threads, which asynchronously perform +crypto operations and send the resulting data to server or submit it up the stack. This number +can be controlled via a mount option. diff --git a/Documentation/filesystems/pohmelfs/info.txt b/Documentation/filesystems/pohmelfs/info.txt new file mode 100644 index 000000000000..db2e41393626 --- /dev/null +++ b/Documentation/filesystems/pohmelfs/info.txt @@ -0,0 +1,99 @@ +POHMELFS usage information. + +Mount options. +All but index, number of crypto threads and maximum IO size can changed via remount. + +idx=%u + Each mountpoint is associated with a special index via this option. + Administrator can add or remove servers from the given index, so all mounts, + which were attached to it, are updated. + Default it is 0. + +trans_scan_timeout=%u + This timeout, expressed in milliseconds, specifies time to scan transaction + trees looking for stale requests, which have to be resent, or if number of + retries exceed specified limit, dropped with error. + Default is 5 seconds. + +drop_scan_timeout=%u + Internal timeout, expressed in milliseconds, which specifies how frequently + inodes marked to be dropped are freed. It also specifies how frequently + the system checks that servers have to be added or removed from current working set. + Default is 1 second. + +wait_on_page_timeout=%u + Number of milliseconds to wait for reply from remote server for data reading command. + If this timeout is exceeded, reading returns an error. + Default is 5 seconds. + +trans_retries=%u + This is the number of times that a transaction will be resent to a server that did + not answer for the last @trans_scan_timeout milliseconds. + When the number of resends exceeds this limit, the transaction is completed with error. + Default is 5 resends. + +crypto_thread_num=%u + Number of crypto processing threads. Threads are used both for RX and TX traffic. + Default is 2, or no threads if crypto operations are not supported. + +trans_max_pages=%u + Maximum number of pages in a single transaction. This parameter also controls + the number of pages, allocated for crypto processing (each crypto thread has + pool of pages, the number of which is equal to 'trans_max_pages'. + Default is 100 pages. + +crypto_fail_unsupported + If specified, mount will fail if the server does not support requested crypto operations. + By default mount will disable non-matching crypto operations. + +mcache_timeout=%u + Maximum number of milliseconds to wait for the mcache objects to be processed. + Mcache includes locks (given lock should be granted by server), attributes (they should be + fully received in the given timeframe). + Default is 5 seconds. + +Usage examples. + +Add server server1.net:1025 into the working set with index $idx +with appropriate hash algorithm and key file and cipher algorithm, mode and key file: +$cfg A add -a server1.net -p 1025 -i $idx -K $hash_key -k $cipher_key + +Mount filesystem with given index $idx to /mnt mountpoint. +Client will connect to all servers specified in the working set via previous command: +mount -t pohmel -o idx=$idx q /mnt + +Change permissions to read-only (-I 1 option, '-I 2' - write-only, 3 - rw): +$cfg A modify -a server1.net -p 1025 -i $idx -I 1 + +Change IO priority to 123 (node with the highest priority gets read requests). +$cfg A modify -a server1.net -p 1025 -i $idx -P 123 + +One can check currect status of all connections in the mountstats file: +# cat /proc/$PID/mountstats +... +device none mounted on /mnt with fstype pohmel +idx addr(:port) socket_type protocol active priority permissions +0 server1.net:1026 1 6 1 250 1 +0 server2.net:1025 1 6 1 123 3 + +Server installation. + +Creating a server, which listens at port 1025 and 0.0.0.0 address. +Working root directory (note, that server chroots there, so you have to have appropriate permissions) +is set to /mnt, server will negotiate hash/cipher with client, in case client requested it, there +are appropriate key files. +Number of working threads is set to 10. + +# ./fserver -a 0.0.0.0 -p 1025 -r /mnt -w 10 -K hash_key -k cipher_key + + -A 6 - listen on ipv6 address. Default: Disabled. + -r root - path to root directory. Default: /tmp. + -a addr - listen address. Default: 0.0.0.0. + -p port - listen port. Default: 1025. + -w workers - number of workers per connected client. Default: 1. + -K file - hash key size. Default: none. + -k file - cipher key size. Default: none. + -h - this help. + +Number of worker threads specifies how many workers will be created for each client. +Bulk single-client transafers usually are better handled with smaller number (like 1-3). diff --git a/Documentation/filesystems/pohmelfs/network_protocol.txt b/Documentation/filesystems/pohmelfs/network_protocol.txt new file mode 100644 index 000000000000..40ea6c295afb --- /dev/null +++ b/Documentation/filesystems/pohmelfs/network_protocol.txt @@ -0,0 +1,227 @@ +POHMELFS network protocol. + +Basic structure used in network communication is following command: + +struct netfs_cmd +{ + __u16 cmd; /* Command number */ + __u16 csize; /* Attached crypto information size */ + __u16 cpad; /* Attached padding size */ + __u16 ext; /* External flags */ + __u32 size; /* Size of the attached data */ + __u32 trans; /* Transaction id */ + __u64 id; /* Object ID to operate on. Used for feedback.*/ + __u64 start; /* Start of the object. */ + __u64 iv; /* IV sequence */ + __u8 data[0]; +}; + +Commands can be embedded into transaction command (which in turn has own command), +so one can extend protocol as needed without breaking backward compatibility as long +as old commands are supported. All string lengths include tail 0 byte. + +All commans are transfered over the network in big-endian. CPU endianess is used at the end peers. + +@cmd - command number, which specifies command to be processed. Following + commands are used currently: + + NETFS_READDIR = 1, /* Read directory for given inode number */ + NETFS_READ_PAGE, /* Read data page from the server */ + NETFS_WRITE_PAGE, /* Write data page to the server */ + NETFS_CREATE, /* Create directory entry */ + NETFS_REMOVE, /* Remove directory entry */ + NETFS_LOOKUP, /* Lookup single object */ + NETFS_LINK, /* Create a link */ + NETFS_TRANS, /* Transaction */ + NETFS_OPEN, /* Open intent */ + NETFS_INODE_INFO, /* Metadata cache coherency synchronization message */ + NETFS_PAGE_CACHE, /* Page cache invalidation message */ + NETFS_READ_PAGES, /* Read multiple contiguous pages in one go */ + NETFS_RENAME, /* Rename object */ + NETFS_CAPABILITIES, /* Capabilities of the client, for example supported crypto */ + NETFS_LOCK, /* Distributed lock message */ + NETFS_XATTR_SET, /* Set extended attribute */ + NETFS_XATTR_GET, /* Get extended attribute */ + +@ext - external flags. Used by different commands to specify some extra arguments + like partial size of the embedded objects or creation flags. + +@size - size of the attached data. For NETFS_READ_PAGE and NETFS_READ_PAGES no data is attached, + but size of the requested data is incorporated here. It does not include size of the command + header (struct netfs_cmd) itself. + +@id - id of the object this command operates on. Each command can use it for own purpose. + +@start - start of the object this command operates on. Each command can use it for own purpose. + +@csize, @cpad - size and padding size of the (attached if needed) crypto information. + +Command specifications. + +@NETFS_READDIR +This command is used to sync content of the remote dir to the client. + +@ext - length of the path to object. +@size - the same. +@id - local inode number of the directory to read. +@start - zero. + + +@NETFS_READ_PAGE +This command is used to read data from remote server. +Data size does not exceed local page cache size. + +@id - inode number. +@start - first byte offset. +@size - number of bytes to read plus length of the path to object. +@ext - object path length. + + +@NETFS_CREATE +Used to create object. +It does not require that all directories on top of the object were +already created, it will create them automatically. Each object has +associated @netfs_path_entry data structure, which contains creation +mode (permissions and type) and length of the name as long as name itself. + +@start - 0 +@size - size of the all data structures needed to create a path +@id - local inode number +@ext - 0 + + +@NETFS_REMOVE +Used to remove object. + +@ext - length of the path to object. +@size - the same. +@id - local inode number. +@start - zero. + + +@NETFS_LOOKUP +Lookup information about object on server. + +@ext - length of the path to object. +@size - the same. +@id - local inode number of the directory to look object in. +@start - local inode number of the object to look at. + + +@NETFS_LINK +Create hard of symlink. +Command is sent as "object_path|target_path". + +@size - size of the above string. +@id - parent local inode number. +@start - 1 for symlink, 0 for hardlink. +@ext - size of the "object_path" above. + + +@NETFS_TRANS +Transaction header. + +@size - incorporates all embedded command sizes including theirs header sizes. +@start - transaction generation number - unique id used to find transaction. +@ext - transaction flags. Unused at the moment. +@id - 0. + + +@NETFS_OPEN +Open intent for given transaction. + +@id - local inode number. +@start - 0. +@size - path length to the object. +@ext - open flags (O_RDWR and so on). + + +@NETFS_INODE_INFO +Metadata update command. +It is sent to servers when attributes of the object are changed and received +when data or metadata were updated. It operates with the following structure: + +struct netfs_inode_info +{ + unsigned int mode; + unsigned int nlink; + unsigned int uid; + unsigned int gid; + unsigned int blocksize; + unsigned int padding; + __u64 ino; + __u64 blocks; + __u64 rdev; + __u64 size; + __u64 version; +}; + +It effectively mirrors stat(2) returned data. + + +@ext - path length to the object. +@size - the same plus size of the netfs_inode_info structure. +@id - local inode number. +@start - 0. + + +@NETFS_PAGE_CACHE +Command is only received by clients. It contains information about +page to be marked as not up-to-date. + +@id - client's inode number. +@start - last byte of the page to be invalidated. If it is not equal to + current inode size, it will be vmtruncated(). +@size - 0 +@ext - 0 + + +@NETFS_READ_PAGES +Used to read multiple contiguous pages in one go. + +@start - first byte of the contiguous region to read. +@size - contains of two fields: lower 8 bits are used to represent page cache shift + used by client, another 3 bytes are used to get number of pages. +@id - local inode number. +@ext - path length to the object. + + +@NETFS_RENAME +Used to rename object. +Attached data is formed into following string: "old_path|new_path". + +@id - local inode number. +@start - parent inode number. +@size - length of the above string. +@ext - length of the old path part. + + +@NETFS_CAPABILITIES +Used to exchange crypto capabilities with server. +If crypto capabilities are not supported by server, then client will disable it +or fail (if 'crypto_fail_unsupported' mount options was specified). + +@id - superblock index. Used to specify crypto information for group of servers. +@size - size of the attached capabilities structure. +@start - 0. +@size - 0. +@scsize - 0. + +@NETFS_LOCK +Used to send lock request/release messages. Although it sends byte range request +and is capable of flushing pages based on that, it is not used, since all Linux +filesystems lock the whole inode. + +@id - lock generation number. +@start - start of the locked range. +@size - size of the locked range. +@ext - lock type: read/write. Not used actually. 15'th bit is used to determine, + if it is lock request (1) or release (0). + +@NETFS_XATTR_SET +@NETFS_XATTR_GET +Used to set/get extended attributes for given inode. +@id - attribute generation number or xattr setting type +@start - size of the attribute (request or attached) +@size - name length, path len and data size for given attribute +@ext - path length for given object diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index a87be42f8211..ce84cfc9eae0 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -5,6 +5,7 @@ Bodo Bauer <bb@ricochet.net> 2.4.x update Jorge Nerin <comandante@zaralinux.com> November 14 2000 +move /proc/sys Shen Feng <shen@cn.fujitsu.com> April 1 2009 ------------------------------------------------------------------------------ Version 1.3 Kernel version 2.2.12 Kernel version 2.4.0-test11-pre4 @@ -26,25 +27,17 @@ Table of Contents 1.6 Parallel port info in /proc/parport 1.7 TTY info in /proc/tty 1.8 Miscellaneous kernel statistics in /proc/stat + 1.9 Ext4 file system parameters 2 Modifying System Parameters - 2.1 /proc/sys/fs - File system data - 2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats - 2.3 /proc/sys/kernel - general kernel parameters - 2.4 /proc/sys/vm - The virtual memory subsystem - 2.5 /proc/sys/dev - Device specific parameters - 2.6 /proc/sys/sunrpc - Remote procedure calls - 2.7 /proc/sys/net - Networking stuff - 2.8 /proc/sys/net/ipv4 - IPV4 settings - 2.9 Appletalk - 2.10 IPX - 2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem - 2.12 /proc/<pid>/oom_adj - Adjust the oom-killer score - 2.13 /proc/<pid>/oom_score - Display current oom-killer score - 2.14 /proc/<pid>/io - Display the IO accounting fields - 2.15 /proc/<pid>/coredump_filter - Core dump filtering settings - 2.16 /proc/<pid>/mountinfo - Information about mounts - 2.17 /proc/sys/fs/epoll - Configuration options for the epoll interface + + 3 Per-Process Parameters + 3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score + 3.2 /proc/<pid>/oom_score - Display current oom-killer score + 3.3 /proc/<pid>/io - Display the IO accounting fields + 3.4 /proc/<pid>/coredump_filter - Core dump filtering settings + 3.5 /proc/<pid>/mountinfo - Information about mounts + ------------------------------------------------------------------------------ Preface @@ -940,27 +933,6 @@ Table 1-10: Files in /proc/fs/ext4/<devname> File Content mb_groups details of multiblock allocator buddy cache of free blocks mb_history multiblock allocation history - stats controls whether the multiblock allocator should start - collecting statistics, which are shown during the unmount - group_prealloc the multiblock allocator will round up allocation - requests to a multiple of this tuning parameter if the - stripe size is not set in the ext4 superblock - max_to_scan The maximum number of extents the multiblock allocator - will search to find the best extent - min_to_scan The minimum number of extents the multiblock allocator - will search to find the best extent - order2_req Tuning parameter which controls the minimum size for - requests (as a power of 2) where the buddy cache is - used - stream_req Files which have fewer blocks than this tunable - parameter will have their blocks allocated out of a - block group specific preallocation pool, so that small - files are packed closely together. Each large file - will have its blocks allocated out of its own unique - preallocation pool. -inode_readahead Tuning parameter which controls the maximum number of - inode table blocks that ext4's inode table readahead - algorithm will pre-read into the buffer cache .............................................................................. @@ -1011,1014 +983,24 @@ review the kernel documentation in the directory /usr/src/linux/Documentation. This chapter is heavily based on the documentation included in the pre 2.2 kernels, and became part of it in version 2.2.1 of the Linux kernel. -2.1 /proc/sys/fs - File system data ------------------------------------ - -This subdirectory contains specific file system, file handle, inode, dentry -and quota information. - -Currently, these files are in /proc/sys/fs: - -dentry-state ------------- - -Status of the directory cache. Since directory entries are dynamically -allocated and deallocated, this file indicates the current status. It holds -six values, in which the last two are not used and are always zero. The others -are listed in table 2-1. - - -Table 2-1: Status files of the directory cache -.............................................................................. - File Content - nr_dentry Almost always zero - nr_unused Number of unused cache entries - age_limit - in seconds after the entry may be reclaimed, when memory is short - want_pages internally -.............................................................................. - -dquot-nr and dquot-max ----------------------- - -The file dquot-max shows the maximum number of cached disk quota entries. - -The file dquot-nr shows the number of allocated disk quota entries and the -number of free disk quota entries. - -If the number of available cached disk quotas is very low and you have a large -number of simultaneous system users, you might want to raise the limit. - -file-nr and file-max --------------------- - -The kernel allocates file handles dynamically, but doesn't free them again at -this time. - -The value in file-max denotes the maximum number of file handles that the -Linux kernel will allocate. When you get a lot of error messages about running -out of file handles, you might want to raise this limit. The default value is -10% of RAM in kilobytes. To change it, just write the new number into the -file: - - # cat /proc/sys/fs/file-max - 4096 - # echo 8192 > /proc/sys/fs/file-max - # cat /proc/sys/fs/file-max - 8192 - - -This method of revision is useful for all customizable parameters of the -kernel - simply echo the new value to the corresponding file. - -Historically, the three values in file-nr denoted the number of allocated file -handles, the number of allocated but unused file handles, and the maximum -number of file handles. Linux 2.6 always reports 0 as the number of free file -handles -- this is not an error, it just means that the number of allocated -file handles exactly matches the number of used file handles. - -Attempts to allocate more file descriptors than file-max are reported with -printk, look for "VFS: file-max limit <number> reached". - -inode-state and inode-nr ------------------------- - -The file inode-nr contains the first two items from inode-state, so we'll skip -to that file... - -inode-state contains two actual numbers and five dummy values. The numbers -are nr_inodes and nr_free_inodes (in order of appearance). - -nr_inodes -~~~~~~~~~ - -Denotes the number of inodes the system has allocated. This number will -grow and shrink dynamically. - -nr_open -------- - -Denotes the maximum number of file-handles a process can -allocate. Default value is 1024*1024 (1048576) which should be -enough for most machines. Actual limit depends on RLIMIT_NOFILE -resource limit. - -nr_free_inodes --------------- - -Represents the number of free inodes. Ie. The number of inuse inodes is -(nr_inodes - nr_free_inodes). - -aio-nr and aio-max-nr ---------------------- - -aio-nr is the running total of the number of events specified on the -io_setup system call for all currently active aio contexts. If aio-nr -reaches aio-max-nr then io_setup will fail with EAGAIN. Note that -raising aio-max-nr does not result in the pre-allocation or re-sizing -of any kernel data structures. - -2.2 /proc/sys/fs/binfmt_misc - Miscellaneous binary formats ------------------------------------------------------------ - -Besides these files, there is the subdirectory /proc/sys/fs/binfmt_misc. This -handles the kernel support for miscellaneous binary formats. - -Binfmt_misc provides the ability to register additional binary formats to the -Kernel without compiling an additional module/kernel. Therefore, binfmt_misc -needs to know magic numbers at the beginning or the filename extension of the -binary. - -It works by maintaining a linked list of structs that contain a description of -a binary format, including a magic with size (or the filename extension), -offset and mask, and the interpreter name. On request it invokes the given -interpreter with the original program as argument, as binfmt_java and -binfmt_em86 and binfmt_mz do. Since binfmt_misc does not define any default -binary-formats, you have to register an additional binary-format. - -There are two general files in binfmt_misc and one file per registered format. -The two general files are register and status. - -Registering a new binary format -------------------------------- - -To register a new binary format you have to issue the command - - echo :name:type:offset:magic:mask:interpreter: > /proc/sys/fs/binfmt_misc/register - - - -with appropriate name (the name for the /proc-dir entry), offset (defaults to -0, if omitted), magic, mask (which can be omitted, defaults to all 0xff) and -last but not least, the interpreter that is to be invoked (for example and -testing /bin/echo). Type can be M for usual magic matching or E for filename -extension matching (give extension in place of magic). - -Check or reset the status of the binary format handler ------------------------------------------------------- - -If you do a cat on the file /proc/sys/fs/binfmt_misc/status, you will get the -current status (enabled/disabled) of binfmt_misc. Change the status by echoing -0 (disables) or 1 (enables) or -1 (caution: this clears all previously -registered binary formats) to status. For example echo 0 > status to disable -binfmt_misc (temporarily). - -Status of a single handler --------------------------- - -Each registered handler has an entry in /proc/sys/fs/binfmt_misc. These files -perform the same function as status, but their scope is limited to the actual -binary format. By cating this file, you also receive all related information -about the interpreter/magic of the binfmt. - -Example usage of binfmt_misc (emulate binfmt_java) --------------------------------------------------- - - cd /proc/sys/fs/binfmt_misc - echo ':Java:M::\xca\xfe\xba\xbe::/usr/local/java/bin/javawrapper:' > register - echo ':HTML:E::html::/usr/local/java/bin/appletviewer:' > register - echo ':Applet:M::<!--applet::/usr/local/java/bin/appletviewer:' > register - echo ':DEXE:M::\x0eDEX::/usr/bin/dosexec:' > register - - -These four lines add support for Java executables and Java applets (like -binfmt_java, additionally recognizing the .html extension with no need to put -<!--applet> to every applet file). You have to install the JDK and the -shell-script /usr/local/java/bin/javawrapper too. It works around the -brokenness of the Java filename handling. To add a Java binary, just create a -link to the class-file somewhere in the path. - -2.3 /proc/sys/kernel - general kernel parameters ------------------------------------------------- - -This directory reflects general kernel behaviors. As I've said before, the -contents depend on your configuration. Here you'll find the most important -files, along with descriptions of what they mean and how to use them. - -acct ----- - -The file contains three values; highwater, lowwater, and frequency. - -It exists only when BSD-style process accounting is enabled. These values -control its behavior. If the free space on the file system where the log lives -goes below lowwater percentage, accounting suspends. If it goes above -highwater percentage, accounting resumes. Frequency determines how often you -check the amount of free space (value is in seconds). Default settings are: 4, -2, and 30. That is, suspend accounting if there is less than 2 percent free; -resume it if we have a value of 3 or more percent; consider information about -the amount of free space valid for 30 seconds - -ctrl-alt-del ------------- - -When the value in this file is 0, ctrl-alt-del is trapped and sent to the init -program to handle a graceful restart. However, when the value is greater that -zero, Linux's reaction to this key combination will be an immediate reboot, -without syncing its dirty buffers. - -[NOTE] - When a program (like dosemu) has the keyboard in raw mode, the - ctrl-alt-del is intercepted by the program before it ever reaches the - kernel tty layer, and it is up to the program to decide what to do with - it. - -domainname and hostname ------------------------ - -These files can be controlled to set the NIS domainname and hostname of your -box. For the classic darkstar.frop.org a simple: - - # echo "darkstar" > /proc/sys/kernel/hostname - # echo "frop.org" > /proc/sys/kernel/domainname - - -would suffice to set your hostname and NIS domainname. - -osrelease, ostype and version ------------------------------ - -The names make it pretty obvious what these fields contain: - - > cat /proc/sys/kernel/osrelease - 2.2.12 - - > cat /proc/sys/kernel/ostype - Linux - - > cat /proc/sys/kernel/version - #4 Fri Oct 1 12:41:14 PDT 1999 - - -The files osrelease and ostype should be clear enough. Version needs a little -more clarification. The #4 means that this is the 4th kernel built from this -source base and the date after it indicates the time the kernel was built. The -only way to tune these values is to rebuild the kernel. - -panic ------ - -The value in this file represents the number of seconds the kernel waits -before rebooting on a panic. When you use the software watchdog, the -recommended setting is 60. If set to 0, the auto reboot after a kernel panic -is disabled, which is the default setting. - -printk ------- - -The four values in printk denote -* console_loglevel, -* default_message_loglevel, -* minimum_console_loglevel and -* default_console_loglevel -respectively. - -These values influence printk() behavior when printing or logging error -messages, which come from inside the kernel. See syslog(2) for more -information on the different log levels. - -console_loglevel ----------------- - -Messages with a higher priority than this will be printed to the console. - -default_message_level ---------------------- - -Messages without an explicit priority will be printed with this priority. - -minimum_console_loglevel ------------------------- - -Minimum (highest) value to which the console_loglevel can be set. - -default_console_loglevel ------------------------- - -Default value for console_loglevel. - -sg-big-buff ------------ - -This file shows the size of the generic SCSI (sg) buffer. At this point, you -can't tune it yet, but you can change it at compile time by editing -include/scsi/sg.h and changing the value of SG_BIG_BUFF. - -If you use a scanner with SANE (Scanner Access Now Easy) you might want to set -this to a higher value. Refer to the SANE documentation on this issue. - -modprobe --------- - -The location where the modprobe binary is located. The kernel uses this -program to load modules on demand. - -unknown_nmi_panic ------------------ - -The value in this file affects behavior of handling NMI. When the value is -non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel -debugging information is displayed on console. - -NMI switch that most IA32 servers have fires unknown NMI up, for example. -If a system hangs up, try pressing the NMI switch. - -panic_on_unrecovered_nmi ------------------------- - -The default Linux behaviour on an NMI of either memory or unknown is to continue -operation. For many environments such as scientific computing it is preferable -that the box is taken out and the error dealt with than an uncorrected -parity/ECC error get propogated. - -A small number of systems do generate NMI's for bizarre random reasons such as -power management so the default is off. That sysctl works like the existing -panic controls already in that directory. - -nmi_watchdog ------------- - -Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero -the NMI watchdog is enabled and will continuously test all online cpus to -determine whether or not they are still functioning properly. Currently, -passing "nmi_watchdog=" parameter at boot time is required for this function -to work. - -If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the -NMI watchdog shares registers with oprofile. By disabling the NMI watchdog, -oprofile may have more registers to utilize. - -msgmni ------- - -Maximum number of message queue ids on the system. -This value scales to the amount of lowmem. It is automatically recomputed -upon memory add/remove or ipc namespace creation/removal. -When a value is written into this file, msgmni's value becomes fixed, i.e. it -is not recomputed anymore when one of the above events occurs. -Use auto_msgmni to change this behavior. - -auto_msgmni ------------ - -Enables/Disables automatic recomputing of msgmni upon memory add/remove or -upon ipc namespace creation/removal (see the msgmni description above). -Echoing "1" into this file enables msgmni automatic recomputing. -Echoing "0" turns it off. -auto_msgmni default value is 1. - - -2.4 /proc/sys/vm - The virtual memory subsystem ------------------------------------------------ - -Please see: Documentation/sysctls/vm.txt for a description of these +Please see: Documentation/sysctls/ directory for descriptions of these entries. +------------------------------------------------------------------------------ +Summary +------------------------------------------------------------------------------ +Certain aspects of kernel behavior can be modified at runtime, without the +need to recompile the kernel, or even to reboot the system. The files in the +/proc/sys tree can not only be read, but also modified. You can use the echo +command to write value into these files, thereby changing the default settings +of the kernel. +------------------------------------------------------------------------------ -2.5 /proc/sys/dev - Device specific parameters ----------------------------------------------- - -Currently there is only support for CDROM drives, and for those, there is only -one read-only file containing information about the CD-ROM drives attached to -the system: - - >cat /proc/sys/dev/cdrom/info - CD-ROM information, Id: cdrom.c 2.55 1999/04/25 - - drive name: sr0 hdb - drive speed: 32 40 - drive # of slots: 1 0 - Can close tray: 1 1 - Can open tray: 1 1 - Can lock tray: 1 1 - Can change speed: 1 1 - Can select disk: 0 1 - Can read multisession: 1 1 - Can read MCN: 1 1 - Reports media changed: 1 1 - Can play audio: 1 1 - - -You see two drives, sr0 and hdb, along with a list of their features. - -2.6 /proc/sys/sunrpc - Remote procedure calls ---------------------------------------------- - -This directory contains four files, which enable or disable debugging for the -RPC functions NFS, NFS-daemon, RPC and NLM. The default values are 0. They can -be set to one to turn debugging on. (The default value is 0 for each) - -2.7 /proc/sys/net - Networking stuff ------------------------------------- - -The interface to the networking parts of the kernel is located in -/proc/sys/net. Table 2-3 shows all possible subdirectories. You may see only -some of them, depending on your kernel's configuration. - - -Table 2-3: Subdirectories in /proc/sys/net -.............................................................................. - Directory Content Directory Content - core General parameter appletalk Appletalk protocol - unix Unix domain sockets netrom NET/ROM - 802 E802 protocol ax25 AX25 - ethernet Ethernet protocol rose X.25 PLP layer - ipv4 IP version 4 x25 X.25 protocol - ipx IPX token-ring IBM token ring - bridge Bridging decnet DEC net - ipv6 IP version 6 -.............................................................................. - -We will concentrate on IP networking here. Since AX15, X.25, and DEC Net are -only minor players in the Linux world, we'll skip them in this chapter. You'll -find some short info on Appletalk and IPX further on in this chapter. Review -the online documentation and the kernel source to get a detailed view of the -parameters for those protocols. In this section we'll discuss the -subdirectories printed in bold letters in the table above. As default values -are suitable for most needs, there is no need to change these values. - -/proc/sys/net/core - Network core options ------------------------------------------ - -rmem_default ------------- - -The default setting of the socket receive buffer in bytes. - -rmem_max --------- - -The maximum receive socket buffer size in bytes. - -wmem_default ------------- - -The default setting (in bytes) of the socket send buffer. - -wmem_max --------- - -The maximum send socket buffer size in bytes. - -message_burst and message_cost ------------------------------- - -These parameters are used to limit the warning messages written to the kernel -log from the networking code. They enforce a rate limit to make a -denial-of-service attack impossible. A higher message_cost factor, results in -fewer messages that will be written. Message_burst controls when messages will -be dropped. The default settings limit warning messages to one every five -seconds. - -warnings --------- - -This controls console messages from the networking stack that can occur because -of problems on the network like duplicate address or bad checksums. Normally, -this should be enabled, but if the problem persists the messages can be -disabled. - - -netdev_max_backlog ------------------- - -Maximum number of packets, queued on the INPUT side, when the interface -receives packets faster than kernel can process them. - -optmem_max ----------- - -Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence -of struct cmsghdr structures with appended data. - -/proc/sys/net/unix - Parameters for Unix domain sockets -------------------------------------------------------- - -There are only two files in this subdirectory. They control the delays for -deleting and destroying socket descriptors. - -2.8 /proc/sys/net/ipv4 - IPV4 settings --------------------------------------- - -IP version 4 is still the most used protocol in Unix networking. It will be -replaced by IP version 6 in the next couple of years, but for the moment it's -the de facto standard for the internet and is used in most networking -environments around the world. Because of the importance of this protocol, -we'll have a deeper look into the subtree controlling the behavior of the IPv4 -subsystem of the Linux kernel. - -Let's start with the entries in /proc/sys/net/ipv4. - -ICMP settings -------------- - -icmp_echo_ignore_all and icmp_echo_ignore_broadcasts ----------------------------------------------------- - -Turn on (1) or off (0), if the kernel should ignore all ICMP ECHO requests, or -just those to broadcast and multicast addresses. - -Please note that if you accept ICMP echo requests with a broadcast/multi\-cast -destination address your network may be used as an exploder for denial of -service packet flooding attacks to other hosts. - -icmp_destunreach_rate, icmp_echoreply_rate, icmp_paramprob_rate and icmp_timeexeed_rate ---------------------------------------------------------------------------------------- - -Sets limits for sending ICMP packets to specific targets. A value of zero -disables all limiting. Any positive value sets the maximum package rate in -hundredth of a second (on Intel systems). - -IP settings ------------ - -ip_autoconfig -------------- - -This file contains the number one if the host received its IP configuration by -RARP, BOOTP, DHCP or a similar mechanism. Otherwise it is zero. - -ip_default_ttl --------------- - -TTL (Time To Live) for IPv4 interfaces. This is simply the maximum number of -hops a packet may travel. - -ip_dynaddr ----------- - -Enable dynamic socket address rewriting on interface address change. This is -useful for dialup interface with changing IP addresses. - -ip_forward ----------- - -Enable or disable forwarding of IP packages between interfaces. Changing this -value resets all other parameters to their default values. They differ if the -kernel is configured as host or router. - -ip_local_port_range -------------------- - -Range of ports used by TCP and UDP to choose the local port. Contains two -numbers, the first number is the lowest port, the second number the highest -local port. Default is 1024-4999. Should be changed to 32768-61000 for -high-usage systems. - -ip_no_pmtu_disc ---------------- - -Global switch to turn path MTU discovery off. It can also be set on a per -socket basis by the applications or on a per route basis. - -ip_masq_debug -------------- - -Enable/disable debugging of IP masquerading. - -IP fragmentation settings -------------------------- - -ipfrag_high_trash and ipfrag_low_trash --------------------------------------- - -Maximum memory used to reassemble IP fragments. When ipfrag_high_thresh bytes -of memory is allocated for this purpose, the fragment handler will toss -packets until ipfrag_low_thresh is reached. - -ipfrag_time ------------ - -Time in seconds to keep an IP fragment in memory. - -TCP settings ------------- - -tcp_ecn -------- - -This file controls the use of the ECN bit in the IPv4 headers. This is a new -feature about Explicit Congestion Notification, but some routers and firewalls -block traffic that has this bit set, so it could be necessary to echo 0 to -/proc/sys/net/ipv4/tcp_ecn if you want to talk to these sites. For more info -you could read RFC2481. - -tcp_retrans_collapse --------------------- - -Bug-to-bug compatibility with some broken printers. On retransmit, try to send -larger packets to work around bugs in certain TCP stacks. Can be turned off by -setting it to zero. - -tcp_keepalive_probes --------------------- - -Number of keep alive probes TCP sends out, until it decides that the -connection is broken. - -tcp_keepalive_time ------------------- - -How often TCP sends out keep alive messages, when keep alive is enabled. The -default is 2 hours. - -tcp_syn_retries ---------------- - -Number of times initial SYNs for a TCP connection attempt will be -retransmitted. Should not be higher than 255. This is only the timeout for -outgoing connections, for incoming connections the number of retransmits is -defined by tcp_retries1. - -tcp_sack --------- - -Enable select acknowledgments after RFC2018. - -tcp_timestamps --------------- - -Enable timestamps as defined in RFC1323. - -tcp_stdurg ----------- - -Enable the strict RFC793 interpretation of the TCP urgent pointer field. The -default is to use the BSD compatible interpretation of the urgent pointer -pointing to the first byte after the urgent data. The RFC793 interpretation is -to have it point to the last byte of urgent data. Enabling this option may -lead to interoperability problems. Disabled by default. - -tcp_syncookies --------------- - -Only valid when the kernel was compiled with CONFIG_SYNCOOKIES. Send out -syncookies when the syn backlog queue of a socket overflows. This is to ward -off the common 'syn flood attack'. Disabled by default. - -Note that the concept of a socket backlog is abandoned. This means the peer -may not receive reliable error messages from an over loaded server with -syncookies enabled. - -tcp_window_scaling ------------------- - -Enable window scaling as defined in RFC1323. - -tcp_fin_timeout ---------------- - -The length of time in seconds it takes to receive a final FIN before the -socket is always closed. This is strictly a violation of the TCP -specification, but required to prevent denial-of-service attacks. - -tcp_max_ka_probes ------------------ - -Indicates how many keep alive probes are sent per slow timer run. Should not -be set too high to prevent bursts. - -tcp_max_syn_backlog -------------------- - -Length of the per socket backlog queue. Since Linux 2.2 the backlog specified -in listen(2) only specifies the length of the backlog queue of already -established sockets. When more connection requests arrive Linux starts to drop -packets. When syncookies are enabled the packets are still answered and the -maximum queue is effectively ignored. - -tcp_retries1 ------------- - -Defines how often an answer to a TCP connection request is retransmitted -before giving up. - -tcp_retries2 ------------- - -Defines how often a TCP packet is retransmitted before giving up. - -Interface specific settings ---------------------------- - -In the directory /proc/sys/net/ipv4/conf you'll find one subdirectory for each -interface the system knows about and one directory calls all. Changes in the -all subdirectory affect all interfaces, whereas changes in the other -subdirectories affect only one interface. All directories have the same -entries: - -accept_redirects ----------------- - -This switch decides if the kernel accepts ICMP redirect messages or not. The -default is 'yes' if the kernel is configured for a regular host and 'no' for a -router configuration. - -accept_source_route -------------------- - -Should source routed packages be accepted or declined. The default is -dependent on the kernel configuration. It's 'yes' for routers and 'no' for -hosts. - -bootp_relay -~~~~~~~~~~~ - -Accept packets with source address 0.b.c.d with destinations not to this host -as local ones. It is supposed that a BOOTP relay daemon will catch and forward -such packets. - -The default is 0, since this feature is not implemented yet (kernel version -2.2.12). - -forwarding ----------- - -Enable or disable IP forwarding on this interface. - -log_martians ------------- - -Log packets with source addresses with no known route to kernel log. - -mc_forwarding -------------- - -Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE and a -multicast routing daemon is required. - -proxy_arp ---------- - -Does (1) or does not (0) perform proxy ARP. - -rp_filter ---------- - -Integer value determines if a source validation should be made. 1 means yes, 0 -means no. Disabled by default, but local/broadcast address spoofing is always -on. - -If you set this to 1 on a router that is the only connection for a network to -the net, it will prevent spoofing attacks against your internal networks -(external addresses can still be spoofed), without the need for additional -firewall rules. - -secure_redirects ----------------- - -Accept ICMP redirect messages only for gateways, listed in default gateway -list. Enabled by default. - -shared_media ------------- - -If it is not set the kernel does not assume that different subnets on this -device can communicate directly. Default setting is 'yes'. - -send_redirects --------------- - -Determines whether to send ICMP redirects to other hosts. - -Routing settings ----------------- - -The directory /proc/sys/net/ipv4/route contains several file to control -routing issues. - -error_burst and error_cost --------------------------- - -These parameters are used to limit how many ICMP destination unreachable to -send from the host in question. ICMP destination unreachable messages are -sent when we cannot reach the next hop while trying to transmit a packet. -It will also print some error messages to kernel logs if someone is ignoring -our ICMP redirects. The higher the error_cost factor is, the fewer -destination unreachable and error messages will be let through. Error_burst -controls when destination unreachable messages and error messages will be -dropped. The default settings limit warning messages to five every second. - -flush ------ - -Writing to this file results in a flush of the routing cache. - -gc_elasticity, gc_interval, gc_min_interval_ms, gc_timeout, gc_thresh ---------------------------------------------------------------------- - -Values to control the frequency and behavior of the garbage collection -algorithm for the routing cache. gc_min_interval is deprecated and replaced -by gc_min_interval_ms. - - -max_size --------- - -Maximum size of the routing cache. Old entries will be purged once the cache -reached has this size. - -redirect_load, redirect_number ------------------------------- - -Factors which determine if more ICPM redirects should be sent to a specific -host. No redirects will be sent once the load limit or the maximum number of -redirects has been reached. - -redirect_silence ----------------- - -Timeout for redirects. After this period redirects will be sent again, even if -this has been stopped, because the load or number limit has been reached. - -Network Neighbor handling -------------------------- - -Settings about how to handle connections with direct neighbors (nodes attached -to the same link) can be found in the directory /proc/sys/net/ipv4/neigh. - -As we saw it in the conf directory, there is a default subdirectory which -holds the default values, and one directory for each interface. The contents -of the directories are identical, with the single exception that the default -settings contain additional options to set garbage collection parameters. - -In the interface directories you'll find the following entries: - -base_reachable_time, base_reachable_time_ms -------------------------------------------- - -A base value used for computing the random reachable time value as specified -in RFC2461. - -Expression of base_reachable_time, which is deprecated, is in seconds. -Expression of base_reachable_time_ms is in milliseconds. - -retrans_time, retrans_time_ms ------------------------------ - -The time between retransmitted Neighbor Solicitation messages. -Used for address resolution and to determine if a neighbor is -unreachable. - -Expression of retrans_time, which is deprecated, is in 1/100 seconds (for -IPv4) or in jiffies (for IPv6). -Expression of retrans_time_ms is in milliseconds. - -unres_qlen ----------- - -Maximum queue length for a pending arp request - the number of packets which -are accepted from other layers while the ARP address is still resolved. - -anycast_delay -------------- - -Maximum for random delay of answers to neighbor solicitation messages in -jiffies (1/100 sec). Not yet implemented (Linux does not have anycast support -yet). - -ucast_solicit -------------- - -Maximum number of retries for unicast solicitation. - -mcast_solicit -------------- - -Maximum number of retries for multicast solicitation. - -delay_first_probe_time ----------------------- - -Delay for the first time probe if the neighbor is reachable. (see -gc_stale_time) - -locktime --------- - -An ARP/neighbor entry is only replaced with a new one if the old is at least -locktime old. This prevents ARP cache thrashing. - -proxy_delay ------------ - -Maximum time (real time is random [0..proxytime]) before answering to an ARP -request for which we have an proxy ARP entry. In some cases, this is used to -prevent network flooding. - -proxy_qlen ----------- - -Maximum queue length of the delayed proxy arp timer. (see proxy_delay). - -app_solicit ----------- - -Determines the number of requests to send to the user level ARP daemon. Use 0 -to turn off. - -gc_stale_time -------------- - -Determines how often to check for stale ARP entries. After an ARP entry is -stale it will be resolved again (which is useful when an IP address migrates -to another machine). When ucast_solicit is greater than 0 it first tries to -send an ARP packet directly to the known host When that fails and -mcast_solicit is greater than 0, an ARP request is broadcasted. - -2.9 Appletalk -------------- - -The /proc/sys/net/appletalk directory holds the Appletalk configuration data -when Appletalk is loaded. The configurable parameters are: - -aarp-expiry-time ----------------- - -The amount of time we keep an ARP entry before expiring it. Used to age out -old hosts. - -aarp-resolve-time ------------------ - -The amount of time we will spend trying to resolve an Appletalk address. - -aarp-retransmit-limit ---------------------- - -The number of times we will retransmit a query before giving up. - -aarp-tick-time --------------- - -Controls the rate at which expires are checked. - -The directory /proc/net/appletalk holds the list of active Appletalk sockets -on a machine. - -The fields indicate the DDP type, the local address (in network:node format) -the remote address, the size of the transmit pending queue, the size of the -received queue (bytes waiting for applications to read) the state and the uid -owning the socket. - -/proc/net/atalk_iface lists all the interfaces configured for appletalk.It -shows the name of the interface, its Appletalk address, the network range on -that address (or network number for phase 1 networks), and the status of the -interface. - -/proc/net/atalk_route lists each known network route. It lists the target -(network) that the route leads to, the router (may be directly connected), the -route flags, and the device the route is using. - -2.10 IPX --------- - -The IPX protocol has no tunable values in proc/sys/net. - -The IPX protocol does, however, provide proc/net/ipx. This lists each IPX -socket giving the local and remote addresses in Novell format (that is -network:node:port). In accordance with the strange Novell tradition, -everything but the port is in hex. Not_Connected is displayed for sockets that -are not tied to a specific remote address. The Tx and Rx queue sizes indicate -the number of bytes pending for transmission and reception. The state -indicates the state the socket is in and the uid is the owning uid of the -socket. - -The /proc/net/ipx_interface file lists all IPX interfaces. For each interface -it gives the network number, the node number, and indicates if the network is -the primary network. It also indicates which device it is bound to (or -Internal for internal networks) and the Frame Type if appropriate. Linux -supports 802.3, 802.2, 802.2 SNAP and DIX (Blue Book) ethernet framing for -IPX. - -The /proc/net/ipx_route table holds a list of IPX routes. For each route it -gives the destination network, the router node (or Directly) and the network -address of the router (or Connected) for internal networks. - -2.11 /proc/sys/fs/mqueue - POSIX message queues filesystem ----------------------------------------------------------- - -The "mqueue" filesystem provides the necessary kernel features to enable the -creation of a user space library that implements the POSIX message queues -API (as noted by the MSG tag in the POSIX 1003.1-2001 version of the System -Interfaces specification.) - -The "mqueue" filesystem contains values for determining/setting the amount of -resources used by the file system. - -/proc/sys/fs/mqueue/queues_max is a read/write file for setting/getting the -maximum number of message queues allowed on the system. - -/proc/sys/fs/mqueue/msg_max is a read/write file for setting/getting the -maximum number of messages in a queue value. In fact it is the limiting value -for another (user) limit which is set in mq_open invocation. This attribute of -a queue must be less or equal then msg_max. - -/proc/sys/fs/mqueue/msgsize_max is a read/write file for setting/getting the -maximum message size value (it is every message queue's attribute set during -its creation). +------------------------------------------------------------------------------ +CHAPTER 3: PER-PROCESS PARAMETERS +------------------------------------------------------------------------------ -2.12 /proc/<pid>/oom_adj - Adjust the oom-killer score +3.1 /proc/<pid>/oom_adj - Adjust the oom-killer score ------------------------------------------------------ This file can be used to adjust the score used to select which processes @@ -2055,25 +1037,15 @@ The task with the highest badness score is then selected and its children are killed, process itself will be killed in an OOM situation when it does not have children or some of them disabled oom like described above. -2.13 /proc/<pid>/oom_score - Display current oom-killer score +3.2 /proc/<pid>/oom_score - Display current oom-killer score ------------------------------------------------------------- ------------------------------------------------------------------------------- This file can be used to check the current score used by the oom-killer is for any given <pid>. Use it together with /proc/<pid>/oom_adj to tune which process should be killed in an out-of-memory situation. ------------------------------------------------------------------------------- -Summary ------------------------------------------------------------------------------- -Certain aspects of kernel behavior can be modified at runtime, without the -need to recompile the kernel, or even to reboot the system. The files in the -/proc/sys tree can not only be read, but also modified. You can use the echo -command to write value into these files, thereby changing the default settings -of the kernel. ------------------------------------------------------------------------------- -2.14 /proc/<pid>/io - Display the IO accounting fields +3.3 /proc/<pid>/io - Display the IO accounting fields ------------------------------------------------------- This file contains IO statistics for each running process @@ -2175,7 +1147,7 @@ those 64-bit counters, process A could see an intermediate result. More information about this can be found within the taskstats documentation in Documentation/accounting. -2.15 /proc/<pid>/coredump_filter - Core dump filtering settings +3.4 /proc/<pid>/coredump_filter - Core dump filtering settings --------------------------------------------------------------- When a process is dumped, all anonymous memory is written to a core file as long as the size of the core file isn't limited. But sometimes we don't want @@ -2219,7 +1191,7 @@ For example: $ echo 0x7 > /proc/self/coredump_filter $ ./some_program -2.16 /proc/<pid>/mountinfo - Information about mounts +3.5 /proc/<pid>/mountinfo - Information about mounts -------------------------------------------------------- This file contains lines of the form: @@ -2256,30 +1228,3 @@ For more information on mount propagation see: Documentation/filesystems/sharedsubtree.txt -2.17 /proc/sys/fs/epoll - Configuration options for the epoll interface --------------------------------------------------------- - -This directory contains configuration options for the epoll(7) interface. - -max_user_instances ------------------- - -This is the maximum number of epoll file descriptors that a single user can -have open at a given time. The default value is 128, and should be enough -for normal users. - -max_user_watches ----------------- - -Every epoll file descriptor can store a number of files to be monitored -for event readiness. Each one of these monitored files constitutes a "watch". -This configuration option sets the maximum number of "watches" that are -allowed for each user. -Each "watch" costs roughly 90 bytes on a 32bit kernel, and roughly 160 bytes -on a 64bit one. -The current default value for max_user_watches is the 1/32 of the available -low memory, divided for the "watch" cost in bytes. - - ------------------------------------------------------------------------------- - diff --git a/Documentation/filesystems/squashfs.txt b/Documentation/filesystems/squashfs.txt index 3e79e4a7a392..b324c033035a 100644 --- a/Documentation/filesystems/squashfs.txt +++ b/Documentation/filesystems/squashfs.txt @@ -22,7 +22,7 @@ Squashfs filesystem features versus Cramfs: Squashfs Cramfs -Max filesystem size: 2^64 16 MiB +Max filesystem size: 2^64 256 MiB Max file size: ~ 2 TiB 16 MiB Max files: unlimited unlimited Max directories: unlimited unlimited diff --git a/Documentation/filesystems/sysfs-pci.txt b/Documentation/filesystems/sysfs-pci.txt index 9f8740ca3f3b..26e4b8bc53ee 100644 --- a/Documentation/filesystems/sysfs-pci.txt +++ b/Documentation/filesystems/sysfs-pci.txt @@ -12,6 +12,7 @@ that support it. For example, a given bus might look like this: | |-- enable | |-- irq | |-- local_cpus + | |-- remove | |-- resource | |-- resource0 | |-- resource1 @@ -36,6 +37,7 @@ files, each with their own function. enable Whether the device is enabled (ascii, rw) irq IRQ number (ascii, ro) local_cpus nearby CPU mask (cpumask, ro) + remove remove device from kernel's list (ascii, wo) resource PCI resource host addresses (ascii, ro) resource0..N PCI resource N, if present (binary, mmap) resource0_wc..N_wc PCI WC map resource N, if prefetchable (binary, mmap) @@ -46,6 +48,7 @@ files, each with their own function. ro - read only file rw - file is readable and writable + wo - write only file mmap - file is mmapable ascii - file contains ascii text binary - file contains binary data @@ -73,6 +76,13 @@ that the device must be enabled for a rom read to return data succesfully. In the event a driver is not bound to the device, it can be enabled using the 'enable' file, documented above. +The 'remove' file is used to remove the PCI device, by writing a non-zero +integer to the file. This does not involve any kind of hot-plug functionality, +e.g. powering off the device. The device is removed from the kernel's list of +PCI devices, the sysfs directory for it is removed, and the device will be +removed from any drivers attached to it. Removal of PCI root buses is +disallowed. + Accessing legacy resources through sysfs ---------------------------------------- diff --git a/Documentation/filesystems/udf.txt b/Documentation/filesystems/udf.txt index fde829a756e6..902b95d0ee51 100644 --- a/Documentation/filesystems/udf.txt +++ b/Documentation/filesystems/udf.txt @@ -24,6 +24,8 @@ The following mount options are supported: gid= Set the default group. umask= Set the default umask. + mode= Set the default file permissions. + dmode= Set the default directory permissions. uid= Set the default user. bs= Set the block size. unhide Show otherwise hidden files. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index deeeed0faa8f..f49eecf2e573 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -277,8 +277,7 @@ or bottom half). unfreeze_fs: called when VFS is unlocking a filesystem and making it writable again. - statfs: called when the VFS needs to get filesystem statistics. This - is called with the kernel lock held + statfs: called when the VFS needs to get filesystem statistics. remount_fs: called when the filesystem is remounted. This is called with the kernel lock held diff --git a/Documentation/gpio.txt b/Documentation/gpio.txt index b1b988701247..145c25a170c7 100644 --- a/Documentation/gpio.txt +++ b/Documentation/gpio.txt @@ -123,7 +123,10 @@ platform-specific implementation issue. Using GPIOs ----------- -One of the first things to do with a GPIO, often in board setup code when +The first thing a system should do with a GPIO is allocate it, using +the gpio_request() call; see later. + +One of the next things to do with a GPIO, often in board setup code when setting up a platform_device using the GPIO, is mark its direction: /* set as input or output, returning 0 or negative errno */ @@ -141,8 +144,8 @@ This helps avoid signal glitching during system startup. For compatibility with legacy interfaces to GPIOs, setting the direction of a GPIO implicitly requests that GPIO (see below) if it has not been -requested already. That compatibility may be removed in the future; -explicitly requesting GPIOs is strongly preferred. +requested already. That compatibility is being removed from the optional +gpiolib framework. Setting the direction can fail if the GPIO number is invalid, or when that particular GPIO can't be used in that mode. It's generally a bad @@ -195,7 +198,7 @@ This requires sleeping, which can't be done from inside IRQ handlers. Platforms that support this type of GPIO distinguish them from other GPIOs by returning nonzero from this call (which requires a valid GPIO number, -either explicitly or implicitly requested): +which should have been previously allocated with gpio_request): int gpio_cansleep(unsigned gpio); @@ -212,10 +215,9 @@ for GPIOs that can't be accessed from IRQ handlers, these calls act the same as the spinlock-safe calls. -Claiming and Releasing GPIOs (OPTIONAL) ---------------------------------------- +Claiming and Releasing GPIOs +---------------------------- To help catch system configuration errors, two calls are defined. -However, many platforms don't currently support this mechanism. /* request GPIO, returning 0 or negative errno. * non-null labels may be useful for diagnostics. @@ -244,13 +246,6 @@ Some platforms may also use knowledge about what GPIOs are active for power management, such as by powering down unused chip sectors and, more easily, gating off unused clocks. -These two calls are optional because not not all current Linux platforms -offer such functionality in their GPIO support; a valid implementation -could return success for all gpio_request() calls. Unlike the other calls, -the state they represent doesn't normally match anything from a hardware -register; it's just a software bitmap which clearly is not necessary for -correct operation of hardware or (bug free) drivers. - Note that requesting a GPIO does NOT cause it to be configured in any way; it just marks that GPIO as in use. Separate code must handle any pin setup (e.g. controlling which pin the GPIO uses, pullup/pulldown). diff --git a/Documentation/hwmon/ds1621 b/Documentation/hwmon/ds1621 index 1fee6f1e6bc5..5e97f333c4df 100644 --- a/Documentation/hwmon/ds1621 +++ b/Documentation/hwmon/ds1621 @@ -49,12 +49,9 @@ of up to +/- 0.5 degrees even when compared against precise temperature readings. Be sure to have a high vs. low temperature limit gap of al least 1.0 degree Celsius to avoid Tout "bouncing", though! -As for alarms, you can read the alarm status of the DS1621 via the 'alarms' -/sys file interface. The result consists mainly of bit 6 and 5 of the -configuration register of the chip; bit 6 (0x40 or 64) is the high alarm -bit and bit 5 (0x20 or 32) the low one. These bits are set when the high or -low limits are met or exceeded and are reset by the module as soon as the -respective temperature ranges are left. +The alarm bits are set when the high or low limits are met or exceeded and +are reset by the module as soon as the respective temperature ranges are +left. The alarm registers are in no way suitable to find out about the actual status of Tout. They will only tell you about its history, whether or not @@ -64,45 +61,3 @@ with neither of the alarms set. Temperature conversion of the DS1621 takes up to 1000ms; internal access to non-volatile registers may last for 10ms or below. - -High Accuracy Temperature Reading ---------------------------------- - -As said before, the temperature issued via the 9-bit i2c-bus data is -somewhat arbitrary. Internally, the temperature conversion is of a -different kind that is explained (not so...) well in the DS1621 data sheet. -To cut the long story short: Inside the DS1621 there are two oscillators, -both of them biassed by a temperature coefficient. - -Higher resolution of the temperature reading can be achieved using the -internal projection, which means taking account of REG_COUNT and REG_SLOPE -(the driver manages them): - -Taken from Dallas Semiconductors App Note 068: 'Increasing Temperature -Resolution on the DS1620' and App Note 105: 'High Resolution Temperature -Measurement with Dallas Direct-to-Digital Temperature Sensors' - -- Read the 9-bit temperature and strip the LSB (Truncate the .5 degs) -- The resulting value is TEMP_READ. -- Then, read REG_COUNT. -- And then, REG_SLOPE. - - TEMP = TEMP_READ - 0.25 + ((REG_SLOPE - REG_COUNT) / REG_SLOPE) - -Note that this is what the DONE bit in the DS1621 configuration register is -good for: Internally, one temperature conversion takes up to 1000ms. Before -that conversion is complete you will not be able to read valid things out -of REG_COUNT and REG_SLOPE. The DONE bit, as you may have guessed by now, -tells you whether the conversion is complete ("done", in plain English) and -thus, whether the values you read are good or not. - -The DS1621 has two modes of operation: "Continuous" conversion, which can -be understood as the default stand-alone mode where the chip gets the -temperature and controls external devices via its Tout pin or tells other -i2c's about it if they care. The other mode is called "1SHOT", that means -that it only figures out about the temperature when it is explicitly told -to do so; this can be seen as power saving mode. - -Now if you want to read REG_COUNT and REG_SLOPE, you have to either stop -the continuous conversions until the contents of these registers are valid, -or, in 1SHOT mode, you have to have one conversion made. diff --git a/Documentation/hwmon/g760a b/Documentation/hwmon/g760a new file mode 100644 index 000000000000..e032eeb75629 --- /dev/null +++ b/Documentation/hwmon/g760a @@ -0,0 +1,36 @@ +Kernel driver g760a +=================== + +Supported chips: + * Global Mixed-mode Technology Inc. G760A + Prefix: 'g760a' + Datasheet: Publicly available at the GMT website + http://www.gmt.com.tw/datasheet/g760a.pdf + +Author: Herbert Valerio Riedel <hvr@gnu.org> + +Description +----------- + +The GMT G760A Fan Speed PWM Controller is connected directly to a fan +and performs closed-loop control of the fan speed. + +The fan speed is programmed by setting the period via 'pwm1' of two +consecutive speed pulses. The period is defined in terms of clock +cycle counts of an assumed 32kHz clock source. + +Setting a period of 0 stops the fan; setting the period to 255 sets +fan to maximum speed. + +The measured fan rotation speed returned via 'fan1_input' is derived +from the measured speed pulse period by assuming again a 32kHz clock +source and a 2 pulse-per-revolution fan. + +The 'alarms' file provides access to the two alarm bits provided by +the G760A chip's status register: Bit 0 is set when the actual fan +speed differs more than 20% with respect to the programmed fan speed; +bit 1 is set when fan speed is below 1920 RPM. + +The g760a driver will not update its values more frequently than every +other second; reading them more often will do no harm, but will return +'old' values. diff --git a/Documentation/hwmon/lis3lv02d b/Documentation/hwmon/lis3lv02d index 287f8c902656..effe949a7282 100644 --- a/Documentation/hwmon/lis3lv02d +++ b/Documentation/hwmon/lis3lv02d @@ -1,11 +1,11 @@ Kernel driver lis3lv02d -================== +======================= Supported chips: * STMicroelectronics LIS3LV02DL and LIS3LV02DQ -Author: +Authors: Yan Burman <burman.yan@gmail.com> Eric Piel <eric.piel@tremplin-utc.net> @@ -15,7 +15,7 @@ Description This driver provides support for the accelerometer found in various HP laptops sporting the feature officially called "HP Mobile Data -Protection System 3D" or "HP 3D DriveGuard". It detect automatically +Protection System 3D" or "HP 3D DriveGuard". It detects automatically laptops with this sensor. Known models (for now the HP 2133, nc6420, nc2510, nc8510, nc84x0, nw9440 and nx9420) will have their axis automatically oriented on standard way (eg: you can directly play @@ -27,7 +27,7 @@ position - 3D position that the accelerometer reports. Format: "(x,y,z)" calibrate - read: values (x, y, z) that are used as the base for input class device operation. write: forces the base to be recalibrated with the current - position. + position. rate - reports the sampling rate of the accelerometer device in HZ This driver also provides an absolute input class device, allowing @@ -48,7 +48,7 @@ For better compatibility between the various laptops. The values reported by the accelerometer are converted into a "standard" organisation of the axes (aka "can play neverball out of the box"): * When the laptop is horizontal the position reported is about 0 for X and Y -and a positive value for Z + and a positive value for Z * If the left side is elevated, X increases (becomes positive) * If the front side (where the touchpad is) is elevated, Y decreases (becomes negative) @@ -59,3 +59,13 @@ email to the authors to add it to the database. When reporting a new laptop, please include the output of "dmidecode" plus the value of /sys/devices/platform/lis3lv02d/position in these four cases. +Q&A +--- + +Q: How do I safely simulate freefall? I have an HP "portable +workstation" which has about 3.5kg and a plastic case, so letting it +fall to the ground is out of question... + +A: The sensor is pretty sensitive, so your hands can do it. Lift it +into free space, follow the fall with your hands for like 10 +centimeters. That should be enough to trigger the detection. diff --git a/Documentation/hwmon/lm90 b/Documentation/hwmon/lm90 index 0e8411710238..93d8e3d55150 100644 --- a/Documentation/hwmon/lm90 +++ b/Documentation/hwmon/lm90 @@ -42,6 +42,11 @@ Supported chips: Addresses scanned: I2C 0x4e Datasheet: Publicly available at the Maxim website http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3497 + * Maxim MAX6648 + Prefix: 'max6646' + Addresses scanned: I2C 0x4c + Datasheet: Publicly available at the Maxim website + http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3500 * Maxim MAX6649 Prefix: 'max6646' Addresses scanned: I2C 0x4c @@ -74,6 +79,11 @@ Supported chips: 0x4c, 0x4d and 0x4e Datasheet: Publicly available at the Maxim website http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3370 + * Maxim MAX6692 + Prefix: 'max6646' + Addresses scanned: I2C 0x4c + Datasheet: Publicly available at the Maxim website + http://www.maxim-ic.com/quick_view2.cfm/qv_pk/3500 Author: Jean Delvare <khali@linux-fr.org> diff --git a/Documentation/hwmon/ltc4215 b/Documentation/hwmon/ltc4215 new file mode 100644 index 000000000000..2e6a21eb656c --- /dev/null +++ b/Documentation/hwmon/ltc4215 @@ -0,0 +1,50 @@ +Kernel driver ltc4215 +===================== + +Supported chips: + * Linear Technology LTC4215 + Prefix: 'ltc4215' + Addresses scanned: 0x44 + Datasheet: + http://www.linear.com/pc/downloadDocument.do?navId=H0,C1,C1003,C1006,C1163,P17572,D12697 + +Author: Ira W. Snyder <iws@ovro.caltech.edu> + + +Description +----------- + +The LTC4215 controller allows a board to be safely inserted and removed +from a live backplane. + + +Usage Notes +----------- + +This driver does not probe for LTC4215 devices, due to the fact that some +of the possible addresses are unfriendly to probing. You will need to use +the "force" parameter to tell the driver where to find the device. + +Example: the following will load the driver for an LTC4215 at address 0x44 +on I2C bus #0: +$ modprobe ltc4215 force=0,0x44 + + +Sysfs entries +------------- + +The LTC4215 has built-in limits for overvoltage, undervoltage, and +undercurrent warnings. This makes it very likely that the reference +circuit will be used. + +in1_input input voltage +in2_input output voltage + +in1_min_alarm input undervoltage alarm +in1_max_alarm input overvoltage alarm + +curr1_input current +curr1_max_alarm overcurrent alarm + +power1_input power usage +power1_alarm power bad alarm diff --git a/Documentation/i2c/chips/pcf8591 b/Documentation/hwmon/pcf8591 index 5628fcf4207f..5628fcf4207f 100644 --- a/Documentation/i2c/chips/pcf8591 +++ b/Documentation/hwmon/pcf8591 diff --git a/Documentation/hwmon/sysfs-interface b/Documentation/hwmon/sysfs-interface index 6dbfd5efd991..2f10ce6a879f 100644 --- a/Documentation/hwmon/sysfs-interface +++ b/Documentation/hwmon/sysfs-interface @@ -365,6 +365,7 @@ energy[1-*]_input Cumulative energy use Unit: microJoule RO + ********** * Alarms * ********** @@ -453,6 +454,27 @@ beep_mask Bitmask for beep. RW +*********************** +* Intrusion detection * +*********************** + +intrusion[0-*]_alarm + Chassis intrusion detection + 0: OK + 1: intrusion detected + RW + Contrary to regular alarm flags which clear themselves + automatically when read, this one sticks until cleared by + the user. This is done by writing 0 to the file. Writing + other values is unsupported. + +intrusion[0-*]_beep + Chassis intrusion beep + 0: disable + 1: enable + RW + + sysfs attribute writes interpretation ------------------------------------- diff --git a/Documentation/hwmon/w83627ehf b/Documentation/hwmon/w83627ehf index d6e1ae30fa6e..b6eb59384bb3 100644 --- a/Documentation/hwmon/w83627ehf +++ b/Documentation/hwmon/w83627ehf @@ -2,30 +2,40 @@ Kernel driver w83627ehf ======================= Supported chips: - * Winbond W83627EHF/EHG/DHG (ISA access ONLY) + * Winbond W83627EHF/EHG (ISA access ONLY) Prefix: 'w83627ehf' Addresses scanned: ISA address retrieved from Super I/O registers Datasheet: - http://www.winbond-usa.com/products/winbond_products/pdfs/PCIC/W83627EHF_%20W83627EHGb.pdf - DHG datasheet confidential. + http://www.nuvoton.com.tw/NR/rdonlyres/A6A258F0-F0C9-4F97-81C0-C4D29E7E943E/0/W83627EHF.pdf + * Winbond W83627DHG + Prefix: 'w83627dhg' + Addresses scanned: ISA address retrieved from Super I/O registers + Datasheet: + http://www.nuvoton.com.tw/NR/rdonlyres/7885623D-A487-4CF9-A47F-30C5F73D6FE6/0/W83627DHG.pdf + * Winbond W83667HG + Prefix: 'w83667hg' + Addresses scanned: ISA address retrieved from Super I/O registers + Datasheet: not available Authors: Jean Delvare <khali@linux-fr.org> Yuan Mu (Winbond) Rudolf Marek <r.marek@assembler.cz> David Hubbard <david.c.hubbard@gmail.com> + Gong Jun <JGong@nuvoton.com> Description ----------- -This driver implements support for the Winbond W83627EHF, W83627EHG, and -W83627DHG super I/O chips. We will refer to them collectively as Winbond chips. +This driver implements support for the Winbond W83627EHF, W83627EHG, +W83627DHG and W83667HG super I/O chips. We will refer to them collectively +as Winbond chips. The chips implement three temperature sensors, five fan rotation speed sensors, ten analog voltage sensors (only nine for the 627DHG), one -VID (6 pins for the 627EHF/EHG, 8 pins for the 627DHG), alarms with beep -warnings (control unimplemented), and some automatic fan regulation -strategies (plus manual fan control mode). +VID (6 pins for the 627EHF/EHG, 8 pins for the 627DHG and 667HG), alarms +with beep warnings (control unimplemented), and some automatic fan +regulation strategies (plus manual fan control mode). Temperatures are measured in degrees Celsius and measurement resolution is 1 degC for temp1 and 0.5 degC for temp2 and temp3. An alarm is triggered when @@ -54,7 +64,8 @@ follows: temp1 -> pwm1 temp2 -> pwm2 temp3 -> pwm3 -prog -> pwm4 (the programmable setting is not supported by the driver) +prog -> pwm4 (not on 667HG; the programmable setting is not supported by + the driver) /sys files ---------- diff --git a/Documentation/i2c/busses/i2c-nforce2 b/Documentation/i2c/busses/i2c-nforce2 index fae3495bcbaf..9698c396b830 100644 --- a/Documentation/i2c/busses/i2c-nforce2 +++ b/Documentation/i2c/busses/i2c-nforce2 @@ -7,10 +7,14 @@ Supported adapters: * nForce3 250Gb MCP 10de:00E4 * nForce4 MCP 10de:0052 * nForce4 MCP-04 10de:0034 - * nForce4 MCP51 10de:0264 - * nForce4 MCP55 10de:0368 - * nForce4 MCP61 10de:03EB - * nForce4 MCP65 10de:0446 + * nForce MCP51 10de:0264 + * nForce MCP55 10de:0368 + * nForce MCP61 10de:03EB + * nForce MCP65 10de:0446 + * nForce MCP67 10de:0542 + * nForce MCP73 10de:07D8 + * nForce MCP78S 10de:0752 + * nForce MCP79 10de:0AA2 Datasheet: not publicly available, but seems to be similar to the AMD-8111 SMBus 2.0 adapter. diff --git a/Documentation/i2c/busses/i2c-piix4 b/Documentation/i2c/busses/i2c-piix4 index ef1efa79b1df..f889481762b5 100644 --- a/Documentation/i2c/busses/i2c-piix4 +++ b/Documentation/i2c/busses/i2c-piix4 @@ -4,7 +4,7 @@ Supported adapters: * Intel 82371AB PIIX4 and PIIX4E * Intel 82443MX (440MX) Datasheet: Publicly available at the Intel website - * ServerWorks OSB4, CSB5, CSB6 and HT-1000 southbridges + * ServerWorks OSB4, CSB5, CSB6, HT-1000 and HT-1100 southbridges Datasheet: Only available via NDA from ServerWorks * ATI IXP200, IXP300, IXP400, SB600, SB700 and SB800 southbridges Datasheet: Not publicly available diff --git a/Documentation/i2c/instantiating-devices b/Documentation/i2c/instantiating-devices new file mode 100644 index 000000000000..b55ce57a84db --- /dev/null +++ b/Documentation/i2c/instantiating-devices @@ -0,0 +1,167 @@ +How to instantiate I2C devices +============================== + +Unlike PCI or USB devices, I2C devices are not enumerated at the hardware +level. Instead, the software must know which devices are connected on each +I2C bus segment, and what address these devices are using. For this +reason, the kernel code must instantiate I2C devices explicitly. There are +several ways to achieve this, depending on the context and requirements. + + +Method 1: Declare the I2C devices by bus number +----------------------------------------------- + +This method is appropriate when the I2C bus is a system bus as is the case +for many embedded systems. On such systems, each I2C bus has a number +which is known in advance. It is thus possible to pre-declare the I2C +devices which live on this bus. This is done with an array of struct +i2c_board_info which is registered by calling i2c_register_board_info(). + +Example (from omap2 h4): + +static struct i2c_board_info __initdata h4_i2c_board_info[] = { + { + I2C_BOARD_INFO("isp1301_omap", 0x2d), + .irq = OMAP_GPIO_IRQ(125), + }, + { /* EEPROM on mainboard */ + I2C_BOARD_INFO("24c01", 0x52), + .platform_data = &m24c01, + }, + { /* EEPROM on cpu card */ + I2C_BOARD_INFO("24c01", 0x57), + .platform_data = &m24c01, + }, +}; + +static void __init omap_h4_init(void) +{ + (...) + i2c_register_board_info(1, h4_i2c_board_info, + ARRAY_SIZE(h4_i2c_board_info)); + (...) +} + +The above code declares 3 devices on I2C bus 1, including their respective +addresses and custom data needed by their drivers. When the I2C bus in +question is registered, the I2C devices will be instantiated automatically +by i2c-core. + +The devices will be automatically unbound and destroyed when the I2C bus +they sit on goes away (if ever.) + + +Method 2: Instantiate the devices explicitly +-------------------------------------------- + +This method is appropriate when a larger device uses an I2C bus for +internal communication. A typical case is TV adapters. These can have a +tuner, a video decoder, an audio decoder, etc. usually connected to the +main chip by the means of an I2C bus. You won't know the number of the I2C +bus in advance, so the method 1 described above can't be used. Instead, +you can instantiate your I2C devices explicitly. This is done by filling +a struct i2c_board_info and calling i2c_new_device(). + +Example (from the sfe4001 network driver): + +static struct i2c_board_info sfe4001_hwmon_info = { + I2C_BOARD_INFO("max6647", 0x4e), +}; + +int sfe4001_init(struct efx_nic *efx) +{ + (...) + efx->board_info.hwmon_client = + i2c_new_device(&efx->i2c_adap, &sfe4001_hwmon_info); + + (...) +} + +The above code instantiates 1 I2C device on the I2C bus which is on the +network adapter in question. + +A variant of this is when you don't know for sure if an I2C device is +present or not (for example for an optional feature which is not present +on cheap variants of a board but you have no way to tell them apart), or +it may have different addresses from one board to the next (manufacturer +changing its design without notice). In this case, you can call +i2c_new_probed_device() instead of i2c_new_device(). + +Example (from the pnx4008 OHCI driver): + +static const unsigned short normal_i2c[] = { 0x2c, 0x2d, I2C_CLIENT_END }; + +static int __devinit usb_hcd_pnx4008_probe(struct platform_device *pdev) +{ + (...) + struct i2c_adapter *i2c_adap; + struct i2c_board_info i2c_info; + + (...) + i2c_adap = i2c_get_adapter(2); + memset(&i2c_info, 0, sizeof(struct i2c_board_info)); + strlcpy(i2c_info.name, "isp1301_pnx", I2C_NAME_SIZE); + isp1301_i2c_client = i2c_new_probed_device(i2c_adap, &i2c_info, + normal_i2c); + i2c_put_adapter(i2c_adap); + (...) +} + +The above code instantiates up to 1 I2C device on the I2C bus which is on +the OHCI adapter in question. It first tries at address 0x2c, if nothing +is found there it tries address 0x2d, and if still nothing is found, it +simply gives up. + +The driver which instantiated the I2C device is responsible for destroying +it on cleanup. This is done by calling i2c_unregister_device() on the +pointer that was earlier returned by i2c_new_device() or +i2c_new_probed_device(). + + +Method 3: Probe an I2C bus for certain devices +---------------------------------------------- + +Sometimes you do not have enough information about an I2C device, not even +to call i2c_new_probed_device(). The typical case is hardware monitoring +chips on PC mainboards. There are several dozen models, which can live +at 25 different addresses. Given the huge number of mainboards out there, +it is next to impossible to build an exhaustive list of the hardware +monitoring chips being used. Fortunately, most of these chips have +manufacturer and device ID registers, so they can be identified by +probing. + +In that case, I2C devices are neither declared nor instantiated +explicitly. Instead, i2c-core will probe for such devices as soon as their +drivers are loaded, and if any is found, an I2C device will be +instantiated automatically. In order to prevent any misbehavior of this +mechanism, the following restrictions apply: +* The I2C device driver must implement the detect() method, which + identifies a supported device by reading from arbitrary registers. +* Only buses which are likely to have a supported device and agree to be + probed, will be probed. For example this avoids probing for hardware + monitoring chips on a TV adapter. + +Example: +See lm90_driver and lm90_detect() in drivers/hwmon/lm90.c + +I2C devices instantiated as a result of such a successful probe will be +destroyed automatically when the driver which detected them is removed, +or when the underlying I2C bus is itself destroyed, whichever happens +first. + +Those of you familiar with the i2c subsystem of 2.4 kernels and early 2.6 +kernels will find out that this method 3 is essentially similar to what +was done there. Two significant differences are: +* Probing is only one way to instantiate I2C devices now, while it was the + only way back then. Where possible, methods 1 and 2 should be preferred. + Method 3 should only be used when there is no other way, as it can have + undesirable side effects. +* I2C buses must now explicitly say which I2C driver classes can probe + them (by the means of the class bitfield), while all I2C buses were + probed by default back then. The default is an empty class which means + that no probing happens. The purpose of the class bitfield is to limit + the aforementioned undesirable side effects. + +Once again, method 3 should be avoided wherever possible. Explicit device +instantiation (methods 1 and 2) is much preferred for it is safer and +faster. diff --git a/Documentation/i2c/writing-clients b/Documentation/i2c/writing-clients index 6b9af7d479c2..c1a06f989cf7 100644 --- a/Documentation/i2c/writing-clients +++ b/Documentation/i2c/writing-clients @@ -207,15 +207,26 @@ You simply have to define a detect callback which will attempt to identify supported devices (returning 0 for supported ones and -ENODEV for unsupported ones), a list of addresses to probe, and a device type (or class) so that only I2C buses which may have that type of device -connected (and not otherwise enumerated) will be probed. The i2c -core will then call you back as needed and will instantiate a device -for you for every successful detection. +connected (and not otherwise enumerated) will be probed. For example, +a driver for a hardware monitoring chip for which auto-detection is +needed would set its class to I2C_CLASS_HWMON, and only I2C adapters +with a class including I2C_CLASS_HWMON would be probed by this driver. +Note that the absence of matching classes does not prevent the use of +a device of that type on the given I2C adapter. All it prevents is +auto-detection; explicit instantiation of devices is still possible. Note that this mechanism is purely optional and not suitable for all devices. You need some reliable way to identify the supported devices (typically using device-specific, dedicated identification registers), otherwise misdetections are likely to occur and things can get wrong -quickly. +quickly. Keep in mind that the I2C protocol doesn't include any +standard way to detect the presence of a chip at a given address, let +alone a standard way to identify devices. Even worse is the lack of +semantics associated to bus transfers, which means that the same +transfer can be seen as a read operation by a chip and as a write +operation by another chip. For these reasons, explicit device +instantiation should always be preferred to auto-detection where +possible. Device Deletion diff --git a/Documentation/ia64/kvm.txt b/Documentation/ia64/kvm.txt index 84f7cb3d5bec..ffb5c80bec3e 100644 --- a/Documentation/ia64/kvm.txt +++ b/Documentation/ia64/kvm.txt @@ -42,7 +42,7 @@ Note: For step 2, please make sure that host page size == TARGET_PAGE_SIZE of qe hg clone http://xenbits.xensource.com/ext/efi-vfirmware.hg you can get the firmware's binary in the directory of efi-vfirmware.hg/binaries. - (3) Rename the firware you owned to Flash.fd, and copy it to /usr/local/share/qemu + (3) Rename the firmware you owned to Flash.fd, and copy it to /usr/local/share/qemu 4. Boot up Linux or Windows guests: 4.1 Create or install a image for guest boot. If you have xen experience, it should be easy. diff --git a/Documentation/infiniband/ipoib.txt b/Documentation/infiniband/ipoib.txt index 864ff3283780..6d40f00b358c 100644 --- a/Documentation/infiniband/ipoib.txt +++ b/Documentation/infiniband/ipoib.txt @@ -24,6 +24,49 @@ Partitions and P_Keys The P_Key for any interface is given by the "pkey" file, and the main interface for a subinterface is in "parent." +Datagram vs Connected modes + + The IPoIB driver supports two modes of operation: datagram and + connected. The mode is set and read through an interface's + /sys/class/net/<intf name>/mode file. + + In datagram mode, the IB UD (Unreliable Datagram) transport is used + and so the interface MTU has is equal to the IB L2 MTU minus the + IPoIB encapsulation header (4 bytes). For example, in a typical IB + fabric with a 2K MTU, the IPoIB MTU will be 2048 - 4 = 2044 bytes. + + In connected mode, the IB RC (Reliable Connected) transport is used. + Connected mode is to takes advantage of the connected nature of the + IB transport and allows an MTU up to the maximal IP packet size of + 64K, which reduces the number of IP packets needed for handling + large UDP datagrams, TCP segments, etc and increases the performance + for large messages. + + In connected mode, the interface's UD QP is still used for multicast + and communication with peers that don't support connected mode. In + this case, RX emulation of ICMP PMTU packets is used to cause the + networking stack to use the smaller UD MTU for these neighbours. + +Stateless offloads + + If the IB HW supports IPoIB stateless offloads, IPoIB advertises + TCP/IP checksum and/or Large Send (LSO) offloading capability to the + network stack. + + Large Receive (LRO) offloading is also implemented and may be turned + on/off using ethtool calls. Currently LRO is supported only for + checksum offload capable devices. + + Stateless offloads are supported only in datagram mode. + +Interrupt moderation + + If the underlying IB device supports CQ event moderation, one can + use ethtool to set interrupt mitigation parameters and thus reduce + the overhead incurred by handling interrupts. The main code path of + IPoIB doesn't use events for TX completion signaling so only RX + moderation is supported. + Debugging Information By compiling the IPoIB driver with CONFIG_INFINIBAND_IPOIB_DEBUG set @@ -55,3 +98,5 @@ References http://ietf.org/rfc/rfc4391.txt IP over InfiniBand (IPoIB) Architecture (RFC 4392) http://ietf.org/rfc/rfc4392.txt + IP over InfiniBand: Connected Mode (RFC 4755) + http://ietf.org/rfc/rfc4755.txt diff --git a/Documentation/input/bcm5974.txt b/Documentation/input/bcm5974.txt new file mode 100644 index 000000000000..5e22dcf6d48d --- /dev/null +++ b/Documentation/input/bcm5974.txt @@ -0,0 +1,65 @@ +BCM5974 Driver (bcm5974) +------------------------ + Copyright (C) 2008-2009 Henrik Rydberg <rydberg@euromail.se> + +The USB initialization and package decoding was made by Scott Shawcroft as +part of the touchd user-space driver project: + Copyright (C) 2008 Scott Shawcroft (scott.shawcroft@gmail.com) + +The BCM5974 driver is based on the appletouch driver: + Copyright (C) 2001-2004 Greg Kroah-Hartman (greg@kroah.com) + Copyright (C) 2005 Johannes Berg (johannes@sipsolutions.net) + Copyright (C) 2005 Stelian Pop (stelian@popies.net) + Copyright (C) 2005 Frank Arnold (frank@scirocco-5v-turbo.de) + Copyright (C) 2005 Peter Osterlund (petero2@telia.com) + Copyright (C) 2005 Michael Hanselmann (linux-kernel@hansmi.ch) + Copyright (C) 2006 Nicolas Boichat (nicolas@boichat.ch) + +This driver adds support for the multi-touch trackpad on the new Apple +Macbook Air and Macbook Pro laptops. It replaces the appletouch driver on +those computers, and integrates well with the synaptics driver of the Xorg +system. + +Known to work on Macbook Air, Macbook Pro Penryn and the new unibody +Macbook 5 and Macbook Pro 5. + +Usage +----- + +The driver loads automatically for the supported usb device ids, and +becomes available both as an event device (/dev/input/event*) and as a +mouse via the mousedev driver (/dev/input/mice). + +USB Race +-------- + +The Apple multi-touch trackpads report both mouse and keyboard events via +different interfaces of the same usb device. This creates a race condition +with the HID driver, which, if not told otherwise, will find the standard +HID mouse and keyboard, and claim the whole device. To remedy, the usb +product id must be listed in the mouse_ignore list of the hid driver. + +Debug output +------------ + +To ease the development for new hardware version, verbose packet output can +be switched on with the debug kernel module parameter. The range [1-9] +yields different levels of verbosity. Example (as root): + +echo -n 9 > /sys/module/bcm5974/parameters/debug + +tail -f /var/log/debug + +echo -n 0 > /sys/module/bcm5974/parameters/debug + +Trivia +------ + +The driver was developed at the ubuntu forums in June 2008 [1], and now has +a more permanent home at bitmath.org [2]. + +Links +----- + +[1] http://ubuntuforums.org/showthread.php?t=840040 +[2] http://http://bitmath.org/code/ diff --git a/Documentation/input/multi-touch-protocol.txt b/Documentation/input/multi-touch-protocol.txt new file mode 100644 index 000000000000..9f09557aea39 --- /dev/null +++ b/Documentation/input/multi-touch-protocol.txt @@ -0,0 +1,140 @@ +Multi-touch (MT) Protocol +------------------------- + Copyright (C) 2009 Henrik Rydberg <rydberg@euromail.se> + + +Introduction +------------ + +In order to utilize the full power of the new multi-touch devices, a way to +report detailed finger data to user space is needed. This document +describes the multi-touch (MT) protocol which allows kernel drivers to +report details for an arbitrary number of fingers. + + +Usage +----- + +Anonymous finger details are sent sequentially as separate packets of ABS +events. Only the ABS_MT events are recognized as part of a finger +packet. The end of a packet is marked by calling the input_mt_sync() +function, which generates a SYN_MT_REPORT event. The end of multi-touch +transfer is marked by calling the usual input_sync() function. + +A set of ABS_MT events with the desired properties is defined. The events +are divided into categories, to allow for partial implementation. The +minimum set consists of ABS_MT_TOUCH_MAJOR, ABS_MT_POSITION_X and +ABS_MT_POSITION_Y, which allows for multiple fingers to be tracked. If the +device supports it, the ABS_MT_WIDTH_MAJOR may be used to provide the size +of the approaching finger. Anisotropy and direction may be specified with +ABS_MT_TOUCH_MINOR, ABS_MT_WIDTH_MINOR and ABS_MT_ORIENTATION. Devices with +more granular information may specify general shapes as blobs, i.e., as a +sequence of rectangular shapes grouped together by an +ABS_MT_BLOB_ID. Finally, the ABS_MT_TOOL_TYPE may be used to specify +whether the touching tool is a finger or a pen or something else. + + +Event Semantics +--------------- + +The word "contact" is used to describe a tool which is in direct contact +with the surface. A finger, a pen or a rubber all classify as contacts. + +ABS_MT_TOUCH_MAJOR + +The length of the major axis of the contact. The length should be given in +surface units. If the surface has an X times Y resolution, the largest +possible value of ABS_MT_TOUCH_MAJOR is sqrt(X^2 + Y^2), the diagonal. + +ABS_MT_TOUCH_MINOR + +The length, in surface units, of the minor axis of the contact. If the +contact is circular, this event can be omitted. + +ABS_MT_WIDTH_MAJOR + +The length, in surface units, of the major axis of the approaching +tool. This should be understood as the size of the tool itself. The +orientation of the contact and the approaching tool are assumed to be the +same. + +ABS_MT_WIDTH_MINOR + +The length, in surface units, of the minor axis of the approaching +tool. Omit if circular. + +The above four values can be used to derive additional information about +the contact. The ratio ABS_MT_TOUCH_MAJOR / ABS_MT_WIDTH_MAJOR approximates +the notion of pressure. The fingers of the hand and the palm all have +different characteristic widths [1]. + +ABS_MT_ORIENTATION + +The orientation of the ellipse. The value should describe half a revolution +clockwise around the touch center. The scale of the value is arbitrary, but +zero should be returned for an ellipse aligned along the Y axis of the +surface. As an example, an index finger placed straight onto the axis could +return zero orientation, something negative when twisted to the left, and +something positive when twisted to the right. This value can be omitted if +the touching object is circular, or if the information is not available in +the kernel driver. + +ABS_MT_POSITION_X + +The surface X coordinate of the center of the touching ellipse. + +ABS_MT_POSITION_Y + +The surface Y coordinate of the center of the touching ellipse. + +ABS_MT_TOOL_TYPE + +The type of approaching tool. A lot of kernel drivers cannot distinguish +between different tool types, such as a finger or a pen. In such cases, the +event should be omitted. The protocol currently supports MT_TOOL_FINGER and +MT_TOOL_PEN [2]. + +ABS_MT_BLOB_ID + +The BLOB_ID groups several packets together into one arbitrarily shaped +contact. This is a low-level anonymous grouping, and should not be confused +with the high-level contactID, explained below. Most kernel drivers will +not have this capability, and can safely omit the event. + + +Finger Tracking +--------------- + +The kernel driver should generate an arbitrary enumeration of the set of +anonymous contacts currently on the surface. The order in which the packets +appear in the event stream is not important. + +The process of finger tracking, i.e., to assign a unique contactID to each +initiated contact on the surface, is left to user space; preferably the +multi-touch X driver [3]. In that driver, the contactID stays the same and +unique until the contact vanishes (when the finger leaves the surface). The +problem of assigning a set of anonymous fingers to a set of identified +fingers is a euclidian bipartite matching problem at each event update, and +relies on a sufficiently rapid update rate. + +Notes +----- + +In order to stay compatible with existing applications, the data +reported in a finger packet must not be recognized as single-touch +events. In addition, all finger data must bypass input filtering, +since subsequent events of the same type refer to different fingers. + +The first kernel driver to utilize the MT protocol is the bcm5974 driver, +where examples can be found. + +[1] With the extension ABS_MT_APPROACH_X and ABS_MT_APPROACH_Y, the +difference between the contact position and the approaching tool position +could be used to derive tilt. +[2] The list can of course be extended. +[3] The multi-touch X driver is currently in the prototyping stage. At the +time of writing (April 2009), the MT protocol is not yet merged, and the +prototype implements finger matching, basic mouse support and two-finger +scrolling. The project aims at improving the quality of current multi-touch +functionality available in the synaptics X driver, and in addition +implement more advanced gestures. diff --git a/Documentation/ioctl/ioctl-number.txt b/Documentation/ioctl/ioctl-number.txt index f1d639903325..1f779a25c703 100644 --- a/Documentation/ioctl/ioctl-number.txt +++ b/Documentation/ioctl/ioctl-number.txt @@ -122,10 +122,8 @@ Code Seq# Include File Comments 'c' 00-7F linux/coda.h conflict! 'c' 80-9F arch/s390/include/asm/chsc.h 'd' 00-FF linux/char/drm/drm/h conflict! -'d' 00-DF linux/video_decoder.h conflict! 'd' F0-FF linux/digi1.h 'e' all linux/digi1.h conflict! -'e' 00-1F linux/video_encoder.h conflict! 'e' 00-1F net/irda/irtty.h conflict! 'f' 00-1F linux/ext2_fs.h 'h' 00-7F Charon filesystem diff --git a/Documentation/isdn/00-INDEX b/Documentation/isdn/00-INDEX index 9fee5f2e5c62..5a2d69989a8c 100644 --- a/Documentation/isdn/00-INDEX +++ b/Documentation/isdn/00-INDEX @@ -2,8 +2,14 @@ - this file (info on ISDN implementation for Linux) CREDITS - list of the kind folks that brought you this stuff. +HiSax.cert + - information about the ITU approval certification of the HiSax driver. INTERFACE - - description of Linklevel and Hardwarelevel ISDN interface. + - description of isdn4linux Link Level and Hardware Level interfaces. +INTERFACE.fax + - description of the fax subinterface of isdn4linux. +INTERFACE.CAPI + - description of kernel CAPI Link Level to Hardware Level interface. README - general info on what you need and what to do for Linux ISDN. README.FAQ @@ -12,6 +18,8 @@ README.audio - info for running audio over ISDN. README.fax - info for using Fax over ISDN. +README.gigaset + - info on the drivers for Siemens Gigaset ISDN adapters. README.icn - info on the ICN-ISDN-card and its driver. README.HiSax @@ -37,7 +45,8 @@ README.diversion README.sc - info on driver for Spellcaster cards. README.x25 - _ info for running X.25 over ISDN. + - info for running X.25 over ISDN. README.hysdn - - info on driver for Hypercope active HYSDN cards - + - info on driver for Hypercope active HYSDN cards +README.mISDN + - info on the Modular ISDN subsystem (mISDN). diff --git a/Documentation/isdn/INTERFACE.CAPI b/Documentation/isdn/INTERFACE.CAPI new file mode 100644 index 000000000000..786d619b36e5 --- /dev/null +++ b/Documentation/isdn/INTERFACE.CAPI @@ -0,0 +1,213 @@ +Kernel CAPI Interface to Hardware Drivers +----------------------------------------- + +1. Overview + +From the CAPI 2.0 specification: +COMMON-ISDN-API (CAPI) is an application programming interface standard used +to access ISDN equipment connected to basic rate interfaces (BRI) and primary +rate interfaces (PRI). + +Kernel CAPI operates as a dispatching layer between CAPI applications and CAPI +hardware drivers. Hardware drivers register ISDN devices (controllers, in CAPI +lingo) with Kernel CAPI to indicate their readiness to provide their service +to CAPI applications. CAPI applications also register with Kernel CAPI, +requesting association with a CAPI device. Kernel CAPI then dispatches the +application registration to an available device, forwarding it to the +corresponding hardware driver. Kernel CAPI then forwards CAPI messages in both +directions between the application and the hardware driver. + +Format and semantics of CAPI messages are specified in the CAPI 2.0 standard. +This standard is freely available from http://www.capi.org. + + +2. Driver and Device Registration + +CAPI drivers optionally register themselves with Kernel CAPI by calling the +Kernel CAPI function register_capi_driver() with a pointer to a struct +capi_driver. This structure must be filled with the name and revision of the +driver, and optionally a pointer to a callback function, add_card(). The +registration can be revoked by calling the function unregister_capi_driver() +with a pointer to the same struct capi_driver. + +CAPI drivers must register each of the ISDN devices they control with Kernel +CAPI by calling the Kernel CAPI function attach_capi_ctr() with a pointer to a +struct capi_ctr before they can be used. This structure must be filled with +the names of the driver and controller, and a number of callback function +pointers which are subsequently used by Kernel CAPI for communicating with the +driver. The registration can be revoked by calling the function +detach_capi_ctr() with a pointer to the same struct capi_ctr. + +Before the device can be actually used, the driver must fill in the device +information fields 'manu', 'version', 'profile' and 'serial' in the capi_ctr +structure of the device, and signal its readiness by calling capi_ctr_ready(). +From then on, Kernel CAPI may call the registered callback functions for the +device. + +If the device becomes unusable for any reason (shutdown, disconnect ...), the +driver has to call capi_ctr_reseted(). This will prevent further calls to the +callback functions by Kernel CAPI. + + +3. Application Registration and Communication + +Kernel CAPI forwards registration requests from applications (calls to CAPI +operation CAPI_REGISTER) to an appropriate hardware driver by calling its +register_appl() callback function. A unique Application ID (ApplID, u16) is +allocated by Kernel CAPI and passed to register_appl() along with the +parameter structure provided by the application. This is analogous to the +open() operation on regular files or character devices. + +After a successful return from register_appl(), CAPI messages from the +application may be passed to the driver for the device via calls to the +send_message() callback function. The CAPI message to send is stored in the +data portion of an skb. Conversely, the driver may call Kernel CAPI's +capi_ctr_handle_message() function to pass a received CAPI message to Kernel +CAPI for forwarding to an application, specifying its ApplID. + +Deregistration requests (CAPI operation CAPI_RELEASE) from applications are +forwarded as calls to the release_appl() callback function, passing the same +ApplID as with register_appl(). After return from release_appl(), no CAPI +messages for that application may be passed to or from the device anymore. + + +4. Data Structures + +4.1 struct capi_driver + +This structure describes a Kernel CAPI driver itself. It is used in the +register_capi_driver() and unregister_capi_driver() functions, and contains +the following non-private fields, all to be set by the driver before calling +register_capi_driver(): + +char name[32] + the name of the driver, as a zero-terminated ASCII string +char revision[32] + the revision number of the driver, as a zero-terminated ASCII string +int (*add_card)(struct capi_driver *driver, capicardparams *data) + a callback function pointer (may be NULL) + + +4.2 struct capi_ctr + +This structure describes an ISDN device (controller) handled by a Kernel CAPI +driver. After registration via the attach_capi_ctr() function it is passed to +all controller specific lower layer interface and callback functions to +identify the controller to operate on. + +It contains the following non-private fields: + +- to be set by the driver before calling attach_capi_ctr(): + +struct module *owner + pointer to the driver module owning the device + +void *driverdata + an opaque pointer to driver specific data, not touched by Kernel CAPI + +char name[32] + the name of the controller, as a zero-terminated ASCII string + +char *driver_name + the name of the driver, as a zero-terminated ASCII string + +int (*load_firmware)(struct capi_ctr *ctrlr, capiloaddata *ldata) + (optional) pointer to a callback function for sending firmware and + configuration data to the device + +void (*reset_ctr)(struct capi_ctr *ctrlr) + pointer to a callback function for performing a reset on the device, + releasing all registered applications + +void (*register_appl)(struct capi_ctr *ctrlr, u16 applid, + capi_register_params *rparam) +void (*release_appl)(struct capi_ctr *ctrlr, u16 applid) + pointers to callback functions for registration and deregistration of + applications with the device + +u16 (*send_message)(struct capi_ctr *ctrlr, struct sk_buff *skb) + pointer to a callback function for sending a CAPI message to the + device + +char *(*procinfo)(struct capi_ctr *ctrlr) + pointer to a callback function returning the entry for the device in + the CAPI controller info table, /proc/capi/controller + +read_proc_t *ctr_read_proc + pointer to the read_proc callback function for the device's proc file + system entry, /proc/capi/controllers/<n>; will be called with a + pointer to the device's capi_ctr structure as the last (data) argument + +- to be filled in before calling capi_ctr_ready(): + +u8 manu[CAPI_MANUFACTURER_LEN] + value to return for CAPI_GET_MANUFACTURER + +capi_version version + value to return for CAPI_GET_VERSION + +capi_profile profile + value to return for CAPI_GET_PROFILE + +u8 serial[CAPI_SERIAL_LEN] + value to return for CAPI_GET_SERIAL + + +5. Lower Layer Interface Functions + +(declared in <linux/isdn/capilli.h>) + +void register_capi_driver(struct capi_driver *drvr) +void unregister_capi_driver(struct capi_driver *drvr) + register/unregister a driver with Kernel CAPI + +int attach_capi_ctr(struct capi_ctr *ctrlr) +int detach_capi_ctr(struct capi_ctr *ctrlr) + register/unregister a device (controller) with Kernel CAPI + +void capi_ctr_ready(struct capi_ctr *ctrlr) +void capi_ctr_reseted(struct capi_ctr *ctrlr) + signal controller ready/not ready + +void capi_ctr_suspend_output(struct capi_ctr *ctrlr) +void capi_ctr_resume_output(struct capi_ctr *ctrlr) + signal suspend/resume + +void capi_ctr_handle_message(struct capi_ctr * ctrlr, u16 applid, + struct sk_buff *skb) + pass a received CAPI message to Kernel CAPI + for forwarding to the specified application + + +6. Helper Functions and Macros + +Library functions (from <linux/isdn/capilli.h>): + +void capilib_new_ncci(struct list_head *head, u16 applid, + u32 ncci, u32 winsize) +void capilib_free_ncci(struct list_head *head, u16 applid, u32 ncci) +void capilib_release_appl(struct list_head *head, u16 applid) +void capilib_release(struct list_head *head) +void capilib_data_b3_conf(struct list_head *head, u16 applid, + u32 ncci, u16 msgid) +u16 capilib_data_b3_req(struct list_head *head, u16 applid, + u32 ncci, u16 msgid) + + +Macros to extract/set element values from/in a CAPI message header +(from <linux/isdn/capiutil.h>): + +Get Macro Set Macro Element (Type) + +CAPIMSG_LEN(m) CAPIMSG_SETLEN(m, len) Total Length (u16) +CAPIMSG_APPID(m) CAPIMSG_SETAPPID(m, applid) ApplID (u16) +CAPIMSG_COMMAND(m) CAPIMSG_SETCOMMAND(m,cmd) Command (u8) +CAPIMSG_SUBCOMMAND(m) CAPIMSG_SETSUBCOMMAND(m, cmd) Subcommand (u8) +CAPIMSG_CMD(m) - Command*256 + + Subcommand (u16) +CAPIMSG_MSGID(m) CAPIMSG_SETMSGID(m, msgid) Message Number (u16) + +CAPIMSG_CONTROL(m) CAPIMSG_SETCONTROL(m, contr) Controller/PLCI/NCCI + (u32) +CAPIMSG_DATALEN(m) CAPIMSG_SETDATALEN(m, len) Data Length (u16) + diff --git a/Documentation/isdn/README.gigaset b/Documentation/isdn/README.gigaset index 55b2852904a4..02c0e9341dd8 100644 --- a/Documentation/isdn/README.gigaset +++ b/Documentation/isdn/README.gigaset @@ -61,24 +61,28 @@ GigaSet 307x Device Driver --------------------- 2.1. Modules ------- - To get the device working, you have to load the proper kernel module. You - can do this using - modprobe modulename - where modulename is ser_gigaset (M101), usb_gigaset (M105), or - bas_gigaset (direct USB connection to the base). + For the devices to work, the proper kernel modules have to be loaded. + This normally happens automatically when the system detects the USB + device (base, M105) or when the line discipline is attached (M101). It + can also be triggered manually using the modprobe(8) command, for example + for troubleshooting or to pass module parameters. The module ser_gigaset provides a serial line discipline N_GIGASET_M101 - which drives the device through the regular serial line driver. To use it, - run the Gigaset M101 daemon "gigasetm101d" (also available from - http://sourceforge.net/projects/gigaset307x/) with the device file of the - RS232 port to the M101 as an argument, for example: - gigasetm101d /dev/ttyS1 - This will open the device file, set its line discipline to N_GIGASET_M101, - and then sleep in the background, keeping the device open so that the - line discipline remains active. To deactivate it, kill the daemon, for - example with - killall gigasetm101d - before disconnecting the device. + which drives the device through the regular serial line driver. It must + be attached to the serial line to which the M101 is connected with the + ldattach(8) command (requires util-linux-ng release 2.14 or later), for + example: + ldattach GIGASET_M101 /dev/ttyS1 + This will open the device file, attach the line discipline to it, and + then sleep in the background, keeping the device open so that the line + discipline remains active. To deactivate it, kill the daemon, for example + with + killall ldattach + before disconnecting the device. To have this happen automatically at + system startup/shutdown on an LSB compatible system, create and activate + an appropriate LSB startup script /etc/init.d/gigaset. (The init name + 'gigaset' is officially assigned to this project by LANANA.) + Alternatively, just add the 'ldattach' command line to /etc/rc.local. 2.2. Device nodes for user space programs ------------------------------------ @@ -194,10 +198,11 @@ GigaSet 307x Device Driver operation (for wireless access to the base), but are needed for access to the M105's own configuration mode (registration to the base, baudrate and line format settings, device status queries) via the gigacontr - utility. Their use is disabled in the driver by default for safety - reasons but can be enabled by setting the kernel configuration option - "Support for undocumented USB requests" (GIGASET_UNDOCREQ) to "Y" and - recompiling. + utility. Their use is controlled by the kernel configuration option + "Support for undocumented USB requests" (CONFIG_GIGASET_UNDOCREQ). If you + encounter error code -ENOTTY when trying to use some features of the + M105, try setting that option to "y" via 'make {x,menu}config' and + recompiling the driver. 3. Troubleshooting @@ -228,6 +233,13 @@ GigaSet 307x Device Driver Solution: Select Unimodem mode for all DECT data adapters. (see section 2.4.) + Problem: + You want to configure your USB DECT data adapter (M105) but gigacontr + reports an error: "/dev/ttyGU0: Inappropriate ioctl for device". + Solution: + Recompile the usb_gigaset driver with the kernel configuration option + CONFIG_GIGASET_UNDOCREQ set to 'y'. (see section 2.6.) + 3.2. Telling the driver to provide more information ---------------------------------------------- Building the driver with the "Gigaset debugging" kernel configuration diff --git a/Documentation/kbuild/makefiles.txt b/Documentation/kbuild/makefiles.txt index 51104f9194a5..d76cfd8712e1 100644 --- a/Documentation/kbuild/makefiles.txt +++ b/Documentation/kbuild/makefiles.txt @@ -40,10 +40,16 @@ This document describes the Linux kernel Makefiles. --- 6.7 Custom kbuild commands --- 6.8 Preprocessing linker scripts - === 7 Kbuild Variables - === 8 Makefile language - === 9 Credits - === 10 TODO + === 7 Kbuild syntax for exported headers + --- 7.1 header-y + --- 7.2 objhdr-y + --- 7.3 destination-y + --- 7.4 unifdef-y (deprecated) + + === 8 Kbuild Variables + === 9 Makefile language + === 10 Credits + === 11 TODO === 1 Overview @@ -310,6 +316,16 @@ more details, with real examples. #arch/m68k/fpsp040/Makefile ldflags-y := -x + subdir-ccflags-y, subdir-asflags-y + The two flags listed above are similar to ccflags-y and as-falgs-y. + The difference is that the subdir- variants has effect for the kbuild + file where tey are present and all subdirectories. + Options specified using subdir-* are added to the commandline before + the options specified using the non-subdir variants. + + Example: + subdir-ccflags-y := -Werror + CFLAGS_$@, AFLAGS_$@ CFLAGS_$@ and AFLAGS_$@ only apply to commands in current @@ -1143,8 +1159,69 @@ When kbuild executes, the following steps are followed (roughly): The kbuild infrastructure for *lds file are used in several architecture-specific files. +=== 7 Kbuild syntax for exported headers + +The kernel include a set of headers that is exported to userspace. +Many headers can be exported as-is but other headers requires a +minimal pre-processing before they are ready for user-space. +The pre-processing does: +- drop kernel specific annotations +- drop include of compiler.h +- drop all sections that is kernel internat (guarded by ifdef __KERNEL__) + +Each relevant directory contain a file name "Kbuild" which specify the +headers to be exported. +See subsequent chapter for the syntax of the Kbuild file. + + --- 7.1 header-y + + header-y specify header files to be exported. + + Example: + #include/linux/Kbuild + header-y += usb/ + header-y += aio_abi.h + + The convention is to list one file per line and + preferably in alphabetic order. + + header-y also specify which subdirectories to visit. + A subdirectory is identified by a trailing '/' which + can be seen in the example above for the usb subdirectory. + + Subdirectories are visited before their parent directories. + + --- 7.2 objhdr-y + + objhdr-y specifies generated files to be exported. + Generated files are special as they need to be looked + up in another directory when doing 'make O=...' builds. + + Example: + #include/linux/Kbuild + objhdr-y += version.h + + --- 7.3 destination-y + + When an architecture have a set of exported headers that needs to be + exported to a different directory destination-y is used. + destination-y specify the destination directory for all exported + headers in the file where it is present. + + Example: + #arch/xtensa/platforms/s6105/include/platform/Kbuild + destination-y := include/linux + + In the example above all exported headers in the Kbuild file + will be located in the directory "include/linux" when exported. + + + --- 7.4 unifdef-y (deprecated) + + unifdef-y is deprecated. A direct replacement is header-y. + -=== 7 Kbuild Variables +=== 8 Kbuild Variables The top Makefile exports the following variables: @@ -1206,7 +1283,7 @@ The top Makefile exports the following variables: INSTALL_MOD_STRIP will used as the option(s) to the strip command. -=== 8 Makefile language +=== 9 Makefile language The kernel Makefiles are designed to be run with GNU Make. The Makefiles use only the documented features of GNU Make, but they do use many @@ -1225,14 +1302,14 @@ time the left-hand side is used. There are some cases where "=" is appropriate. Usually, though, ":=" is the right choice. -=== 9 Credits +=== 10 Credits Original version made by Michael Elizabeth Chastain, <mailto:mec@shout.net> Updates by Kai Germaschewski <kai@tp1.ruhr-uni-bochum.de> Updates by Sam Ravnborg <sam@ravnborg.org> Language QA by Jan Engelhardt <jengelh@gmx.de> -=== 10 TODO +=== 11 TODO - Describe how kbuild supports shipped files with _shipped. - Generating offset header files. diff --git a/Documentation/kernel-doc-nano-HOWTO.txt b/Documentation/kernel-doc-nano-HOWTO.txt index 026ec7d57384..4d04572b6549 100644 --- a/Documentation/kernel-doc-nano-HOWTO.txt +++ b/Documentation/kernel-doc-nano-HOWTO.txt @@ -269,7 +269,10 @@ Use the argument mechanism to document members or constants. Inside a struct description, you can use the "private:" and "public:" comment tags. Structure fields that are inside a "private:" area -are not listed in the generated output documentation. +are not listed in the generated output documentation. The "private:" +and "public:" tags must begin immediately following a "/*" comment +marker. They may optionally include comments between the ":" and the +ending "*/" marker. Example: @@ -283,7 +286,7 @@ Example: struct my_struct { int a; int b; -/* private: */ +/* private: internal use only */ int c; }; diff --git a/Documentation/kernel-parameters.txt b/Documentation/kernel-parameters.txt index 54f21a5c262b..e87bdbfbcc75 100644 --- a/Documentation/kernel-parameters.txt +++ b/Documentation/kernel-parameters.txt @@ -17,6 +17,12 @@ are specified on the kernel command line with the module name plus usbcore.blinkenlights=1 +Hyphens (dashes) and underscores are equivalent in parameter names, so + log_buf_len=1M print-fatal-signals=1 +can also be entered as + log-buf-len=1M print_fatal_signals=1 + + This document may not be entirely up to date and comprehensive. The command "modinfo -p ${modulename}" shows a current list of all parameters of a loadable module. Loadable modules, after being loaded into the running kernel, also @@ -44,11 +50,13 @@ parameter is applicable: FB The frame buffer device is enabled. HW Appropriate hardware is enabled. IA-64 IA-64 architecture is enabled. + IMA Integrity measurement architecture is enabled. IOSCHED More than one I/O scheduler is enabled. IP_PNP IP DHCP, BOOTP, or RARP is enabled. ISAPNP ISA PnP code is enabled. ISDN Appropriate ISDN support is enabled. JOY Appropriate joystick support is enabled. + KMEMTRACE kmemtrace is enabled. LIBATA Libata driver is enabled LP Printer support is enabled. LOOP Loopback device support is enabled. @@ -132,7 +140,7 @@ and is between 256 and 4096 characters. It is defined in the file ./include/asm/setup.h as COMMAND_LINE_SIZE. - acpi= [HW,ACPI,X86-64,i386] + acpi= [HW,ACPI,X86] Advanced Configuration and Power Interface Format: { force | off | ht | strict | noirq | rsdt } force -- enable ACPI if default was off @@ -151,60 +159,6 @@ and is between 256 and 4096 characters. It is defined in the file 1,0: use 1st APIC table default: 0 - acpi_sleep= [HW,ACPI] Sleep options - Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, - old_ordering, s4_nonvs } - See Documentation/power/video.txt for information on - s3_bios and s3_mode. - s3_beep is for debugging; it makes the PC's speaker beep - as soon as the kernel's real-mode entry point is called. - s4_nohwsig prevents ACPI hardware signature from being - used during resume from hibernation. - old_ordering causes the ACPI 1.0 ordering of the _PTS - control method, with respect to putting devices into - low power states, to be enforced (the ACPI 2.0 ordering - of _PTS is used by default). - s4_nonvs prevents the kernel from saving/restoring the - ACPI NVS memory during hibernation. - - acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode - Format: { level | edge | high | low } - - acpi_irq_balance [HW,ACPI] - ACPI will balance active IRQs - default in APIC mode - - acpi_irq_nobalance [HW,ACPI] - ACPI will not move active IRQs (default) - default in PIC mode - - acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for - use by PCI - Format: <irq>,<irq>... - - acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA - Format: <irq>,<irq>... - - acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT - - acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS - Format: To spoof as Windows 98: ="Microsoft Windows" - - acpi_osi= [HW,ACPI] Modify list of supported OS interface strings - acpi_osi="string1" # add string1 -- only one string - acpi_osi="!string2" # remove built-in string2 - acpi_osi= # disable all strings - - acpi_serialize [HW,ACPI] force serialization of AML methods - - acpi_skip_timer_override [HW,ACPI] - Recognize and ignore IRQ0/pin2 Interrupt Override. - For broken nForce2 BIOS resulting in XT-PIC timer. - acpi_use_timer_override [HW,ACPI] - Use timer override. For some broken Nvidia NF5 boards - that require a timer override, but don't have - HPET - acpi_backlight= [HW,ACPI] acpi_backlight=vendor acpi_backlight=video @@ -212,11 +166,6 @@ and is between 256 and 4096 characters. It is defined in the file (e.g. thinkpad_acpi, sony_acpi, etc.) instead of the ACPI video.ko driver. - acpi_display_output= [HW,ACPI] - acpi_display_output=vendor - acpi_display_output=video - See above. - acpi.debug_layer= [HW,ACPI,ACPI_DEBUG] acpi.debug_level= [HW,ACPI,ACPI_DEBUG] Format: <int> @@ -245,6 +194,41 @@ and is between 256 and 4096 characters. It is defined in the file unusable. The "log_buf_len" parameter may be useful if you need to capture more output. + acpi_display_output= [HW,ACPI] + acpi_display_output=vendor + acpi_display_output=video + See above. + + acpi_irq_balance [HW,ACPI] + ACPI will balance active IRQs + default in APIC mode + + acpi_irq_nobalance [HW,ACPI] + ACPI will not move active IRQs (default) + default in PIC mode + + acpi_irq_isa= [HW,ACPI] If irq_balance, mark listed IRQs used by ISA + Format: <irq>,<irq>... + + acpi_irq_pci= [HW,ACPI] If irq_balance, clear listed IRQs for + use by PCI + Format: <irq>,<irq>... + + acpi_no_auto_ssdt [HW,ACPI] Disable automatic loading of SSDT + + acpi_os_name= [HW,ACPI] Tell ACPI BIOS the name of the OS + Format: To spoof as Windows 98: ="Microsoft Windows" + + acpi_osi= [HW,ACPI] Modify list of supported OS interface strings + acpi_osi="string1" # add string1 -- only one string + acpi_osi="!string2" # remove built-in string2 + acpi_osi= # disable all strings + + acpi_pm_good [X86] + Override the pmtimer bug detection: force the kernel + to assume that this machine's pmtimer latches its value + and always returns good values. + acpi.power_nocheck= [HW,ACPI] Format: 1/0 enable/disable the check of power state. On some bogus BIOS the _PSC object/_STA object of @@ -253,30 +237,57 @@ and is between 256 and 4096 characters. It is defined in the file power state again in power transition. 1 : disable the power state check - acpi_pm_good [X86-32,X86-64] - Override the pmtimer bug detection: force the kernel - to assume that this machine's pmtimer latches its value - and always returns good values. + acpi_sci= [HW,ACPI] ACPI System Control Interrupt trigger mode + Format: { level | edge | high | low } - agp= [AGP] - { off | try_unsupported } - off: disable AGP support - try_unsupported: try to drive unsupported chipsets - (may crash computer or cause data corruption) + acpi_serialize [HW,ACPI] force serialization of AML methods - enable_timer_pin_1 [i386,x86-64] - Enable PIN 1 of APIC timer - Can be useful to work around chipset bugs - (in particular on some ATI chipsets). - The kernel tries to set a reasonable default. + acpi_skip_timer_override [HW,ACPI] + Recognize and ignore IRQ0/pin2 Interrupt Override. + For broken nForce2 BIOS resulting in XT-PIC timer. - disable_timer_pin_1 [i386,x86-64] - Disable PIN 1 of APIC timer - Can be useful to work around chipset bugs. + acpi_sleep= [HW,ACPI] Sleep options + Format: { s3_bios, s3_mode, s3_beep, s4_nohwsig, + old_ordering, s4_nonvs } + See Documentation/power/video.txt for information on + s3_bios and s3_mode. + s3_beep is for debugging; it makes the PC's speaker beep + as soon as the kernel's real-mode entry point is called. + s4_nohwsig prevents ACPI hardware signature from being + used during resume from hibernation. + old_ordering causes the ACPI 1.0 ordering of the _PTS + control method, with respect to putting devices into + low power states, to be enforced (the ACPI 2.0 ordering + of _PTS is used by default). + s4_nonvs prevents the kernel from saving/restoring the + ACPI NVS memory during hibernation. + + acpi_use_timer_override [HW,ACPI] + Use timer override. For some broken Nvidia NF5 boards + that require a timer override, but don't have HPET + + acpi_enforce_resources= [ACPI] + { strict | lax | no } + Check for resource conflicts between native drivers + and ACPI OperationRegions (SystemIO and SystemMemory + only). IO ports and memory declared in ACPI might be + used by the ACPI subsystem in arbitrary AML code and + can interfere with legacy drivers. + strict (default): access to resources claimed by ACPI + is denied; legacy drivers trying to access reserved + resources will fail to bind to device using them. + lax: access to resources claimed by ACPI is allowed; + legacy drivers trying to access reserved resources + will bind successfully but a warning message is logged. + no: ACPI OperationRegions are not marked as reserved, + no further checks are performed. ad1848= [HW,OSS] Format: <io>,<irq>,<dma>,<dma2>,<type> + add_efi_memmap [EFI; X86] Include EFI memory map in + kernel's map of available physical RAM. + advansys= [HW,SCSI] See header of drivers/scsi/advansys.c. @@ -287,6 +298,12 @@ and is between 256 and 4096 characters. It is defined in the file Format: <io>,<irq>,<dma>,<mss_io>,<mpu_io>,<mpu_irq> See also header of sound/oss/aedsp16.c. + agp= [AGP] + { off | try_unsupported } + off: disable AGP support + try_unsupported: try to drive unsupported chipsets + (may crash computer or cause data corruption) + aha152x= [HW,SCSI] See Documentation/scsi/aha152x.txt. @@ -334,7 +351,7 @@ and is between 256 and 4096 characters. It is defined in the file not play well with APC CPU idle - disable it if you have APC and your system crashes randomly. - apic= [APIC,i386] Advanced Programmable Interrupt Controller + apic= [APIC,X86-32] Advanced Programmable Interrupt Controller Change the output verbosity whilst booting Format: { quiet (default) | verbose | debug } Change the amount of debugging information output @@ -414,12 +431,6 @@ and is between 256 and 4096 characters. It is defined in the file possible to determine what the correct size should be. This option provides an override for these situations. - security= [SECURITY] Choose a security module to enable at boot. - If this boot parameter is not specified, only the first - security module asking for security registration will be - loaded. An invalid security module name will be treated - as if no module has been chosen. - capability.disable= [SECURITY] Disable capabilities. This would normally be used only if an alternative security model is to be @@ -486,17 +497,11 @@ and is between 256 and 4096 characters. It is defined in the file Also note the kernel might malfunction if you disable some critical bits. - code_bytes [IA32/X86_64] How many bytes of object code to print + code_bytes [X86] How many bytes of object code to print in an oops report. Range: 0 - 8192 Default: 64 - hpet= [X86-32,HPET] option to control HPET usage - Format: { enable (default) | disable | force } - disable: disable HPET and use PIT instead - force: allow force enabled of undocumented chips (ICH4, - VIA, nVidia) - com20020= [HW,NET] ARCnet - COM20020 chipset Format: <io>[,<irq>[,<nodeID>[,<backplane>[,<ckp>[,<timeout>]]]]] @@ -540,23 +545,6 @@ and is between 256 and 4096 characters. It is defined in the file console=brl,ttyS0 For now, only VisioBraille is supported. - earlycon= [KNL] Output early console device and options. - uart[8250],io,<addr>[,options] - uart[8250],mmio,<addr>[,options] - Start an early, polled-mode console on the 8250/16550 - UART at the specified I/O port or MMIO address. - The options are the same as for ttyS, above. - - no_console_suspend - [HW] Never suspend the console - Disable suspending of consoles during suspend and - hibernate operations. Once disabled, debugging - messages can reach various consoles while the rest - of the system is being put to sleep (ie, while - debugging driver suspend/resume hooks). This may - not work reliably with all consoles, but is known - to work with serial and VGA consoles. - coredump_filter= [KNL] Change the default value for /proc/<pid>/coredump_filter. @@ -604,36 +592,22 @@ and is between 256 and 4096 characters. It is defined in the file debug_objects [KNL] Enable object debugging + no_debug_objects + [KNL] Disable object debugging + debugpat [X86] Enable PAT debugging decnet.addr= [HW,NET] Format: <area>[,<node>] See also Documentation/networking/decnet.txt. - vt.default_blu= [VT] - Format: <blue0>,<blue1>,<blue2>,...,<blue15> - Change the default blue palette of the console. - This is a 16-member array composed of values - ranging from 0-255. - - vt.default_grn= [VT] - Format: <green0>,<green1>,<green2>,...,<green15> - Change the default green palette of the console. - This is a 16-member array composed of values - ranging from 0-255. - - vt.default_red= [VT] - Format: <red0>,<red1>,<red2>,...,<red15> - Change the default red palette of the console. - This is a 16-member array composed of values - ranging from 0-255. - - vt.default_utf8= - [VT] - Format=<0|1> - Set system-wide default UTF-8 mode for all tty's. - Default is 1, i.e. UTF-8 mode is enabled for all - newly opened terminals. + default_hugepagesz= + [same as hugepagesz=] The size of the default + HugeTLB page size. This is the size represented by + the legacy /proc/ hugepages APIs, used for SHM, and + default size when mounting hugetlbfs filesystems. + Defaults to the default architecture's huge page size + if not specified. dhash_entries= [KNL] Set number of hash buckets for dentry cache. @@ -646,27 +620,9 @@ and is between 256 and 4096 characters. It is defined in the file Documentation/serial/digiepca.txt. disable_mtrr_cleanup [X86] - enable_mtrr_cleanup [X86] The kernel tries to adjust MTRR layout from continuous to discrete, to make X server driver able to add WB - entry later. This parameter enables/disables that. - - mtrr_chunk_size=nn[KMG] [X86] - used for mtrr cleanup. It is largest continous chunk - that could hold holes aka. UC entries. - - mtrr_gran_size=nn[KMG] [X86] - Used for mtrr cleanup. It is granularity of mtrr block. - Default is 1. - Large value could prevent small alignment from - using up MTRRs. - - mtrr_spare_reg_nr=n [X86] - Format: <integer> - Range: 0,7 : spare reg number - Default : 1 - Used for mtrr cleanup. It is spare mtrr entries number. - Set to 2 or more if your graphical card needs more. + entry later. This parameter disables that. disable_mtrr_trim [X86, Intel and AMD only] By default the kernel will trim any uncacheable @@ -674,13 +630,39 @@ and is between 256 and 4096 characters. It is defined in the file MTRR settings. This parameter disables that behavior, possibly causing your machine to run very slowly. + disable_timer_pin_1 [X86] + Disable PIN 1 of APIC timer + Can be useful to work around chipset bugs. + dmasound= [HW,OSS] Sound subsystem buffers + dma_debug=off If the kernel is compiled with DMA_API_DEBUG support, + this option disables the debugging code at boot. + + dma_debug_entries=<number> + This option allows to tune the number of preallocated + entries for DMA-API debugging code. One entry is + required per DMA-API allocation. Use this if the + DMA-API debugging code disables itself because the + architectural default is too low. + dscc4.setup= [NET] dtc3181e= [HW,SCSI] - earlyprintk= [X86-32,X86-64,SH,BLACKFIN] + dynamic_printk Enables pr_debug()/dev_dbg() calls if + CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. + These can also be switched on/off via + <debugfs>/dynamic_printk/modules + + earlycon= [KNL] Output early console device and options. + uart[8250],io,<addr>[,options] + uart[8250],mmio,<addr>[,options] + Start an early, polled-mode console on the 8250/16550 + UART at the specified I/O port or MMIO address. + The options are the same as for ttyS, above. + + earlyprintk= [X86,SH,BLACKFIN] earlyprintk=vga earlyprintk=serial[,ttySn[,baudrate]] earlyprintk=dbgp @@ -715,12 +697,23 @@ and is between 256 and 4096 characters. It is defined in the file See Documentation/block/as-iosched.txt and Documentation/block/deadline-iosched.txt for details. - elfcorehdr= [IA64,PPC,SH,X86-32,X86_64] + elfcorehdr= [IA64,PPC,SH,X86] Specifies physical address of start of kernel core image elf header. Generally kexec loader will pass this option to capture kernel. See Documentation/kdump/kdump.txt for details. + enable_mtrr_cleanup [X86] + The kernel tries to adjust MTRR layout from continuous + to discrete, to make X server driver able to add WB + entry later. This parameter enables that. + + enable_timer_pin_1 [X86] + Enable PIN 1 of APIC timer + Can be useful to work around chipset bugs + (in particular on some ATI chipsets). + The kernel tries to set a reasonable default. + enforcing [SELINUX] Set initial enforcing status. Format: {"0" | "1"} See security/selinux/Kconfig help text. @@ -788,7 +781,7 @@ and is between 256 and 4096 characters. It is defined in the file hashdist= [KNL,NUMA] Large hashes allocated during boot are distributed across NUMA nodes. Defaults on - for IA-64, off otherwise. + for 64bit NUMA, off otherwise. Format: 0 | 1 (for off | on) hcl= [IA-64] SGI's Hardware Graph compatibility layer @@ -808,6 +801,16 @@ and is between 256 and 4096 characters. It is defined in the file hisax= [HW,ISDN] See Documentation/isdn/README.HiSax. + hlt [BUGS=ARM,SH] + + hpet= [X86-32,HPET] option to control HPET usage + Format: { enable (default) | disable | force | + verbose } + disable: disable HPET and use PIT instead + force: allow force enabled of undocumented chips (ICH4, + VIA, nVidia) + verbose: show contents of HPET registers during setup + hugepages= [HW,X86-32,IA-64] HugeTLB pages to allocate at boot. hugepagesz= [HW,IA-64,PPC,X86-64] The size of the HugeTLB pages. On x86-64 and powerpc, this option can be specified @@ -817,18 +820,18 @@ and is between 256 and 4096 characters. It is defined in the file (when the CPU supports the "pdpe1gb" cpuinfo flag) Note that 1GB pages can only be allocated at boot time using hugepages= and not freed afterwards. - default_hugepagesz= - [same as hugepagesz=] The size of the default - HugeTLB page size. This is the size represented by - the legacy /proc/ hugepages APIs, used for SHM, and - default size when mounting hugetlbfs filesystems. - Defaults to the default architecture's huge page size - if not specified. - - hlt [BUGS=ARM,SH] hvc_iucv= [S390] Number of z/VM IUCV hypervisor console (HVC) terminal devices. Valid values: 0..8 + hvc_iucv_allow= [S390] Comma-separated list of z/VM user IDs. + If specified, z/VM IUCV HVC accepts connections + from listed z/VM user IDs only. + + i2c_bus= [HW] Override the default board specific I2C bus speed + or register an additional I2C bus that is not + registered from board initialization code. + Format: + <bus_id>,<clkrate> i8042.debug [HW] Toggle i8042 debug mode i8042.direct [HW] Put keyboard port into non-translated mode @@ -877,6 +880,9 @@ and is between 256 and 4096 characters. It is defined in the file idebus= [HW] (E)IDE subsystem - VLB/PCI bus speed See Documentation/ide/ide.txt. + ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem + Claim all unknown PCI IDE storage controllers. + idle= [X86] Format: idle=poll, idle=mwait, idle=halt, idle=nomwait Poll forces a polling idle loop that can slightly @@ -892,9 +898,6 @@ and is between 256 and 4096 characters. It is defined in the file In such case C2/C3 won't be used again. idle=nomwait: Disable mwait for CPU C-states - ide-pci-generic.all-generic-ide [HW] (E)IDE subsystem - Claim all unknown PCI IDE storage controllers. - ignore_loglevel [KNL] Ignore loglevel setting - this will print /all/ kernel messages to the console. Useful for debugging. @@ -902,6 +905,15 @@ and is between 256 and 4096 characters. It is defined in the file ihash_entries= [KNL] Set number of hash buckets for inode cache. + ima_audit= [IMA] + Format: { "0" | "1" } + 0 -- integrity auditing messages. (Default) + 1 -- enable informational integrity auditing messages. + + ima_hash= [IMA] + Formt: { "sha1" | "md5" } + default: "sha1" + in2000= [HW,SCSI] See header of drivers/scsi/in2000.c. @@ -919,25 +931,6 @@ and is between 256 and 4096 characters. It is defined in the file inport.irq= [HW] Inport (ATI XL and Microsoft) busmouse driver Format: <irq> - inttest= [IA64] - - iomem= Disable strict checking of access to MMIO memory - strict regions from userspace. - relaxed - - iommu= [x86] - off - force - noforce - biomerge - panic - nopanic - merge - nomerge - forcesac - soft - - intel_iommu= [DMAR] Intel IOMMU driver (DMAR) option on Enable intel iommu driver. @@ -961,7 +954,29 @@ and is between 256 and 4096 characters. It is defined in the file result in a hardware IOTLB flush operation as opposed to batching them for performance. - io_delay= [X86-32,X86-64] I/O delay method + inttest= [IA64] + + iomem= Disable strict checking of access to MMIO memory + strict regions from userspace. + relaxed + + iommu= [x86] + off + force + noforce + biomerge + panic + nopanic + merge + nomerge + forcesac + soft + + io7= [HW] IO7 for Marvel based alpha systems + See comment before marvel_specify_io7 in + arch/alpha/kernel/core_marvel.c. + + io_delay= [X86] I/O delay method 0x80 Standard port 0x80 based delay 0xed @@ -971,10 +986,6 @@ and is between 256 and 4096 characters. It is defined in the file none No delay - io7= [HW] IO7 for Marvel based alpha systems - See comment before marvel_specify_io7 in - arch/alpha/kernel/core_marvel.c. - ip= [IP_PNP] See Documentation/filesystems/nfsroot.txt. @@ -985,12 +996,6 @@ and is between 256 and 4096 characters. It is defined in the file ips= [HW,SCSI] Adaptec / IBM ServeRAID controller See header of drivers/scsi/ips.c. - ports= [IP_VS_FTP] IPVS ftp helper module - Default is 21. - Up to 8 (IP_VS_APP_MAX_PORTS) ports - may be specified. - Format: <port>,<port>.... - irqfixup [HW] When an interrupt is not handled search all handlers for it. Intended to get systems with badly broken @@ -1031,7 +1036,9 @@ and is between 256 and 4096 characters. It is defined in the file js= [HW,JOY] Analog joystick See Documentation/input/joystick.txt. - kernelcore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter + keepinitrd [HW,ARM] + + kernelcore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter specifies the amount of memory usable by the kernel for non-movable allocations. The requested amount is spread evenly throughout all nodes in the system. The @@ -1047,20 +1054,14 @@ and is between 256 and 4096 characters. It is defined in the file use the HighMem zone if it exists, and the Normal zone if it does not. - movablecore=nn[KMG] [KNL,X86-32,IA-64,PPC,X86-64] This parameter - is similar to kernelcore except it specifies the - amount of memory used for migratable allocations. - If both kernelcore and movablecore is specified, - then kernelcore will be at *least* the specified - value but may be more. If movablecore on its own - is specified, the administrator must be careful - that the amount of memory usable for all allocations - is not too small. + kmemtrace.enable= [KNL,KMEMTRACE] Format: { yes | no } + Controls whether kmemtrace is enabled + at boot-time. - keepinitrd [HW,ARM] - - kstack=N [X86-32,X86-64] Print N words from the kernel stack - in oops dumps. + kmemtrace.subbufs=n [KNL,KMEMTRACE] Overrides the number of + subbufs kmemtrace's relay channel has. Set this + higher than default (KMEMTRACE_N_SUBBUFS in code) if + you experience buffer overruns. kgdboc= [HW] kgdb over consoles. Requires a tty driver that supports console polling. @@ -1071,6 +1072,9 @@ and is between 256 and 4096 characters. It is defined in the file Configure the RouterBoard 532 series on-chip Ethernet adapter MAC address. + kstack=N [X86] Print N words from the kernel stack + in oops dumps. + l2cr= [PPC] l3cr= [PPC] @@ -1078,7 +1082,7 @@ and is between 256 and 4096 characters. It is defined in the file lapic [X86-32,APIC] Enable the local APIC even if BIOS disabled it. - lapic_timer_c2_ok [X86-32,x86-64,APIC] trust the local apic timer + lapic_timer_c2_ok [X86,APIC] trust the local apic timer in C2 power state. libata.dma= [LIBATA] DMA control @@ -1216,9 +1220,8 @@ and is between 256 and 4096 characters. It is defined in the file (machvec) in a generic kernel. Example: machvec=hpzx1_swiotlb - max_loop= [LOOP] Maximum number of loopback devices that can - be mounted - Format: <1-256> + max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater + than or equal to this physical address is ignored. maxcpus= [SMP] Maximum number of processors that an SMP kernel should make use of. maxcpus=n : n >= 0 limits the @@ -1226,8 +1229,9 @@ and is between 256 and 4096 characters. It is defined in the file it is equivalent to "nosmp", which also disables the IO APIC. - max_addr=nn[KMG] [KNL,BOOT,ia64] All physical memory greater than - or equal to this physical address is ignored. + max_loop= [LOOP] Maximum number of loopback devices that can + be mounted + Format: <1-256> max_luns= [SCSI] Maximum number of LUNs to probe. Should be between 1 and 2^32-1. @@ -1263,7 +1267,7 @@ and is between 256 and 4096 characters. It is defined in the file [KNL,SH] Allow user to override the default size for per-device physically contiguous DMA buffers. - memmap=exactmap [KNL,X86-32,X86_64] Enable setting of an exact + memmap=exactmap [KNL,X86] Enable setting of an exact E820 memory map, as specified by the user. Such memmap=exactmap lines can be constructed based on BIOS output or other requirements. See the memmap=nn@ss @@ -1310,8 +1314,13 @@ and is between 256 and 4096 characters. It is defined in the file memtest= [KNL,X86] Enable memtest Format: <integer> - range: 0,4 : pattern number default : 0 <disable> + Specifies the number of memtest passes to be + performed. Each pass selects another test + pattern from a given set of patterns. Memtest + fills the memory with this pattern, validates + memory contents and reserves bad memory + regions that are detected. meye.*= [HW] Set MotionEye Camera parameters See Documentation/video4linux/meye.txt. @@ -1349,6 +1358,16 @@ and is between 256 and 4096 characters. It is defined in the file mousedev.yres= [MOUSE] Vertical screen resolution, used for devices reporting absolute coordinates, such as tablets + movablecore=nn[KMG] [KNL,X86,IA-64,PPC] This parameter + is similar to kernelcore except it specifies the + amount of memory used for migratable allocations. + If both kernelcore and movablecore is specified, + then kernelcore will be at *least* the specified + value but may be more. If movablecore on its own + is specified, the administrator must be careful + that the amount of memory usable for all allocations + is not too small. + mpu401= [HW,OSS] Format: <io>,<irq> @@ -1370,6 +1389,23 @@ and is between 256 and 4096 characters. It is defined in the file [HW] Make the MicroTouch USB driver use raw coordinates ('y', default) or cooked coordinates ('n') + mtrr_chunk_size=nn[KMG] [X86] + used for mtrr cleanup. It is largest continous chunk + that could hold holes aka. UC entries. + + mtrr_gran_size=nn[KMG] [X86] + Used for mtrr cleanup. It is granularity of mtrr block. + Default is 1. + Large value could prevent small alignment from + using up MTRRs. + + mtrr_spare_reg_nr=n [X86] + Format: <integer> + Range: 0,7 : spare reg number + Default : 1 + Used for mtrr cleanup. It is spare mtrr entries number. + Set to 2 or more if your graphical card needs more. + n2= [NET] SDL Inc. RISCom/N2 synchronous serial card NCR_D700= [HW,SCSI] @@ -1424,17 +1460,19 @@ and is between 256 and 4096 characters. It is defined in the file when a NMI is triggered. Format: [state][,regs][,debounce][,die] - nmi_watchdog= [KNL,BUGS=X86-32,X86-64] Debugging features for SMP kernels + nmi_watchdog= [KNL,BUGS=X86] Debugging features for SMP kernels Format: [panic,][num] Valid num: 0,1,2 0 - turn nmi_watchdog off 1 - use the IO-APIC timer for the NMI watchdog 2 - use the local APIC for the NMI watchdog using - a performance counter. Note: This will use one performance - counter and the local APIC's performance vector. - When panic is specified panic when an NMI watchdog timeout occurs. - This is useful when you use a panic=... timeout and need the box - quickly up again. + a performance counter. Note: This will use one + performance counter and the local APIC's performance + vector. + When panic is specified, panic when an NMI watchdog + timeout occurs. + This is useful when you use a panic=... timeout and + need the box quickly up again. Instead of 1 and 2 it is possible to use the following symbolic names: lapic and ioapic Example: nmi_watchdog=2 or nmi_watchdog=panic,lapic @@ -1443,6 +1481,16 @@ and is between 256 and 4096 characters. It is defined in the file emulation library even if a 387 maths coprocessor is present. + no_console_suspend + [HW] Never suspend the console + Disable suspending of consoles during suspend and + hibernate operations. Once disabled, debugging + messages can reach various consoles while the rest + of the system is being put to sleep (ie, while + debugging driver suspend/resume hooks). This may + not work reliably with all consoles, but is known + to work with serial and VGA consoles. + noaliencache [MM, NUMA, SLAB] Disables the allocation of alien caches in the slab allocator. Saves per-node memory, but will impact performance. @@ -1457,17 +1505,19 @@ and is between 256 and 4096 characters. It is defined in the file nocache [ARM] + noclflush [BUGS=X86] Don't use the CLFLUSH instruction + nodelayacct [KNL] Disable per-task delay accounting nodisconnect [HW,SCSI,M68K] Disables SCSI disconnects. nodsp [SH] Disable hardware DSP at boot time. - noefi [X86-32,X86-64] Disable EFI runtime services support. + noefi [X86] Disable EFI runtime services support. noexec [IA-64] - noexec [X86-32,X86-64] + noexec [X86] On X86-32 available only on PAE configured kernels. noexec=on: enable non-executable mappings (default) noexec=off: disable non-executable mappings @@ -1485,9 +1535,9 @@ and is between 256 and 4096 characters. It is defined in the file register save and restore. The kernel will only save legacy floating-point registers on task switch. - noclflush [BUGS=X86] Don't use the CLFLUSH instruction - - nohlt [BUGS=ARM,SH] + nohlt [BUGS=ARM,SH] Tells the kernel that the sleep(SH) or + wfi(ARM) instruction doesn't work correctly and not to + use it. This is also useful when using JTAG debugger. no-hlt [BUGS=X86-32] Tells the kernel that the hlt instruction doesn't work correctly and not to @@ -1508,10 +1558,12 @@ and is between 256 and 4096 characters. It is defined in the file Valid arguments: on, off Default: on + noiotrap [SH] Disables trapped I/O port accesses. + noirqdebug [X86-32] Disables the code which attempts to detect and disable unhandled interrupt sources. - no_timer_check [X86-32,X86_64,APIC] Disables the code which tests for + no_timer_check [X86,APIC] Disables the code which tests for broken timer IRQ sources. noisapnp [ISAPNP] Disables ISA PnP code. @@ -1527,12 +1579,6 @@ and is between 256 and 4096 characters. It is defined in the file nolapic_timer [X86-32,APIC] Do not use the local APIC timer. - nox2apic [X86-64,APIC] Do not enable x2APIC mode. - - x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of - default x2apic cluster mode on platforms - supporting x2apic. - noltlbs [PPC] Do not use large page/tlb entries for kernel lowmem mapping on PPC40x. @@ -1543,6 +1589,9 @@ and is between 256 and 4096 characters. It is defined in the file nomfgpt [X86-32] Disable Multi-Function General Purpose Timer usage (for AMD Geode machines). + norandmaps Don't use address space randomization. Equivalent to + echo 0 > /proc/sys/kernel/randomize_va_space + noreplace-paravirt [X86-32,PV_OPS] Don't patch paravirt_ops noreplace-smp [X86-32,SMP] Don't replace SMP instructions @@ -1567,7 +1616,7 @@ and is between 256 and 4096 characters. It is defined in the file nosoftlockup [KNL] Disable the soft-lockup detector. noswapaccount [KNL] Disable accounting of swap in memory resource - controller. (See Documentation/controllers/memory.txt) + controller. (See Documentation/cgroups/memory.txt) nosync [HW,M68K] Disables sync negotiation for all devices. @@ -1577,17 +1626,19 @@ and is between 256 and 4096 characters. It is defined in the file nowb [ARM] + nox2apic [X86-64,APIC] Do not enable x2APIC mode. + nptcg= [IA64] Override max number of concurrent global TLB purges which is reported from either PAL_VM_SUMMARY or SAL PALO. + nr_uarts= [SERIAL] maximum number of UARTs to be registered. + numa_zonelist_order= [KNL, BOOT] Select zonelist order for NUMA. one of ['zone', 'node', 'default'] can be specified This can be set from sysctl after boot. See Documentation/sysctl/vm.txt for details. - nr_uarts= [SERIAL] maximum number of UARTs to be registered. - ohci1394_dma=early [HW] enable debugging via the ohci1394 driver. See Documentation/debugging-via-ohci1394.txt for more info. @@ -1659,6 +1710,8 @@ and is between 256 and 4096 characters. It is defined in the file See also Documentation/blockdev/paride.txt. pci=option[,option...] [PCI] various PCI subsystem options: + earlydump [X86] dump PCI config space before the kernel + changes anything off [X86] don't probe for the PCI bus bios [X86-32] force use of PCI BIOS, don't access the hardware directly. Use this if your machine @@ -1676,7 +1729,7 @@ and is between 256 and 4096 characters. It is defined in the file disable the use of PCIE advanced error reporting. nodomains [PCI] Disable support for multiple PCI root domains (aka PCI segments, in ACPI-speak). - nommconf [X86-32,X86_64] Disable use of MMCONFIG for PCI + nommconf [X86] Disable use of MMCONFIG for PCI Configuration nomsi [MSI] If the PCI_MSI kernel config parameter is enabled, this kernel boot option can be used to @@ -1758,6 +1811,15 @@ and is between 256 and 4096 characters. It is defined in the file cbmemsize=nn[KMG] The fixed amount of bus space which is reserved for the CardBus bridge's memory window. The default value is 64 megabytes. + resource_alignment= + Format: + [<order of align>@][<domain>:]<bus>:<slot>.<func>[; ...] + Specifies alignment and device to reassign + aligned memory resources. + If <order of align> is not specified, + PAGE_SIZE is used as alignment. + PCI-PCI bridge can be specified, if resource + windows need to be expanded. pcie_aspm= [PCIE] Forcibly enable or disable PCIe Active State Power Management. @@ -1816,10 +1878,11 @@ and is between 256 and 4096 characters. It is defined in the file autoconfiguration. Ranges are in pairs (memory base and size). - dynamic_printk Enables pr_debug()/dev_dbg() calls if - CONFIG_DYNAMIC_PRINTK_DEBUG has been enabled. - These can also be switched on/off via - <debugfs>/dynamic_printk/modules + ports= [IP_VS_FTP] IPVS ftp helper module + Default is 21. + Up to 8 (IP_VS_APP_MAX_PORTS) ports + may be specified. + Format: <port>,<port>.... print-fatal-signals= [KNL] debug: print fatal signals @@ -1830,6 +1893,14 @@ and is between 256 and 4096 characters. It is defined in the file printk.time= Show timing data prefixed to each printk message line Format: <bool> (1/Y/y=enable, 0/N/n=disable) + processor.max_cstate= [HW,ACPI] + Limit processor to maximum C-state + max_cstate=9 overrides any DMI blacklist limit. + + processor.nocst [HW,ACPI] + Ignore the _CST method to determine C-states, + instead using the legacy FADT method + profile= [KNL] Enable kernel profiling via /proc/profile Format: [schedule,]<number> Param: "schedule" - profile schedule points. @@ -1839,14 +1910,6 @@ and is between 256 and 4096 characters. It is defined in the file Requires CONFIG_SCHEDSTATS Param: "kvm" - profile VM exits. - processor.max_cstate= [HW,ACPI] - Limit processor to maximum C-state - max_cstate=9 overrides any DMI blacklist limit. - - processor.nocst [HW,ACPI] - Ignore the _CST method to determine C-states, - instead using the legacy FADT method - prompt_ramdisk= [RAM] List of RAM disks to prompt for floppy disk before loading. See Documentation/blockdev/ramdisk.txt. @@ -1911,7 +1974,7 @@ and is between 256 and 4096 characters. It is defined in the file relax_domain_level= [KNL, SMP] Set scheduler's default relax_domain_level. - See Documentation/cpusets.txt. + See Documentation/cgroups/cpusets.txt. reserve= [KNL,BUGS] Force the kernel to ignore some iomem area @@ -2000,7 +2063,13 @@ and is between 256 and 4096 characters. It is defined in the file allowing boot to proceed. none ignores them, expecting user space to do the scan. - selinux [SELINUX] Disable or enable SELinux at boot time. + security= [SECURITY] Choose a security module to enable at boot. + If this boot parameter is not specified, only the first + security module asking for security registration will be + loaded. An invalid security module name will be treated + as if no module has been chosen. + + selinux= [SELINUX] Disable or enable SELinux at boot time. Format: { "0" | "1" } See security/selinux/Kconfig help text. 0 -- disable. @@ -2009,15 +2078,6 @@ and is between 256 and 4096 characters. It is defined in the file If enabled at boot time, /selinux/disable can be used later to disable prior to initial policy load. - selinux_compat_net = - [SELINUX] Set initial selinux_compat_net flag value. - Format: { "0" | "1" } - 0 -- use new secmark-based packet controls - 1 -- use legacy packet controls - Default value is 0 (preferred). - Value can be changed at runtime via - /selinux/compat_net. - serialnumber [BUGS=X86-32] shapers= [NET] @@ -2329,6 +2389,8 @@ and is between 256 and 4096 characters. It is defined in the file tp720= [HW,PS2] + trace_buf_size=nn[KMG] [ftrace] will set tracing buffer size. + trix= [HW,OSS] MediaTrix AudioTrix Pro Format: <io>,<irq>,<dma>,<dma2>,<sb_io>,<sb_irq>,<sb_dma>,<mpu_io>,<mpu_irq> @@ -2364,7 +2426,7 @@ and is between 256 and 4096 characters. It is defined in the file reported either. unknown_nmi_panic - [X86-32,X86-64] + [X86] Set unknown_nmi_panic=1 early on boot. usbcore.autosuspend= @@ -2431,15 +2493,12 @@ and is between 256 and 4096 characters. It is defined in the file medium is write-protected). Example: quirks=0419:aaf5:rl,0421:0433:rc - add_efi_memmap [EFI; x86-32,X86-64] Include EFI memory map in - kernel's map of available physical RAM. - - vdso= [X86-32,SH,x86-64] + vdso= [X86,SH] vdso=2: enable compat VDSO (default with COMPAT_VDSO) vdso=1: enable VDSO (default) vdso=0: disable VDSO mapping - vdso32= [X86-32,X86-64] + vdso32= [X86] vdso32=2: enable compat VDSO (default with COMPAT_VDSO) vdso32=1: enable 32-bit VDSO (default) vdso32=0: disable 32-bit VDSO mapping @@ -2472,6 +2531,31 @@ and is between 256 and 4096 characters. It is defined in the file vmpoff= [KNL,S390] Perform z/VM CP command after power off. Format: <command> + vt.default_blu= [VT] + Format: <blue0>,<blue1>,<blue2>,...,<blue15> + Change the default blue palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + vt.default_grn= [VT] + Format: <green0>,<green1>,<green2>,...,<green15> + Change the default green palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + vt.default_red= [VT] + Format: <red0>,<red1>,<red2>,...,<red15> + Change the default red palette of the console. + This is a 16-member array composed of values + ranging from 0-255. + + vt.default_utf8= + [VT] + Format=<0|1> + Set system-wide default UTF-8 mode for all tty's. + Default is 1, i.e. UTF-8 mode is enabled for all + newly opened terminals. + waveartist= [HW,OSS] Format: <io>,<irq>,<dma>,<dma2> @@ -2484,6 +2568,10 @@ and is between 256 and 4096 characters. It is defined in the file wdt= [WDT] Watchdog See Documentation/watchdog/wdt.txt. + x2apic_phys [X86-64,APIC] Use x2apic physical mode instead of + default x2apic cluster mode on platforms + supporting x2apic. + xd= [HW,XT] Original XT pre-IDE (RLL encoded) disks. xd_geo= See header of drivers/block/xd.c. @@ -2491,9 +2579,6 @@ and is between 256 and 4096 characters. It is defined in the file Format: <irq>,<irq_mask>,<io>,<full_duplex>,<do_sound>,<lockup_hack>[,<irq2>[,<irq3>[,<irq4>]]] - norandmaps Don't use address space randomization. Equivalent to - echo 0 > /proc/sys/kernel/randomize_va_space - ______________________________________________________________________ TODO: diff --git a/Documentation/kprobes.txt b/Documentation/kprobes.txt index 48b3de90eb1e..1e7a769a10f9 100644 --- a/Documentation/kprobes.txt +++ b/Documentation/kprobes.txt @@ -212,7 +212,9 @@ hit, Kprobes calls kp->pre_handler. After the probed instruction is single-stepped, Kprobe calls kp->post_handler. If a fault occurs during execution of kp->pre_handler or kp->post_handler, or during single-stepping of the probed instruction, Kprobes calls -kp->fault_handler. Any or all handlers can be NULL. +kp->fault_handler. Any or all handlers can be NULL. If kp->flags +is set KPROBE_FLAG_DISABLED, that kp will be registered but disabled, +so, it's handlers aren't hit until calling enable_kprobe(kp). NOTE: 1. With the introduction of the "symbol_name" field to struct kprobe, @@ -363,6 +365,26 @@ probes) in the specified array, they clear the addr field of those incorrect probes. However, other probes in the array are unregistered correctly. +4.7 disable_*probe + +#include <linux/kprobes.h> +int disable_kprobe(struct kprobe *kp); +int disable_kretprobe(struct kretprobe *rp); +int disable_jprobe(struct jprobe *jp); + +Temporarily disables the specified *probe. You can enable it again by using +enable_*probe(). You must specify the probe which has been registered. + +4.8 enable_*probe + +#include <linux/kprobes.h> +int enable_kprobe(struct kprobe *kp); +int enable_kretprobe(struct kretprobe *rp); +int enable_jprobe(struct jprobe *jp); + +Enables *probe which has been disabled by disable_*probe(). You must specify +the probe which has been registered. + 5. Kprobes Features and Limitations Kprobes allows multiple probes at the same address. Currently, @@ -500,10 +522,14 @@ the probe. If the probed function belongs to a module, the module name is also specified. Following columns show probe status. If the probe is on a virtual address that is no longer valid (module init sections, module virtual addresses that correspond to modules that've been unloaded), -such probes are marked with [GONE]. +such probes are marked with [GONE]. If the probe is temporarily disabled, +such probes are marked with [DISABLED]. -/debug/kprobes/enabled: Turn kprobes ON/OFF +/debug/kprobes/enabled: Turn kprobes ON/OFF forcibly. -Provides a knob to globally turn registered kprobes ON or OFF. By default, -all kprobes are enabled. By echoing "0" to this file, all registered probes -will be disarmed, till such time a "1" is echoed to this file. +Provides a knob to globally and forcibly turn registered kprobes ON or OFF. +By default, all kprobes are enabled. By echoing "0" to this file, all +registered probes will be disarmed, till such time a "1" is echoed to this +file. Note that this knob just disarms and arms all kprobes and doesn't +change each probe's disabling state. This means that disabled kprobes (marked +[DISABLED]) will be not enabled if you turn ON all kprobes by this knob. diff --git a/Documentation/laptops/acer-wmi.txt b/Documentation/laptops/acer-wmi.txt index 2b3a6b5260bf..5ee2a02b3b40 100644 --- a/Documentation/laptops/acer-wmi.txt +++ b/Documentation/laptops/acer-wmi.txt @@ -1,9 +1,9 @@ Acer Laptop WMI Extras Driver http://code.google.com/p/aceracpi -Version 0.2 -18th August 2008 +Version 0.3 +4th April 2009 -Copyright 2007-2008 Carlos Corbacho <carlos@strangeworlds.co.uk> +Copyright 2007-2009 Carlos Corbacho <carlos@strangeworlds.co.uk> acer-wmi is a driver to allow you to control various parts of your Acer laptop hardware under Linux which are exposed via ACPI-WMI. @@ -36,6 +36,10 @@ not possible in kernel space from a 64 bit OS. Supported Hardware ****************** +NOTE: The Acer Aspire One is not supported hardware. It cannot work with +acer-wmi until Acer fix their ACPI-WMI implementation on them, so has been +blacklisted until that happens. + Please see the website for the current list of known working hardare: http://code.google.com/p/aceracpi/wiki/SupportedHardware diff --git a/Documentation/laptops/thinkpad-acpi.txt b/Documentation/laptops/thinkpad-acpi.txt index 41bc99fa1884..e7e9a69069e1 100644 --- a/Documentation/laptops/thinkpad-acpi.txt +++ b/Documentation/laptops/thinkpad-acpi.txt @@ -1,7 +1,7 @@ ThinkPad ACPI Extras Driver - Version 0.22 - November 23rd, 2008 + Version 0.23 + April 10th, 2009 Borislav Deianov <borislav@users.sf.net> Henrique de Moraes Holschuh <hmh@hmh.eng.br> @@ -20,7 +20,8 @@ moved to the drivers/misc tree and renamed to thinkpad-acpi for kernel kernel 2.6.29 and release 0.22. The driver is named "thinkpad-acpi". In some places, like module -names, "thinkpad_acpi" is used because of userspace issues. +names and log messages, "thinkpad_acpi" is used because of userspace +issues. "tpacpi" is used as a shorthand where "thinkpad-acpi" would be too long due to length limitations on some Linux kernel versions. @@ -37,7 +38,7 @@ detailed description): - ThinkLight on and off - limited docking and undocking - UltraBay eject - - CMOS control + - CMOS/UCMS control - LED control - ACPI sounds - temperature sensors @@ -46,6 +47,7 @@ detailed description): - Volume control - Fan control and monitoring: fan speed, fan enable/disable - WAN enable and disable + - UWB enable and disable A compatibility table by model and feature is maintained on the web site, http://ibm-acpi.sf.net/. I appreciate any success or failure @@ -53,7 +55,7 @@ reports, especially if they add to or correct the compatibility table. Please include the following information in your report: - ThinkPad model name - - a copy of your DSDT, from /proc/acpi/dsdt + - a copy of your ACPI tables, using the "acpidump" utility - a copy of the output of dmidecode, with serial numbers and UUIDs masked off - which driver features work and which don't @@ -66,17 +68,18 @@ Installation ------------ If you are compiling this driver as included in the Linux kernel -sources, simply enable the CONFIG_THINKPAD_ACPI option, and optionally -enable the CONFIG_THINKPAD_ACPI_BAY option if you want the -thinkpad-specific bay functionality. +sources, look for the CONFIG_THINKPAD_ACPI Kconfig option. +It is located on the menu path: "Device Drivers" -> "X86 Platform +Specific Device Drivers" -> "ThinkPad ACPI Laptop Extras". + Features -------- The driver exports two different interfaces to userspace, which can be used to access the features it provides. One is a legacy procfs-based -interface, which will be removed at some time in the distant future. -The other is a new sysfs-based interface which is not complete yet. +interface, which will be removed at some time in the future. The other +is a new sysfs-based interface which is not complete yet. The procfs interface creates the /proc/acpi/ibm directory. There is a file under that directory for each feature it supports. The procfs @@ -111,15 +114,17 @@ The version of thinkpad-acpi's sysfs interface is exported by the driver as a driver attribute (see below). Sysfs driver attributes are on the driver's sysfs attribute space, -for 2.6.23 this is /sys/bus/platform/drivers/thinkpad_acpi/ and +for 2.6.23+ this is /sys/bus/platform/drivers/thinkpad_acpi/ and /sys/bus/platform/drivers/thinkpad_hwmon/ Sysfs device attributes are on the thinkpad_acpi device sysfs attribute -space, for 2.6.23 this is /sys/devices/platform/thinkpad_acpi/. +space, for 2.6.23+ this is /sys/devices/platform/thinkpad_acpi/. Sysfs device attributes for the sensors and fan are on the thinkpad_hwmon device's sysfs attribute space, but you should locate it -looking for a hwmon device with the name attribute of "thinkpad". +looking for a hwmon device with the name attribute of "thinkpad", or +better yet, through libsensors. + Driver version -------------- @@ -129,6 +134,7 @@ sysfs driver attribute: version The driver name and version. No commands can be written to this file. + Sysfs interface version ----------------------- @@ -160,6 +166,7 @@ expect that an attribute might not be there, and deal with it properly (an attribute not being there *is* a valid way to make it clear that a feature is not available in sysfs). + Hot keys -------- @@ -172,17 +179,14 @@ system. Enabling the hotkey functionality of thinkpad-acpi signals the firmware that such a driver is present, and modifies how the ThinkPad firmware will behave in many situations. -The driver enables the hot key feature automatically when loaded. The -feature can later be disabled and enabled back at runtime. The driver -will also restore the hot key feature to its previous state and mask -when it is unloaded. +The driver enables the HKEY ("hot key") event reporting automatically +when loaded, and disables it when it is removed. -When the hotkey feature is enabled and the hot key mask is set (see -below), the driver will report HKEY events in the following format: +The driver will report HKEY events in the following format: ibm/hotkey HKEY 00000080 0000xxxx -Some of these events refer to hot key presses, but not all. +Some of these events refer to hot key presses, but not all of them. The driver will generate events over the input layer for hot keys and radio switches, and over the ACPI netlink layer for other events. The @@ -214,13 +218,17 @@ procfs notes: The following commands can be written to the /proc/acpi/ibm/hotkey file: - echo enable > /proc/acpi/ibm/hotkey -- enable the hot keys feature - echo disable > /proc/acpi/ibm/hotkey -- disable the hot keys feature echo 0xffffffff > /proc/acpi/ibm/hotkey -- enable all hot keys echo 0 > /proc/acpi/ibm/hotkey -- disable all possible hot keys ... any other 8-hex-digit mask ... echo reset > /proc/acpi/ibm/hotkey -- restore the original mask +The following commands have been deprecated and will cause the kernel +to log a warning: + + echo enable > /proc/acpi/ibm/hotkey -- does nothing + echo disable > /proc/acpi/ibm/hotkey -- returns an error + The procfs interface does not support NVRAM polling control. So as to maintain maximum bug-to-bug compatibility, it does not report any masks, nor does it allow one to manipulate the hot key mask when the firmware @@ -229,12 +237,9 @@ does not support masks at all, even if NVRAM polling is in use. sysfs notes: hotkey_bios_enabled: - Returns the status of the hot keys feature when - thinkpad-acpi was loaded. Upon module unload, the hot - key feature status will be restored to this value. + DEPRECATED, WILL BE REMOVED SOON. - 0: hot keys were disabled - 1: hot keys were enabled (unusual) + Returns 0. hotkey_bios_mask: Returns the hot keys mask when thinkpad-acpi was loaded. @@ -242,13 +247,10 @@ sysfs notes: to this value. hotkey_enable: - Enables/disables the hot keys feature in the ACPI - firmware, and reports current status of the hot keys - feature. Has no effect on the NVRAM hot key polling - functionality. + DEPRECATED, WILL BE REMOVED SOON. - 0: disables the hot keys feature / feature disabled - 1: enables the hot keys feature / feature enabled + 0: returns -EPERM + 1: does nothing hotkey_mask: bit mask to enable driver-handling (and depending on @@ -618,6 +620,7 @@ For Lenovo models *with* ACPI backlight control: and map them to KEY_BRIGHTNESS_UP and KEY_BRIGHTNESS_DOWN. Process these keys on userspace somehow (e.g. by calling xbacklight). + Bluetooth --------- @@ -628,6 +631,9 @@ sysfs rfkill class: switch "tpacpi_bluetooth_sw" This feature shows the presence and current state of a ThinkPad Bluetooth device in the internal ThinkPad CDC slot. +If the ThinkPad supports it, the Bluetooth state is stored in NVRAM, +so it is kept across reboots and power-off. + Procfs notes: If Bluetooth is installed, the following commands can be used: @@ -652,6 +658,7 @@ Sysfs notes: rfkill controller switch "tpacpi_bluetooth_sw": refer to Documentation/rfkill.txt for details. + Video output control -- /proc/acpi/ibm/video -------------------------------------------- @@ -693,11 +700,8 @@ Fn-F7 from working. This also disables the video output switching features of this driver, as it uses the same ACPI methods as Fn-F7. Video switching on the console should still work. -UPDATE: There's now a patch for the X.org Radeon driver which -addresses this issue. Some people are reporting success with the patch -while others are still having problems. For more information: +UPDATE: refer to https://bugs.freedesktop.org/show_bug.cgi?id=2000 -https://bugs.freedesktop.org/show_bug.cgi?id=2000 ThinkLight control ------------------ @@ -720,10 +724,11 @@ The ThinkLight sysfs interface is documented by the LED class documentation, in Documentation/leds-class.txt. The ThinkLight LED name is "tpacpi::thinklight". -Due to limitations in the sysfs LED class, if the status of the thinklight +Due to limitations in the sysfs LED class, if the status of the ThinkLight cannot be read or if it is unknown, thinkpad-acpi will report it as "off". It is impossible to know if the status returned through sysfs is valid. + Docking / undocking -- /proc/acpi/ibm/dock ------------------------------------------ @@ -784,6 +789,7 @@ the only docking stations currently supported are the X-series UltraBase docks and "dumb" port replicators like the Mini Dock (the latter don't need any ACPI support, actually). + UltraBay eject -- /proc/acpi/ibm/bay ------------------------------------ @@ -847,8 +853,9 @@ supported. Use "eject2" instead of "eject" for the second bay. Note: the UltraBay eject support on the 600e/x, A22p and A3x is EXPERIMENTAL and may not work as expected. USE WITH CAUTION! -CMOS control ------------- + +CMOS/UCMS control +----------------- procfs: /proc/acpi/ibm/cmos sysfs device attribute: cmos_command @@ -882,6 +889,7 @@ The cmos command interface is prone to firmware split-brain problems, as in newer ThinkPads it is just a compatibility layer. Do not use it, it is exported just as a debug tool. + LED control ----------- @@ -893,6 +901,17 @@ some older ThinkPad models, it is possible to query the status of the LED indicators as well. Newer ThinkPads cannot query the real status of the LED indicators. +Because misuse of the LEDs could induce an unaware user to perform +dangerous actions (like undocking or ejecting a bay device while the +buses are still active), or mask an important alarm (such as a nearly +empty battery, or a broken battery), access to most LEDs is +restricted. + +Unrestricted access to all LEDs requires that thinkpad-acpi be +compiled with the CONFIG_THINKPAD_ACPI_UNSAFE_LEDS option enabled. +Distributions must never enable this option. Individual users that +are aware of the consequences are welcome to enabling it. + procfs notes: The available commands are: @@ -939,6 +958,7 @@ ThinkPad indicator LED should blink in hardware accelerated mode, use the "timer" trigger, and leave the delay_on and delay_off parameters set to zero (to request hardware acceleration autodetection). + ACPI sounds -- /proc/acpi/ibm/beep ---------------------------------- @@ -968,6 +988,7 @@ X40: 16 - one medium-pitched beep repeating constantly, stop with 17 17 - stop 16 + Temperature sensors ------------------- @@ -1115,6 +1136,7 @@ registers contain the current battery capacity, etc. If you experiment with this, do send me your results (including some complete dumps with a description of the conditions when they were taken.) + LCD brightness control ---------------------- @@ -1124,10 +1146,9 @@ sysfs backlight device "thinkpad_screen" This feature allows software control of the LCD brightness on ThinkPad models which don't have a hardware brightness slider. -It has some limitations: the LCD backlight cannot be actually turned on or -off by this interface, and in many ThinkPad models, the "dim while on -battery" functionality will be enabled by the BIOS when this interface is -used, and cannot be controlled. +It has some limitations: the LCD backlight cannot be actually turned +on or off by this interface, it just controls the backlight brightness +level. On IBM (and some of the earlier Lenovo) ThinkPads, the backlight control has eight brightness levels, ranging from 0 to 7. Some of the levels @@ -1136,10 +1157,15 @@ display backlight brightness control methods have 16 levels, ranging from 0 to 15. There are two interfaces to the firmware for direct brightness control, -EC and CMOS. To select which one should be used, use the +EC and UCMS (or CMOS). To select which one should be used, use the brightness_mode module parameter: brightness_mode=1 selects EC mode, -brightness_mode=2 selects CMOS mode, brightness_mode=3 selects both EC -and CMOS. The driver tries to auto-detect which interface to use. +brightness_mode=2 selects UCMS mode, brightness_mode=3 selects EC +mode with NVRAM backing (so that brightness changes are remembered +across shutdown/reboot). + +The driver tries to select which interface to use from a table of +defaults for each ThinkPad model. If it makes a wrong choice, please +report this as a bug, so that we can fix it. When display backlight brightness controls are available through the standard ACPI interface, it is best to use it instead of this direct @@ -1201,6 +1227,7 @@ WARNING: and maybe reduce the life of the backlight lamps by needlessly kicking its level up and down at every change. + Volume control -- /proc/acpi/ibm/volume --------------------------------------- @@ -1217,6 +1244,11 @@ distinct. The unmute the volume after the mute command, use either the up or down command (the level command will not unmute the volume). The current volume level and mute state is shown in the file. +The ALSA mixer interface to this feature is still missing, but patches +to add it exist. That problem should be addressed in the not so +distant future. + + Fan control and monitoring: fan speed, fan enable/disable --------------------------------------------------------- @@ -1383,8 +1415,11 @@ procfs: /proc/acpi/ibm/wan sysfs device attribute: wwan_enable (deprecated) sysfs rfkill class: switch "tpacpi_wwan_sw" -This feature shows the presence and current state of a W-WAN (Sierra -Wireless EV-DO) device. +This feature shows the presence and current state of the built-in +Wireless WAN device. + +If the ThinkPad supports it, the WWAN state is stored in NVRAM, +so it is kept across reboots and power-off. It was tested on a Lenovo ThinkPad X60. It should probably work on other ThinkPad models which come with this module installed. @@ -1413,6 +1448,7 @@ Sysfs notes: rfkill controller switch "tpacpi_wwan_sw": refer to Documentation/rfkill.txt for details. + EXPERIMENTAL: UWB ----------------- @@ -1431,6 +1467,7 @@ Sysfs notes: rfkill controller switch "tpacpi_uwb_sw": refer to Documentation/rfkill.txt for details. + Multiple Commands, Module Parameters ------------------------------------ @@ -1445,6 +1482,7 @@ for example: modprobe thinkpad_acpi hotkey=enable,0xffff video=auto_disable + Enabling debugging output ------------------------- @@ -1457,8 +1495,15 @@ will enable all debugging output classes. It takes a bitmask, so to enable more than one output class, just add their values. Debug bitmask Description + 0x8000 Disclose PID of userspace programs + accessing some functions of the driver 0x0001 Initialization and probing 0x0002 Removal + 0x0004 RF Transmitter control (RFKILL) + (bluetooth, WWAN, UWB...) + 0x0008 HKEY event interface, hotkeys + 0x0010 Fan control + 0x0020 Backlight brightness There is also a kernel build option to enable more debugging information, which may be necessary to debug driver problems. @@ -1467,6 +1512,7 @@ The level of debugging information output by the driver can be changed at runtime through sysfs, using the driver attribute debug_level. The attribute takes the same bitmask as the debug module parameter above. + Force loading of module ----------------------- @@ -1505,3 +1551,7 @@ Sysfs interface changelog: 0x020200: Add poll()/select() support to the following attributes: hotkey_radio_sw, wakeup_hotunplug_complete, wakeup_reason + +0x020300: hotkey enable/disable support removed, attributes + hotkey_bios_enabled and hotkey_enable deprecated and + marked for removal. diff --git a/Documentation/lguest/.gitignore b/Documentation/lguest/.gitignore new file mode 100644 index 000000000000..115587fd5f65 --- /dev/null +++ b/Documentation/lguest/.gitignore @@ -0,0 +1 @@ +lguest diff --git a/Documentation/lguest/lguest.c b/Documentation/lguest/lguest.c index f2dbbf3bdeab..d36fcc0f2715 100644 --- a/Documentation/lguest/lguest.c +++ b/Documentation/lguest/lguest.c @@ -1630,6 +1630,13 @@ static bool service_io(struct device *dev) } } + /* OK, so we noted that it was pretty poor to use an fdatasync as a + * barrier. But Christoph Hellwig points out that we need a sync + * *afterwards* as well: "Barriers specify no reordering to the front + * or the back." And Jens Axboe confirmed it, so here we are: */ + if (out->type & VIRTIO_BLK_T_BARRIER) + fdatasync(vblk->fd); + /* We can't trigger an IRQ, because we're not the Launcher. It does * that when we tell it we're done. */ add_used(dev->vq, head, wlen); diff --git a/Documentation/lguest/lguest.txt b/Documentation/lguest/lguest.txt index 29510dc51510..28c747362f95 100644 --- a/Documentation/lguest/lguest.txt +++ b/Documentation/lguest/lguest.txt @@ -3,11 +3,11 @@ /, /` - or, A Young Coder's Illustrated Hypervisor \\"--\\ http://lguest.ozlabs.org -Lguest is designed to be a minimal hypervisor for the Linux kernel, for -Linux developers and users to experiment with virtualization with the -minimum of complexity. Nonetheless, it should have sufficient -features to make it useful for specific tasks, and, of course, you are -encouraged to fork and enhance it (see drivers/lguest/README). +Lguest is designed to be a minimal 32-bit x86 hypervisor for the Linux kernel, +for Linux developers and users to experiment with virtualization with the +minimum of complexity. Nonetheless, it should have sufficient features to +make it useful for specific tasks, and, of course, you are encouraged to fork +and enhance it (see drivers/lguest/README). Features: @@ -37,6 +37,7 @@ Running Lguest: "Paravirtualized guest support" = Y "Lguest guest support" = Y "High Memory Support" = off/4GB + "PAE (Physical Address Extension) Support" = N "Alignment value to which kernel should be aligned" = 0x100000 (CONFIG_PARAVIRT=y, CONFIG_LGUEST_GUEST=y, CONFIG_HIGHMEM64G=n and CONFIG_PHYSICAL_ALIGN=0x100000) diff --git a/Documentation/lockdep-design.txt b/Documentation/lockdep-design.txt index 488773018152..e20d913d5914 100644 --- a/Documentation/lockdep-design.txt +++ b/Documentation/lockdep-design.txt @@ -27,33 +27,37 @@ lock-class. State ----- -The validator tracks lock-class usage history into 5 separate state bits: +The validator tracks lock-class usage history into 4n + 1 separate state bits: -- 'ever held in hardirq context' [ == hardirq-safe ] -- 'ever held in softirq context' [ == softirq-safe ] -- 'ever held with hardirqs enabled' [ == hardirq-unsafe ] -- 'ever held with softirqs and hardirqs enabled' [ == softirq-unsafe ] +- 'ever held in STATE context' +- 'ever head as readlock in STATE context' +- 'ever head with STATE enabled' +- 'ever head as readlock with STATE enabled' + +Where STATE can be either one of (kernel/lockdep_states.h) + - hardirq + - softirq + - reclaim_fs - 'ever used' [ == !unused ] -When locking rules are violated, these 4 state bits are presented in the -locking error messages, inside curlies. A contrived example: +When locking rules are violated, these state bits are presented in the +locking error messages, inside curlies. A contrived example: modprobe/2287 is trying to acquire lock: - (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 + (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24 but task is already holding lock: - (&sio_locks[i].lock){--..}, at: [<c02867fd>] mutex_lock+0x21/0x24 + (&sio_locks[i].lock){-.-...}, at: [<c02867fd>] mutex_lock+0x21/0x24 -The bit position indicates hardirq, softirq, hardirq-read, -softirq-read respectively, and the character displayed in each -indicates: +The bit position indicates STATE, STATE-read, for each of the states listed +above, and the character displayed in each indicates: - '.' acquired while irqs disabled - '+' acquired in irq context - '-' acquired with irqs enabled - '?' read acquired in irq context with irqs enabled. + '.' acquired while irqs disabled and not in irq context + '-' acquired in irq context + '+' acquired with irqs enabled + '?' acquired in irq context with irqs enabled. Unused mutexes cannot be part of the cause of an error. diff --git a/Documentation/md.txt b/Documentation/md.txt index 1da9d1b1793f..4edd39ec7db9 100644 --- a/Documentation/md.txt +++ b/Documentation/md.txt @@ -164,15 +164,19 @@ All md devices contain: raid_disks a text file with a simple number indicating the number of devices in a fully functional array. If this is not yet known, the file - will be empty. If an array is being resized (not currently - possible) this will contain the larger of the old and new sizes. - Some raid level (RAID1) allow this value to be set while the - array is active. This will reconfigure the array. Otherwise - it can only be set while assembling an array. + will be empty. If an array is being resized this will contain + the new number of devices. + Some raid levels allow this value to be set while the array is + active. This will reconfigure the array. Otherwise it can only + be set while assembling an array. + A change to this attribute will not be permitted if it would + reduce the size of the array. To reduce the number of drives + in an e.g. raid5, the array size must first be reduced by + setting the 'array_size' attribute. chunk_size - This is the size if bytes for 'chunks' and is only relevant to - raid levels that involve striping (1,4,5,6,10). The address space + This is the size in bytes for 'chunks' and is only relevant to + raid levels that involve striping (0,4,5,6,10). The address space of the array is conceptually divided into chunks and consecutive chunks are striped onto neighbouring devices. The size should be at least PAGE_SIZE (4k) and should be a power @@ -183,6 +187,20 @@ All md devices contain: simply a number that is interpretted differently by different levels. It can be written while assembling an array. + array_size + This can be used to artificially constrain the available space in + the array to be less than is actually available on the combined + devices. Writing a number (in Kilobytes) which is less than + the available size will set the size. Any reconfiguration of the + array (e.g. adding devices) will not cause the size to change. + Writing the word 'default' will cause the effective size of the + array to be whatever size is actually available based on + 'level', 'chunk_size' and 'component_size'. + + This can be used to reduce the size of the array before reducing + the number of devices in a raid4/5/6, or to support external + metadata formats which mandate such clipping. + reshape_position This is either "none" or a sector number within the devices of the array where "reshape" is up to. If this is set, the three @@ -207,6 +225,11 @@ All md devices contain: about the array. It can be 0.90 (traditional format), 1.0, 1.1, 1.2 (newer format in varying locations) or "none" indicating that the kernel isn't managing metadata at all. + Alternately it can be "external:" followed by a string which + is set by user-space. This indicates that metadata is managed + by a user-space program. Any device failure or other event that + requires a metadata update will cause array activity to be + suspended until the event is acknowledged. resync_start The point at which resync should start. If no resync is needed, diff --git a/Documentation/misc-devices/isl29003 b/Documentation/misc-devices/isl29003 new file mode 100644 index 000000000000..c4ff5f38e010 --- /dev/null +++ b/Documentation/misc-devices/isl29003 @@ -0,0 +1,62 @@ +Kernel driver isl29003 +===================== + +Supported chips: +* Intersil ISL29003 +Prefix: 'isl29003' +Addresses scanned: none +Datasheet: +http://www.intersil.com/data/fn/fn7464.pdf + +Author: Daniel Mack <daniel@caiaq.de> + + +Description +----------- +The ISL29003 is an integrated light sensor with a 16-bit integrating type +ADC, I2C user programmable lux range select for optimized counts/lux, and +I2C multi-function control and monitoring capabilities. The internal ADC +provides 16-bit resolution while rejecting 50Hz and 60Hz flicker caused by +artificial light sources. + +The driver allows to set the lux range, the bit resolution, the operational +mode (see below) and the power state of device and can read the current lux +value, of course. + + +Detection +--------- + +The ISL29003 does not have an ID register which could be used to identify +it, so the detection routine will just try to read from the configured I2C +addess and consider the device to be present as soon as it ACKs the +transfer. + + +Sysfs entries +------------- + +range: + 0: 0 lux to 1000 lux (default) + 1: 0 lux to 4000 lux + 2: 0 lux to 16,000 lux + 3: 0 lux to 64,000 lux + +resolution: + 0: 2^16 cycles (default) + 1: 2^12 cycles + 2: 2^8 cycles + 3: 2^4 cycles + +mode: + 0: diode1's current (unsigned 16bit) (default) + 1: diode1's current (unsigned 16bit) + 2: difference between diodes (l1 - l2, signed 15bit) + +power_state: + 0: device is disabled (default) + 1: device is enabled + +lux (read only): + returns the value from the last sensor reading + diff --git a/Documentation/networking/bonding.txt b/Documentation/networking/bonding.txt index 5ede7473b425..08762750f121 100644 --- a/Documentation/networking/bonding.txt +++ b/Documentation/networking/bonding.txt @@ -1242,7 +1242,7 @@ monitoring is enabled, and vice-versa. To add ARP targets: # echo +192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target # echo +192.168.0.101 > /sys/class/net/bond0/bonding/arp_ip_target - NOTE: up to 10 target addresses may be specified. + NOTE: up to 16 target addresses may be specified. To remove an ARP target: # echo -192.168.0.100 > /sys/class/net/bond0/bonding/arp_ip_target diff --git a/Documentation/networking/dccp.txt b/Documentation/networking/dccp.txt index 7a3bb1abb830..b132e4a3cf0f 100644 --- a/Documentation/networking/dccp.txt +++ b/Documentation/networking/dccp.txt @@ -141,7 +141,8 @@ rx_ccid = 2 Default CCID for the receiver-sender half-connection; see tx_ccid. seq_window = 100 - The initial sequence window (sec. 7.5.2). + The initial sequence window (sec. 7.5.2) of the sender. This influences + the local ackno validity and the remote seqno validity windows (7.5.1). tx_qlen = 5 The size of the transmit buffer in packets. A value of 0 corresponds diff --git a/Documentation/networking/ip-sysctl.txt b/Documentation/networking/ip-sysctl.txt index c7712787933c..ec5de02f543f 100644 --- a/Documentation/networking/ip-sysctl.txt +++ b/Documentation/networking/ip-sysctl.txt @@ -2,7 +2,7 @@ ip_forward - BOOLEAN 0 - disabled (default) - not 0 - enabled + not 0 - enabled Forward Packets between interfaces. @@ -36,49 +36,49 @@ rt_cache_rebuild_count - INTEGER IP Fragmentation: ipfrag_high_thresh - INTEGER - Maximum memory used to reassemble IP fragments. When + Maximum memory used to reassemble IP fragments. When ipfrag_high_thresh bytes of memory is allocated for this purpose, the fragment handler will toss packets until ipfrag_low_thresh is reached. - + ipfrag_low_thresh - INTEGER - See ipfrag_high_thresh + See ipfrag_high_thresh ipfrag_time - INTEGER - Time in seconds to keep an IP fragment in memory. + Time in seconds to keep an IP fragment in memory. ipfrag_secret_interval - INTEGER - Regeneration interval (in seconds) of the hash secret (or lifetime + Regeneration interval (in seconds) of the hash secret (or lifetime for the hash secret) for IP fragments. Default: 600 ipfrag_max_dist - INTEGER - ipfrag_max_dist is a non-negative integer value which defines the - maximum "disorder" which is allowed among fragments which share a - common IP source address. Note that reordering of packets is - not unusual, but if a large number of fragments arrive from a source - IP address while a particular fragment queue remains incomplete, it - probably indicates that one or more fragments belonging to that queue - have been lost. When ipfrag_max_dist is positive, an additional check - is done on fragments before they are added to a reassembly queue - if - ipfrag_max_dist (or more) fragments have arrived from a particular IP - address between additions to any IP fragment queue using that source - address, it's presumed that one or more fragments in the queue are - lost. The existing fragment queue will be dropped, and a new one + ipfrag_max_dist is a non-negative integer value which defines the + maximum "disorder" which is allowed among fragments which share a + common IP source address. Note that reordering of packets is + not unusual, but if a large number of fragments arrive from a source + IP address while a particular fragment queue remains incomplete, it + probably indicates that one or more fragments belonging to that queue + have been lost. When ipfrag_max_dist is positive, an additional check + is done on fragments before they are added to a reassembly queue - if + ipfrag_max_dist (or more) fragments have arrived from a particular IP + address between additions to any IP fragment queue using that source + address, it's presumed that one or more fragments in the queue are + lost. The existing fragment queue will be dropped, and a new one started. An ipfrag_max_dist value of zero disables this check. Using a very small value, e.g. 1 or 2, for ipfrag_max_dist can result in unnecessarily dropping fragment queues when normal - reordering of packets occurs, which could lead to poor application - performance. Using a very large value, e.g. 50000, increases the - likelihood of incorrectly reassembling IP fragments that originate + reordering of packets occurs, which could lead to poor application + performance. Using a very large value, e.g. 50000, increases the + likelihood of incorrectly reassembling IP fragments that originate from different IP datagrams, which could result in data corruption. Default: 64 INET peer storage: inet_peer_threshold - INTEGER - The approximate size of the storage. Starting from this threshold + The approximate size of the storage. Starting from this threshold entries will be thrown aggressively. This threshold also determines entries' time-to-live and time intervals between garbage collection passes. More entries, less time-to-live, less GC interval. @@ -105,7 +105,7 @@ inet_peer_gc_maxtime - INTEGER in effect under low (or absent) memory pressure on the pool. Measured in seconds. -TCP variables: +TCP variables: somaxconn - INTEGER Limit of socket listen() backlog, known in userspace as SOMAXCONN. @@ -310,7 +310,7 @@ tcp_orphan_retries - INTEGER tcp_reordering - INTEGER Maximal reordering of packets in a TCP stream. - Default: 3 + Default: 3 tcp_retrans_collapse - BOOLEAN Bug-to-bug compatibility with some broken printers. @@ -521,7 +521,7 @@ IP Variables: ip_local_port_range - 2 INTEGERS Defines the local port range that is used by TCP and UDP to - choose the local port. The first number is the first, the + choose the local port. The first number is the first, the second the last local port number. Default value depends on amount of memory available on the system: > 128Mb 32768-61000 @@ -594,12 +594,12 @@ icmp_errors_use_inbound_ifaddr - BOOLEAN If zero, icmp error messages are sent with the primary address of the exiting interface. - + If non-zero, the message will be sent with the primary address of the interface that received the packet that caused the icmp error. This is the behaviour network many administrators will expect from a router. And it can make debugging complicated network layouts - much easier. + much easier. Note that if no primary address exists for the interface selected, then the primary address of the first non-loopback interface that @@ -611,7 +611,7 @@ igmp_max_memberships - INTEGER Change the maximum number of multicast groups we can subscribe to. Default: 20 -conf/interface/* changes special settings per interface (where "interface" is +conf/interface/* changes special settings per interface (where "interface" is the name of your network interface) conf/all/* is special, changes the settings for all interfaces @@ -625,11 +625,11 @@ log_martians - BOOLEAN accept_redirects - BOOLEAN Accept ICMP redirect messages. accept_redirects for the interface will be enabled if: - - both conf/{all,interface}/accept_redirects are TRUE in the case forwarding - for the interface is enabled + - both conf/{all,interface}/accept_redirects are TRUE in the case + forwarding for the interface is enabled or - - at least one of conf/{all,interface}/accept_redirects is TRUE in the case - forwarding for the interface is disabled + - at least one of conf/{all,interface}/accept_redirects is TRUE in the + case forwarding for the interface is disabled accept_redirects for the interface will be disabled otherwise default TRUE (host) FALSE (router) @@ -640,8 +640,8 @@ forwarding - BOOLEAN mc_forwarding - BOOLEAN Do multicast routing. The kernel needs to be compiled with CONFIG_MROUTE and a multicast routing daemon is required. - conf/all/mc_forwarding must also be set to TRUE to enable multicast routing - for the interface + conf/all/mc_forwarding must also be set to TRUE to enable multicast + routing for the interface medium_id - INTEGER Integer value used to differentiate the devices by the medium they @@ -649,7 +649,7 @@ medium_id - INTEGER the broadcast packets are received only on one of them. The default value 0 means that the device is the only interface to its medium, value of -1 means that medium is not known. - + Currently, it is used to change the proxy_arp behavior: the proxy_arp feature is enabled for packets forwarded between two devices attached to different media. @@ -699,16 +699,22 @@ accept_source_route - BOOLEAN default TRUE (router) FALSE (host) -rp_filter - BOOLEAN - 1 - do source validation by reversed path, as specified in RFC1812 - Recommended option for single homed hosts and stub network - routers. Could cause troubles for complicated (not loop free) - networks running a slow unreliable protocol (sort of RIP), - or using static routes. - +rp_filter - INTEGER 0 - No source validation. - - conf/all/rp_filter must also be set to TRUE to do source validation + 1 - Strict mode as defined in RFC3704 Strict Reverse Path + Each incoming packet is tested against the FIB and if the interface + is not the best reverse path the packet check will fail. + By default failed packets are discarded. + 2 - Loose mode as defined in RFC3704 Loose Reverse Path + Each incoming packet's source address is also tested against the FIB + and if the source address is not reachable via any interface + the packet check will fail. + + Current recommended practice in RFC3704 is to enable strict mode + to prevent IP spoofing from DDos attacks. If using asymmetric routing + or other complicated routing, then loose mode is recommended. + + conf/all/rp_filter must also be set to non-zero to do source validation on the interface Default value is 0. Note that some distributions enable it @@ -782,6 +788,12 @@ arp_ignore - INTEGER The max value from conf/{all,interface}/arp_ignore is used when ARP request is received on the {interface} +arp_notify - BOOLEAN + Define mode for notification of address and device changes. + 0 - (default): do nothing + 1 - Generate gratuitous arp replies when device is brought up + or hardware address changes. + arp_accept - BOOLEAN Define behavior when gratuitous arp replies are received: 0 - drop gratuitous arp frames @@ -823,7 +835,7 @@ apply to IPv6 [XXX?]. bindv6only - BOOLEAN Default value for IPV6_V6ONLY socket option, - which restricts use of the IPv6 socket to IPv6 communication + which restricts use of the IPv6 socket to IPv6 communication only. TRUE: disable IPv4-mapped address feature FALSE: enable IPv4-mapped address feature @@ -833,19 +845,19 @@ bindv6only - BOOLEAN IPv6 Fragmentation: ip6frag_high_thresh - INTEGER - Maximum memory used to reassemble IPv6 fragments. When + Maximum memory used to reassemble IPv6 fragments. When ip6frag_high_thresh bytes of memory is allocated for this purpose, the fragment handler will toss packets until ip6frag_low_thresh is reached. - + ip6frag_low_thresh - INTEGER - See ip6frag_high_thresh + See ip6frag_high_thresh ip6frag_time - INTEGER Time in seconds to keep an IPv6 fragment in memory. ip6frag_secret_interval - INTEGER - Regeneration interval (in seconds) of the hash secret (or lifetime + Regeneration interval (in seconds) of the hash secret (or lifetime for the hash secret) for IPv6 fragments. Default: 600 @@ -854,17 +866,17 @@ conf/default/*: conf/all/*: - Change all the interface-specific settings. + Change all the interface-specific settings. [XXX: Other special features than forwarding?] conf/all/forwarding - BOOLEAN - Enable global IPv6 forwarding between all interfaces. + Enable global IPv6 forwarding between all interfaces. - IPv4 and IPv6 work differently here; e.g. netfilter must be used + IPv4 and IPv6 work differently here; e.g. netfilter must be used to control which interfaces may forward packets and which not. - This also sets all interfaces' Host/Router setting + This also sets all interfaces' Host/Router setting 'forwarding' to the specified value. See below for details. This referred to as global forwarding. @@ -875,12 +887,12 @@ proxy_ndp - BOOLEAN conf/interface/*: Change special settings per interface. - The functional behaviour for certain settings is different + The functional behaviour for certain settings is different depending on whether local forwarding is enabled or not. accept_ra - BOOLEAN Accept Router Advertisements; autoconfigure using them. - + Functional default: enabled if local forwarding is disabled. disabled if local forwarding is enabled. @@ -926,7 +938,7 @@ accept_source_route - INTEGER Default: 0 autoconf - BOOLEAN - Autoconfigure addresses using Prefix Information in Router + Autoconfigure addresses using Prefix Information in Router Advertisements. Functional default: enabled if accept_ra_pinfo is enabled. @@ -935,11 +947,11 @@ autoconf - BOOLEAN dad_transmits - INTEGER The amount of Duplicate Address Detection probes to send. Default: 1 - + forwarding - BOOLEAN - Configure interface-specific Host/Router behaviour. + Configure interface-specific Host/Router behaviour. - Note: It is recommended to have the same setting on all + Note: It is recommended to have the same setting on all interfaces; mixed router/host scenarios are rather uncommon. FALSE: @@ -948,13 +960,13 @@ forwarding - BOOLEAN 1. IsRouter flag is not set in Neighbour Advertisements. 2. Router Solicitations are being sent when necessary. - 3. If accept_ra is TRUE (default), accept Router + 3. If accept_ra is TRUE (default), accept Router Advertisements (and do autoconfiguration). 4. If accept_redirects is TRUE (default), accept Redirects. TRUE: - If local forwarding is enabled, Router behaviour is assumed. + If local forwarding is enabled, Router behaviour is assumed. This means exactly the reverse from the above: 1. IsRouter flag is set in Neighbour Advertisements. @@ -989,7 +1001,7 @@ router_solicitation_interval - INTEGER Default: 4 router_solicitations - INTEGER - Number of Router Solicitations to send until assuming no + Number of Router Solicitations to send until assuming no routers are present. Default: 3 @@ -1013,11 +1025,11 @@ temp_prefered_lft - INTEGER max_desync_factor - INTEGER Maximum value for DESYNC_FACTOR, which is a random value - that ensures that clients don't synchronize with each + that ensures that clients don't synchronize with each other and generate new addresses at exactly the same time. value is in seconds. Default: 600 - + regen_max_retry - INTEGER Number of attempts before give up attempting to generate valid temporary addresses. @@ -1025,13 +1037,15 @@ regen_max_retry - INTEGER max_addresses - INTEGER Number of maximum addresses per interface. 0 disables limitation. - It is recommended not set too large value (or 0) because it would - be too easy way to crash kernel to allow to create too much of + It is recommended not set too large value (or 0) because it would + be too easy way to crash kernel to allow to create too much of autoconfigured addresses. Default: 16 disable_ipv6 - BOOLEAN - Disable IPv6 operation. + Disable IPv6 operation. If accept_dad is set to 2, this value + will be dynamically set to TRUE if DAD fails for the link-local + address. Default: FALSE (enable IPv6 operation) accept_dad - INTEGER diff --git a/Documentation/networking/ipv6.txt b/Documentation/networking/ipv6.txt new file mode 100644 index 000000000000..268e5c103dd8 --- /dev/null +++ b/Documentation/networking/ipv6.txt @@ -0,0 +1,35 @@ + +Options for the ipv6 module are supplied as parameters at load time. + +Module options may be given as command line arguments to the insmod +or modprobe command, but are usually specified in either the +/etc/modules.conf or /etc/modprobe.conf configuration file, or in a +distro-specific configuration file. + +The available ipv6 module parameters are listed below. If a parameter +is not specified the default value is used. + +The parameters are as follows: + +disable + + Specifies whether to load the IPv6 module, but disable all + its functionality. This might be used when another module + has a dependency on the IPv6 module being loaded, but no + IPv6 addresses or operations are desired. + + The possible values and their effects are: + + 0 + IPv6 is enabled. + + This is the default value. + + 1 + IPv6 is disabled. + + No IPv6 addresses will be added to interfaces, and + it will not be possible to open an IPv6 socket. + + A reboot is required to enable IPv6. + diff --git a/Documentation/networking/ixgbe.txt b/Documentation/networking/ixgbe.txt new file mode 100644 index 000000000000..eeb68685c788 --- /dev/null +++ b/Documentation/networking/ixgbe.txt @@ -0,0 +1,199 @@ +Linux Base Driver for 10 Gigabit PCI Express Intel(R) Network Connection +======================================================================== + +March 10, 2009 + + +Contents +======== + +- In This Release +- Identifying Your Adapter +- Building and Installation +- Additional Configurations +- Support + + + +In This Release +=============== + +This file describes the ixgbe Linux Base Driver for the 10 Gigabit PCI +Express Intel(R) Network Connection. This driver includes support for +Itanium(R)2-based systems. + +For questions related to hardware requirements, refer to the documentation +supplied with your 10 Gigabit adapter. All hardware requirements listed apply +to use with Linux. + +The following features are available in this kernel: + - Native VLANs + - Channel Bonding (teaming) + - SNMP + - Generic Receive Offload + - Data Center Bridging + +Channel Bonding documentation can be found in the Linux kernel source: +/Documentation/networking/bonding.txt + +Ethtool, lspci, and ifconfig can be used to display device and driver +specific information. + + +Identifying Your Adapter +======================== + +This driver supports devices based on the 82598 controller and the 82599 +controller. + +For specific information on identifying which adapter you have, please visit: + + http://support.intel.com/support/network/sb/CS-008441.htm + + +Building and Installation +========================= + +select m for "Intel(R) 10GbE PCI Express adapters support" located at: + Location: + -> Device Drivers + -> Network device support (NETDEVICES [=y]) + -> Ethernet (10000 Mbit) (NETDEV_10000 [=y]) + +1. make modules & make modules_install + +2. Load the module: + +# modprobe ixgbe + + The insmod command can be used if the full + path to the driver module is specified. For example: + + insmod /lib/modules/<KERNEL VERSION>/kernel/drivers/net/ixgbe/ixgbe.ko + + With 2.6 based kernels also make sure that older ixgbe drivers are + removed from the kernel, before loading the new module: + + rmmod ixgbe; modprobe ixgbe + +3. Assign an IP address to the interface by entering the following, where + x is the interface number: + + ifconfig ethx <IP_address> + +4. Verify that the interface works. Enter the following, where <IP_address> + is the IP address for another machine on the same subnet as the interface + that is being tested: + + ping <IP_address> + + +Additional Configurations +========================= + + Viewing Link Messages + --------------------- + Link messages will not be displayed to the console if the distribution is + restricting system messages. In order to see network driver link messages on + your console, set dmesg to eight by entering the following: + + dmesg -n 8 + + NOTE: This setting is not saved across reboots. + + + Jumbo Frames + ------------ + The driver supports Jumbo Frames for all adapters. Jumbo Frames support is + enabled by changing the MTU to a value larger than the default of 1500. + The maximum value for the MTU is 16110. Use the ifconfig command to + increase the MTU size. For example: + + ifconfig ethx mtu 9000 up + + The maximum MTU setting for Jumbo Frames is 16110. This value coincides + with the maximum Jumbo Frames size of 16128. + + Generic Receive Offload, aka GRO + -------------------------------- + The driver supports the in-kernel software implementation of GRO. GRO has + shown that by coalescing Rx traffic into larger chunks of data, CPU + utilization can be significantly reduced when under large Rx load. GRO is an + evolution of the previously-used LRO interface. GRO is able to coalesce + other protocols besides TCP. It's also safe to use with configurations that + are problematic for LRO, namely bridging and iSCSI. + + GRO is enabled by default in the driver. Future versions of ethtool will + support disabling and re-enabling GRO on the fly. + + + Data Center Bridging, aka DCB + ----------------------------- + + DCB is a configuration Quality of Service implementation in hardware. + It uses the VLAN priority tag (802.1p) to filter traffic. That means + that there are 8 different priorities that traffic can be filtered into. + It also enables priority flow control which can limit or eliminate the + number of dropped packets during network stress. Bandwidth can be + allocated to each of these priorities, which is enforced at the hardware + level. + + To enable DCB support in ixgbe, you must enable the DCB netlink layer to + allow the userspace tools (see below) to communicate with the driver. + This can be found in the kernel configuration here: + + -> Networking support + -> Networking options + -> Data Center Bridging support + + Once this is selected, DCB support must be selected for ixgbe. This can + be found here: + + -> Device Drivers + -> Network device support (NETDEVICES [=y]) + -> Ethernet (10000 Mbit) (NETDEV_10000 [=y]) + -> Intel(R) 10GbE PCI Express adapters support + -> Data Center Bridging (DCB) Support + + After these options are selected, you must rebuild your kernel and your + modules. + + In order to use DCB, userspace tools must be downloaded and installed. + The dcbd tools can be found at: + + http://e1000.sf.net + + + Ethtool + ------- + The driver utilizes the ethtool interface for driver configuration and + diagnostics, as well as displaying statistical information. Ethtool + version 3.0 or later is required for this functionality. + + The latest release of ethtool can be found from + http://sourceforge.net/projects/gkernel. + + + NAPI + ---- + + NAPI (Rx polling mode) is supported in the ixgbe driver. NAPI is enabled + by default in the driver. + + See www.cyberus.ca/~hadi/usenix-paper.tgz for more information on NAPI. + + +Support +======= + +For general information, go to the Intel support website at: + + http://support.intel.com + +or the Intel Wired Networking project hosted by Sourceforge at: + + http://e1000.sourceforge.net + +If an issue is identified with the released source code on the supported +kernel with a supported adapter, email the specific information related +to the issue to e1000-devel@lists.sf.net diff --git a/Documentation/networking/rds.txt b/Documentation/networking/rds.txt new file mode 100644 index 000000000000..c67077cbeb80 --- /dev/null +++ b/Documentation/networking/rds.txt @@ -0,0 +1,356 @@ + +Overview +======== + +This readme tries to provide some background on the hows and whys of RDS, +and will hopefully help you find your way around the code. + +In addition, please see this email about RDS origins: +http://oss.oracle.com/pipermail/rds-devel/2007-November/000228.html + +RDS Architecture +================ + +RDS provides reliable, ordered datagram delivery by using a single +reliable connection between any two nodes in the cluster. This allows +applications to use a single socket to talk to any other process in the +cluster - so in a cluster with N processes you need N sockets, in contrast +to N*N if you use a connection-oriented socket transport like TCP. + +RDS is not Infiniband-specific; it was designed to support different +transports. The current implementation used to support RDS over TCP as well +as IB. Work is in progress to support RDS over iWARP, and using DCE to +guarantee no dropped packets on Ethernet, it may be possible to use RDS over +UDP in the future. + +The high-level semantics of RDS from the application's point of view are + + * Addressing + RDS uses IPv4 addresses and 16bit port numbers to identify + the end point of a connection. All socket operations that involve + passing addresses between kernel and user space generally + use a struct sockaddr_in. + + The fact that IPv4 addresses are used does not mean the underlying + transport has to be IP-based. In fact, RDS over IB uses a + reliable IB connection; the IP address is used exclusively to + locate the remote node's GID (by ARPing for the given IP). + + The port space is entirely independent of UDP, TCP or any other + protocol. + + * Socket interface + RDS sockets work *mostly* as you would expect from a BSD + socket. The next section will cover the details. At any rate, + all I/O is performed through the standard BSD socket API. + Some additions like zerocopy support are implemented through + control messages, while other extensions use the getsockopt/ + setsockopt calls. + + Sockets must be bound before you can send or receive data. + This is needed because binding also selects a transport and + attaches it to the socket. Once bound, the transport assignment + does not change. RDS will tolerate IPs moving around (eg in + a active-active HA scenario), but only as long as the address + doesn't move to a different transport. + + * sysctls + RDS supports a number of sysctls in /proc/sys/net/rds + + +Socket Interface +================ + + AF_RDS, PF_RDS, SOL_RDS + These constants haven't been assigned yet, because RDS isn't in + mainline yet. Currently, the kernel module assigns some constant + and publishes it to user space through two sysctl files + /proc/sys/net/rds/pf_rds + /proc/sys/net/rds/sol_rds + + fd = socket(PF_RDS, SOCK_SEQPACKET, 0); + This creates a new, unbound RDS socket. + + setsockopt(SOL_SOCKET): send and receive buffer size + RDS honors the send and receive buffer size socket options. + You are not allowed to queue more than SO_SNDSIZE bytes to + a socket. A message is queued when sendmsg is called, and + it leaves the queue when the remote system acknowledges + its arrival. + + The SO_RCVSIZE option controls the maximum receive queue length. + This is a soft limit rather than a hard limit - RDS will + continue to accept and queue incoming messages, even if that + takes the queue length over the limit. However, it will also + mark the port as "congested" and send a congestion update to + the source node. The source node is supposed to throttle any + processes sending to this congested port. + + bind(fd, &sockaddr_in, ...) + This binds the socket to a local IP address and port, and a + transport. + + sendmsg(fd, ...) + Sends a message to the indicated recipient. The kernel will + transparently establish the underlying reliable connection + if it isn't up yet. + + An attempt to send a message that exceeds SO_SNDSIZE will + return with -EMSGSIZE + + An attempt to send a message that would take the total number + of queued bytes over the SO_SNDSIZE threshold will return + EAGAIN. + + An attempt to send a message to a destination that is marked + as "congested" will return ENOBUFS. + + recvmsg(fd, ...) + Receives a message that was queued to this socket. The sockets + recv queue accounting is adjusted, and if the queue length + drops below SO_SNDSIZE, the port is marked uncongested, and + a congestion update is sent to all peers. + + Applications can ask the RDS kernel module to receive + notifications via control messages (for instance, there is a + notification when a congestion update arrived, or when a RDMA + operation completes). These notifications are received through + the msg.msg_control buffer of struct msghdr. The format of the + messages is described in manpages. + + poll(fd) + RDS supports the poll interface to allow the application + to implement async I/O. + + POLLIN handling is pretty straightforward. When there's an + incoming message queued to the socket, or a pending notification, + we signal POLLIN. + + POLLOUT is a little harder. Since you can essentially send + to any destination, RDS will always signal POLLOUT as long as + there's room on the send queue (ie the number of bytes queued + is less than the sendbuf size). + + However, the kernel will refuse to accept messages to + a destination marked congested - in this case you will loop + forever if you rely on poll to tell you what to do. + This isn't a trivial problem, but applications can deal with + this - by using congestion notifications, and by checking for + ENOBUFS errors returned by sendmsg. + + setsockopt(SOL_RDS, RDS_CANCEL_SENT_TO, &sockaddr_in) + This allows the application to discard all messages queued to a + specific destination on this particular socket. + + This allows the application to cancel outstanding messages if + it detects a timeout. For instance, if it tried to send a message, + and the remote host is unreachable, RDS will keep trying forever. + The application may decide it's not worth it, and cancel the + operation. In this case, it would use RDS_CANCEL_SENT_TO to + nuke any pending messages. + + +RDMA for RDS +============ + + see rds-rdma(7) manpage (available in rds-tools) + + +Congestion Notifications +======================== + + see rds(7) manpage + + +RDS Protocol +============ + + Message header + + The message header is a 'struct rds_header' (see rds.h): + Fields: + h_sequence: + per-packet sequence number + h_ack: + piggybacked acknowledgment of last packet received + h_len: + length of data, not including header + h_sport: + source port + h_dport: + destination port + h_flags: + CONG_BITMAP - this is a congestion update bitmap + ACK_REQUIRED - receiver must ack this packet + RETRANSMITTED - packet has previously been sent + h_credit: + indicate to other end of connection that + it has more credits available (i.e. there is + more send room) + h_padding[4]: + unused, for future use + h_csum: + header checksum + h_exthdr: + optional data can be passed here. This is currently used for + passing RDMA-related information. + + ACK and retransmit handling + + One might think that with reliable IB connections you wouldn't need + to ack messages that have been received. The problem is that IB + hardware generates an ack message before it has DMAed the message + into memory. This creates a potential message loss if the HCA is + disabled for any reason between when it sends the ack and before + the message is DMAed and processed. This is only a potential issue + if another HCA is available for fail-over. + + Sending an ack immediately would allow the sender to free the sent + message from their send queue quickly, but could cause excessive + traffic to be used for acks. RDS piggybacks acks on sent data + packets. Ack-only packets are reduced by only allowing one to be + in flight at a time, and by the sender only asking for acks when + its send buffers start to fill up. All retransmissions are also + acked. + + Flow Control + + RDS's IB transport uses a credit-based mechanism to verify that + there is space in the peer's receive buffers for more data. This + eliminates the need for hardware retries on the connection. + + Congestion + + Messages waiting in the receive queue on the receiving socket + are accounted against the sockets SO_RCVBUF option value. Only + the payload bytes in the message are accounted for. If the + number of bytes queued equals or exceeds rcvbuf then the socket + is congested. All sends attempted to this socket's address + should return block or return -EWOULDBLOCK. + + Applications are expected to be reasonably tuned such that this + situation very rarely occurs. An application encountering this + "back-pressure" is considered a bug. + + This is implemented by having each node maintain bitmaps which + indicate which ports on bound addresses are congested. As the + bitmap changes it is sent through all the connections which + terminate in the local address of the bitmap which changed. + + The bitmaps are allocated as connections are brought up. This + avoids allocation in the interrupt handling path which queues + sages on sockets. The dense bitmaps let transports send the + entire bitmap on any bitmap change reasonably efficiently. This + is much easier to implement than some finer-grained + communication of per-port congestion. The sender does a very + inexpensive bit test to test if the port it's about to send to + is congested or not. + + +RDS Transport Layer +================== + + As mentioned above, RDS is not IB-specific. Its code is divided + into a general RDS layer and a transport layer. + + The general layer handles the socket API, congestion handling, + loopback, stats, usermem pinning, and the connection state machine. + + The transport layer handles the details of the transport. The IB + transport, for example, handles all the queue pairs, work requests, + CM event handlers, and other Infiniband details. + + +RDS Kernel Structures +===================== + + struct rds_message + aka possibly "rds_outgoing", the generic RDS layer copies data to + be sent and sets header fields as needed, based on the socket API. + This is then queued for the individual connection and sent by the + connection's transport. + struct rds_incoming + a generic struct referring to incoming data that can be handed from + the transport to the general code and queued by the general code + while the socket is awoken. It is then passed back to the transport + code to handle the actual copy-to-user. + struct rds_socket + per-socket information + struct rds_connection + per-connection information + struct rds_transport + pointers to transport-specific functions + struct rds_statistics + non-transport-specific statistics + struct rds_cong_map + wraps the raw congestion bitmap, contains rbnode, waitq, etc. + +Connection management +===================== + + Connections may be in UP, DOWN, CONNECTING, DISCONNECTING, and + ERROR states. + + The first time an attempt is made by an RDS socket to send data to + a node, a connection is allocated and connected. That connection is + then maintained forever -- if there are transport errors, the + connection will be dropped and re-established. + + Dropping a connection while packets are queued will cause queued or + partially-sent datagrams to be retransmitted when the connection is + re-established. + + +The send path +============= + + rds_sendmsg() + struct rds_message built from incoming data + CMSGs parsed (e.g. RDMA ops) + transport connection alloced and connected if not already + rds_message placed on send queue + send worker awoken + rds_send_worker() + calls rds_send_xmit() until queue is empty + rds_send_xmit() + transmits congestion map if one is pending + may set ACK_REQUIRED + calls transport to send either non-RDMA or RDMA message + (RDMA ops never retransmitted) + rds_ib_xmit() + allocs work requests from send ring + adds any new send credits available to peer (h_credits) + maps the rds_message's sg list + piggybacks ack + populates work requests + post send to connection's queue pair + +The recv path +============= + + rds_ib_recv_cq_comp_handler() + looks at write completions + unmaps recv buffer from device + no errors, call rds_ib_process_recv() + refill recv ring + rds_ib_process_recv() + validate header checksum + copy header to rds_ib_incoming struct if start of a new datagram + add to ibinc's fraglist + if competed datagram: + update cong map if datagram was cong update + call rds_recv_incoming() otherwise + note if ack is required + rds_recv_incoming() + drop duplicate packets + respond to pings + find the sock associated with this datagram + add to sock queue + wake up sock + do some congestion calculations + rds_recvmsg + copy data into user iovec + handle CMSGs + return to application + + diff --git a/Documentation/networking/timestamping.txt b/Documentation/networking/timestamping.txt new file mode 100644 index 000000000000..0e58b4539176 --- /dev/null +++ b/Documentation/networking/timestamping.txt @@ -0,0 +1,180 @@ +The existing interfaces for getting network packages time stamped are: + +* SO_TIMESTAMP + Generate time stamp for each incoming packet using the (not necessarily + monotonous!) system time. Result is returned via recv_msg() in a + control message as timeval (usec resolution). + +* SO_TIMESTAMPNS + Same time stamping mechanism as SO_TIMESTAMP, but returns result as + timespec (nsec resolution). + +* IP_MULTICAST_LOOP + SO_TIMESTAMP[NS] + Only for multicasts: approximate send time stamp by receiving the looped + packet and using its receive time stamp. + +The following interface complements the existing ones: receive time +stamps can be generated and returned for arbitrary packets and much +closer to the point where the packet is really sent. Time stamps can +be generated in software (as before) or in hardware (if the hardware +has such a feature). + +SO_TIMESTAMPING: + +Instructs the socket layer which kind of information is wanted. The +parameter is an integer with some of the following bits set. Setting +other bits is an error and doesn't change the current state. + +SOF_TIMESTAMPING_TX_HARDWARE: try to obtain send time stamp in hardware +SOF_TIMESTAMPING_TX_SOFTWARE: if SOF_TIMESTAMPING_TX_HARDWARE is off or + fails, then do it in software +SOF_TIMESTAMPING_RX_HARDWARE: return the original, unmodified time stamp + as generated by the hardware +SOF_TIMESTAMPING_RX_SOFTWARE: if SOF_TIMESTAMPING_RX_HARDWARE is off or + fails, then do it in software +SOF_TIMESTAMPING_RAW_HARDWARE: return original raw hardware time stamp +SOF_TIMESTAMPING_SYS_HARDWARE: return hardware time stamp transformed to + the system time base +SOF_TIMESTAMPING_SOFTWARE: return system time stamp generated in + software + +SOF_TIMESTAMPING_TX/RX determine how time stamps are generated. +SOF_TIMESTAMPING_RAW/SYS determine how they are reported in the +following control message: + struct scm_timestamping { + struct timespec systime; + struct timespec hwtimetrans; + struct timespec hwtimeraw; + }; + +recvmsg() can be used to get this control message for regular incoming +packets. For send time stamps the outgoing packet is looped back to +the socket's error queue with the send time stamp(s) attached. It can +be received with recvmsg(flags=MSG_ERRQUEUE). The call returns the +original outgoing packet data including all headers preprended down to +and including the link layer, the scm_timestamping control message and +a sock_extended_err control message with ee_errno==ENOMSG and +ee_origin==SO_EE_ORIGIN_TIMESTAMPING. A socket with such a pending +bounced packet is ready for reading as far as select() is concerned. +If the outgoing packet has to be fragmented, then only the first +fragment is time stamped and returned to the sending socket. + +All three values correspond to the same event in time, but were +generated in different ways. Each of these values may be empty (= all +zero), in which case no such value was available. If the application +is not interested in some of these values, they can be left blank to +avoid the potential overhead of calculating them. + +systime is the value of the system time at that moment. This +corresponds to the value also returned via SO_TIMESTAMP[NS]. If the +time stamp was generated by hardware, then this field is +empty. Otherwise it is filled in if SOF_TIMESTAMPING_SOFTWARE is +set. + +hwtimeraw is the original hardware time stamp. Filled in if +SOF_TIMESTAMPING_RAW_HARDWARE is set. No assumptions about its +relation to system time should be made. + +hwtimetrans is the hardware time stamp transformed so that it +corresponds as good as possible to system time. This correlation is +not perfect; as a consequence, sorting packets received via different +NICs by their hwtimetrans may differ from the order in which they were +received. hwtimetrans may be non-monotonic even for the same NIC. +Filled in if SOF_TIMESTAMPING_SYS_HARDWARE is set. Requires support +by the network device and will be empty without that support. + + +SIOCSHWTSTAMP: + +Hardware time stamping must also be initialized for each device driver +that is expected to do hardware time stamping. The parameter is: + +struct hwtstamp_config { + int flags; /* no flags defined right now, must be zero */ + int tx_type; /* HWTSTAMP_TX_* */ + int rx_filter; /* HWTSTAMP_FILTER_* */ +}; + +Desired behavior is passed into the kernel and to a specific device by +calling ioctl(SIOCSHWTSTAMP) with a pointer to a struct ifreq whose +ifr_data points to a struct hwtstamp_config. The tx_type and +rx_filter are hints to the driver what it is expected to do. If +the requested fine-grained filtering for incoming packets is not +supported, the driver may time stamp more than just the requested types +of packets. + +A driver which supports hardware time stamping shall update the struct +with the actual, possibly more permissive configuration. If the +requested packets cannot be time stamped, then nothing should be +changed and ERANGE shall be returned (in contrast to EINVAL, which +indicates that SIOCSHWTSTAMP is not supported at all). + +Only a processes with admin rights may change the configuration. User +space is responsible to ensure that multiple processes don't interfere +with each other and that the settings are reset. + +/* possible values for hwtstamp_config->tx_type */ +enum { + /* + * no outgoing packet will need hardware time stamping; + * should a packet arrive which asks for it, no hardware + * time stamping will be done + */ + HWTSTAMP_TX_OFF, + + /* + * enables hardware time stamping for outgoing packets; + * the sender of the packet decides which are to be + * time stamped by setting SOF_TIMESTAMPING_TX_SOFTWARE + * before sending the packet + */ + HWTSTAMP_TX_ON, +}; + +/* possible values for hwtstamp_config->rx_filter */ +enum { + /* time stamp no incoming packet at all */ + HWTSTAMP_FILTER_NONE, + + /* time stamp any incoming packet */ + HWTSTAMP_FILTER_ALL, + + /* return value: time stamp all packets requested plus some others */ + HWTSTAMP_FILTER_SOME, + + /* PTP v1, UDP, any kind of event packet */ + HWTSTAMP_FILTER_PTP_V1_L4_EVENT, + + ... +}; + + +DEVICE IMPLEMENTATION + +A driver which supports hardware time stamping must support the +SIOCSHWTSTAMP ioctl. Time stamps for received packets must be stored +in the skb with skb_hwtstamp_set(). + +Time stamps for outgoing packets are to be generated as follows: +- In hard_start_xmit(), check if skb_hwtstamp_check_tx_hardware() + returns non-zero. If yes, then the driver is expected + to do hardware time stamping. +- If this is possible for the skb and requested, then declare + that the driver is doing the time stamping by calling + skb_hwtstamp_tx_in_progress(). A driver not supporting + hardware time stamping doesn't do that. A driver must never + touch sk_buff::tstamp! It is used to store how time stamping + for an outgoing packets is to be done. +- As soon as the driver has sent the packet and/or obtained a + hardware time stamp for it, it passes the time stamp back by + calling skb_hwtstamp_tx() with the original skb, the raw + hardware time stamp and a handle to the device (necessary + to convert the hardware time stamp to system time). If obtaining + the hardware time stamp somehow fails, then the driver should + not fall back to software time stamping. The rationale is that + this would occur at a later time in the processing pipeline + than other software time stamping and therefore could lead + to unexpected deltas between time stamps. +- If the driver did not call skb_hwtstamp_tx_in_progress(), then + dev_hard_start_xmit() checks whether software time stamping + is wanted as fallback and potentially generates the time stamp. diff --git a/Documentation/networking/timestamping/.gitignore b/Documentation/networking/timestamping/.gitignore new file mode 100644 index 000000000000..71e81eb2e22f --- /dev/null +++ b/Documentation/networking/timestamping/.gitignore @@ -0,0 +1 @@ +timestamping diff --git a/Documentation/networking/timestamping/Makefile b/Documentation/networking/timestamping/Makefile new file mode 100644 index 000000000000..2a1489fdc036 --- /dev/null +++ b/Documentation/networking/timestamping/Makefile @@ -0,0 +1,6 @@ +CPPFLAGS = -I../../../include + +timestamping: timestamping.c + +clean: + rm -f timestamping diff --git a/Documentation/networking/timestamping/timestamping.c b/Documentation/networking/timestamping/timestamping.c new file mode 100644 index 000000000000..43d143104210 --- /dev/null +++ b/Documentation/networking/timestamping/timestamping.c @@ -0,0 +1,533 @@ +/* + * This program demonstrates how the various time stamping features in + * the Linux kernel work. It emulates the behavior of a PTP + * implementation in stand-alone master mode by sending PTPv1 Sync + * multicasts once every second. It looks for similar packets, but + * beyond that doesn't actually implement PTP. + * + * Outgoing packets are time stamped with SO_TIMESTAMPING with or + * without hardware support. + * + * Incoming packets are time stamped with SO_TIMESTAMPING with or + * without hardware support, SIOCGSTAMP[NS] (per-socket time stamp) and + * SO_TIMESTAMP[NS]. + * + * Copyright (C) 2009 Intel Corporation. + * Author: Patrick Ohly <patrick.ohly@intel.com> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms and conditions of the GNU General Public License, + * version 2, as published by the Free Software Foundation. + * + * This program is distributed in the hope it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. * See the GNU General Public License for + * more details. + * + * You should have received a copy of the GNU General Public License along with + * this program; if not, write to the Free Software Foundation, Inc., + * 51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA. + */ + +#include <stdio.h> +#include <stdlib.h> +#include <errno.h> +#include <string.h> + +#include <sys/time.h> +#include <sys/socket.h> +#include <sys/select.h> +#include <sys/ioctl.h> +#include <arpa/inet.h> +#include <net/if.h> + +#include "asm/types.h" +#include "linux/net_tstamp.h" +#include "linux/errqueue.h" + +#ifndef SO_TIMESTAMPING +# define SO_TIMESTAMPING 37 +# define SCM_TIMESTAMPING SO_TIMESTAMPING +#endif + +#ifndef SO_TIMESTAMPNS +# define SO_TIMESTAMPNS 35 +#endif + +#ifndef SIOCGSTAMPNS +# define SIOCGSTAMPNS 0x8907 +#endif + +#ifndef SIOCSHWTSTAMP +# define SIOCSHWTSTAMP 0x89b0 +#endif + +static void usage(const char *error) +{ + if (error) + printf("invalid option: %s\n", error); + printf("timestamping interface option*\n\n" + "Options:\n" + " IP_MULTICAST_LOOP - looping outgoing multicasts\n" + " SO_TIMESTAMP - normal software time stamping, ms resolution\n" + " SO_TIMESTAMPNS - more accurate software time stamping\n" + " SOF_TIMESTAMPING_TX_HARDWARE - hardware time stamping of outgoing packets\n" + " SOF_TIMESTAMPING_TX_SOFTWARE - software fallback for outgoing packets\n" + " SOF_TIMESTAMPING_RX_HARDWARE - hardware time stamping of incoming packets\n" + " SOF_TIMESTAMPING_RX_SOFTWARE - software fallback for incoming packets\n" + " SOF_TIMESTAMPING_SOFTWARE - request reporting of software time stamps\n" + " SOF_TIMESTAMPING_SYS_HARDWARE - request reporting of transformed HW time stamps\n" + " SOF_TIMESTAMPING_RAW_HARDWARE - request reporting of raw HW time stamps\n" + " SIOCGSTAMP - check last socket time stamp\n" + " SIOCGSTAMPNS - more accurate socket time stamp\n"); + exit(1); +} + +static void bail(const char *error) +{ + printf("%s: %s\n", error, strerror(errno)); + exit(1); +} + +static const unsigned char sync[] = { + 0x00, 0x01, 0x00, 0x01, + 0x5f, 0x44, 0x46, 0x4c, + 0x54, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x01, 0x01, + + /* fake uuid */ + 0x00, 0x01, + 0x02, 0x03, 0x04, 0x05, + + 0x00, 0x01, 0x00, 0x37, + 0x00, 0x00, 0x00, 0x08, + 0x00, 0x00, 0x00, 0x00, + 0x49, 0x05, 0xcd, 0x01, + 0x29, 0xb1, 0x8d, 0xb0, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x01, + + /* fake uuid */ + 0x00, 0x01, + 0x02, 0x03, 0x04, 0x05, + + 0x00, 0x00, 0x00, 0x37, + 0x00, 0x00, 0x00, 0x04, + 0x44, 0x46, 0x4c, 0x54, + 0x00, 0x00, 0xf0, 0x60, + 0x00, 0x01, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x01, + 0x00, 0x00, 0xf0, 0x60, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x04, + 0x44, 0x46, 0x4c, 0x54, + 0x00, 0x01, + + /* fake uuid */ + 0x00, 0x01, + 0x02, 0x03, 0x04, 0x05, + + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00 +}; + +static void sendpacket(int sock, struct sockaddr *addr, socklen_t addr_len) +{ + struct timeval now; + int res; + + res = sendto(sock, sync, sizeof(sync), 0, + addr, addr_len); + gettimeofday(&now, 0); + if (res < 0) + printf("%s: %s\n", "send", strerror(errno)); + else + printf("%ld.%06ld: sent %d bytes\n", + (long)now.tv_sec, (long)now.tv_usec, + res); +} + +static void printpacket(struct msghdr *msg, int res, + char *data, + int sock, int recvmsg_flags, + int siocgstamp, int siocgstampns) +{ + struct sockaddr_in *from_addr = (struct sockaddr_in *)msg->msg_name; + struct cmsghdr *cmsg; + struct timeval tv; + struct timespec ts; + struct timeval now; + + gettimeofday(&now, 0); + + printf("%ld.%06ld: received %s data, %d bytes from %s, %d bytes control messages\n", + (long)now.tv_sec, (long)now.tv_usec, + (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular", + res, + inet_ntoa(from_addr->sin_addr), + msg->msg_controllen); + for (cmsg = CMSG_FIRSTHDR(msg); + cmsg; + cmsg = CMSG_NXTHDR(msg, cmsg)) { + printf(" cmsg len %d: ", cmsg->cmsg_len); + switch (cmsg->cmsg_level) { + case SOL_SOCKET: + printf("SOL_SOCKET "); + switch (cmsg->cmsg_type) { + case SO_TIMESTAMP: { + struct timeval *stamp = + (struct timeval *)CMSG_DATA(cmsg); + printf("SO_TIMESTAMP %ld.%06ld", + (long)stamp->tv_sec, + (long)stamp->tv_usec); + break; + } + case SO_TIMESTAMPNS: { + struct timespec *stamp = + (struct timespec *)CMSG_DATA(cmsg); + printf("SO_TIMESTAMPNS %ld.%09ld", + (long)stamp->tv_sec, + (long)stamp->tv_nsec); + break; + } + case SO_TIMESTAMPING: { + struct timespec *stamp = + (struct timespec *)CMSG_DATA(cmsg); + printf("SO_TIMESTAMPING "); + printf("SW %ld.%09ld ", + (long)stamp->tv_sec, + (long)stamp->tv_nsec); + stamp++; + printf("HW transformed %ld.%09ld ", + (long)stamp->tv_sec, + (long)stamp->tv_nsec); + stamp++; + printf("HW raw %ld.%09ld", + (long)stamp->tv_sec, + (long)stamp->tv_nsec); + break; + } + default: + printf("type %d", cmsg->cmsg_type); + break; + } + break; + case IPPROTO_IP: + printf("IPPROTO_IP "); + switch (cmsg->cmsg_type) { + case IP_RECVERR: { + struct sock_extended_err *err = + (struct sock_extended_err *)CMSG_DATA(cmsg); + printf("IP_RECVERR ee_errno '%s' ee_origin %d => %s", + strerror(err->ee_errno), + err->ee_origin, +#ifdef SO_EE_ORIGIN_TIMESTAMPING + err->ee_origin == SO_EE_ORIGIN_TIMESTAMPING ? + "bounced packet" : "unexpected origin" +#else + "probably SO_EE_ORIGIN_TIMESTAMPING" +#endif + ); + if (res < sizeof(sync)) + printf(" => truncated data?!"); + else if (!memcmp(sync, data + res - sizeof(sync), + sizeof(sync))) + printf(" => GOT OUR DATA BACK (HURRAY!)"); + break; + } + case IP_PKTINFO: { + struct in_pktinfo *pktinfo = + (struct in_pktinfo *)CMSG_DATA(cmsg); + printf("IP_PKTINFO interface index %u", + pktinfo->ipi_ifindex); + break; + } + default: + printf("type %d", cmsg->cmsg_type); + break; + } + break; + default: + printf("level %d type %d", + cmsg->cmsg_level, + cmsg->cmsg_type); + break; + } + printf("\n"); + } + + if (siocgstamp) { + if (ioctl(sock, SIOCGSTAMP, &tv)) + printf(" %s: %s\n", "SIOCGSTAMP", strerror(errno)); + else + printf("SIOCGSTAMP %ld.%06ld\n", + (long)tv.tv_sec, + (long)tv.tv_usec); + } + if (siocgstampns) { + if (ioctl(sock, SIOCGSTAMPNS, &ts)) + printf(" %s: %s\n", "SIOCGSTAMPNS", strerror(errno)); + else + printf("SIOCGSTAMPNS %ld.%09ld\n", + (long)ts.tv_sec, + (long)ts.tv_nsec); + } +} + +static void recvpacket(int sock, int recvmsg_flags, + int siocgstamp, int siocgstampns) +{ + char data[256]; + struct msghdr msg; + struct iovec entry; + struct sockaddr_in from_addr; + struct { + struct cmsghdr cm; + char control[512]; + } control; + int res; + + memset(&msg, 0, sizeof(msg)); + msg.msg_iov = &entry; + msg.msg_iovlen = 1; + entry.iov_base = data; + entry.iov_len = sizeof(data); + msg.msg_name = (caddr_t)&from_addr; + msg.msg_namelen = sizeof(from_addr); + msg.msg_control = &control; + msg.msg_controllen = sizeof(control); + + res = recvmsg(sock, &msg, recvmsg_flags|MSG_DONTWAIT); + if (res < 0) { + printf("%s %s: %s\n", + "recvmsg", + (recvmsg_flags & MSG_ERRQUEUE) ? "error" : "regular", + strerror(errno)); + } else { + printpacket(&msg, res, data, + sock, recvmsg_flags, + siocgstamp, siocgstampns); + } +} + +int main(int argc, char **argv) +{ + int so_timestamping_flags = 0; + int so_timestamp = 0; + int so_timestampns = 0; + int siocgstamp = 0; + int siocgstampns = 0; + int ip_multicast_loop = 0; + char *interface; + int i; + int enabled = 1; + int sock; + struct ifreq device; + struct ifreq hwtstamp; + struct hwtstamp_config hwconfig, hwconfig_requested; + struct sockaddr_in addr; + struct ip_mreq imr; + struct in_addr iaddr; + int val; + socklen_t len; + struct timeval next; + + if (argc < 2) + usage(0); + interface = argv[1]; + + for (i = 2; i < argc; i++) { + if (!strcasecmp(argv[i], "SO_TIMESTAMP")) + so_timestamp = 1; + else if (!strcasecmp(argv[i], "SO_TIMESTAMPNS")) + so_timestampns = 1; + else if (!strcasecmp(argv[i], "SIOCGSTAMP")) + siocgstamp = 1; + else if (!strcasecmp(argv[i], "SIOCGSTAMPNS")) + siocgstampns = 1; + else if (!strcasecmp(argv[i], "IP_MULTICAST_LOOP")) + ip_multicast_loop = 1; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_TX_HARDWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_TX_HARDWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_TX_SOFTWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_TX_SOFTWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RX_HARDWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_RX_HARDWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RX_SOFTWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_RX_SOFTWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_SOFTWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_SOFTWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_SYS_HARDWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_SYS_HARDWARE; + else if (!strcasecmp(argv[i], "SOF_TIMESTAMPING_RAW_HARDWARE")) + so_timestamping_flags |= SOF_TIMESTAMPING_RAW_HARDWARE; + else + usage(argv[i]); + } + + sock = socket(PF_INET, SOCK_DGRAM, IPPROTO_UDP); + if (socket < 0) + bail("socket"); + + memset(&device, 0, sizeof(device)); + strncpy(device.ifr_name, interface, sizeof(device.ifr_name)); + if (ioctl(sock, SIOCGIFADDR, &device) < 0) + bail("getting interface IP address"); + + memset(&hwtstamp, 0, sizeof(hwtstamp)); + strncpy(hwtstamp.ifr_name, interface, sizeof(hwtstamp.ifr_name)); + hwtstamp.ifr_data = (void *)&hwconfig; + memset(&hwconfig, 0, sizeof(&hwconfig)); + hwconfig.tx_type = + (so_timestamping_flags & SOF_TIMESTAMPING_TX_HARDWARE) ? + HWTSTAMP_TX_ON : HWTSTAMP_TX_OFF; + hwconfig.rx_filter = + (so_timestamping_flags & SOF_TIMESTAMPING_RX_HARDWARE) ? + HWTSTAMP_FILTER_PTP_V1_L4_SYNC : HWTSTAMP_FILTER_NONE; + hwconfig_requested = hwconfig; + if (ioctl(sock, SIOCSHWTSTAMP, &hwtstamp) < 0) { + if ((errno == EINVAL || errno == ENOTSUP) && + hwconfig_requested.tx_type == HWTSTAMP_TX_OFF && + hwconfig_requested.rx_filter == HWTSTAMP_FILTER_NONE) + printf("SIOCSHWTSTAMP: disabling hardware time stamping not possible\n"); + else + bail("SIOCSHWTSTAMP"); + } + printf("SIOCSHWTSTAMP: tx_type %d requested, got %d; rx_filter %d requested, got %d\n", + hwconfig_requested.tx_type, hwconfig.tx_type, + hwconfig_requested.rx_filter, hwconfig.rx_filter); + + /* bind to PTP port */ + addr.sin_family = AF_INET; + addr.sin_addr.s_addr = htonl(INADDR_ANY); + addr.sin_port = htons(319 /* PTP event port */); + if (bind(sock, + (struct sockaddr *)&addr, + sizeof(struct sockaddr_in)) < 0) + bail("bind"); + + /* set multicast group for outgoing packets */ + inet_aton("224.0.1.130", &iaddr); /* alternate PTP domain 1 */ + addr.sin_addr = iaddr; + imr.imr_multiaddr.s_addr = iaddr.s_addr; + imr.imr_interface.s_addr = + ((struct sockaddr_in *)&device.ifr_addr)->sin_addr.s_addr; + if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_IF, + &imr.imr_interface.s_addr, sizeof(struct in_addr)) < 0) + bail("set multicast"); + + /* join multicast group, loop our own packet */ + if (setsockopt(sock, IPPROTO_IP, IP_ADD_MEMBERSHIP, + &imr, sizeof(struct ip_mreq)) < 0) + bail("join multicast group"); + + if (setsockopt(sock, IPPROTO_IP, IP_MULTICAST_LOOP, + &ip_multicast_loop, sizeof(enabled)) < 0) { + bail("loop multicast"); + } + + /* set socket options for time stamping */ + if (so_timestamp && + setsockopt(sock, SOL_SOCKET, SO_TIMESTAMP, + &enabled, sizeof(enabled)) < 0) + bail("setsockopt SO_TIMESTAMP"); + + if (so_timestampns && + setsockopt(sock, SOL_SOCKET, SO_TIMESTAMPNS, + &enabled, sizeof(enabled)) < 0) + bail("setsockopt SO_TIMESTAMPNS"); + + if (so_timestamping_flags && + setsockopt(sock, SOL_SOCKET, SO_TIMESTAMPING, + &so_timestamping_flags, + sizeof(so_timestamping_flags)) < 0) + bail("setsockopt SO_TIMESTAMPING"); + + /* request IP_PKTINFO for debugging purposes */ + if (setsockopt(sock, SOL_IP, IP_PKTINFO, + &enabled, sizeof(enabled)) < 0) + printf("%s: %s\n", "setsockopt IP_PKTINFO", strerror(errno)); + + /* verify socket options */ + len = sizeof(val); + if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMP, &val, &len) < 0) + printf("%s: %s\n", "getsockopt SO_TIMESTAMP", strerror(errno)); + else + printf("SO_TIMESTAMP %d\n", val); + + if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMPNS, &val, &len) < 0) + printf("%s: %s\n", "getsockopt SO_TIMESTAMPNS", + strerror(errno)); + else + printf("SO_TIMESTAMPNS %d\n", val); + + if (getsockopt(sock, SOL_SOCKET, SO_TIMESTAMPING, &val, &len) < 0) { + printf("%s: %s\n", "getsockopt SO_TIMESTAMPING", + strerror(errno)); + } else { + printf("SO_TIMESTAMPING %d\n", val); + if (val != so_timestamping_flags) + printf(" not the expected value %d\n", + so_timestamping_flags); + } + + /* send packets forever every five seconds */ + gettimeofday(&next, 0); + next.tv_sec = (next.tv_sec + 1) / 5 * 5; + next.tv_usec = 0; + while (1) { + struct timeval now; + struct timeval delta; + long delta_us; + int res; + fd_set readfs, errorfs; + + gettimeofday(&now, 0); + delta_us = (long)(next.tv_sec - now.tv_sec) * 1000000 + + (long)(next.tv_usec - now.tv_usec); + if (delta_us > 0) { + /* continue waiting for timeout or data */ + delta.tv_sec = delta_us / 1000000; + delta.tv_usec = delta_us % 1000000; + + FD_ZERO(&readfs); + FD_ZERO(&errorfs); + FD_SET(sock, &readfs); + FD_SET(sock, &errorfs); + printf("%ld.%06ld: select %ldus\n", + (long)now.tv_sec, (long)now.tv_usec, + delta_us); + res = select(sock + 1, &readfs, 0, &errorfs, &delta); + gettimeofday(&now, 0); + printf("%ld.%06ld: select returned: %d, %s\n", + (long)now.tv_sec, (long)now.tv_usec, + res, + res < 0 ? strerror(errno) : "success"); + if (res > 0) { + if (FD_ISSET(sock, &readfs)) + printf("ready for reading\n"); + if (FD_ISSET(sock, &errorfs)) + printf("has error\n"); + recvpacket(sock, 0, + siocgstamp, + siocgstampns); + recvpacket(sock, MSG_ERRQUEUE, + siocgstamp, + siocgstampns); + } + } else { + /* write one packet */ + sendpacket(sock, + (struct sockaddr *)&addr, + sizeof(addr)); + next.tv_sec += 5; + continue; + } + } + + return 0; +} diff --git a/Documentation/networking/vxge.txt b/Documentation/networking/vxge.txt new file mode 100644 index 000000000000..d2e2997e6fa0 --- /dev/null +++ b/Documentation/networking/vxge.txt @@ -0,0 +1,100 @@ +Neterion's (Formerly S2io) X3100 Series 10GbE PCIe Server Adapter Linux driver +============================================================================== + +Contents +-------- + +1) Introduction +2) Features supported +3) Configurable driver parameters +4) Troubleshooting + +1) Introduction: +---------------- +This Linux driver supports all Neterion's X3100 series 10 GbE PCIe I/O +Virtualized Server adapters. +The X3100 series supports four modes of operation, configurable via +firmware - + Single function mode + Multi function mode + SRIOV mode + MRIOV mode +The functions share a 10GbE link and the pci-e bus, but hardly anything else +inside the ASIC. Features like independent hw reset, statistics, bandwidth/ +priority allocation and guarantees, GRO, TSO, interrupt moderation etc are +supported independently on each function. + +(See below for a complete list of features supported for both IPv4 and IPv6) + +2) Features supported: +---------------------- + +i) Single function mode (up to 17 queues) + +ii) Multi function mode (up to 17 functions) + +iii) PCI-SIG's I/O Virtualization + - Single Root mode: v1.0 (up to 17 functions) + - Multi-Root mode: v1.0 (up to 17 functions) + +iv) Jumbo frames + X3100 Series supports MTU up to 9600 bytes, modifiable using + ifconfig command. + +v) Offloads supported: (Enabled by default) + Checksum offload (TCP/UDP/IP) on transmit and receive paths + TCP Segmentation Offload (TSO) on transmit path + Generic Receive Offload (GRO) on receive path + +vi) MSI-X: (Enabled by default) + Resulting in noticeable performance improvement (up to 7% on certain + platforms). + +vii) NAPI: (Enabled by default) + For better Rx interrupt moderation. + +viii)RTH (Receive Traffic Hash): (Enabled by default) + Receive side steering for better scaling. + +ix) Statistics + Comprehensive MAC-level and software statistics displayed using + "ethtool -S" option. + +x) Multiple hardware queues: (Enabled by default) + Up to 17 hardware based transmit and receive data channels, with + multiple steering options (transmit multiqueue enabled by default). + +3) Configurable driver parameters: +---------------------------------- + +i) max_config_dev + Specifies maximum device functions to be enabled. + Valid range: 1-8 + +ii) max_config_port + Specifies number of ports to be enabled. + Valid range: 1,2 + Default: 1 + +iii)max_config_vpath + Specifies maximum VPATH(s) configured for each device function. + Valid range: 1-17 + +iv) vlan_tag_strip + Enables/disables vlan tag stripping from all received tagged frames that + are not replicated at the internal L2 switch. + Valid range: 0,1 (disabled, enabled respectively) + Default: 1 + +v) addr_learn_en + Enable learning the mac address of the guest OS interface in + virtualization environment. + Valid range: 0,1 (disabled, enabled respectively) + Default: 0 + +4) Troubleshooting: +------------------- + +To resolve an issue with the source code or X3100 series adapter, please collect +the statistics, register dumps using ethool, relevant logs and email them to +support@neterion.com. diff --git a/Documentation/powerpc/booting-without-of.txt b/Documentation/powerpc/booting-without-of.txt index 0ab0230cbcb0..d16b7a1c3793 100644 --- a/Documentation/powerpc/booting-without-of.txt +++ b/Documentation/powerpc/booting-without-of.txt @@ -43,12 +43,11 @@ Table of Contents 2) Representing devices without a current OF specification a) PHY nodes b) Interrupt controllers - c) CFI or JEDEC memory-mapped NOR flash - d) 4xx/Axon EMAC ethernet nodes - e) Xilinx IP cores - f) USB EHCI controllers - g) MDIO on GPIOs - h) SPI busses + c) 4xx/Axon EMAC ethernet nodes + d) Xilinx IP cores + e) USB EHCI controllers + f) MDIO on GPIOs + g) SPI busses VII - Marvell Discovery mv64[345]6x System Controller chips 1) The /system-controller node @@ -999,7 +998,7 @@ compatibility. translation of SOC addresses for memory mapped SOC registers. - bus-frequency: Contains the bus frequency for the SOC node. Typically, the value of this field is filled in by the boot - loader. + loader. Recommended properties: @@ -1287,71 +1286,7 @@ platforms are moved over to use the flattened-device-tree model. device_type = "open-pic"; }; - c) CFI or JEDEC memory-mapped NOR flash - - Flash chips (Memory Technology Devices) are often used for solid state - file systems on embedded devices. - - - compatible : should contain the specific model of flash chip(s) - used, if known, followed by either "cfi-flash" or "jedec-flash" - - reg : Address range of the flash chip - - bank-width : Width (in bytes) of the flash bank. Equal to the - device width times the number of interleaved chips. - - device-width : (optional) Width of a single flash chip. If - omitted, assumed to be equal to 'bank-width'. - - #address-cells, #size-cells : Must be present if the flash has - sub-nodes representing partitions (see below). In this case - both #address-cells and #size-cells must be equal to 1. - - For JEDEC compatible devices, the following additional properties - are defined: - - - vendor-id : Contains the flash chip's vendor id (1 byte). - - device-id : Contains the flash chip's device id (1 byte). - - In addition to the information on the flash bank itself, the - device tree may optionally contain additional information - describing partitions of the flash address space. This can be - used on platforms which have strong conventions about which - portions of the flash are used for what purposes, but which don't - use an on-flash partition table such as RedBoot. - - Each partition is represented as a sub-node of the flash device. - Each node's name represents the name of the corresponding - partition of the flash device. - - Flash partitions - - reg : The partition's offset and size within the flash bank. - - label : (optional) The label / name for this flash partition. - If omitted, the label is taken from the node name (excluding - the unit address). - - read-only : (optional) This parameter, if present, is a hint to - Linux that this flash partition should only be mounted - read-only. This is usually used for flash partitions - containing early-boot firmware images or data which should not - be clobbered. - - Example: - - flash@ff000000 { - compatible = "amd,am29lv128ml", "cfi-flash"; - reg = <ff000000 01000000>; - bank-width = <4>; - device-width = <1>; - #address-cells = <1>; - #size-cells = <1>; - fs@0 { - label = "fs"; - reg = <0 f80000>; - }; - firmware@f80000 { - label ="firmware"; - reg = <f80000 80000>; - read-only; - }; - }; - - d) 4xx/Axon EMAC ethernet nodes + c) 4xx/Axon EMAC ethernet nodes The EMAC ethernet controller in IBM and AMCC 4xx chips, and also the Axon bridge. To operate this needs to interact with a ths @@ -1499,7 +1434,7 @@ platforms are moved over to use the flattened-device-tree model. available. For Axon: 0x0000012a - e) Xilinx IP cores + d) Xilinx IP cores The Xilinx EDK toolchain ships with a set of IP cores (devices) for use in Xilinx Spartan and Virtex FPGAs. The devices cover the whole range @@ -1761,7 +1696,7 @@ platforms are moved over to use the flattened-device-tree model. listed above, nodes for these devices should include a phy-handle property, and may include other common network device properties like local-mac-address. - + iv) Xilinx Uartlite Xilinx uartlite devices are simple fixed speed serial ports. @@ -1793,7 +1728,7 @@ platforms are moved over to use the flattened-device-tree model. - reg-offset : A value of 3 is required - reg-shift : A value of 2 is required - f) USB EHCI controllers + e) USB EHCI controllers Required properties: - compatible : should be "usb-ehci". @@ -1819,7 +1754,7 @@ platforms are moved over to use the flattened-device-tree model. big-endian; }; - g) MDIO on GPIOs + f) MDIO on GPIOs Currently defined compatibles: - virtual,gpio-mdio @@ -1839,7 +1774,7 @@ platforms are moved over to use the flattened-device-tree model. &qe_pio_c 6>; }; - h) SPI (Serial Peripheral Interface) busses + g) SPI (Serial Peripheral Interface) busses SPI busses can be described with a node for the SPI master device and a set of child nodes for each SPI slave on the bus. For this diff --git a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe/firmware.txt b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe/firmware.txt index 6c238f59b2a9..249db3a15d15 100644 --- a/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe/firmware.txt +++ b/Documentation/powerpc/dts-bindings/fsl/cpm_qe/qe/firmware.txt @@ -1,6 +1,6 @@ * Uploaded QE firmware - If a new firwmare has been uploaded to the QE (usually by the + If a new firmware has been uploaded to the QE (usually by the boot loader), then a 'firmware' child node should be added to the QE node. This node provides information on the uploaded firmware that device drivers may need. diff --git a/Documentation/powerpc/dts-bindings/fsl/dma.txt b/Documentation/powerpc/dts-bindings/fsl/dma.txt index cc453110fc46..0732cdd05ba1 100644 --- a/Documentation/powerpc/dts-bindings/fsl/dma.txt +++ b/Documentation/powerpc/dts-bindings/fsl/dma.txt @@ -35,30 +35,30 @@ Example: #address-cells = <1>; #size-cells = <1>; compatible = "fsl,mpc8349-dma", "fsl,elo-dma"; - reg = <82a8 4>; - ranges = <0 8100 1a4>; + reg = <0x82a8 4>; + ranges = <0 0x8100 0x1a4>; interrupt-parent = <&ipic>; - interrupts = <47 8>; + interrupts = <71 8>; cell-index = <0>; dma-channel@0 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <0>; - reg = <0 80>; + reg = <0 0x80>; }; dma-channel@80 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <1>; - reg = <80 80>; + reg = <0x80 0x80>; }; dma-channel@100 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <2>; - reg = <100 80>; + reg = <0x100 0x80>; }; dma-channel@180 { compatible = "fsl,mpc8349-dma-channel", "fsl,elo-dma-channel"; cell-index = <3>; - reg = <180 80>; + reg = <0x180 0x80>; }; }; @@ -93,36 +93,36 @@ Example: #address-cells = <1>; #size-cells = <1>; compatible = "fsl,mpc8540-dma", "fsl,eloplus-dma"; - reg = <21300 4>; - ranges = <0 21100 200>; + reg = <0x21300 4>; + ranges = <0 0x21100 0x200>; cell-index = <0>; dma-channel@0 { compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel"; - reg = <0 80>; + reg = <0 0x80>; cell-index = <0>; interrupt-parent = <&mpic>; - interrupts = <14 2>; + interrupts = <20 2>; }; dma-channel@80 { compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel"; - reg = <80 80>; + reg = <0x80 0x80>; cell-index = <1>; interrupt-parent = <&mpic>; - interrupts = <15 2>; + interrupts = <21 2>; }; dma-channel@100 { compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel"; - reg = <100 80>; + reg = <0x100 0x80>; cell-index = <2>; interrupt-parent = <&mpic>; - interrupts = <16 2>; + interrupts = <22 2>; }; dma-channel@180 { compatible = "fsl,mpc8540-dma-channel", "fsl,eloplus-dma-channel"; - reg = <180 80>; + reg = <0x180 0x80>; cell-index = <3>; interrupt-parent = <&mpic>; - interrupts = <17 2>; + interrupts = <23 2>; }; }; diff --git a/Documentation/powerpc/dts-bindings/fsl/esdhc.txt b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt new file mode 100644 index 000000000000..600846557763 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/fsl/esdhc.txt @@ -0,0 +1,24 @@ +* Freescale Enhanced Secure Digital Host Controller (eSDHC) + +The Enhanced Secure Digital Host Controller provides an interface +for MMC, SD, and SDIO types of memory cards. + +Required properties: + - compatible : should be + "fsl,<chip>-esdhc", "fsl,mpc8379-esdhc" for MPC83xx processors. + "fsl,<chip>-esdhc", "fsl,mpc8536-esdhc" for MPC85xx processors. + - reg : should contain eSDHC registers location and length. + - interrupts : should contain eSDHC interrupt. + - interrupt-parent : interrupt source phandle. + - clock-frequency : specifies eSDHC base clock frequency. + +Example: + +sdhci@2e000 { + compatible = "fsl,mpc8378-esdhc", "fsl,mpc8379-esdhc"; + reg = <0x2e000 0x1000>; + interrupts = <42 0x8>; + interrupt-parent = <&ipic>; + /* Filled in by U-Boot */ + clock-frequency = <0>; +}; diff --git a/Documentation/powerpc/dts-bindings/fsl/i2c.txt b/Documentation/powerpc/dts-bindings/fsl/i2c.txt index d0ab33e21fe6..b6d2e21474f9 100644 --- a/Documentation/powerpc/dts-bindings/fsl/i2c.txt +++ b/Documentation/powerpc/dts-bindings/fsl/i2c.txt @@ -7,8 +7,10 @@ Required properties : Recommended properties : - - compatible : Should be "fsl-i2c" for parts compatible with - Freescale I2C specifications. + - compatible : compatibility list with 2 entries, the first should + be "fsl,CHIP-i2c" where CHIP is the name of a compatible processor, + e.g. mpc8313, mpc8543, mpc8544, mpc5200 or mpc5200b. The second one + should be "fsl-i2c". - interrupts : <a b> where a is the interrupt number and b is a field that represents an encoding of the sense and level information for the interrupt. This should be encoded based on @@ -16,17 +18,31 @@ Recommended properties : controller you have. - interrupt-parent : the phandle for the interrupt controller that services interrupts for this device. - - dfsrr : boolean; if defined, indicates that this I2C device has - a digital filter sampling rate register - - fsl5200-clocking : boolean; if defined, indicated that this device - uses the FSL 5200 clocking mechanism. - -Example : - i2c@3000 { - interrupt-parent = <40000>; - interrupts = <1b 3>; - reg = <3000 18>; - device_type = "i2c"; - compatible = "fsl-i2c"; - dfsrr; + - fsl,preserve-clocking : boolean; if defined, the clock settings + from the bootloader are preserved (not touched). + - clock-frequency : desired I2C bus clock frequency in Hz. + +Examples : + + i2c@3d00 { + #address-cells = <1>; + #size-cells = <0>; + compatible = "fsl,mpc5200b-i2c","fsl,mpc5200-i2c","fsl-i2c"; + cell-index = <0>; + reg = <0x3d00 0x40>; + interrupts = <2 15 0>; + interrupt-parent = <&mpc5200_pic>; + fsl,preserve-clocking; }; + + i2c@3100 { + #address-cells = <1>; + #size-cells = <0>; + cell-index = <1>; + compatible = "fsl,mpc8544-i2c", "fsl-i2c"; + reg = <0x3100 0x100>; + interrupts = <43 2>; + interrupt-parent = <&mpic>; + clock-frequency = <400000>; + }; + diff --git a/Documentation/powerpc/dts-bindings/fsl/ssi.txt b/Documentation/powerpc/dts-bindings/fsl/ssi.txt index a2d963998a65..5ff76c9c57d2 100644 --- a/Documentation/powerpc/dts-bindings/fsl/ssi.txt +++ b/Documentation/powerpc/dts-bindings/fsl/ssi.txt @@ -4,44 +4,56 @@ The SSI is a serial device that communicates with audio codecs. It can be programmed in AC97, I2S, left-justified, or right-justified modes. Required properties: -- compatible : compatible list, containing "fsl,ssi" -- cell-index : the SSI, <0> = SSI1, <1> = SSI2, and so on -- reg : offset and length of the register set for the device -- interrupts : <a b> where a is the interrupt number and b is a - field that represents an encoding of the sense and - level information for the interrupt. This should be - encoded based on the information in section 2) - depending on the type of interrupt controller you - have. -- interrupt-parent : the phandle for the interrupt controller that - services interrupts for this device. -- fsl,mode : the operating mode for the SSI interface - "i2s-slave" - I2S mode, SSI is clock slave - "i2s-master" - I2S mode, SSI is clock master - "lj-slave" - left-justified mode, SSI is clock slave - "lj-master" - l.j. mode, SSI is clock master - "rj-slave" - right-justified mode, SSI is clock slave - "rj-master" - r.j., SSI is clock master - "ac97-slave" - AC97 mode, SSI is clock slave - "ac97-master" - AC97 mode, SSI is clock master -- fsl,playback-dma: phandle to a node for the DMA channel to use for +- compatible: Compatible list, contains "fsl,ssi". +- cell-index: The SSI, <0> = SSI1, <1> = SSI2, and so on. +- reg: Offset and length of the register set for the device. +- interrupts: <a b> where a is the interrupt number and b is a + field that represents an encoding of the sense and + level information for the interrupt. This should be + encoded based on the information in section 2) + depending on the type of interrupt controller you + have. +- interrupt-parent: The phandle for the interrupt controller that + services interrupts for this device. +- fsl,mode: The operating mode for the SSI interface. + "i2s-slave" - I2S mode, SSI is clock slave + "i2s-master" - I2S mode, SSI is clock master + "lj-slave" - left-justified mode, SSI is clock slave + "lj-master" - l.j. mode, SSI is clock master + "rj-slave" - right-justified mode, SSI is clock slave + "rj-master" - r.j., SSI is clock master + "ac97-slave" - AC97 mode, SSI is clock slave + "ac97-master" - AC97 mode, SSI is clock master +- fsl,playback-dma: Phandle to a node for the DMA channel to use for playback of audio. This is typically dictated by SOC design. See the notes below. -- fsl,capture-dma: phandle to a node for the DMA channel to use for +- fsl,capture-dma: Phandle to a node for the DMA channel to use for capture (recording) of audio. This is typically dictated by SOC design. See the notes below. +- fsl,fifo-depth: The number of elements in the transmit and receive FIFOs. + This number is the maximum allowed value for SFCSR[TFWM0]. +- fsl,ssi-asynchronous: + If specified, the SSI is to be programmed in asynchronous + mode. In this mode, pins SRCK, STCK, SRFS, and STFS must + all be connected to valid signals. In synchronous mode, + SRCK and SRFS are ignored. Asynchronous mode allows + playback and capture to use different sample sizes and + sample rates. Some drivers may require that SRCK and STCK + be connected together, and SRFS and STFS be connected + together. This would still allow different sample sizes, + but not different sample rates. Optional properties: -- codec-handle : phandle to a 'codec' node that defines an audio - codec connected to this SSI. This node is typically - a child of an I2C or other control node. +- codec-handle: Phandle to a 'codec' node that defines an audio + codec connected to this SSI. This node is typically + a child of an I2C or other control node. Child 'codec' node required properties: -- compatible : compatible list, contains the name of the codec +- compatible: Compatible list, contains the name of the codec Child 'codec' node optional properties: -- clock-frequency : The frequency of the input clock, which typically - comes from an on-board dedicated oscillator. +- clock-frequency: The frequency of the input clock, which typically comes + from an on-board dedicated oscillator. Notes on fsl,playback-dma and fsl,capture-dma: diff --git a/Documentation/powerpc/dts-bindings/fsl/tsec.txt b/Documentation/powerpc/dts-bindings/fsl/tsec.txt index 7fa4b27574b5..edb7ae19e868 100644 --- a/Documentation/powerpc/dts-bindings/fsl/tsec.txt +++ b/Documentation/powerpc/dts-bindings/fsl/tsec.txt @@ -56,6 +56,12 @@ Properties: hardware. - fsl,magic-packet : If present, indicates that the hardware supports waking up via magic packet. + - bd-stash : If present, indicates that the hardware supports stashing + buffer descriptors in the L2. + - rx-stash-len : Denotes the number of bytes of a received buffer to stash + in the L2. + - rx-stash-idx : Denotes the index of the first byte from the received + buffer to stash in the L2. Example: ethernet@24000 { diff --git a/Documentation/powerpc/dts-bindings/fsl/upm-nand.txt b/Documentation/powerpc/dts-bindings/fsl/upm-nand.txt index 84a04d5eb8e6..a48b2cadc7f0 100644 --- a/Documentation/powerpc/dts-bindings/fsl/upm-nand.txt +++ b/Documentation/powerpc/dts-bindings/fsl/upm-nand.txt @@ -5,9 +5,21 @@ Required properties: - reg : should specify localbus chip select and size used for the chip. - fsl,upm-addr-offset : UPM pattern offset for the address latch. - fsl,upm-cmd-offset : UPM pattern offset for the command latch. -- gpios : may specify optional GPIO connected to the Ready-Not-Busy pin. -Example: +Optional properties: +- fsl,upm-wait-flags : add chip-dependent short delays after running the + UPM pattern (0x1), after writing a data byte (0x2) or after + writing out a buffer (0x4). +- fsl,upm-addr-line-cs-offsets : address offsets for multi-chip support. + The corresponding address lines are used to select the chip. +- gpios : may specify optional GPIOs connected to the Ready-Not-Busy pins + (R/B#). For multi-chip devices, "n" GPIO definitions are required + according to the number of chips. +- chip-delay : chip dependent delay for transfering data from array to + read registers (tR). Required if property "gpios" is not used + (R/B# pins not connected). + +Examples: upm@1,0 { compatible = "fsl,upm-nand"; @@ -26,3 +38,26 @@ upm@1,0 { }; }; }; + +upm@3,0 { + #address-cells = <0>; + #size-cells = <0>; + compatible = "tqc,tqm8548-upm-nand", "fsl,upm-nand"; + reg = <3 0x0 0x800>; + fsl,upm-addr-offset = <0x10>; + fsl,upm-cmd-offset = <0x08>; + /* Multi-chip NAND device */ + fsl,upm-addr-line-cs-offsets = <0x0 0x200>; + fsl,upm-wait-flags = <0x5>; + chip-delay = <25>; // in micro-seconds + + nand@0 { + #address-cells = <1>; + #size-cells = <1>; + + partition@0 { + label = "fs"; + reg = <0x00000000 0x10000000>; + }; + }; +}; diff --git a/Documentation/powerpc/dts-bindings/gpio/led.txt b/Documentation/powerpc/dts-bindings/gpio/led.txt index ff51f4c0fa9d..4fe14deedc0a 100644 --- a/Documentation/powerpc/dts-bindings/gpio/led.txt +++ b/Documentation/powerpc/dts-bindings/gpio/led.txt @@ -1,15 +1,43 @@ -LED connected to GPIO +LEDs connected to GPIO lines Required properties: -- compatible : should be "gpio-led". -- label : (optional) the label for this LED. If omitted, the label is +- compatible : should be "gpio-leds". + +Each LED is represented as a sub-node of the gpio-leds device. Each +node's name represents the name of the corresponding LED. + +LED sub-node properties: +- gpios : Should specify the LED's GPIO, see "Specifying GPIO information + for devices" in Documentation/powerpc/booting-without-of.txt. Active + low LEDs should be indicated using flags in the GPIO specifier. +- label : (optional) The label for this LED. If omitted, the label is taken from the node name (excluding the unit address). -- gpios : should specify LED GPIO. +- linux,default-trigger : (optional) This parameter, if present, is a + string defining the trigger assigned to the LED. Current triggers are: + "backlight" - LED will act as a back-light, controlled by the framebuffer + system + "default-on" - LED will turn on + "heartbeat" - LED "double" flashes at a load average based rate + "ide-disk" - LED indicates disk activity + "timer" - LED flashes at a fixed, configurable rate -Example: +Examples: -led@0 { - compatible = "gpio-led"; - label = "hdd"; - gpios = <&mcu_pio 0 1>; +leds { + compatible = "gpio-leds"; + hdd { + label = "IDE Activity"; + gpios = <&mcu_pio 0 1>; /* Active low */ + linux,default-trigger = "ide-disk"; + }; }; + +run-control { + compatible = "gpio-leds"; + red { + gpios = <&mpc8572 6 0>; + }; + green { + gpios = <&mpc8572 7 0>; + }; +} diff --git a/Documentation/powerpc/dts-bindings/mmc-spi-slot.txt b/Documentation/powerpc/dts-bindings/mmc-spi-slot.txt new file mode 100644 index 000000000000..c39ac2891951 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/mmc-spi-slot.txt @@ -0,0 +1,23 @@ +MMC/SD/SDIO slot directly connected to a SPI bus + +Required properties: +- compatible : should be "mmc-spi-slot". +- reg : should specify SPI address (chip-select number). +- spi-max-frequency : maximum frequency for this device (Hz). +- voltage-ranges : two cells are required, first cell specifies minimum + slot voltage (mV), second cell specifies maximum slot voltage (mV). + Several ranges could be specified. +- gpios : (optional) may specify GPIOs in this order: Card-Detect GPIO, + Write-Protect GPIO. + +Example: + + mmc-slot@0 { + compatible = "fsl,mpc8323rdb-mmc-slot", + "mmc-spi-slot"; + reg = <0>; + gpios = <&qe_pio_d 14 1 + &qe_pio_d 15 0>; + voltage-ranges = <3300 3300>; + spi-max-frequency = <50000000>; + }; diff --git a/Documentation/powerpc/dts-bindings/mtd-physmap.txt b/Documentation/powerpc/dts-bindings/mtd-physmap.txt new file mode 100644 index 000000000000..667c9bde8699 --- /dev/null +++ b/Documentation/powerpc/dts-bindings/mtd-physmap.txt @@ -0,0 +1,80 @@ +CFI or JEDEC memory-mapped NOR flash + +Flash chips (Memory Technology Devices) are often used for solid state +file systems on embedded devices. + + - compatible : should contain the specific model of flash chip(s) + used, if known, followed by either "cfi-flash" or "jedec-flash" + - reg : Address range(s) of the flash chip(s) + It's possible to (optionally) define multiple "reg" tuples so that + non-identical NOR chips can be described in one flash node. + - bank-width : Width (in bytes) of the flash bank. Equal to the + device width times the number of interleaved chips. + - device-width : (optional) Width of a single flash chip. If + omitted, assumed to be equal to 'bank-width'. + - #address-cells, #size-cells : Must be present if the flash has + sub-nodes representing partitions (see below). In this case + both #address-cells and #size-cells must be equal to 1. + +For JEDEC compatible devices, the following additional properties +are defined: + + - vendor-id : Contains the flash chip's vendor id (1 byte). + - device-id : Contains the flash chip's device id (1 byte). + +In addition to the information on the flash bank itself, the +device tree may optionally contain additional information +describing partitions of the flash address space. This can be +used on platforms which have strong conventions about which +portions of the flash are used for what purposes, but which don't +use an on-flash partition table such as RedBoot. + +Each partition is represented as a sub-node of the flash device. +Each node's name represents the name of the corresponding +partition of the flash device. + +Flash partitions + - reg : The partition's offset and size within the flash bank. + - label : (optional) The label / name for this flash partition. + If omitted, the label is taken from the node name (excluding + the unit address). + - read-only : (optional) This parameter, if present, is a hint to + Linux that this flash partition should only be mounted + read-only. This is usually used for flash partitions + containing early-boot firmware images or data which should not + be clobbered. + +Example: + + flash@ff000000 { + compatible = "amd,am29lv128ml", "cfi-flash"; + reg = <ff000000 01000000>; + bank-width = <4>; + device-width = <1>; + #address-cells = <1>; + #size-cells = <1>; + fs@0 { + label = "fs"; + reg = <0 f80000>; + }; + firmware@f80000 { + label ="firmware"; + reg = <f80000 80000>; + read-only; + }; + }; + +Here an example with multiple "reg" tuples: + + flash@f0000000,0 { + #address-cells = <1>; + #size-cells = <1>; + compatible = "intel,PC48F4400P0VB", "cfi-flash"; + reg = <0 0x00000000 0x02000000 + 0 0x02000000 0x02000000>; + bank-width = <2>; + partition@0 { + label = "test-part1"; + reg = <0 0x04000000>; + }; + }; diff --git a/Documentation/scheduler/00-INDEX b/Documentation/scheduler/00-INDEX index aabcc3a089ba..3c00c9c3219e 100644 --- a/Documentation/scheduler/00-INDEX +++ b/Documentation/scheduler/00-INDEX @@ -2,8 +2,6 @@ - this file. sched-arch.txt - CPU Scheduler implementation hints for architecture specific code. -sched-coding.txt - - reference for various scheduler-related methods in the O(1) scheduler. sched-design-CFS.txt - goals, design and implementation of the Complete Fair Scheduler. sched-domains.txt diff --git a/Documentation/scheduler/sched-coding.txt b/Documentation/scheduler/sched-coding.txt deleted file mode 100644 index cbd8db752acf..000000000000 --- a/Documentation/scheduler/sched-coding.txt +++ /dev/null @@ -1,126 +0,0 @@ - Reference for various scheduler-related methods in the O(1) scheduler - Robert Love <rml@tech9.net>, MontaVista Software - - -Note most of these methods are local to kernel/sched.c - this is by design. -The scheduler is meant to be self-contained and abstracted away. This document -is primarily for understanding the scheduler, not interfacing to it. Some of -the discussed interfaces, however, are general process/scheduling methods. -They are typically defined in include/linux/sched.h. - - -Main Scheduling Methods ------------------------ - -void load_balance(runqueue_t *this_rq, int idle) - Attempts to pull tasks from one cpu to another to balance cpu usage, - if needed. This method is called explicitly if the runqueues are - imbalanced or periodically by the timer tick. Prior to calling, - the current runqueue must be locked and interrupts disabled. - -void schedule() - The main scheduling function. Upon return, the highest priority - process will be active. - - -Locking -------- - -Each runqueue has its own lock, rq->lock. When multiple runqueues need -to be locked, lock acquires must be ordered by ascending &runqueue value. - -A specific runqueue is locked via - - task_rq_lock(task_t pid, unsigned long *flags) - -which disables preemption, disables interrupts, and locks the runqueue pid is -running on. Likewise, - - task_rq_unlock(task_t pid, unsigned long *flags) - -unlocks the runqueue pid is running on, restores interrupts to their previous -state, and reenables preemption. - -The routines - - double_rq_lock(runqueue_t *rq1, runqueue_t *rq2) - -and - - double_rq_unlock(runqueue_t *rq1, runqueue_t *rq2) - -safely lock and unlock, respectively, the two specified runqueues. They do -not, however, disable and restore interrupts. Users are required to do so -manually before and after calls. - - -Values ------- - -MAX_PRIO - The maximum priority of the system, stored in the task as task->prio. - Lower priorities are higher. Normal (non-RT) priorities range from - MAX_RT_PRIO to (MAX_PRIO - 1). -MAX_RT_PRIO - The maximum real-time priority of the system. Valid RT priorities - range from 0 to (MAX_RT_PRIO - 1). -MAX_USER_RT_PRIO - The maximum real-time priority that is exported to user-space. Should - always be equal to or less than MAX_RT_PRIO. Setting it less allows - kernel threads to have higher priorities than any user-space task. -MIN_TIMESLICE -MAX_TIMESLICE - Respectively, the minimum and maximum timeslices (quanta) of a process. - -Data ----- - -struct runqueue - The main per-CPU runqueue data structure. -struct task_struct - The main per-process data structure. - - -General Methods ---------------- - -cpu_rq(cpu) - Returns the runqueue of the specified cpu. -this_rq() - Returns the runqueue of the current cpu. -task_rq(pid) - Returns the runqueue which holds the specified pid. -cpu_curr(cpu) - Returns the task currently running on the given cpu. -rt_task(pid) - Returns true if pid is real-time, false if not. - - -Process Control Methods ------------------------ - -void set_user_nice(task_t *p, long nice) - Sets the "nice" value of task p to the given value. -int setscheduler(pid_t pid, int policy, struct sched_param *param) - Sets the scheduling policy and parameters for the given pid. -int set_cpus_allowed(task_t *p, unsigned long new_mask) - Sets a given task's CPU affinity and migrates it to a proper cpu. - Callers must have a valid reference to the task and assure the - task not exit prematurely. No locks can be held during the call. -set_task_state(tsk, state_value) - Sets the given task's state to the given value. -set_current_state(state_value) - Sets the current task's state to the given value. -void set_tsk_need_resched(struct task_struct *tsk) - Sets need_resched in the given task. -void clear_tsk_need_resched(struct task_struct *tsk) - Clears need_resched in the given task. -void set_need_resched() - Sets need_resched in the current task. -void clear_need_resched() - Clears need_resched in the current task. -int need_resched() - Returns true if need_resched is set in the current task, false - otherwise. -yield() - Place the current process at the end of the runqueue and call schedule. diff --git a/Documentation/scheduler/sched-rt-group.txt b/Documentation/scheduler/sched-rt-group.txt index 3ef339f491e0..5ba4d3fc625a 100644 --- a/Documentation/scheduler/sched-rt-group.txt +++ b/Documentation/scheduler/sched-rt-group.txt @@ -126,7 +126,7 @@ This uses the /cgroup virtual file system and "/cgroup/<cgroup>/cpu.rt_runtime_u to control the CPU time reserved for each control group instead. For more information on working with control groups, you should read -Documentation/cgroups.txt as well. +Documentation/cgroups/cgroups.txt as well. Group settings are checked against the following limits in order to keep the configuration schedulable: diff --git a/Documentation/scsi/aacraid.txt b/Documentation/scsi/aacraid.txt index ddace3afc83b..30f643f611b2 100644 --- a/Documentation/scsi/aacraid.txt +++ b/Documentation/scsi/aacraid.txt @@ -60,17 +60,9 @@ Supported Cards/Chipsets 9005:0285:9005:02d5 Adaptec ASR-2405 (Voodoo40 Lite) 9005:0285:9005:02d6 Adaptec ASR-2445 (Voodoo44 Lite) 9005:0285:9005:02d7 Adaptec ASR-2805 (Voodoo80 Lite) - 9005:0285:9005:02d8 Adaptec 5405G (Voodoo40 PM) - 9005:0285:9005:02d9 Adaptec 5445G (Voodoo44 PM) - 9005:0285:9005:02da Adaptec 5805G (Voodoo80 PM) - 9005:0285:9005:02db Adaptec 5085G (Voodoo08 PM) - 9005:0285:9005:02dc Adaptec 51245G (Voodoo124 PM) - 9005:0285:9005:02dd Adaptec 51645G (Voodoo164 PM) - 9005:0285:9005:02de Adaptec 52445G (Voodoo244 PM) - 9005:0285:9005:02df Adaptec ASR-2045G (Voodoo04 Lite PM) - 9005:0285:9005:02e0 Adaptec ASR-2405G (Voodoo40 Lite PM) - 9005:0285:9005:02e1 Adaptec ASR-2445G (Voodoo44 Lite PM) - 9005:0285:9005:02e2 Adaptec ASR-2805G (Voodoo80 Lite PM) + 9005:0285:9005:02d8 Adaptec 5405Z (Voodoo40 BLBU) + 9005:0285:9005:02d9 Adaptec 5445Z (Voodoo44 BLBU) + 9005:0285:9005:02da Adaptec 5805Z (Voodoo80 BLBU) 1011:0046:9005:0364 Adaptec 5400S (Mustang) 1011:0046:9005:0365 Adaptec 5400S (Mustang) 9005:0287:9005:0800 Adaptec Themisto (Jupiter) @@ -140,6 +132,7 @@ Deanna Bonds (non-DASD support, PAE fibs and 64 bit, where fibs that go to the hardware are consistently called hw_fibs and not just fibs like the name of the driver tracking structure) Mark Salyzyn <Mark_Salyzyn@adaptec.com> Fixed panic issues and added some new product ids for upcoming hbas. Performance tuning, card failover and bug mitigations. +Achim Leubner <Achim_Leubner@adaptec.com> Original Driver ------------------------- diff --git a/Documentation/scsi/osd.txt b/Documentation/scsi/osd.txt new file mode 100644 index 000000000000..da162f7fd5f5 --- /dev/null +++ b/Documentation/scsi/osd.txt @@ -0,0 +1,198 @@ +The OSD Standard +================ +OSD (Object-Based Storage Device) is a T10 SCSI command set that is designed +to provide efficient operation of input/output logical units that manage the +allocation, placement, and accessing of variable-size data-storage containers, +called objects. Objects are intended to contain operating system and application +constructs. Each object has associated attributes attached to it, which are +integral part of the object and provide metadata about the object. The standard +defines some common obligatory attributes, but user attributes can be added as +needed. + +See: http://www.t10.org/ftp/t10/drafts/osd2/ for the latest draft for OSD 2 +or search the web for "OSD SCSI" + +OSD in the Linux Kernel +======================= +osd-initiator: + The main component of OSD in Kernel is the osd-initiator library. Its main +user is intended to be the pNFS-over-objects layout driver, which uses objects +as its back-end data storage. Other clients are the other osd parts listed below. + +osd-uld: + This is a SCSI ULD that registers for OSD type devices and provides a testing +platform, both for the in-kernel initiator as well as connected targets. It +currently has no useful user-mode API, though it could have if need be. + +exofs: + Is an OSD based Linux file system. It uses the osd-initiator and osd-uld, +to export a usable file system for users. +See Documentation/filesystems/exofs.txt for more details + +osd target: + There are no current plans for an OSD target implementation in kernel. For all +needs, a user-mode target that is based on the scsi tgt target framework is +available from Ohio Supercomputer Center (OSC) at: +http://www.open-osd.org/bin/view/Main/OscOsdProject +There are several other target implementations. See http://open-osd.org for more +links. + +Files and Folders +================= +This is the complete list of files included in this work: +include/scsi/ + osd_initiator.h Main API for the initiator library + osd_types.h Common OSD types + osd_sec.h Security Manager API + osd_protocol.h Wire definitions of the OSD standard protocol + osd_attributes.h Wire definitions of OSD attributes + +drivers/scsi/osd/ + osd_initiator.c OSD-Initiator library implementation + osd_uld.c The OSD scsi ULD + osd_ktest.{h,c} In-kernel test suite (called by osd_uld) + osd_debug.h Some printk macros + Makefile For both in-tree and out-of-tree compilation + Kconfig Enables inclusion of the different pieces + osd_test.c User-mode application to call the kernel tests + +The OSD-Initiator Library +========================= +osd_initiator is a low level implementation of an osd initiator encoder. +But even though, it should be intuitive and easy to use. Perhaps over time an +higher lever will form that automates some of the more common recipes. + +init/fini: +- osd_dev_init() associates a scsi_device with an osd_dev structure + and initializes some global pools. This should be done once per scsi_device + (OSD LUN). The osd_dev structure is needed for calling osd_start_request(). + +- osd_dev_fini() cleans up before a osd_dev/scsi_device destruction. + +OSD commands encoding, execution, and decoding of results: + +struct osd_request's is used to iteratively encode an OSD command and carry +its state throughout execution. Each request goes through these stages: + +a. osd_start_request() allocates the request. + +b. Any of the osd_req_* methods is used to encode a request of the specified + type. + +c. osd_req_add_{get,set}_attr_* may be called to add get/set attributes to the + CDB. "List" or "Page" mode can be used exclusively. The attribute-list API + can be called multiple times on the same request. However, only one + attribute-page can be read, as mandated by the OSD standard. + +d. osd_finalize_request() computes offsets into the data-in and data-out buffers + and signs the request using the provided capability key and integrity- + check parameters. + +e. osd_execute_request() may be called to execute the request via the block + layer and wait for its completion. The request can be executed + asynchronously by calling the block layer API directly. + +f. After execution, osd_req_decode_sense() can be called to decode the request's + sense information. + +g. osd_req_decode_get_attr() may be called to retrieve osd_add_get_attr_list() + values. + +h. osd_end_request() must be called to deallocate the request and any resource + associated with it. Note that osd_end_request cleans up the request at any + stage and it must always be called after a successful osd_start_request(). + +osd_request's structure: + +The OSD standard defines a complex structure of IO segments pointed to by +members in the CDB. Up to 3 segments can be deployed in the IN-Buffer and up to +4 in the OUT-Buffer. The ASCII illustration below depicts a secure-read with +associated get+set of attributes-lists. Other combinations very on the same +basic theme. From no-segments-used up to all-segments-used. + +|________OSD-CDB__________| +| | +|read_len (offset=0) -|---------\ +| | | +|get_attrs_list_length | | +|get_attrs_list_offset -|----\ | +| | | | +|retrieved_attrs_alloc_len| | | +|retrieved_attrs_offset -|----|----|-\ +| | | | | +|set_attrs_list_length | | | | +|set_attrs_list_offset -|-\ | | | +| | | | | | +|in_data_integ_offset -|-|--|----|-|-\ +|out_data_integ_offset -|-|--|--\ | | | +\_________________________/ | | | | | | + | | | | | | +|_______OUT-BUFFER________| | | | | | | +| Set attr list |</ | | | | | +| | | | | | | +|-------------------------| | | | | | +| Get attr descriptors |<---/ | | | | +| | | | | | +|-------------------------| | | | | +| Out-data integrity |<------/ | | | +| | | | | +\_________________________/ | | | + | | | +|________IN-BUFFER________| | | | +| In-Data read |<--------/ | | +| | | | +|-------------------------| | | +| Get attr list |<----------/ | +| | | +|-------------------------| | +| In-data integrity |<------------/ +| | +\_________________________/ + +A block device request can carry bidirectional payload by means of associating +a bidi_read request with a main write-request. Each in/out request is described +by a chain of BIOs associated with each request. +The CDB is of a SCSI VARLEN CDB format, as described by OSD standard. +The OSD standard also mandates alignment restrictions at start of each segment. + +In the code, in struct osd_request, there are two _osd_io_info structures to +describe the IN/OUT buffers above, two BIOs for the data payload and up to five +_osd_req_data_segment structures to hold the different segments allocation and +information. + +Important: We have chosen to disregard the assumption that a BIO-chain (and +the resulting sg-list) describes a linear memory buffer. Meaning only first and +last scatter chain can be incomplete and all the middle chains are of PAGE_SIZE. +For us, a scatter-gather-list, as its name implies and as used by the Networking +layer, is to describe a vector of buffers that will be transferred to/from the +wire. It works very well with current iSCSI transport. iSCSI is currently the +only deployed OSD transport. In the future we anticipate SAS and FC attached OSD +devices as well. + +The OSD Testing ULD +=================== +TODO: More user-mode control on tests. + +Authors, Mailing list +===================== +Please communicate with us on any deployment of osd, whether using this code +or not. + +Any problems, questions, bug reports, lonely OSD nights, please email: + OSD Dev List <osd-dev@open-osd.org> + +More up-to-date information can be found on: +http://open-osd.org + +Boaz Harrosh <bharrosh@panasas.com> +Benny Halevy <bhalevy@panasas.com> + +References +========== +Weber, R., "SCSI Object-Based Storage Device Commands", +T10/1355-D ANSI/INCITS 400-2004, +http://www.t10.org/ftp/t10/drafts/osd/osd-r10.pdf + +Weber, R., "SCSI Object-Based Storage Device Commands -2 (OSD-2)" +T10/1729-D, Working Draft, rev. 3 +http://www.t10.org/ftp/t10/drafts/osd2/osd2r03.pdf diff --git a/Documentation/slow-work.txt b/Documentation/slow-work.txt new file mode 100644 index 000000000000..ebc50f808ea4 --- /dev/null +++ b/Documentation/slow-work.txt @@ -0,0 +1,174 @@ + ==================================== + SLOW WORK ITEM EXECUTION THREAD POOL + ==================================== + +By: David Howells <dhowells@redhat.com> + +The slow work item execution thread pool is a pool of threads for performing +things that take a relatively long time, such as making mkdir calls. +Typically, when processing something, these items will spend a lot of time +blocking a thread on I/O, thus making that thread unavailable for doing other +work. + +The standard workqueue model is unsuitable for this class of work item as that +limits the owner to a single thread or a single thread per CPU. For some +tasks, however, more threads - or fewer - are required. + +There is just one pool per system. It contains no threads unless something +wants to use it - and that something must register its interest first. When +the pool is active, the number of threads it contains is dynamic, varying +between a maximum and minimum setting, depending on the load. + + +==================== +CLASSES OF WORK ITEM +==================== + +This pool support two classes of work items: + + (*) Slow work items. + + (*) Very slow work items. + +The former are expected to finish much quicker than the latter. + +An operation of the very slow class may do a batch combination of several +lookups, mkdirs, and a create for instance. + +An operation of the ordinarily slow class may, for example, write stuff or +expand files, provided the time taken to do so isn't too long. + +Operations of both types may sleep during execution, thus tying up the thread +loaned to it. + + +THREAD-TO-CLASS ALLOCATION +-------------------------- + +Not all the threads in the pool are available to work on very slow work items. +The number will be between one and one fewer than the number of active threads. +This is configurable (see the "Pool Configuration" section). + +All the threads are available to work on ordinarily slow work items, but a +percentage of the threads will prefer to work on very slow work items. + +The configuration ensures that at least one thread will be available to work on +very slow work items, and at least one thread will be available that won't work +on very slow work items at all. + + +===================== +USING SLOW WORK ITEMS +===================== + +Firstly, a module or subsystem wanting to make use of slow work items must +register its interest: + + int ret = slow_work_register_user(); + +This will return 0 if successful, or a -ve error upon failure. + + +Slow work items may then be set up by: + + (1) Declaring a slow_work struct type variable: + + #include <linux/slow-work.h> + + struct slow_work myitem; + + (2) Declaring the operations to be used for this item: + + struct slow_work_ops myitem_ops = { + .get_ref = myitem_get_ref, + .put_ref = myitem_put_ref, + .execute = myitem_execute, + }; + + [*] For a description of the ops, see section "Item Operations". + + (3) Initialising the item: + + slow_work_init(&myitem, &myitem_ops); + + or: + + vslow_work_init(&myitem, &myitem_ops); + + depending on its class. + +A suitably set up work item can then be enqueued for processing: + + int ret = slow_work_enqueue(&myitem); + +This will return a -ve error if the thread pool is unable to gain a reference +on the item, 0 otherwise. + + +The items are reference counted, so there ought to be no need for a flush +operation. When all a module's slow work items have been processed, and the +module has no further interest in the facility, it should unregister its +interest: + + slow_work_unregister_user(); + + +=============== +ITEM OPERATIONS +=============== + +Each work item requires a table of operations of type struct slow_work_ops. +All members are required: + + (*) Get a reference on an item: + + int (*get_ref)(struct slow_work *work); + + This allows the thread pool to attempt to pin an item by getting a + reference on it. This function should return 0 if the reference was + granted, or a -ve error otherwise. If an error is returned, + slow_work_enqueue() will fail. + + The reference is held whilst the item is queued and whilst it is being + executed. The item may then be requeued with the same reference held, or + the reference will be released. + + (*) Release a reference on an item: + + void (*put_ref)(struct slow_work *work); + + This allows the thread pool to unpin an item by releasing the reference on + it. The thread pool will not touch the item again once this has been + called. + + (*) Execute an item: + + void (*execute)(struct slow_work *work); + + This should perform the work required of the item. It may sleep, it may + perform disk I/O and it may wait for locks. + + +================== +POOL CONFIGURATION +================== + +The slow-work thread pool has a number of configurables: + + (*) /proc/sys/kernel/slow-work/min-threads + + The minimum number of threads that should be in the pool whilst it is in + use. This may be anywhere between 2 and max-threads. + + (*) /proc/sys/kernel/slow-work/max-threads + + The maximum number of threads that should in the pool. This may be + anywhere between min-threads and 255 or NR_CPUS * 2, whichever is greater. + + (*) /proc/sys/kernel/slow-work/vslow-percentage + + The percentage of active threads in the pool that may be used to execute + very slow work items. This may be between 1 and 99. The resultant number + is bounded to between 1 and one fewer than the number of active threads. + This ensures there is always at least one thread that can process very + slow work items, and always at least one thread that won't. diff --git a/Documentation/sound/alsa/ALSA-Configuration.txt b/Documentation/sound/alsa/ALSA-Configuration.txt index 841a9365d5fd..012858d2b119 100644 --- a/Documentation/sound/alsa/ALSA-Configuration.txt +++ b/Documentation/sound/alsa/ALSA-Configuration.txt @@ -346,6 +346,9 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. sbirq - IRQ # for CMI8330 chip (SB16) sbdma8 - 8bit DMA # for CMI8330 chip (SB16) sbdma16 - 16bit DMA # for CMI8330 chip (SB16) + fmport - (optional) OPL3 I/O port + mpuport - (optional) MPU401 I/O port + mpuirq - (optional) MPU401 irq # This module supports multiple cards and autoprobe. @@ -388,34 +391,11 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. The power-management is supported. - Module snd-cs4232 - ----------------- - - Module for sound cards based on CS4232/CS4232A ISA chips. - - isapnp - ISA PnP detection - 0 = disable, 1 = enable (default) - - with isapnp=0, the following options are available: - - port - port # for CS4232 chip (PnP setup - 0x534) - cport - control port # for CS4232 chip (PnP setup - 0x120,0x210,0xf00) - mpu_port - port # for MPU-401 UART (PnP setup - 0x300), -1 = disable - fm_port - FM port # for CS4232 chip (PnP setup - 0x388), -1 = disable - irq - IRQ # for CS4232 chip (5,7,9,11,12,15) - mpu_irq - IRQ # for MPU-401 UART (9,11,12,15) - dma1 - first DMA # for CS4232 chip (0,1,3) - dma2 - second DMA # for Yamaha CS4232 chip (0,1,3), -1 = disable - - This module supports multiple cards. This module does not support autoprobe - (if ISA PnP is not used) thus main port must be specified!!! Other ports are - optional. - - The power-management is supported. - Module snd-cs4236 ----------------- - Module for sound cards based on CS4235/CS4236/CS4236B/CS4237B/ + Module for sound cards based on CS4232/CS4232A, + CS4235/CS4236/CS4236B/CS4237B/ CS4238B/CS4239 ISA chips. isapnp - ISA PnP detection - 0 = disable, 1 = enable (default) @@ -437,6 +417,9 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. The power-management is supported. + This module is aliased as snd-cs4232 since it provides the old + snd-cs4232 functionality, too. + Module snd-cs4281 ----------------- @@ -606,6 +589,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. Module for ESS AudioDrive ES-1688 and ES-688 sound cards. port - port # for ES-1688 chip (0x220,0x240,0x260) + fm_port - port # for OPL3 (option; share the same port as default) mpu_port - port # for MPU-401 port (0x300,0x310,0x320,0x330), -1 = disable (default) irq - IRQ # for ES-1688 chip (5,7,9,10) mpu_irq - IRQ # for MPU-401 port (5,7,9,10) @@ -757,6 +741,9 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. model - force the model name position_fix - Fix DMA pointer (0 = auto, 1 = use LPIB, 2 = POSBUF) probe_mask - Bitmask to probe codecs (default = -1, meaning all slots) + When the bit 8 (0x100) is set, the lower 8 bits are used + as the "fixed" codec slots; i.e. the driver probes the + slots regardless what hardware reports back probe_only - Only probing and no codec initialization (default=off); Useful to check the initial codec status for debugging bdl_pos_adj - Specifies the DMA IRQ timing delay in samples. @@ -1185,6 +1172,54 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. This module supports multiple devices and PnP. + Module snd-msnd-classic + ----------------------- + + Module for Turtle Beach MultiSound Classic, Tahiti or Monterey + soundcards. + + io - Port # for msnd-classic card + irq - IRQ # for msnd-classic card + mem - Memory address (0xb0000, 0xc8000, 0xd0000, 0xd8000, + 0xe0000 or 0xe8000) + write_ndelay - enable write ndelay (default = 1) + calibrate_signal - calibrate signal (default = 0) + isapnp - ISA PnP detection - 0 = disable, 1 = enable (default) + digital - Digital daughterboard present (default = 0) + cfg - Config port (0x250, 0x260 or 0x270) default = PnP + reset - Reset all devices + mpu_io - MPU401 I/O port + mpu_irq - MPU401 irq# + ide_io0 - IDE port #0 + ide_io1 - IDE port #1 + ide_irq - IDE irq# + joystick_io - Joystick I/O port + + The driver requires firmware files "turtlebeach/msndinit.bin" and + "turtlebeach/msndperm.bin" in the proper firmware directory. + + See Documentation/sound/oss/MultiSound for important information + about this driver. Note that it has been discontinued, but the + Voyetra Turtle Beach knowledge base entry for it is still available + at + http://www.turtlebeach.com/site/kb_ftp/790.asp + + Module snd-msnd-pinnacle + ------------------------ + + Module for Turtle Beach MultiSound Pinnacle/Fiji soundcards. + + io - Port # for pinnacle/fiji card + irq - IRQ # for pinnalce/fiji card + mem - Memory address (0xb0000, 0xc8000, 0xd0000, 0xd8000, + 0xe0000 or 0xe8000) + write_ndelay - enable write ndelay (default = 1) + calibrate_signal - calibrate signal (default = 0) + isapnp - ISA PnP detection - 0 = disable, 1 = enable (default) + + The driver requires firmware files "turtlebeach/pndspini.bin" and + "turtlebeach/pndsperm.bin" in the proper firmware directory. + Module snd-mtpav ---------------- @@ -1824,7 +1859,7 @@ Prior to version 0.9.0rc4 options had a 'snd_' prefix. This was removed. ------------------- Module for sound cards based on the Asus AV100/AV200 chips, - i.e., Xonar D1, DX, D2, D2X and HDAV1.3 (Deluxe). + i.e., Xonar D1, DX, D2, D2X, HDAV1.3 (Deluxe), and Essence STX. This module supports autoprobe and multiple cards. diff --git a/Documentation/sound/alsa/HD-Audio-Models.txt b/Documentation/sound/alsa/HD-Audio-Models.txt index 0f5d26bea80f..8eec05bc079e 100644 --- a/Documentation/sound/alsa/HD-Audio-Models.txt +++ b/Documentation/sound/alsa/HD-Audio-Models.txt @@ -56,6 +56,7 @@ ALC262 sony-assamd Sony ASSAMD toshiba-s06 Toshiba S06 toshiba-rx1 Toshiba RX1 + tyan Tyan Thunder n6650W (S2915-E) ultra Samsung Q1 Ultra Vista model lenovo-3000 Lenovo 3000 y410 nec NEC Versa S9100 @@ -261,6 +262,8 @@ Conexant 5051 ============= laptop Basic Laptop config (default) hp HP Spartan laptop + hp-dv6736 HP dv6736 + lenovo-x200 Lenovo X200 laptop STAC9200 ======== @@ -278,6 +281,7 @@ STAC9200 gateway-m4 Gateway laptops with EAPD control gateway-m4-2 Gateway laptops with EAPD control panasonic Panasonic CF-74 + auto BIOS setup (default) STAC9205/9254 ============= @@ -285,6 +289,8 @@ STAC9205/9254 dell-m42 Dell (unknown) dell-m43 Dell Precision dell-m44 Dell Inspiron + eapd Keep EAPD on (e.g. Gateway T1616) + auto BIOS setup (default) STAC9220/9221 ============= @@ -308,6 +314,7 @@ STAC9220/9221 dell-d82 Dell (unknown) dell-m81 Dell (unknown) dell-m82 Dell XPS M1210 + auto BIOS setup (default) STAC9202/9250/9251 ================== @@ -319,6 +326,7 @@ STAC9202/9250/9251 m3 Some Gateway MX series laptops m5 Some Gateway MX series laptops (MP6954) m6 Some Gateway NX series laptops + auto BIOS setup (default) STAC9227/9228/9229/927x ======================= @@ -328,6 +336,7 @@ STAC9227/9228/9229/927x 5stack D965 5stack + SPDIF dell-3stack Dell Dimension E520 dell-bios Fixes with Dell BIOS setup + auto BIOS setup (default) STAC92HD71B* ============ @@ -335,7 +344,10 @@ STAC92HD71B* dell-m4-1 Dell desktops dell-m4-2 Dell desktops dell-m4-3 Dell desktops - hp-m4 HP dv laptops + hp-m4 HP mini 1000 + hp-dv5 HP dv series + hp-hdx HP HDX series + auto BIOS setup (default) STAC92HD73* =========== @@ -345,13 +357,16 @@ STAC92HD73* dell-m6-dmic Dell desktops/laptops with digital mics dell-m6 Dell desktops/laptops with both type of mics dell-eq Dell desktops/laptops + auto BIOS setup (default) STAC92HD83* =========== ref Reference board mic-ref Reference board with power managment for ports + dell-s14 Dell laptop + auto BIOS setup (default) STAC9872 ======== - vaio Setup for VAIO FE550G/SZ110 - vaio-ar Setup for VAIO AR + vaio VAIO laptop without SPDIF + auto BIOS setup (default) diff --git a/Documentation/sound/alsa/HD-Audio.txt b/Documentation/sound/alsa/HD-Audio.txt index 8d68fff71839..88b7433d2f11 100644 --- a/Documentation/sound/alsa/HD-Audio.txt +++ b/Documentation/sound/alsa/HD-Audio.txt @@ -109,6 +109,13 @@ slot, pass `probe_mask=1`. For the first and the third slots, pass Since 2.6.29 kernel, the driver has a more robust probing method, so this error might happen rarely, though. +On a machine with a broken BIOS, sometimes you need to force the +driver to probe the codec slots the hardware doesn't report for use. +In such a case, turn the bit 8 (0x100) of `probe_mask` option on. +Then the rest 8 bits are passed as the codec slots to probe +unconditionally. For example, `probe_mask=0x103` will force to probe +the codec slots 0 and 1 no matter what the hardware reports. + Interrupt Handling ~~~~~~~~~~~~~~~~~~ @@ -162,7 +169,7 @@ PCI SSID look-up. What `model` option values are available depends on the codec chip. Check your codec chip from the codec proc file (see "Codec Proc-File" section below). It will show the vendor/product name of your codec -chip. Then, see Documentation/sound/alsa/HD-Audio-Modelstxt file, +chip. Then, see Documentation/sound/alsa/HD-Audio-Models.txt file, the section of HD-audio driver. You can find a list of codecs and `model` options belonging to each codec. For example, for Realtek ALC262 codec chip, pass `model=ultra` for devices that are compatible @@ -170,7 +177,7 @@ with Samsung Q1 Ultra. Thus, the first thing you can do for any brand-new, unsupported and non-working HD-audio hardware is to check HD-audio codec and several -different `model` option values. If you have a luck, some of them +different `model` option values. If you have any luck, some of them might suit with your device well. Some codecs such as ALC880 have a special model option `model=test`. @@ -358,10 +365,26 @@ modelname:: to this file. init_verbs:: The extra verbs to execute at initialization. You can add a verb by - writing to this file. Pass tree numbers, nid, verb and parameter. + writing to this file. Pass three numbers: nid, verb and parameter + (separated with a space). hints:: - Shows hint strings for codec parsers for any use. Right now it's - not used. + Shows / stores hint strings for codec parsers for any use. + Its format is `key = value`. For example, passing `hp_detect = yes` + to IDT/STAC codec parser will result in the disablement of the + headphone detection. +init_pin_configs:: + Shows the initial pin default config values set by BIOS. +driver_pin_configs:: + Shows the pin default values set by the codec parser explicitly. + This doesn't show all pin values but only the changed values by + the parser. That is, if the parser doesn't change the pin default + config values by itself, this will contain nothing. +user_pin_configs:: + Shows the pin default config values to override the BIOS setup. + Writing this (with two numbers, NID and value) appends the new + value. The given will be used instead of the initial BIOS value at + the next reconfiguration time. Note that this config will override + even the driver pin configs, too. reconfig:: Triggers the codec re-configuration. When any value is written to this file, the driver re-initialize and parses the codec tree @@ -371,6 +394,14 @@ clear:: Resets the codec, removes the mixer elements and PCM stuff of the specified codec, and clear all init verbs and hints. +For example, when you want to change the pin default configuration +value of the pin widget 0x14 to 0x9993013f, and let the driver +re-configure based on that state, run like below: +------------------------------------------------------------------------ + # echo 0x14 0x9993013f > /sys/class/sound/hwC0D0/user_pin_configs + # echo 1 > /sys/class/sound/hwC0D0/reconfig +------------------------------------------------------------------------ + Power-Saving ~~~~~~~~~~~~ @@ -461,6 +492,16 @@ run with `--no-upload` option, and attach the generated file. There are some other useful options. See `--help` option output for details. +When a probe error occurs or when the driver obviously assigns a +mismatched model, it'd be helpful to load the driver with +`probe_only=1` option (at best after the cold reboot) and run +alsa-info at this state. With this option, the driver won't configure +the mixer and PCM but just tries to probe the codec slot. After +probing, the proc file is available, so you can get the raw codec +information before modified by the driver. Of course, the driver +isn't usable with `probe_only=1`. But you can continue the +configuration via hwdep sysfs file if hda-reconfig option is enabled. + hda-verb ~~~~~~~~ diff --git a/Documentation/sound/alsa/soc/dapm.txt b/Documentation/sound/alsa/soc/dapm.txt index 46f9684d0b29..9e6763264a2e 100644 --- a/Documentation/sound/alsa/soc/dapm.txt +++ b/Documentation/sound/alsa/soc/dapm.txt @@ -116,6 +116,9 @@ SOC_DAPM_SINGLE("HiFi Playback Switch", WM8731_APANA, 4, 1, 0), SND_SOC_DAPM_MIXER("Output Mixer", WM8731_PWR, 4, 1, wm8731_output_mixer_controls, ARRAY_SIZE(wm8731_output_mixer_controls)), +If you dont want the mixer elements prefixed with the name of the mixer widget, +you can use SND_SOC_DAPM_MIXER_NAMED_CTL instead. the parameters are the same +as for SND_SOC_DAPM_MIXER. 2.3 Platform/Machine domain Widgets ----------------------------------- diff --git a/Documentation/sound/alsa/soc/jack.txt b/Documentation/sound/alsa/soc/jack.txt new file mode 100644 index 000000000000..fcf82a417293 --- /dev/null +++ b/Documentation/sound/alsa/soc/jack.txt @@ -0,0 +1,71 @@ +ASoC jack detection +=================== + +ALSA has a standard API for representing physical jacks to user space, +the kernel side of which can be seen in include/sound/jack.h. ASoC +provides a version of this API adding two additional features: + + - It allows more than one jack detection method to work together on one + user visible jack. In embedded systems it is common for multiple + to be present on a single jack but handled by separate bits of + hardware. + + - Integration with DAPM, allowing DAPM endpoints to be updated + automatically based on the detected jack status (eg, turning off the + headphone outputs if no headphones are present). + +This is done by splitting the jacks up into three things working +together: the jack itself represented by a struct snd_soc_jack, sets of +snd_soc_jack_pins representing DAPM endpoints to update and blocks of +code providing jack reporting mechanisms. + +For example, a system may have a stereo headset jack with two reporting +mechanisms, one for the headphone and one for the microphone. Some +systems won't be able to use their speaker output while a headphone is +connected and so will want to make sure to update both speaker and +headphone when the headphone jack status changes. + +The jack - struct snd_soc_jack +============================== + +This represents a physical jack on the system and is what is visible to +user space. The jack itself is completely passive, it is set up by the +machine driver and updated by jack detection methods. + +Jacks are created by the machine driver calling snd_soc_jack_new(). + +snd_soc_jack_pin +================ + +These represent a DAPM pin to update depending on some of the status +bits supported by the jack. Each snd_soc_jack has zero or more of these +which are updated automatically. They are created by the machine driver +and associated with the jack using snd_soc_jack_add_pins(). The status +of the endpoint may configured to be the opposite of the jack status if +required (eg, enabling a built in microphone if a microphone is not +connected via a jack). + +Jack detection methods +====================== + +Actual jack detection is done by code which is able to monitor some +input to the system and update a jack by calling snd_soc_jack_report(), +specifying a subset of bits to update. The jack detection code should +be set up by the machine driver, taking configuration for the jack to +update and the set of things to report when the jack is connected. + +Often this is done based on the status of a GPIO - a handler for this is +provided by the snd_soc_jack_add_gpio() function. Other methods are +also available, for example integrated into CODECs. One example of +CODEC integrated jack detection can be see in the WM8350 driver. + +Each jack may have multiple reporting mechanisms, though it will need at +least one to be useful. + +Machine drivers +=============== + +These are all hooked together by the machine driver depending on the +system hardware. The machine driver will set up the snd_soc_jack and +the list of pins to update then set up one or more jack detection +mechanisms to update that jack based on their current status. diff --git a/Documentation/sound/oss/CS4232 b/Documentation/sound/oss/CS4232 deleted file mode 100644 index 7d6af7a5c1c2..000000000000 --- a/Documentation/sound/oss/CS4232 +++ /dev/null @@ -1,23 +0,0 @@ -To configure the Crystal CS423x sound chip and activate its DSP functions, -modules may be loaded in this order: - - modprobe sound - insmod ad1848 - insmod uart401 - insmod cs4232 io=* irq=* dma=* dma2=* - -This is the meaning of the parameters: - - io--I/O address of the Windows Sound System (normally 0x534) - irq--IRQ of this device - dma and dma2--DMA channels (DMA2 may be 0) - -On some cards, the board attempts to do non-PnP setup, and fails. If you -have problems, use Linux' PnP facilities. - -To get MIDI facilities add - - insmod opl3 io=* - -where "io" is the I/O address of the OPL3 synthesizer. This will be shown -in /proc/sys/pnp and is normally 0x388. diff --git a/Documentation/sound/oss/Introduction b/Documentation/sound/oss/Introduction index f04ba6bb7395..75d967ff9266 100644 --- a/Documentation/sound/oss/Introduction +++ b/Documentation/sound/oss/Introduction @@ -80,7 +80,7 @@ Notes: additional features. 2. The commercial OSS driver may be obtained from the site: - http://www/opensound.com. This may be used for cards that + http://www.opensound.com. This may be used for cards that are unsupported by the kernel driver, or may be used by other operating systems. diff --git a/Documentation/sparse.txt b/Documentation/sparse.txt index 42f43fa59f24..34c76a55bc04 100644 --- a/Documentation/sparse.txt +++ b/Documentation/sparse.txt @@ -42,6 +42,14 @@ sure that bitwise types don't get mixed up (little-endian vs big-endian vs cpu-endian vs whatever), and there the constant "0" really _is_ special. +__bitwise__ - to be used for relatively compact stuff (gfp_t, etc.) that +is mostly warning-free and is supposed to stay that way. Warnings will +be generated without __CHECK_ENDIAN__. + +__bitwise - noisy stuff; in particular, __le*/__be* are that. We really +don't want to drown in noise unless we'd explicitly asked for it. + + Getting sparse ~~~~~~~~~~~~~~ diff --git a/Documentation/spi/spi-summary b/Documentation/spi/spi-summary index 0f5122eb282b..4a02d2508bc8 100644 --- a/Documentation/spi/spi-summary +++ b/Documentation/spi/spi-summary @@ -511,10 +511,16 @@ SPI MASTER METHODS This sets up the device clock rate, SPI mode, and word sizes. Drivers may change the defaults provided by board_info, and then call spi_setup(spi) to invoke this routine. It may sleep. + Unless each SPI slave has its own configuration registers, don't change them right away ... otherwise drivers could corrupt I/O that's in progress for other SPI devices. + ** BUG ALERT: for some reason the first version of + ** many spi_master drivers seems to get this wrong. + ** When you code setup(), ASSUME that the controller + ** is actively processing transfers for another device. + master->transfer(struct spi_device *spi, struct spi_message *message) This must not sleep. Its responsibility is arrange that the transfer happens and its complete() callback is issued. The two diff --git a/Documentation/sysctl/00-INDEX b/Documentation/sysctl/00-INDEX index a20a9066dc4c..1286f455992f 100644 --- a/Documentation/sysctl/00-INDEX +++ b/Documentation/sysctl/00-INDEX @@ -10,6 +10,8 @@ fs.txt - documentation for /proc/sys/fs/*. kernel.txt - documentation for /proc/sys/kernel/*. +net.txt + - documentation for /proc/sys/net/*. sunrpc.txt - documentation for /proc/sys/sunrpc/*. vm.txt diff --git a/Documentation/sysctl/fs.txt b/Documentation/sysctl/fs.txt index f99254327ae5..1458448436cc 100644 --- a/Documentation/sysctl/fs.txt +++ b/Documentation/sysctl/fs.txt @@ -1,5 +1,6 @@ Documentation for /proc/sys/fs/* kernel version 2.2.10 (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> + (c) 2009, Shen Feng<shen@cn.fujitsu.com> For general info and legal blurb, please look in README. @@ -14,7 +15,12 @@ kernel. Since some of the files _can_ be used to screw up your system, it is advisable to read both documentation and source before actually making adjustments. +1. /proc/sys/fs +---------------------------------------------------------- + Currently, these files are in /proc/sys/fs: +- aio-max-nr +- aio-nr - dentry-state - dquot-max - dquot-nr @@ -30,8 +36,15 @@ Currently, these files are in /proc/sys/fs: - super-max - super-nr -Documentation for the files in /proc/sys/fs/binfmt_misc is -in Documentation/binfmt_misc.txt. +============================================================== + +aio-nr & aio-max-nr: + +aio-nr is the running total of the number of events specified on the +io_setup system call for all currently active aio contexts. If aio-nr +reaches aio-max-nr then io_setup will fail with EAGAIN. Note that +raising aio-max-nr does not result in the pre-allocation or re-sizing +of any kernel data structures. ============================================================== @@ -178,3 +191,60 @@ requests. aio-max-nr allows you to change the maximum value aio-nr can grow to. ============================================================== + + +2. /proc/sys/fs/binfmt_misc +---------------------------------------------------------- + +Documentation for the files in /proc/sys/fs/binfmt_misc is +in Documentation/binfmt_misc.txt. + + +3. /proc/sys/fs/mqueue - POSIX message queues filesystem +---------------------------------------------------------- + +The "mqueue" filesystem provides the necessary kernel features to enable the +creation of a user space library that implements the POSIX message queues +API (as noted by the MSG tag in the POSIX 1003.1-2001 version of the System +Interfaces specification.) + +The "mqueue" filesystem contains values for determining/setting the amount of +resources used by the file system. + +/proc/sys/fs/mqueue/queues_max is a read/write file for setting/getting the +maximum number of message queues allowed on the system. + +/proc/sys/fs/mqueue/msg_max is a read/write file for setting/getting the +maximum number of messages in a queue value. In fact it is the limiting value +for another (user) limit which is set in mq_open invocation. This attribute of +a queue must be less or equal then msg_max. + +/proc/sys/fs/mqueue/msgsize_max is a read/write file for setting/getting the +maximum message size value (it is every message queue's attribute set during +its creation). + + +4. /proc/sys/fs/epoll - Configuration options for the epoll interface +-------------------------------------------------------- + +This directory contains configuration options for the epoll(7) interface. + +max_user_instances +------------------ + +This is the maximum number of epoll file descriptors that a single user can +have open at a given time. The default value is 128, and should be enough +for normal users. + +max_user_watches +---------------- + +Every epoll file descriptor can store a number of files to be monitored +for event readiness. Each one of these monitored files constitutes a "watch". +This configuration option sets the maximum number of "watches" that are +allowed for each user. +Each "watch" costs roughly 90 bytes on a 32bit kernel, and roughly 160 bytes +on a 64bit one. +The current default value for max_user_watches is the 1/32 of the available +low memory, divided for the "watch" cost in bytes. + diff --git a/Documentation/sysctl/kernel.txt b/Documentation/sysctl/kernel.txt index a4ccdd1981cf..f11ca7979fa6 100644 --- a/Documentation/sysctl/kernel.txt +++ b/Documentation/sysctl/kernel.txt @@ -1,5 +1,6 @@ Documentation for /proc/sys/kernel/* kernel version 2.2.10 (c) 1998, 1999, Rik van Riel <riel@nl.linux.org> + (c) 2009, Shen Feng<shen@cn.fujitsu.com> For general info and legal blurb, please look in README. @@ -18,6 +19,7 @@ Currently, these files might (depending on your configuration) show up in /proc/sys/kernel: - acpi_video_flags - acct +- auto_msgmni - core_pattern - core_uses_pid - ctrl-alt-del @@ -33,6 +35,7 @@ show up in /proc/sys/kernel: - msgmax - msgmnb - msgmni +- nmi_watchdog - osrelease - ostype - overflowgid @@ -40,6 +43,7 @@ show up in /proc/sys/kernel: - panic - pid_max - powersave-nap [ PPC only ] +- panic_on_unrecovered_nmi - printk - randomize_va_space - real-root-dev ==> Documentation/initrd.txt @@ -55,6 +59,7 @@ show up in /proc/sys/kernel: - sysrq ==> Documentation/sysrq.txt - tainted - threads-max +- unknown_nmi_panic - version ============================================================== @@ -381,3 +386,51 @@ can be ORed together: 512 - A kernel warning has occurred. 1024 - A module from drivers/staging was loaded. +============================================================== + +auto_msgmni: + +Enables/Disables automatic recomputing of msgmni upon memory add/remove or +upon ipc namespace creation/removal (see the msgmni description above). +Echoing "1" into this file enables msgmni automatic recomputing. +Echoing "0" turns it off. +auto_msgmni default value is 1. + +============================================================== + +nmi_watchdog: + +Enables/Disables the NMI watchdog on x86 systems. When the value is non-zero +the NMI watchdog is enabled and will continuously test all online cpus to +determine whether or not they are still functioning properly. Currently, +passing "nmi_watchdog=" parameter at boot time is required for this function +to work. + +If LAPIC NMI watchdog method is in use (nmi_watchdog=2 kernel parameter), the +NMI watchdog shares registers with oprofile. By disabling the NMI watchdog, +oprofile may have more registers to utilize. + +============================================================== + +unknown_nmi_panic: + +The value in this file affects behavior of handling NMI. When the value is +non-zero, unknown NMI is trapped and then panic occurs. At that time, kernel +debugging information is displayed on console. + +NMI switch that most IA32 servers have fires unknown NMI up, for example. +If a system hangs up, try pressing the NMI switch. + +============================================================== + +panic_on_unrecovered_nmi: + +The default Linux behaviour on an NMI of either memory or unknown is to continue +operation. For many environments such as scientific computing it is preferable +that the box is taken out and the error dealt with than an uncorrected +parity/ECC error get propogated. + +A small number of systems do generate NMI's for bizarre random reasons such as +power management so the default is off. That sysctl works like the existing +panic controls already in that directory. + diff --git a/Documentation/sysctl/net.txt b/Documentation/sysctl/net.txt new file mode 100644 index 000000000000..df38ef046f8d --- /dev/null +++ b/Documentation/sysctl/net.txt @@ -0,0 +1,175 @@ +Documentation for /proc/sys/net/* kernel version 2.4.0-test11-pre4 + (c) 1999 Terrehon Bowden <terrehon@pacbell.net> + Bodo Bauer <bb@ricochet.net> + (c) 2000 Jorge Nerin <comandante@zaralinux.com> + (c) 2009 Shen Feng <shen@cn.fujitsu.com> + +For general info and legal blurb, please look in README. + +============================================================== + +This file contains the documentation for the sysctl files in +/proc/sys/net and is valid for Linux kernel version 2.4.0-test11-pre4. + +The interface to the networking parts of the kernel is located in +/proc/sys/net. The following table shows all possible subdirectories.You may +see only some of them, depending on your kernel's configuration. + + +Table : Subdirectories in /proc/sys/net +.............................................................................. + Directory Content Directory Content + core General parameter appletalk Appletalk protocol + unix Unix domain sockets netrom NET/ROM + 802 E802 protocol ax25 AX25 + ethernet Ethernet protocol rose X.25 PLP layer + ipv4 IP version 4 x25 X.25 protocol + ipx IPX token-ring IBM token ring + bridge Bridging decnet DEC net + ipv6 IP version 6 +.............................................................................. + +1. /proc/sys/net/core - Network core options +------------------------------------------------------- + +rmem_default +------------ + +The default setting of the socket receive buffer in bytes. + +rmem_max +-------- + +The maximum receive socket buffer size in bytes. + +wmem_default +------------ + +The default setting (in bytes) of the socket send buffer. + +wmem_max +-------- + +The maximum send socket buffer size in bytes. + +message_burst and message_cost +------------------------------ + +These parameters are used to limit the warning messages written to the kernel +log from the networking code. They enforce a rate limit to make a +denial-of-service attack impossible. A higher message_cost factor, results in +fewer messages that will be written. Message_burst controls when messages will +be dropped. The default settings limit warning messages to one every five +seconds. + +warnings +-------- + +This controls console messages from the networking stack that can occur because +of problems on the network like duplicate address or bad checksums. Normally, +this should be enabled, but if the problem persists the messages can be +disabled. + +netdev_budget +------------- + +Maximum number of packets taken from all interfaces in one polling cycle (NAPI +poll). In one polling cycle interfaces which are registered to polling are +probed in a round-robin manner. The limit of packets in one such probe can be +set per-device via sysfs class/net/<device>/weight . + +netdev_max_backlog +------------------ + +Maximum number of packets, queued on the INPUT side, when the interface +receives packets faster than kernel can process them. + +optmem_max +---------- + +Maximum ancillary buffer size allowed per socket. Ancillary data is a sequence +of struct cmsghdr structures with appended data. + +2. /proc/sys/net/unix - Parameters for Unix domain sockets +------------------------------------------------------- + +There is only one file in this directory. +unix_dgram_qlen limits the max number of datagrams queued in Unix domain +socket's buffer. It will not take effect unless PF_UNIX flag is specified. + + +3. /proc/sys/net/ipv4 - IPV4 settings +------------------------------------------------------- +Please see: Documentation/networking/ip-sysctl.txt and ipvs-sysctl.txt for +descriptions of these entries. + + +4. Appletalk +------------------------------------------------------- + +The /proc/sys/net/appletalk directory holds the Appletalk configuration data +when Appletalk is loaded. The configurable parameters are: + +aarp-expiry-time +---------------- + +The amount of time we keep an ARP entry before expiring it. Used to age out +old hosts. + +aarp-resolve-time +----------------- + +The amount of time we will spend trying to resolve an Appletalk address. + +aarp-retransmit-limit +--------------------- + +The number of times we will retransmit a query before giving up. + +aarp-tick-time +-------------- + +Controls the rate at which expires are checked. + +The directory /proc/net/appletalk holds the list of active Appletalk sockets +on a machine. + +The fields indicate the DDP type, the local address (in network:node format) +the remote address, the size of the transmit pending queue, the size of the +received queue (bytes waiting for applications to read) the state and the uid +owning the socket. + +/proc/net/atalk_iface lists all the interfaces configured for appletalk.It +shows the name of the interface, its Appletalk address, the network range on +that address (or network number for phase 1 networks), and the status of the +interface. + +/proc/net/atalk_route lists each known network route. It lists the target +(network) that the route leads to, the router (may be directly connected), the +route flags, and the device the route is using. + + +5. IPX +------------------------------------------------------- + +The IPX protocol has no tunable values in proc/sys/net. + +The IPX protocol does, however, provide proc/net/ipx. This lists each IPX +socket giving the local and remote addresses in Novell format (that is +network:node:port). In accordance with the strange Novell tradition, +everything but the port is in hex. Not_Connected is displayed for sockets that +are not tied to a specific remote address. The Tx and Rx queue sizes indicate +the number of bytes pending for transmission and reception. The state +indicates the state the socket is in and the uid is the owning uid of the +socket. + +The /proc/net/ipx_interface file lists all IPX interfaces. For each interface +it gives the network number, the node number, and indicates if the network is +the primary network. It also indicates which device it is bound to (or +Internal for internal networks) and the Frame Type if appropriate. Linux +supports 802.3, 802.2, 802.2 SNAP and DIX (Blue Book) ethernet framing for +IPX. + +The /proc/net/ipx_route table holds a list of IPX routes. For each route it +gives the destination network, the router node (or Directly) and the network +address of the router (or Connected) for internal networks. diff --git a/Documentation/sysctl/vm.txt b/Documentation/sysctl/vm.txt index 3197fc83bc51..b716d33912d8 100644 --- a/Documentation/sysctl/vm.txt +++ b/Documentation/sysctl/vm.txt @@ -39,6 +39,8 @@ Currently, these files are in /proc/sys/vm: - nr_hugepages - nr_overcommit_hugepages - nr_pdflush_threads +- nr_pdflush_threads_min +- nr_pdflush_threads_max - nr_trim_pages (only if CONFIG_MMU=n) - numa_zonelist_order - oom_dump_tasks @@ -88,6 +90,10 @@ will itself start writeback. If dirty_bytes is written, dirty_ratio becomes a function of its value (dirty_bytes / the amount of dirtyable system memory). +Note: the minimum value allowed for dirty_bytes is two pages (in bytes); any +value lower than this limit will be ignored and the old configuration will be +retained. + ============================================================== dirty_expire_centisecs @@ -463,6 +469,32 @@ The default value is 0. ============================================================== +nr_pdflush_threads_min + +This value controls the minimum number of pdflush threads. + +At boot time, the kernel will create and maintain 'nr_pdflush_threads_min' +threads for the kernel's lifetime. + +The default value is 2. The minimum value you can specify is 1, and +the maximum value is the current setting of 'nr_pdflush_threads_max'. + +See 'nr_pdflush_threads_max' below for more information. + +============================================================== + +nr_pdflush_threads_max + +This value controls the maximum number of pdflush threads that can be +created. The pdflush algorithm will create a new pdflush thread (up to +this maximum) if no pdflush threads have been available for >= 1 second. + +The default value is 8. The minimum value you can specify is the +current value of 'nr_pdflush_threads_min' and the +maximum is 1000. + +============================================================== + overcommit_memory: This value contains a flag that enables memory overcommitment. diff --git a/Documentation/sysrq.txt b/Documentation/sysrq.txt index 9e592c718afb..cf42b820ff9d 100644 --- a/Documentation/sysrq.txt +++ b/Documentation/sysrq.txt @@ -81,6 +81,8 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 'i' - Send a SIGKILL to all processes, except for init. +'j' - Forcibly "Just thaw it" - filesystems frozen by the FIFREEZE ioctl. + 'k' - Secure Access Key (SAK) Kills all programs on the current virtual console. NOTE: See important comments below in SAK section. @@ -113,6 +115,8 @@ On all - write a character to /proc/sysrq-trigger. e.g.: 'x' - Used by xmon interface on ppc/powerpc platforms. +'z' - Dump the ftrace buffer + '0'-'9' - Sets the console log level, controlling which kernel messages will be printed to your console. ('0', for example would make it so that only emergency messages like PANICs or OOPSes would @@ -160,6 +164,9 @@ t'E'rm and k'I'll are useful if you have some sort of runaway process you are unable to kill any other way, especially if it's spawning other processes. +"'J'ust thaw it" is useful if your system becomes unresponsive due to a frozen +(probably root) filesystem via the FIFREEZE ioctl. + * Sometimes SysRq seems to get 'stuck' after using it, what can I do? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ That happens to me, also. I've found that tapping shift, alt, and control diff --git a/Documentation/tomoyo.txt b/Documentation/tomoyo.txt new file mode 100644 index 000000000000..b3a232cae7f8 --- /dev/null +++ b/Documentation/tomoyo.txt @@ -0,0 +1,55 @@ +--- What is TOMOYO? --- + +TOMOYO is a name-based MAC extension (LSM module) for the Linux kernel. + +LiveCD-based tutorials are available at +http://tomoyo.sourceforge.jp/en/1.6.x/1st-step/ubuntu8.04-live/ +http://tomoyo.sourceforge.jp/en/1.6.x/1st-step/centos5-live/ . +Though these tutorials use non-LSM version of TOMOYO, they are useful for you +to know what TOMOYO is. + +--- How to enable TOMOYO? --- + +Build the kernel with CONFIG_SECURITY_TOMOYO=y and pass "security=tomoyo" on +kernel's command line. + +Please see http://tomoyo.sourceforge.jp/en/2.2.x/ for details. + +--- Where is documentation? --- + +User <-> Kernel interface documentation is available at +http://tomoyo.sourceforge.jp/en/2.2.x/policy-reference.html . + +Materials we prepared for seminars and symposiums are available at +http://sourceforge.jp/projects/tomoyo/docs/?category_id=532&language_id=1 . +Below lists are chosen from three aspects. + +What is TOMOYO? + TOMOYO Linux Overview + http://sourceforge.jp/projects/tomoyo/docs/lca2009-takeda.pdf + TOMOYO Linux: pragmatic and manageable security for Linux + http://sourceforge.jp/projects/tomoyo/docs/freedomhectaipei-tomoyo.pdf + TOMOYO Linux: A Practical Method to Understand and Protect Your Own Linux Box + http://sourceforge.jp/projects/tomoyo/docs/PacSec2007-en-no-demo.pdf + +What can TOMOYO do? + Deep inside TOMOYO Linux + http://sourceforge.jp/projects/tomoyo/docs/lca2009-kumaneko.pdf + The role of "pathname based access control" in security. + http://sourceforge.jp/projects/tomoyo/docs/lfj2008-bof.pdf + +History of TOMOYO? + Realities of Mainlining + http://sourceforge.jp/projects/tomoyo/docs/lfj2008.pdf + +--- What is future plan? --- + +We believe that inode based security and name based security are complementary +and both should be used together. But unfortunately, so far, we cannot enable +multiple LSM modules at the same time. We feel sorry that you have to give up +SELinux/SMACK/AppArmor etc. when you want to use TOMOYO. + +We hope that LSM becomes stackable in future. Meanwhile, you can use non-LSM +version of TOMOYO, available at http://tomoyo.sourceforge.jp/en/1.6.x/ . +LSM version of TOMOYO is a subset of non-LSM version of TOMOYO. We are planning +to port non-LSM version's functionalities to LSM versions. diff --git a/Documentation/ftrace.txt b/Documentation/trace/ftrace.txt index 803b1318b13d..fd9a3e693813 100644 --- a/Documentation/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -15,31 +15,31 @@ Introduction Ftrace is an internal tracer designed to help out developers and designers of systems to find what is going on inside the kernel. -It can be used for debugging or analyzing latencies and performance -issues that take place outside of user-space. +It can be used for debugging or analyzing latencies and +performance issues that take place outside of user-space. Although ftrace is the function tracer, it also includes an -infrastructure that allows for other types of tracing. Some of the -tracers that are currently in ftrace include a tracer to trace -context switches, the time it takes for a high priority task to -run after it was woken up, the time interrupts are disabled, and -more (ftrace allows for tracer plugins, which means that the list of -tracers can always grow). +infrastructure that allows for other types of tracing. Some of +the tracers that are currently in ftrace include a tracer to +trace context switches, the time it takes for a high priority +task to run after it was woken up, the time interrupts are +disabled, and more (ftrace allows for tracer plugins, which +means that the list of tracers can always grow). The File System --------------- -Ftrace uses the debugfs file system to hold the control files as well -as the files to display output. +Ftrace uses the debugfs file system to hold the control files as +well as the files to display output. To mount the debugfs system: # mkdir /debug # mount -t debugfs nodev /debug -(Note: it is more common to mount at /sys/kernel/debug, but for simplicity - this document will use /debug) +( Note: it is more common to mount at /sys/kernel/debug, but for + simplicity this document will use /debug) That's it! (assuming that you have ftrace configured into your kernel) @@ -50,90 +50,124 @@ of ftrace. Here is a list of some of the key files: Note: all time values are in microseconds. - current_tracer: This is used to set or display the current tracer - that is configured. - - available_tracers: This holds the different types of tracers that - have been compiled into the kernel. The tracers - listed here can be configured by echoing their name - into current_tracer. - - tracing_enabled: This sets or displays whether the current_tracer - is activated and tracing or not. Echo 0 into this - file to disable the tracer or 1 to enable it. - - trace: This file holds the output of the trace in a human readable - format (described below). - - latency_trace: This file shows the same trace but the information - is organized more to display possible latencies - in the system (described below). - - trace_pipe: The output is the same as the "trace" file but this - file is meant to be streamed with live tracing. - Reads from this file will block until new data - is retrieved. Unlike the "trace" and "latency_trace" - files, this file is a consumer. This means reading - from this file causes sequential reads to display - more current data. Once data is read from this - file, it is consumed, and will not be read - again with a sequential read. The "trace" and - "latency_trace" files are static, and if the - tracer is not adding more data, they will display - the same information every time they are read. - - trace_options: This file lets the user control the amount of data - that is displayed in one of the above output - files. - - trace_max_latency: Some of the tracers record the max latency. - For example, the time interrupts are disabled. - This time is saved in this file. The max trace - will also be stored, and displayed by either - "trace" or "latency_trace". A new max trace will - only be recorded if the latency is greater than - the value in this file. (in microseconds) - - buffer_size_kb: This sets or displays the number of kilobytes each CPU - buffer can hold. The tracer buffers are the same size - for each CPU. The displayed number is the size of the - CPU buffer and not total size of all buffers. The - trace buffers are allocated in pages (blocks of memory - that the kernel uses for allocation, usually 4 KB in size). - If the last page allocated has room for more bytes - than requested, the rest of the page will be used, - making the actual allocation bigger than requested. - (Note, the size may not be a multiple of the page size due - to buffer managment overhead.) - - This can only be updated when the current_tracer - is set to "nop". - - tracing_cpumask: This is a mask that lets the user only trace - on specified CPUS. The format is a hex string - representing the CPUS. - - set_ftrace_filter: When dynamic ftrace is configured in (see the - section below "dynamic ftrace"), the code is dynamically - modified (code text rewrite) to disable calling of the - function profiler (mcount). This lets tracing be configured - in with practically no overhead in performance. This also - has a side effect of enabling or disabling specific functions - to be traced. Echoing names of functions into this file - will limit the trace to only those functions. - - set_ftrace_notrace: This has an effect opposite to that of - set_ftrace_filter. Any function that is added here will not - be traced. If a function exists in both set_ftrace_filter - and set_ftrace_notrace, the function will _not_ be traced. - - set_ftrace_pid: Have the function tracer only trace a single thread. - - available_filter_functions: This lists the functions that ftrace - has processed and can trace. These are the function - names that you can pass to "set_ftrace_filter" or - "set_ftrace_notrace". (See the section "dynamic ftrace" - below for more details.) + current_tracer: + + This is used to set or display the current tracer + that is configured. + + available_tracers: + + This holds the different types of tracers that + have been compiled into the kernel. The + tracers listed here can be configured by + echoing their name into current_tracer. + + tracing_enabled: + + This sets or displays whether the current_tracer + is activated and tracing or not. Echo 0 into this + file to disable the tracer or 1 to enable it. + + trace: + + This file holds the output of the trace in a human + readable format (described below). + + latency_trace: + + This file shows the same trace but the information + is organized more to display possible latencies + in the system (described below). + + trace_pipe: + + The output is the same as the "trace" file but this + file is meant to be streamed with live tracing. + Reads from this file will block until new data + is retrieved. Unlike the "trace" and "latency_trace" + files, this file is a consumer. This means reading + from this file causes sequential reads to display + more current data. Once data is read from this + file, it is consumed, and will not be read + again with a sequential read. The "trace" and + "latency_trace" files are static, and if the + tracer is not adding more data, they will display + the same information every time they are read. + + trace_options: + + This file lets the user control the amount of data + that is displayed in one of the above output + files. + + tracing_max_latency: + + Some of the tracers record the max latency. + For example, the time interrupts are disabled. + This time is saved in this file. The max trace + will also be stored, and displayed by either + "trace" or "latency_trace". A new max trace will + only be recorded if the latency is greater than + the value in this file. (in microseconds) + + buffer_size_kb: + + This sets or displays the number of kilobytes each CPU + buffer can hold. The tracer buffers are the same size + for each CPU. The displayed number is the size of the + CPU buffer and not total size of all buffers. The + trace buffers are allocated in pages (blocks of memory + that the kernel uses for allocation, usually 4 KB in size). + If the last page allocated has room for more bytes + than requested, the rest of the page will be used, + making the actual allocation bigger than requested. + ( Note, the size may not be a multiple of the page size + due to buffer managment overhead. ) + + This can only be updated when the current_tracer + is set to "nop". + + tracing_cpumask: + + This is a mask that lets the user only trace + on specified CPUS. The format is a hex string + representing the CPUS. + + set_ftrace_filter: + + When dynamic ftrace is configured in (see the + section below "dynamic ftrace"), the code is dynamically + modified (code text rewrite) to disable calling of the + function profiler (mcount). This lets tracing be configured + in with practically no overhead in performance. This also + has a side effect of enabling or disabling specific functions + to be traced. Echoing names of functions into this file + will limit the trace to only those functions. + + set_ftrace_notrace: + + This has an effect opposite to that of + set_ftrace_filter. Any function that is added here will not + be traced. If a function exists in both set_ftrace_filter + and set_ftrace_notrace, the function will _not_ be traced. + + set_ftrace_pid: + + Have the function tracer only trace a single thread. + + set_graph_function: + + Set a "trigger" function where tracing should start + with the function graph tracer (See the section + "dynamic ftrace" for more details). + + available_filter_functions: + + This lists the functions that ftrace + has processed and can trace. These are the function + names that you can pass to "set_ftrace_filter" or + "set_ftrace_notrace". (See the section "dynamic ftrace" + below for more details.) The Tracers @@ -141,36 +175,66 @@ The Tracers Here is the list of current tracers that may be configured. - function - function tracer that uses mcount to trace all functions. + "function" + + Function call tracer to trace all kernel functions. + + "function_graph_tracer" + + Similar to the function tracer except that the + function tracer probes the functions on their entry + whereas the function graph tracer traces on both entry + and exit of the functions. It then provides the ability + to draw a graph of function calls similar to C code + source. - sched_switch - traces the context switches between tasks. + "sched_switch" - irqsoff - traces the areas that disable interrupts and saves - the trace with the longest max latency. - See tracing_max_latency. When a new max is recorded, - it replaces the old trace. It is best to view this - trace via the latency_trace file. + Traces the context switches and wakeups between tasks. - preemptoff - Similar to irqsoff but traces and records the amount of - time for which preemption is disabled. + "irqsoff" - preemptirqsoff - Similar to irqsoff and preemptoff, but traces and - records the largest time for which irqs and/or preemption - is disabled. + Traces the areas that disable interrupts and saves + the trace with the longest max latency. + See tracing_max_latency. When a new max is recorded, + it replaces the old trace. It is best to view this + trace via the latency_trace file. - wakeup - Traces and records the max latency that it takes for - the highest priority task to get scheduled after - it has been woken up. + "preemptoff" - nop - This is not a tracer. To remove all tracers from tracing - simply echo "nop" into current_tracer. + Similar to irqsoff but traces and records the amount of + time for which preemption is disabled. + + "preemptirqsoff" + + Similar to irqsoff and preemptoff, but traces and + records the largest time for which irqs and/or preemption + is disabled. + + "wakeup" + + Traces and records the max latency that it takes for + the highest priority task to get scheduled after + it has been woken up. + + "hw-branch-tracer" + + Uses the BTS CPU feature on x86 CPUs to traces all + branches executed. + + "nop" + + This is the "trace nothing" tracer. To remove all + tracers from tracing simply echo "nop" into + current_tracer. Examples of using the tracer ---------------------------- -Here are typical examples of using the tracers when controlling them only -with the debugfs interface (without using any user-land utilities). +Here are typical examples of using the tracers when controlling +them only with the debugfs interface (without using any +user-land utilities). Output format: -------------- @@ -187,16 +251,16 @@ Here is an example of the output format of the file "trace" bash-4251 [01] 10152.583855: _atomic_dec_and_lock <-dput -------- -A header is printed with the tracer name that is represented by the trace. -In this case the tracer is "function". Then a header showing the format. Task -name "bash", the task PID "4251", the CPU that it was running on -"01", the timestamp in <secs>.<usecs> format, the function name that was -traced "path_put" and the parent function that called this function -"path_walk". The timestamp is the time at which the function was -entered. +A header is printed with the tracer name that is represented by +the trace. In this case the tracer is "function". Then a header +showing the format. Task name "bash", the task PID "4251", the +CPU that it was running on "01", the timestamp in <secs>.<usecs> +format, the function name that was traced "path_put" and the +parent function that called this function "path_walk". The +timestamp is the time at which the function was entered. -The sched_switch tracer also includes tracing of task wakeups and -context switches. +The sched_switch tracer also includes tracing of task wakeups +and context switches. ksoftirqd/1-7 [01] 1453.070013: 7:115:R + 2916:115:S ksoftirqd/1-7 [01] 1453.070013: 7:115:R + 10:115:S @@ -205,8 +269,8 @@ context switches. kondemand/1-2916 [01] 1453.070013: 2916:115:S ==> 7:115:R ksoftirqd/1-7 [01] 1453.070013: 7:115:S ==> 0:140:R -Wake ups are represented by a "+" and the context switches are shown as -"==>". The format is: +Wake ups are represented by a "+" and the context switches are +shown as "==>". The format is: Context switches: @@ -220,19 +284,20 @@ Wake ups are represented by a "+" and the context switches are shown as <pid>:<prio>:<state> + <pid>:<prio>:<state> -The prio is the internal kernel priority, which is the inverse of the -priority that is usually displayed by user-space tools. Zero represents -the highest priority (99). Prio 100 starts the "nice" priorities with -100 being equal to nice -20 and 139 being nice 19. The prio "140" is -reserved for the idle task which is the lowest priority thread (pid 0). +The prio is the internal kernel priority, which is the inverse +of the priority that is usually displayed by user-space tools. +Zero represents the highest priority (99). Prio 100 starts the +"nice" priorities with 100 being equal to nice -20 and 139 being +nice 19. The prio "140" is reserved for the idle task which is +the lowest priority thread (pid 0). Latency trace format -------------------- -For traces that display latency times, the latency_trace file gives -somewhat more information to see why a latency happened. Here is a typical -trace. +For traces that display latency times, the latency_trace file +gives somewhat more information to see why a latency happened. +Here is a typical trace. # tracer: irqsoff # @@ -259,20 +324,20 @@ irqsoff latency trace v1.1.5 on 2.6.26-rc8 <idle>-0 0d.s1 98us : trace_hardirqs_on (do_softirq) +This shows that the current tracer is "irqsoff" tracing the time +for which interrupts were disabled. It gives the trace version +and the version of the kernel upon which this was executed on +(2.6.26-rc8). Then it displays the max latency in microsecs (97 +us). The number of trace entries displayed and the total number +recorded (both are three: #3/3). The type of preemption that was +used (PREEMPT). VP, KP, SP, and HP are always zero and are +reserved for later use. #P is the number of online CPUS (#P:2). -This shows that the current tracer is "irqsoff" tracing the time for which -interrupts were disabled. It gives the trace version and the version -of the kernel upon which this was executed on (2.6.26-rc8). Then it displays -the max latency in microsecs (97 us). The number of trace entries displayed -and the total number recorded (both are three: #3/3). The type of -preemption that was used (PREEMPT). VP, KP, SP, and HP are always zero -and are reserved for later use. #P is the number of online CPUS (#P:2). - -The task is the process that was running when the latency occurred. -(swapper pid: 0). +The task is the process that was running when the latency +occurred. (swapper pid: 0). -The start and stop (the functions in which the interrupts were disabled and -enabled respectively) that caused the latencies: +The start and stop (the functions in which the interrupts were +disabled and enabled respectively) that caused the latencies: apic_timer_interrupt is where the interrupts were disabled. do_softirq is where they were enabled again. @@ -308,12 +373,12 @@ The above is mostly meaningful for kernel developers. latency_trace file is relative to the start of the trace. delay: This is just to help catch your eye a bit better. And - needs to be fixed to be only relative to the same CPU. - The marks are determined by the difference between this - current trace and the next trace. - '!' - greater than preempt_mark_thresh (default 100) - '+' - greater than 1 microsecond - ' ' - less than or equal to 1 microsecond. + needs to be fixed to be only relative to the same CPU. + The marks are determined by the difference between this + current trace and the next trace. + '!' - greater than preempt_mark_thresh (default 100) + '+' - greater than 1 microsecond + ' ' - less than or equal to 1 microsecond. The rest is the same as the 'trace' file. @@ -321,14 +386,15 @@ The above is mostly meaningful for kernel developers. trace_options ------------- -The trace_options file is used to control what gets printed in the trace -output. To see what is available, simply cat the file: +The trace_options file is used to control what gets printed in +the trace output. To see what is available, simply cat the file: cat /debug/tracing/trace_options print-parent nosym-offset nosym-addr noverbose noraw nohex nobin \ - noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj + noblock nostacktrace nosched-tree nouserstacktrace nosym-userobj -To disable one of the options, echo in the option prepended with "no". +To disable one of the options, echo in the option prepended with +"no". echo noprint-parent > /debug/tracing/trace_options @@ -338,8 +404,8 @@ To enable an option, leave off the "no". Here are the available options: - print-parent - On function traces, display the calling function - as well as the function being traced. + print-parent - On function traces, display the calling (parent) + function as well as the function being traced. print-parent: bash-4000 [01] 1477.606694: simple_strtoul <-strict_strtoul @@ -348,15 +414,16 @@ Here are the available options: bash-4000 [01] 1477.606694: simple_strtoul - sym-offset - Display not only the function name, but also the offset - in the function. For example, instead of seeing just - "ktime_get", you will see "ktime_get+0xb/0x20". + sym-offset - Display not only the function name, but also the + offset in the function. For example, instead of + seeing just "ktime_get", you will see + "ktime_get+0xb/0x20". sym-offset: bash-4000 [01] 1477.606694: simple_strtoul+0x6/0xa0 - sym-addr - this will also display the function address as well as - the function name. + sym-addr - this will also display the function address as well + as the function name. sym-addr: bash-4000 [01] 1477.606694: simple_strtoul <c0339346> @@ -366,35 +433,41 @@ Here are the available options: bash 4000 1 0 00000000 00010a95 [58127d26] 1720.415ms \ (+0.000ms): simple_strtoul (strict_strtoul) - raw - This will display raw numbers. This option is best for use with - user applications that can translate the raw numbers better than - having it done in the kernel. + raw - This will display raw numbers. This option is best for + use with user applications that can translate the raw + numbers better than having it done in the kernel. - hex - Similar to raw, but the numbers will be in a hexadecimal format. + hex - Similar to raw, but the numbers will be in a hexadecimal + format. bin - This will print out the formats in raw binary. block - TBD (needs update) - stacktrace - This is one of the options that changes the trace itself. - When a trace is recorded, so is the stack of functions. - This allows for back traces of trace sites. + stacktrace - This is one of the options that changes the trace + itself. When a trace is recorded, so is the stack + of functions. This allows for back traces of + trace sites. - userstacktrace - This option changes the trace. - It records a stacktrace of the current userspace thread. + userstacktrace - This option changes the trace. It records a + stacktrace of the current userspace thread. - sym-userobj - when user stacktrace are enabled, look up which object the - address belongs to, and print a relative address - This is especially useful when ASLR is on, otherwise you don't - get a chance to resolve the address to object/file/line after the app is no - longer running + sym-userobj - when user stacktrace are enabled, look up which + object the address belongs to, and print a + relative address. This is especially useful when + ASLR is on, otherwise you don't get a chance to + resolve the address to object/file/line after + the app is no longer running - The lookup is performed when you read trace,trace_pipe,latency_trace. Example: + The lookup is performed when you read + trace,trace_pipe,latency_trace. Example: a.out-1623 [000] 40874.465068: /root/a.out[+0x480] <-/root/a.out[+0 x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6] - sched-tree - TBD (any users??) + sched-tree - trace all tasks that are on the runqueue, at + every scheduling event. Will add overhead if + there's a lot of tasks running at once. sched_switch @@ -431,18 +504,19 @@ of how to use it. [...] -As we have discussed previously about this format, the header shows -the name of the trace and points to the options. The "FUNCTION" -is a misnomer since here it represents the wake ups and context -switches. +As we have discussed previously about this format, the header +shows the name of the trace and points to the options. The +"FUNCTION" is a misnomer since here it represents the wake ups +and context switches. -The sched_switch file only lists the wake ups (represented with '+') -and context switches ('==>') with the previous task or current task -first followed by the next task or task waking up. The format for both -of these is PID:KERNEL-PRIO:TASK-STATE. Remember that the KERNEL-PRIO -is the inverse of the actual priority with zero (0) being the highest -priority and the nice values starting at 100 (nice -20). Below is -a quick chart to map the kernel priority to user land priorities. +The sched_switch file only lists the wake ups (represented with +'+') and context switches ('==>') with the previous task or +current task first followed by the next task or task waking up. +The format for both of these is PID:KERNEL-PRIO:TASK-STATE. +Remember that the KERNEL-PRIO is the inverse of the actual +priority with zero (0) being the highest priority and the nice +values starting at 100 (nice -20). Below is a quick chart to map +the kernel priority to user land priorities. Kernel priority: 0 to 99 ==> user RT priority 99 to 0 Kernel priority: 100 to 139 ==> user nice -20 to 19 @@ -463,10 +537,10 @@ The task states are: ftrace_enabled -------------- -The following tracers (listed below) give different output depending -on whether or not the sysctl ftrace_enabled is set. To set ftrace_enabled, -one can either use the sysctl function or set it via the proc -file system interface. +The following tracers (listed below) give different output +depending on whether or not the sysctl ftrace_enabled is set. To +set ftrace_enabled, one can either use the sysctl function or +set it via the proc file system interface. sysctl kernel.ftrace_enabled=1 @@ -474,12 +548,12 @@ file system interface. echo 1 > /proc/sys/kernel/ftrace_enabled -To disable ftrace_enabled simply replace the '1' with '0' in -the above commands. +To disable ftrace_enabled simply replace the '1' with '0' in the +above commands. -When ftrace_enabled is set the tracers will also record the functions -that are within the trace. The descriptions of the tracers -will also show an example with ftrace enabled. +When ftrace_enabled is set the tracers will also record the +functions that are within the trace. The descriptions of the +tracers will also show an example with ftrace enabled. irqsoff @@ -487,17 +561,18 @@ irqsoff When interrupts are disabled, the CPU can not react to any other external event (besides NMIs and SMIs). This prevents the timer -interrupt from triggering or the mouse interrupt from letting the -kernel know of a new mouse event. The result is a latency with the -reaction time. +interrupt from triggering or the mouse interrupt from letting +the kernel know of a new mouse event. The result is a latency +with the reaction time. -The irqsoff tracer tracks the time for which interrupts are disabled. -When a new maximum latency is hit, the tracer saves the trace leading up -to that latency point so that every time a new maximum is reached, the old -saved trace is discarded and the new trace is saved. +The irqsoff tracer tracks the time for which interrupts are +disabled. When a new maximum latency is hit, the tracer saves +the trace leading up to that latency point so that every time a +new maximum is reached, the old saved trace is discarded and the +new trace is saved. -To reset the maximum, echo 0 into tracing_max_latency. Here is an -example: +To reset the maximum, echo 0 into tracing_max_latency. Here is +an example: # echo irqsoff > /debug/tracing/current_tracer # echo 0 > /debug/tracing/tracing_max_latency @@ -532,10 +607,11 @@ irqsoff latency trace v1.1.5 on 2.6.26 Here we see that that we had a latency of 12 microsecs (which is -very good). The _write_lock_irq in sys_setpgid disabled interrupts. -The difference between the 12 and the displayed timestamp 14us occurred -because the clock was incremented between the time of recording the max -latency and the time of recording the function that had that latency. +very good). The _write_lock_irq in sys_setpgid disabled +interrupts. The difference between the 12 and the displayed +timestamp 14us occurred because the clock was incremented +between the time of recording the max latency and the time of +recording the function that had that latency. Note the above example had ftrace_enabled not set. If we set the ftrace_enabled, we get a much larger output: @@ -586,24 +662,24 @@ irqsoff latency trace v1.1.5 on 2.6.26-rc8 Here we traced a 50 microsecond latency. But we also see all the -functions that were called during that time. Note that by enabling -function tracing, we incur an added overhead. This overhead may -extend the latency times. But nevertheless, this trace has provided -some very helpful debugging information. +functions that were called during that time. Note that by +enabling function tracing, we incur an added overhead. This +overhead may extend the latency times. But nevertheless, this +trace has provided some very helpful debugging information. preemptoff ---------- -When preemption is disabled, we may be able to receive interrupts but -the task cannot be preempted and a higher priority task must wait -for preemption to be enabled again before it can preempt a lower -priority task. +When preemption is disabled, we may be able to receive +interrupts but the task cannot be preempted and a higher +priority task must wait for preemption to be enabled again +before it can preempt a lower priority task. The preemptoff tracer traces the places that disable preemption. -Like the irqsoff tracer, it records the maximum latency for which preemption -was disabled. The control of preemptoff tracer is much like the irqsoff -tracer. +Like the irqsoff tracer, it records the maximum latency for +which preemption was disabled. The control of preemptoff tracer +is much like the irqsoff tracer. # echo preemptoff > /debug/tracing/current_tracer # echo 0 > /debug/tracing/tracing_max_latency @@ -637,11 +713,12 @@ preemptoff latency trace v1.1.5 on 2.6.26-rc8 sshd-4261 0d.s1 30us : trace_preempt_on (__do_softirq) -This has some more changes. Preemption was disabled when an interrupt -came in (notice the 'h'), and was enabled while doing a softirq. -(notice the 's'). But we also see that interrupts have been disabled -when entering the preempt off section and leaving it (the 'd'). -We do not know if interrupts were enabled in the mean time. +This has some more changes. Preemption was disabled when an +interrupt came in (notice the 'h'), and was enabled while doing +a softirq. (notice the 's'). But we also see that interrupts +have been disabled when entering the preempt off section and +leaving it (the 'd'). We do not know if interrupts were enabled +in the mean time. # tracer: preemptoff # @@ -700,28 +777,30 @@ preemptoff latency trace v1.1.5 on 2.6.26-rc8 sshd-4261 0d.s1 64us : trace_preempt_on (__do_softirq) -The above is an example of the preemptoff trace with ftrace_enabled -set. Here we see that interrupts were disabled the entire time. -The irq_enter code lets us know that we entered an interrupt 'h'. -Before that, the functions being traced still show that it is not -in an interrupt, but we can see from the functions themselves that -this is not the case. +The above is an example of the preemptoff trace with +ftrace_enabled set. Here we see that interrupts were disabled +the entire time. The irq_enter code lets us know that we entered +an interrupt 'h'. Before that, the functions being traced still +show that it is not in an interrupt, but we can see from the +functions themselves that this is not the case. -Notice that __do_softirq when called does not have a preempt_count. -It may seem that we missed a preempt enabling. What really happened -is that the preempt count is held on the thread's stack and we -switched to the softirq stack (4K stacks in effect). The code -does not copy the preempt count, but because interrupts are disabled, -we do not need to worry about it. Having a tracer like this is good -for letting people know what really happens inside the kernel. +Notice that __do_softirq when called does not have a +preempt_count. It may seem that we missed a preempt enabling. +What really happened is that the preempt count is held on the +thread's stack and we switched to the softirq stack (4K stacks +in effect). The code does not copy the preempt count, but +because interrupts are disabled, we do not need to worry about +it. Having a tracer like this is good for letting people know +what really happens inside the kernel. preemptirqsoff -------------- -Knowing the locations that have interrupts disabled or preemption -disabled for the longest times is helpful. But sometimes we would -like to know when either preemption and/or interrupts are disabled. +Knowing the locations that have interrupts disabled or +preemption disabled for the longest times is helpful. But +sometimes we would like to know when either preemption and/or +interrupts are disabled. Consider the following code: @@ -741,11 +820,13 @@ The preemptoff tracer will record the total length of call_function_with_irqs_and_preemption_off() and call_function_with_preemption_off(). -But neither will trace the time that interrupts and/or preemption -is disabled. This total time is the time that we can not schedule. -To record this time, use the preemptirqsoff tracer. +But neither will trace the time that interrupts and/or +preemption is disabled. This total time is the time that we can +not schedule. To record this time, use the preemptirqsoff +tracer. -Again, using this trace is much like the irqsoff and preemptoff tracers. +Again, using this trace is much like the irqsoff and preemptoff +tracers. # echo preemptirqsoff > /debug/tracing/current_tracer # echo 0 > /debug/tracing/tracing_max_latency @@ -781,9 +862,10 @@ preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8 The trace_hardirqs_off_thunk is called from assembly on x86 when -interrupts are disabled in the assembly code. Without the function -tracing, we do not know if interrupts were enabled within the preemption -points. We do see that it started with preemption enabled. +interrupts are disabled in the assembly code. Without the +function tracing, we do not know if interrupts were enabled +within the preemption points. We do see that it started with +preemption enabled. Here is a trace with ftrace_enabled set: @@ -871,40 +953,42 @@ preemptirqsoff latency trace v1.1.5 on 2.6.26-rc8 sshd-4261 0d.s1 105us : trace_preempt_on (__do_softirq) -This is a very interesting trace. It started with the preemption of -the ls task. We see that the task had the "need_resched" bit set -via the 'N' in the trace. Interrupts were disabled before the spin_lock -at the beginning of the trace. We see that a schedule took place to run -sshd. When the interrupts were enabled, we took an interrupt. -On return from the interrupt handler, the softirq ran. We took another -interrupt while running the softirq as we see from the capital 'H'. +This is a very interesting trace. It started with the preemption +of the ls task. We see that the task had the "need_resched" bit +set via the 'N' in the trace. Interrupts were disabled before +the spin_lock at the beginning of the trace. We see that a +schedule took place to run sshd. When the interrupts were +enabled, we took an interrupt. On return from the interrupt +handler, the softirq ran. We took another interrupt while +running the softirq as we see from the capital 'H'. wakeup ------ -In a Real-Time environment it is very important to know the wakeup -time it takes for the highest priority task that is woken up to the -time that it executes. This is also known as "schedule latency". -I stress the point that this is about RT tasks. It is also important -to know the scheduling latency of non-RT tasks, but the average -schedule latency is better for non-RT tasks. Tools like -LatencyTop are more appropriate for such measurements. +In a Real-Time environment it is very important to know the +wakeup time it takes for the highest priority task that is woken +up to the time that it executes. This is also known as "schedule +latency". I stress the point that this is about RT tasks. It is +also important to know the scheduling latency of non-RT tasks, +but the average schedule latency is better for non-RT tasks. +Tools like LatencyTop are more appropriate for such +measurements. Real-Time environments are interested in the worst case latency. -That is the longest latency it takes for something to happen, and -not the average. We can have a very fast scheduler that may only -have a large latency once in a while, but that would not work well -with Real-Time tasks. The wakeup tracer was designed to record -the worst case wakeups of RT tasks. Non-RT tasks are not recorded -because the tracer only records one worst case and tracing non-RT -tasks that are unpredictable will overwrite the worst case latency -of RT tasks. - -Since this tracer only deals with RT tasks, we will run this slightly -differently than we did with the previous tracers. Instead of performing -an 'ls', we will run 'sleep 1' under 'chrt' which changes the -priority of the task. +That is the longest latency it takes for something to happen, +and not the average. We can have a very fast scheduler that may +only have a large latency once in a while, but that would not +work well with Real-Time tasks. The wakeup tracer was designed +to record the worst case wakeups of RT tasks. Non-RT tasks are +not recorded because the tracer only records one worst case and +tracing non-RT tasks that are unpredictable will overwrite the +worst case latency of RT tasks. + +Since this tracer only deals with RT tasks, we will run this +slightly differently than we did with the previous tracers. +Instead of performing an 'ls', we will run 'sleep 1' under +'chrt' which changes the priority of the task. # echo wakeup > /debug/tracing/current_tracer # echo 0 > /debug/tracing/tracing_max_latency @@ -934,17 +1018,16 @@ wakeup latency trace v1.1.5 on 2.6.26-rc8 <idle>-0 1d..4 4us : schedule (cpu_idle) +Running this on an idle system, we see that it only took 4 +microseconds to perform the task switch. Note, since the trace +marker in the schedule is before the actual "switch", we stop +the tracing when the recorded task is about to schedule in. This +may change if we add a new marker at the end of the scheduler. -Running this on an idle system, we see that it only took 4 microseconds -to perform the task switch. Note, since the trace marker in the -schedule is before the actual "switch", we stop the tracing when -the recorded task is about to schedule in. This may change if -we add a new marker at the end of the scheduler. - -Notice that the recorded task is 'sleep' with the PID of 4901 and it -has an rt_prio of 5. This priority is user-space priority and not -the internal kernel priority. The policy is 1 for SCHED_FIFO and 2 -for SCHED_RR. +Notice that the recorded task is 'sleep' with the PID of 4901 +and it has an rt_prio of 5. This priority is user-space priority +and not the internal kernel priority. The policy is 1 for +SCHED_FIFO and 2 for SCHED_RR. Doing the same with chrt -r 5 and ftrace_enabled set. @@ -1001,24 +1084,25 @@ ksoftirq-7 1d..6 49us : _spin_unlock (tracing_record_cmdline) ksoftirq-7 1d..6 49us : sub_preempt_count (_spin_unlock) ksoftirq-7 1d..4 50us : schedule (__cond_resched) -The interrupt went off while running ksoftirqd. This task runs at -SCHED_OTHER. Why did not we see the 'N' set early? This may be -a harmless bug with x86_32 and 4K stacks. On x86_32 with 4K stacks -configured, the interrupt and softirq run with their own stack. -Some information is held on the top of the task's stack (need_resched -and preempt_count are both stored there). The setting of the NEED_RESCHED -bit is done directly to the task's stack, but the reading of the -NEED_RESCHED is done by looking at the current stack, which in this case -is the stack for the hard interrupt. This hides the fact that NEED_RESCHED -has been set. We do not see the 'N' until we switch back to the task's +The interrupt went off while running ksoftirqd. This task runs +at SCHED_OTHER. Why did not we see the 'N' set early? This may +be a harmless bug with x86_32 and 4K stacks. On x86_32 with 4K +stacks configured, the interrupt and softirq run with their own +stack. Some information is held on the top of the task's stack +(need_resched and preempt_count are both stored there). The +setting of the NEED_RESCHED bit is done directly to the task's +stack, but the reading of the NEED_RESCHED is done by looking at +the current stack, which in this case is the stack for the hard +interrupt. This hides the fact that NEED_RESCHED has been set. +We do not see the 'N' until we switch back to the task's assigned stack. function -------- This tracer is the function tracer. Enabling the function tracer -can be done from the debug file system. Make sure the ftrace_enabled is -set; otherwise this tracer is a nop. +can be done from the debug file system. Make sure the +ftrace_enabled is set; otherwise this tracer is a nop. # sysctl kernel.ftrace_enabled=1 # echo function > /debug/tracing/current_tracer @@ -1048,14 +1132,15 @@ set; otherwise this tracer is a nop. [...] -Note: function tracer uses ring buffers to store the above entries. -The newest data may overwrite the oldest data. Sometimes using echo to -stop the trace is not sufficient because the tracing could have overwritten -the data that you wanted to record. For this reason, it is sometimes better to -disable tracing directly from a program. This allows you to stop the -tracing at the point that you hit the part that you are interested in. -To disable the tracing directly from a C program, something like following -code snippet can be used: +Note: function tracer uses ring buffers to store the above +entries. The newest data may overwrite the oldest data. +Sometimes using echo to stop the trace is not sufficient because +the tracing could have overwritten the data that you wanted to +record. For this reason, it is sometimes better to disable +tracing directly from a program. This allows you to stop the +tracing at the point that you hit the part that you are +interested in. To disable the tracing directly from a C program, +something like following code snippet can be used: int trace_fd; [...] @@ -1070,10 +1155,10 @@ int main(int argc, char *argv[]) { } Note: Here we hard coded the path name. The debugfs mount is not -guaranteed to be at /debug (and is more commonly at /sys/kernel/debug). -For simple one time traces, the above is sufficent. For anything else, -a search through /proc/mounts may be needed to find where the debugfs -file-system is mounted. +guaranteed to be at /debug (and is more commonly at +/sys/kernel/debug). For simple one time traces, the above is +sufficent. For anything else, a search through /proc/mounts may +be needed to find where the debugfs file-system is mounted. Single thread tracing @@ -1152,49 +1237,297 @@ int main (int argc, char **argv) return 0; } + +hw-branch-tracer (x86 only) +--------------------------- + +This tracer uses the x86 last branch tracing hardware feature to +collect a branch trace on all cpus with relatively low overhead. + +The tracer uses a fixed-size circular buffer per cpu and only +traces ring 0 branches. The trace file dumps that buffer in the +following format: + +# tracer: hw-branch-tracer +# +# CPU# TO <- FROM + 0 scheduler_tick+0xb5/0x1bf <- task_tick_idle+0x5/0x6 + 2 run_posix_cpu_timers+0x2b/0x72a <- run_posix_cpu_timers+0x25/0x72a + 0 scheduler_tick+0x139/0x1bf <- scheduler_tick+0xed/0x1bf + 0 scheduler_tick+0x17c/0x1bf <- scheduler_tick+0x148/0x1bf + 2 run_posix_cpu_timers+0x9e/0x72a <- run_posix_cpu_timers+0x5e/0x72a + 0 scheduler_tick+0x1b6/0x1bf <- scheduler_tick+0x1aa/0x1bf + + +The tracer may be used to dump the trace for the oops'ing cpu on +a kernel oops into the system log. To enable this, +ftrace_dump_on_oops must be set. To set ftrace_dump_on_oops, one +can either use the sysctl function or set it via the proc system +interface. + + sysctl kernel.ftrace_dump_on_oops=1 + +or + + echo 1 > /proc/sys/kernel/ftrace_dump_on_oops + + +Here's an example of such a dump after a null pointer +dereference in a kernel module: + +[57848.105921] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 +[57848.106019] IP: [<ffffffffa0000006>] open+0x6/0x14 [oops] +[57848.106019] PGD 2354e9067 PUD 2375e7067 PMD 0 +[57848.106019] Oops: 0002 [#1] SMP +[57848.106019] last sysfs file: /sys/devices/pci0000:00/0000:00:1e.0/0000:20:05.0/local_cpus +[57848.106019] Dumping ftrace buffer: +[57848.106019] --------------------------------- +[...] +[57848.106019] 0 chrdev_open+0xe6/0x165 <- cdev_put+0x23/0x24 +[57848.106019] 0 chrdev_open+0x117/0x165 <- chrdev_open+0xfa/0x165 +[57848.106019] 0 chrdev_open+0x120/0x165 <- chrdev_open+0x11c/0x165 +[57848.106019] 0 chrdev_open+0x134/0x165 <- chrdev_open+0x12b/0x165 +[57848.106019] 0 open+0x0/0x14 [oops] <- chrdev_open+0x144/0x165 +[57848.106019] 0 page_fault+0x0/0x30 <- open+0x6/0x14 [oops] +[57848.106019] 0 error_entry+0x0/0x5b <- page_fault+0x4/0x30 +[57848.106019] 0 error_kernelspace+0x0/0x31 <- error_entry+0x59/0x5b +[57848.106019] 0 error_sti+0x0/0x1 <- error_kernelspace+0x2d/0x31 +[57848.106019] 0 page_fault+0x9/0x30 <- error_sti+0x0/0x1 +[57848.106019] 0 do_page_fault+0x0/0x881 <- page_fault+0x1a/0x30 +[...] +[57848.106019] 0 do_page_fault+0x66b/0x881 <- is_prefetch+0x1ee/0x1f2 +[57848.106019] 0 do_page_fault+0x6e0/0x881 <- do_page_fault+0x67a/0x881 +[57848.106019] 0 oops_begin+0x0/0x96 <- do_page_fault+0x6e0/0x881 +[57848.106019] 0 trace_hw_branch_oops+0x0/0x2d <- oops_begin+0x9/0x96 +[...] +[57848.106019] 0 ds_suspend_bts+0x2a/0xe3 <- ds_suspend_bts+0x1a/0xe3 +[57848.106019] --------------------------------- +[57848.106019] CPU 0 +[57848.106019] Modules linked in: oops +[57848.106019] Pid: 5542, comm: cat Tainted: G W 2.6.28 #23 +[57848.106019] RIP: 0010:[<ffffffffa0000006>] [<ffffffffa0000006>] open+0x6/0x14 [oops] +[57848.106019] RSP: 0018:ffff880235457d48 EFLAGS: 00010246 +[...] + + +function graph tracer +--------------------------- + +This tracer is similar to the function tracer except that it +probes a function on its entry and its exit. This is done by +using a dynamically allocated stack of return addresses in each +task_struct. On function entry the tracer overwrites the return +address of each function traced to set a custom probe. Thus the +original return address is stored on the stack of return address +in the task_struct. + +Probing on both ends of a function leads to special features +such as: + +- measure of a function's time execution +- having a reliable call stack to draw function calls graph + +This tracer is useful in several situations: + +- you want to find the reason of a strange kernel behavior and + need to see what happens in detail on any areas (or specific + ones). + +- you are experiencing weird latencies but it's difficult to + find its origin. + +- you want to find quickly which path is taken by a specific + function + +- you just want to peek inside a working kernel and want to see + what happens there. + +# tracer: function_graph +# +# CPU DURATION FUNCTION CALLS +# | | | | | | | + + 0) | sys_open() { + 0) | do_sys_open() { + 0) | getname() { + 0) | kmem_cache_alloc() { + 0) 1.382 us | __might_sleep(); + 0) 2.478 us | } + 0) | strncpy_from_user() { + 0) | might_fault() { + 0) 1.389 us | __might_sleep(); + 0) 2.553 us | } + 0) 3.807 us | } + 0) 7.876 us | } + 0) | alloc_fd() { + 0) 0.668 us | _spin_lock(); + 0) 0.570 us | expand_files(); + 0) 0.586 us | _spin_unlock(); + + +There are several columns that can be dynamically +enabled/disabled. You can use every combination of options you +want, depending on your needs. + +- The cpu number on which the function executed is default + enabled. It is sometimes better to only trace one cpu (see + tracing_cpu_mask file) or you might sometimes see unordered + function calls while cpu tracing switch. + + hide: echo nofuncgraph-cpu > /debug/tracing/trace_options + show: echo funcgraph-cpu > /debug/tracing/trace_options + +- The duration (function's time of execution) is displayed on + the closing bracket line of a function or on the same line + than the current function in case of a leaf one. It is default + enabled. + + hide: echo nofuncgraph-duration > /debug/tracing/trace_options + show: echo funcgraph-duration > /debug/tracing/trace_options + +- The overhead field precedes the duration field in case of + reached duration thresholds. + + hide: echo nofuncgraph-overhead > /debug/tracing/trace_options + show: echo funcgraph-overhead > /debug/tracing/trace_options + depends on: funcgraph-duration + + ie: + + 0) | up_write() { + 0) 0.646 us | _spin_lock_irqsave(); + 0) 0.684 us | _spin_unlock_irqrestore(); + 0) 3.123 us | } + 0) 0.548 us | fput(); + 0) + 58.628 us | } + + [...] + + 0) | putname() { + 0) | kmem_cache_free() { + 0) 0.518 us | __phys_addr(); + 0) 1.757 us | } + 0) 2.861 us | } + 0) ! 115.305 us | } + 0) ! 116.402 us | } + + + means that the function exceeded 10 usecs. + ! means that the function exceeded 100 usecs. + + +- The task/pid field displays the thread cmdline and pid which + executed the function. It is default disabled. + + hide: echo nofuncgraph-proc > /debug/tracing/trace_options + show: echo funcgraph-proc > /debug/tracing/trace_options + + ie: + + # tracer: function_graph + # + # CPU TASK/PID DURATION FUNCTION CALLS + # | | | | | | | | | + 0) sh-4802 | | d_free() { + 0) sh-4802 | | call_rcu() { + 0) sh-4802 | | __call_rcu() { + 0) sh-4802 | 0.616 us | rcu_process_gp_end(); + 0) sh-4802 | 0.586 us | check_for_new_grace_period(); + 0) sh-4802 | 2.899 us | } + 0) sh-4802 | 4.040 us | } + 0) sh-4802 | 5.151 us | } + 0) sh-4802 | + 49.370 us | } + + +- The absolute time field is an absolute timestamp given by the + system clock since it started. A snapshot of this time is + given on each entry/exit of functions + + hide: echo nofuncgraph-abstime > /debug/tracing/trace_options + show: echo funcgraph-abstime > /debug/tracing/trace_options + + ie: + + # + # TIME CPU DURATION FUNCTION CALLS + # | | | | | | | | + 360.774522 | 1) 0.541 us | } + 360.774522 | 1) 4.663 us | } + 360.774523 | 1) 0.541 us | __wake_up_bit(); + 360.774524 | 1) 6.796 us | } + 360.774524 | 1) 7.952 us | } + 360.774525 | 1) 9.063 us | } + 360.774525 | 1) 0.615 us | journal_mark_dirty(); + 360.774527 | 1) 0.578 us | __brelse(); + 360.774528 | 1) | reiserfs_prepare_for_journal() { + 360.774528 | 1) | unlock_buffer() { + 360.774529 | 1) | wake_up_bit() { + 360.774529 | 1) | bit_waitqueue() { + 360.774530 | 1) 0.594 us | __phys_addr(); + + +You can put some comments on specific functions by using +trace_printk() For example, if you want to put a comment inside +the __might_sleep() function, you just have to include +<linux/ftrace.h> and call trace_printk() inside __might_sleep() + +trace_printk("I'm a comment!\n") + +will produce: + + 1) | __might_sleep() { + 1) | /* I'm a comment! */ + 1) 1.449 us | } + + +You might find other useful features for this tracer in the +following "dynamic ftrace" section such as tracing only specific +functions or tasks. + dynamic ftrace -------------- If CONFIG_DYNAMIC_FTRACE is set, the system will run with virtually no overhead when function tracing is disabled. The way this works is the mcount function call (placed at the start of -every kernel function, produced by the -pg switch in gcc), starts -of pointing to a simple return. (Enabling FTRACE will include the --pg switch in the compiling of the kernel.) +every kernel function, produced by the -pg switch in gcc), +starts of pointing to a simple return. (Enabling FTRACE will +include the -pg switch in the compiling of the kernel.) At compile time every C file object is run through the recordmcount.pl script (located in the scripts directory). This script will process the C object using objdump to find all the -locations in the .text section that call mcount. (Note, only -the .text section is processed, since processing other sections -like .init.text may cause races due to those sections being freed). +locations in the .text section that call mcount. (Note, only the +.text section is processed, since processing other sections like +.init.text may cause races due to those sections being freed). -A new section called "__mcount_loc" is created that holds references -to all the mcount call sites in the .text section. This section is -compiled back into the original object. The final linker will add -all these references into a single table. +A new section called "__mcount_loc" is created that holds +references to all the mcount call sites in the .text section. +This section is compiled back into the original object. The +final linker will add all these references into a single table. On boot up, before SMP is initialized, the dynamic ftrace code -scans this table and updates all the locations into nops. It also -records the locations, which are added to the available_filter_functions -list. Modules are processed as they are loaded and before they are -executed. When a module is unloaded, it also removes its functions from -the ftrace function list. This is automatic in the module unload -code, and the module author does not need to worry about it. - -When tracing is enabled, kstop_machine is called to prevent races -with the CPUS executing code being modified (which can cause the -CPU to do undesireable things), and the nops are patched back -to calls. But this time, they do not call mcount (which is just -a function stub). They now call into the ftrace infrastructure. +scans this table and updates all the locations into nops. It +also records the locations, which are added to the +available_filter_functions list. Modules are processed as they +are loaded and before they are executed. When a module is +unloaded, it also removes its functions from the ftrace function +list. This is automatic in the module unload code, and the +module author does not need to worry about it. + +When tracing is enabled, kstop_machine is called to prevent +races with the CPUS executing code being modified (which can +cause the CPU to do undesireable things), and the nops are +patched back to calls. But this time, they do not call mcount +(which is just a function stub). They now call into the ftrace +infrastructure. One special side-effect to the recording of the functions being traced is that we can now selectively choose which functions we -wish to trace and which ones we want the mcount calls to remain as -nops. +wish to trace and which ones we want the mcount calls to remain +as nops. -Two files are used, one for enabling and one for disabling the tracing -of specified functions. They are: +Two files are used, one for enabling and one for disabling the +tracing of specified functions. They are: set_ftrace_filter @@ -1202,8 +1535,8 @@ and set_ftrace_notrace -A list of available functions that you can add to these files is listed -in: +A list of available functions that you can add to these files is +listed in: available_filter_functions @@ -1240,8 +1573,8 @@ hrtimer_interrupt sys_nanosleep -Perhaps this is not enough. The filters also allow simple wild cards. -Only the following are currently available +Perhaps this is not enough. The filters also allow simple wild +cards. Only the following are currently available <match>* - will match functions that begin with <match> *<match> - will match functions that end with <match> @@ -1251,9 +1584,9 @@ These are the only wild cards which are supported. <match>*<match> will not work. -Note: It is better to use quotes to enclose the wild cards, otherwise - the shell may expand the parameters into names of files in the local - directory. +Note: It is better to use quotes to enclose the wild cards, + otherwise the shell may expand the parameters into names + of files in the local directory. # echo 'hrtimer_*' > /debug/tracing/set_ftrace_filter @@ -1299,7 +1632,8 @@ This is because the '>' and '>>' act just like they do in bash. To rewrite the filters, use '>' To append to the filters, use '>>' -To clear out a filter so that all functions will be recorded again: +To clear out a filter so that all functions will be recorded +again: # echo > /debug/tracing/set_ftrace_filter # cat /debug/tracing/set_ftrace_filter @@ -1331,7 +1665,8 @@ hrtimer_get_res hrtimer_init_sleeper -The set_ftrace_notrace prevents those functions from being traced. +The set_ftrace_notrace prevents those functions from being +traced. # echo '*preempt*' '*lock*' > /debug/tracing/set_ftrace_notrace @@ -1353,13 +1688,75 @@ Produces: We can see that there's no more lock or preempt tracing. + +Dynamic ftrace with the function graph tracer +--------------------------------------------- + +Although what has been explained above concerns both the +function tracer and the function-graph-tracer, there are some +special features only available in the function-graph tracer. + +If you want to trace only one function and all of its children, +you just have to echo its name into set_graph_function: + + echo __do_fault > set_graph_function + +will produce the following "expanded" trace of the __do_fault() +function: + + 0) | __do_fault() { + 0) | filemap_fault() { + 0) | find_lock_page() { + 0) 0.804 us | find_get_page(); + 0) | __might_sleep() { + 0) 1.329 us | } + 0) 3.904 us | } + 0) 4.979 us | } + 0) 0.653 us | _spin_lock(); + 0) 0.578 us | page_add_file_rmap(); + 0) 0.525 us | native_set_pte_at(); + 0) 0.585 us | _spin_unlock(); + 0) | unlock_page() { + 0) 0.541 us | page_waitqueue(); + 0) 0.639 us | __wake_up_bit(); + 0) 2.786 us | } + 0) + 14.237 us | } + 0) | __do_fault() { + 0) | filemap_fault() { + 0) | find_lock_page() { + 0) 0.698 us | find_get_page(); + 0) | __might_sleep() { + 0) 1.412 us | } + 0) 3.950 us | } + 0) 5.098 us | } + 0) 0.631 us | _spin_lock(); + 0) 0.571 us | page_add_file_rmap(); + 0) 0.526 us | native_set_pte_at(); + 0) 0.586 us | _spin_unlock(); + 0) | unlock_page() { + 0) 0.533 us | page_waitqueue(); + 0) 0.638 us | __wake_up_bit(); + 0) 2.793 us | } + 0) + 14.012 us | } + +You can also expand several functions at once: + + echo sys_open > set_graph_function + echo sys_close >> set_graph_function + +Now if you want to go back to trace all functions you can clear +this special filter via: + + echo > set_graph_function + + trace_pipe ---------- -The trace_pipe outputs the same content as the trace file, but the effect -on the tracing is different. Every read from trace_pipe is consumed. -This means that subsequent reads will be different. The trace -is live. +The trace_pipe outputs the same content as the trace file, but +the effect on the tracing is different. Every read from +trace_pipe is consumed. This means that subsequent reads will be +different. The trace is live. # echo function > /debug/tracing/current_tracer # cat /debug/tracing/trace_pipe > /tmp/trace.out & @@ -1387,38 +1784,45 @@ is live. bash-4043 [00] 41.267111: select_task_rq_rt <-try_to_wake_up -Note, reading the trace_pipe file will block until more input is added. -By changing the tracer, trace_pipe will issue an EOF. We needed -to set the function tracer _before_ we "cat" the trace_pipe file. +Note, reading the trace_pipe file will block until more input is +added. By changing the tracer, trace_pipe will issue an EOF. We +needed to set the function tracer _before_ we "cat" the +trace_pipe file. trace entries ------------- -Having too much or not enough data can be troublesome in diagnosing -an issue in the kernel. The file buffer_size_kb is used to modify -the size of the internal trace buffers. The number listed -is the number of entries that can be recorded per CPU. To know -the full size, multiply the number of possible CPUS with the -number of entries. +Having too much or not enough data can be troublesome in +diagnosing an issue in the kernel. The file buffer_size_kb is +used to modify the size of the internal trace buffers. The +number listed is the number of entries that can be recorded per +CPU. To know the full size, multiply the number of possible CPUS +with the number of entries. # cat /debug/tracing/buffer_size_kb 1408 (units kilobytes) -Note, to modify this, you must have tracing completely disabled. To do that, -echo "nop" into the current_tracer. If the current_tracer is not set -to "nop", an EINVAL error will be returned. +Note, to modify this, you must have tracing completely disabled. +To do that, echo "nop" into the current_tracer. If the +current_tracer is not set to "nop", an EINVAL error will be +returned. # echo nop > /debug/tracing/current_tracer # echo 10000 > /debug/tracing/buffer_size_kb # cat /debug/tracing/buffer_size_kb 10000 (units kilobytes) -The number of pages which will be allocated is limited to a percentage -of available memory. Allocating too much will produce an error. +The number of pages which will be allocated is limited to a +percentage of available memory. Allocating too much will produce +an error. # echo 1000000000000 > /debug/tracing/buffer_size_kb -bash: echo: write error: Cannot allocate memory # cat /debug/tracing/buffer_size_kb 85 +----------- + +More details can be found in the source code, in the +kernel/tracing/*.c files. diff --git a/Documentation/trace/kmemtrace.txt b/Documentation/trace/kmemtrace.txt new file mode 100644 index 000000000000..a956d9b7f943 --- /dev/null +++ b/Documentation/trace/kmemtrace.txt @@ -0,0 +1,126 @@ + kmemtrace - Kernel Memory Tracer + + by Eduard - Gabriel Munteanu + <eduard.munteanu@linux360.ro> + +I. Introduction +=============== + +kmemtrace helps kernel developers figure out two things: +1) how different allocators (SLAB, SLUB etc.) perform +2) how kernel code allocates memory and how much + +To do this, we trace every allocation and export information to the userspace +through the relay interface. We export things such as the number of requested +bytes, the number of bytes actually allocated (i.e. including internal +fragmentation), whether this is a slab allocation or a plain kmalloc() and so +on. + +The actual analysis is performed by a userspace tool (see section III for +details on where to get it from). It logs the data exported by the kernel, +processes it and (as of writing this) can provide the following information: +- the total amount of memory allocated and fragmentation per call-site +- the amount of memory allocated and fragmentation per allocation +- total memory allocated and fragmentation in the collected dataset +- number of cross-CPU allocation and frees (makes sense in NUMA environments) + +Moreover, it can potentially find inconsistent and erroneous behavior in +kernel code, such as using slab free functions on kmalloc'ed memory or +allocating less memory than requested (but not truly failed allocations). + +kmemtrace also makes provisions for tracing on some arch and analysing the +data on another. + +II. Design and goals +==================== + +kmemtrace was designed to handle rather large amounts of data. Thus, it uses +the relay interface to export whatever is logged to userspace, which then +stores it. Analysis and reporting is done asynchronously, that is, after the +data is collected and stored. By design, it allows one to log and analyse +on different machines and different arches. + +As of writing this, the ABI is not considered stable, though it might not +change much. However, no guarantees are made about compatibility yet. When +deemed stable, the ABI should still allow easy extension while maintaining +backward compatibility. This is described further in Documentation/ABI. + +Summary of design goals: + - allow logging and analysis to be done across different machines + - be fast and anticipate usage in high-load environments (*) + - be reasonably extensible + - make it possible for GNU/Linux distributions to have kmemtrace + included in their repositories + +(*) - one of the reasons Pekka Enberg's original userspace data analysis + tool's code was rewritten from Perl to C (although this is more than a + simple conversion) + + +III. Quick usage guide +====================== + +1) Get a kernel that supports kmemtrace and build it accordingly (i.e. enable +CONFIG_KMEMTRACE). + +2) Get the userspace tool and build it: +$ git-clone git://repo.or.cz/kmemtrace-user.git # current repository +$ cd kmemtrace-user/ +$ ./autogen.sh +$ ./configure +$ make + +3) Boot the kmemtrace-enabled kernel if you haven't, preferably in the +'single' runlevel (so that relay buffers don't fill up easily), and run +kmemtrace: +# '$' does not mean user, but root here. +$ mount -t debugfs none /sys/kernel/debug +$ mount -t proc none /proc +$ cd path/to/kmemtrace-user/ +$ ./kmemtraced +Wait a bit, then stop it with CTRL+C. +$ cat /sys/kernel/debug/kmemtrace/total_overruns # Check if we didn't + # overrun, should + # be zero. +$ (Optionally) [Run kmemtrace_check separately on each cpu[0-9]*.out file to + check its correctness] +$ ./kmemtrace-report + +Now you should have a nice and short summary of how the allocator performs. + +IV. FAQ and known issues +======================== + +Q: 'cat /sys/kernel/debug/kmemtrace/total_overruns' is non-zero, how do I fix +this? Should I worry? +A: If it's non-zero, this affects kmemtrace's accuracy, depending on how +large the number is. You can fix it by supplying a higher +'kmemtrace.subbufs=N' kernel parameter. +--- + +Q: kmemtrace_check reports errors, how do I fix this? Should I worry? +A: This is a bug and should be reported. It can occur for a variety of +reasons: + - possible bugs in relay code + - possible misuse of relay by kmemtrace + - timestamps being collected unorderly +Or you may fix it yourself and send us a patch. +--- + +Q: kmemtrace_report shows many errors, how do I fix this? Should I worry? +A: This is a known issue and I'm working on it. These might be true errors +in kernel code, which may have inconsistent behavior (e.g. allocating memory +with kmem_cache_alloc() and freeing it with kfree()). Pekka Enberg pointed +out this behavior may work with SLAB, but may fail with other allocators. + +It may also be due to lack of tracing in some unusual allocator functions. + +We don't want bug reports regarding this issue yet. +--- + +V. See also +=========== + +Documentation/kernel-parameters.txt +Documentation/ABI/testing/debugfs-kmemtrace + diff --git a/Documentation/tracers/mmiotrace.txt b/Documentation/trace/mmiotrace.txt index 5731c67abc55..5731c67abc55 100644 --- a/Documentation/tracers/mmiotrace.txt +++ b/Documentation/trace/mmiotrace.txt diff --git a/Documentation/tracepoints.txt b/Documentation/trace/tracepoints.txt index 6f0a044f5b5e..c0e1ceed75a4 100644 --- a/Documentation/tracepoints.txt +++ b/Documentation/trace/tracepoints.txt @@ -45,8 +45,8 @@ In include/trace/subsys.h : #include <linux/tracepoint.h> DECLARE_TRACE(subsys_eventname, - TPPROTO(int firstarg, struct task_struct *p), - TPARGS(firstarg, p)); + TP_PROTO(int firstarg, struct task_struct *p), + TP_ARGS(firstarg, p)); In subsys/file.c (where the tracing statement must be added) : @@ -66,10 +66,10 @@ Where : - subsys is the name of your subsystem. - eventname is the name of the event to trace. -- TPPROTO(int firstarg, struct task_struct *p) is the prototype of the +- TP_PROTO(int firstarg, struct task_struct *p) is the prototype of the function called by this tracepoint. -- TPARGS(firstarg, p) are the parameters names, same as found in the +- TP_ARGS(firstarg, p) are the parameters names, same as found in the prototype. Connecting a function (probe) to a tracepoint is done by providing a @@ -103,13 +103,14 @@ used to export the defined tracepoints. * Probe / tracepoint example -See the example provided in samples/tracepoints/src +See the example provided in samples/tracepoints -Compile them with your kernel. +Compile them with your kernel. They are built during 'make' (not +'make modules') when CONFIG_SAMPLE_TRACEPOINTS=m. Run, as root : -modprobe tracepoint-example (insmod order is not important) -modprobe tracepoint-probe-example -cat /proc/tracepoint-example (returns an expected error) -rmmod tracepoint-example tracepoint-probe-example +modprobe tracepoint-sample (insmod order is not important) +modprobe tracepoint-probe-sample +cat /proc/tracepoint-sample (returns an expected error) +rmmod tracepoint-sample tracepoint-probe-sample dmesg diff --git a/Documentation/usb/usbmon.txt b/Documentation/usb/usbmon.txt index 270481906dc8..6c3c625b7f30 100644 --- a/Documentation/usb/usbmon.txt +++ b/Documentation/usb/usbmon.txt @@ -229,16 +229,26 @@ struct usbmon_packet { int status; /* 28: */ unsigned int length; /* 32: Length of data (submitted or actual) */ unsigned int len_cap; /* 36: Delivered length */ - unsigned char setup[8]; /* 40: Only for Control 'S' */ -}; /* 48 bytes total */ + union { /* 40: */ + unsigned char setup[SETUP_LEN]; /* Only for Control S-type */ + struct iso_rec { /* Only for ISO */ + int error_count; + int numdesc; + } iso; + } s; + int interval; /* 48: Only for Interrupt and ISO */ + int start_frame; /* 52: For ISO */ + unsigned int xfer_flags; /* 56: copy of URB's transfer_flags */ + unsigned int ndesc; /* 60: Actual number of ISO descriptors */ +}; /* 64 total length */ These events can be received from a character device by reading with read(2), -with an ioctl(2), or by accessing the buffer with mmap. +with an ioctl(2), or by accessing the buffer with mmap. However, read(2) +only returns first 48 bytes for compatibility reasons. The character device is usually called /dev/usbmonN, where N is the USB bus number. Number zero (/dev/usbmon0) is special and means "all buses". -However, this feature is not implemented yet. Note that specific naming -policy is set by your Linux distribution. +Note that specific naming policy is set by your Linux distribution. If you create /dev/usbmon0 by hand, make sure that it is owned by root and has mode 0600. Otherwise, unpriviledged users will be able to snoop @@ -279,9 +289,10 @@ size is out of [unspecified] bounds for this kernel, the call fails with This call returns the current size of the buffer in bytes. MON_IOCX_GET, defined as _IOW(MON_IOC_MAGIC, 6, struct mon_get_arg) + MON_IOCX_GETX, defined as _IOW(MON_IOC_MAGIC, 10, struct mon_get_arg) -This call waits for events to arrive if none were in the kernel buffer, -then returns the first event. Its argument is a pointer to the following +These calls wait for events to arrive if none were in the kernel buffer, +then return the first event. The argument is a pointer to the following structure: struct mon_get_arg { @@ -294,6 +305,8 @@ Before the call, hdr, data, and alloc should be filled. Upon return, the area pointed by hdr contains the next event structure, and the data buffer contains the data, if any. The event is removed from the kernel buffer. +The MON_IOCX_GET copies 48 bytes, MON_IOCX_GETX copies 64 bytes. + MON_IOCX_MFETCH, defined as _IOWR(MON_IOC_MAGIC, 7, struct mon_mfetch_arg) This ioctl is primarily used when the application accesses the buffer diff --git a/Documentation/video4linux/CARDLIST.bttv b/Documentation/video4linux/CARDLIST.bttv index 0d93fa1ac25e..f11c583295e9 100644 --- a/Documentation/video4linux/CARDLIST.bttv +++ b/Documentation/video4linux/CARDLIST.bttv @@ -135,7 +135,7 @@ 134 -> Adlink RTV24 135 -> DViCO FusionHDTV 5 Lite [18ac:d500] 136 -> Acorp Y878F [9511:1540] -137 -> Conceptronic CTVFMi v2 +137 -> Conceptronic CTVFMi v2 [036e:109e] 138 -> Prolink Pixelview PV-BT878P+ (Rev.2E) 139 -> Prolink PixelView PlayTV MPEG2 PV-M4900 140 -> Osprey 440 [0070:ff07] @@ -154,3 +154,7 @@ 153 -> PHYTEC VD-012 (bt878) 154 -> PHYTEC VD-012-X1 (bt878) 155 -> PHYTEC VD-012-X2 (bt878) +156 -> IVCE-8784 [0000:f050,0001:f050,0002:f050,0003:f050] +157 -> Geovision GV-800(S) (master) [800a:763d] +158 -> Geovision GV-800(S) (slave) [800b:763d,800c:763d,800d:763d] +159 -> ProVideo PV183 [1830:1540,1831:1540,1832:1540,1833:1540,1834:1540,1835:1540,1836:1540,1837:1540] diff --git a/Documentation/video4linux/CARDLIST.cx23885 b/Documentation/video4linux/CARDLIST.cx23885 index 35ea130e9898..91aa3c0f0dd2 100644 --- a/Documentation/video4linux/CARDLIST.cx23885 +++ b/Documentation/video4linux/CARDLIST.cx23885 @@ -12,3 +12,7 @@ 11 -> DViCO FusionHDTV DVB-T Dual Express [18ac:db78] 12 -> Leadtek Winfast PxDVR3200 H [107d:6681] 13 -> Compro VideoMate E650F [185b:e800] + 14 -> TurboSight TBS 6920 [6920:8888] + 15 -> TeVii S470 [d470:9022] + 16 -> DVBWorld DVB-S2 2005 [0001:2005] + 17 -> NetUP Dual DVB-S2 CI [1b55:2a2c] diff --git a/Documentation/video4linux/CARDLIST.cx88 b/Documentation/video4linux/CARDLIST.cx88 index 0d08f1edcf6d..71e9db0b26f7 100644 --- a/Documentation/video4linux/CARDLIST.cx88 +++ b/Documentation/video4linux/CARDLIST.cx88 @@ -77,3 +77,4 @@ 76 -> SATTRADE ST4200 DVB-S/S2 [b200:4200] 77 -> TBS 8910 DVB-S [8910:8888] 78 -> Prof 6200 DVB-S [b022:3022] + 79 -> Terratec Cinergy HT PCI MKII [153b:1177] diff --git a/Documentation/video4linux/CARDLIST.em28xx b/Documentation/video4linux/CARDLIST.em28xx index 75bded8a4aa2..78d0a6eed571 100644 --- a/Documentation/video4linux/CARDLIST.em28xx +++ b/Documentation/video4linux/CARDLIST.em28xx @@ -7,12 +7,12 @@ 6 -> Terratec Cinergy 200 USB (em2800) 7 -> Leadtek Winfast USB II (em2800) [0413:6023] 8 -> Kworld USB2800 (em2800) - 9 -> Pinnacle Dazzle DVC 90/DVC 100 (em2820/em2840) [2304:0207,2304:021a] + 9 -> Pinnacle Dazzle DVC 90/100/101/107 / Kaiser Baas Video to DVD maker (em2820/em2840) [1b80:e302,2304:0207,2304:021a] 10 -> Hauppauge WinTV HVR 900 (em2880) [2040:6500] 11 -> Terratec Hybrid XS (em2880) [0ccd:0042] 12 -> Kworld PVR TV 2800 RF (em2820/em2840) 13 -> Terratec Prodigy XS (em2880) [0ccd:0047] - 14 -> Pixelview Prolink PlayTV USB 2.0 (em2820/em2840) + 14 -> SIIG AVTuner-PVR / Pixelview Prolink PlayTV USB 2.0 (em2820/em2840) 15 -> V-Gear PocketTV (em2800) 16 -> Hauppauge WinTV HVR 950 (em2883) [2040:6513,2040:6517,2040:651b] 17 -> Pinnacle PCTV HD Pro Stick (em2880) [2304:0227] @@ -30,7 +30,6 @@ 30 -> Videology 20K14XUSB USB2.0 (em2820/em2840) 31 -> Usbgear VD204v9 (em2821) 32 -> Supercomp USB 2.0 TV (em2821) - 33 -> SIIG AVTuner-PVR/Prolink PlayTV USB 2.0 (em2821) 34 -> Terratec Cinergy A Hybrid XS (em2860) [0ccd:004f] 35 -> Typhoon DVD Maker (em2860) 36 -> NetGMBH Cam (em2860) @@ -58,3 +57,7 @@ 58 -> Compro VideoMate ForYou/Stereo (em2820/em2840) [185b:2041] 60 -> Hauppauge WinTV HVR 850 (em2883) [2040:651f] 61 -> Pixelview PlayTV Box 4 USB 2.0 (em2820/em2840) + 62 -> Gadmei TVR200 (em2820/em2840) + 63 -> Kaiomy TVnPC U2 (em2860) [eb1a:e303] + 64 -> Easy Cap Capture DC-60 (em2860) + 65 -> IO-DATA GV-MVP/SZ (em2820/em2840) [04bb:0515] diff --git a/Documentation/video4linux/CARDLIST.saa7134 b/Documentation/video4linux/CARDLIST.saa7134 index b8d470596b0c..6dacf2825259 100644 --- a/Documentation/video4linux/CARDLIST.saa7134 +++ b/Documentation/video4linux/CARDLIST.saa7134 @@ -153,3 +153,5 @@ 152 -> Asus Tiger Rev:1.00 [1043:4857] 153 -> Kworld Plus TV Analog Lite PCI [17de:7128] 154 -> Avermedia AVerTV GO 007 FM Plus [1461:f31d] +155 -> Hauppauge WinTV-HVR1120 ATSC/QAM-Hybrid [0070:6706,0070:6708] +156 -> Hauppauge WinTV-HVR1110r3 [0070:6707,0070:6709,0070:670a] diff --git a/Documentation/video4linux/Zoran b/Documentation/video4linux/Zoran index 295462b2317a..0e89e7676298 100644 --- a/Documentation/video4linux/Zoran +++ b/Documentation/video4linux/Zoran @@ -401,8 +401,7 @@ Additional notes for software developers: first set the correct norm. Well, it seems logically correct: TV standard is "more constant" for current country than geometry settings of a variety of TV capture cards which may work in ITU or - square pixel format. Remember that users now can lock the norm to - avoid any ambiguity. + square pixel format. -- Please note that lavplay/lavrec are also included in the MJPEG-tools (http://mjpeg.sf.net/). diff --git a/Documentation/video4linux/bttv/Insmod-options b/Documentation/video4linux/bttv/Insmod-options index 5ef75787f83a..bbe3ed667d91 100644 --- a/Documentation/video4linux/bttv/Insmod-options +++ b/Documentation/video4linux/bttv/Insmod-options @@ -81,16 +81,6 @@ tuner.o pal=[bdgil] select PAL variant (used for some tuners only, important for the audio carrier). -tvmixer.o - registers a mixer device for the TV card's volume/bass/treble - controls (requires a i2c audio control chip like the msp3400). - - insmod args: - debug=1 print some debug info to the syslog. - devnr=n allocate device #n (0 == /dev/mixer, - 1 = /dev/mixer1, ...), default is to - use the first free one. - tvaudio.o new, experimental module which is supported to provide a single driver for all simple i2c audio control chips (tda/tea*). diff --git a/Documentation/video4linux/bttv/README b/Documentation/video4linux/bttv/README index 7ca2154c2bf5..3a367cdb664e 100644 --- a/Documentation/video4linux/bttv/README +++ b/Documentation/video4linux/bttv/README @@ -63,8 +63,8 @@ If you have some knowledge and spare time, please try to fix this yourself (patches very welcome of course...) You know: The linux slogan is "Do it yourself". -There is a mailing list: video4linux-list@redhat.com. -https://listman.redhat.com/mailman/listinfo/video4linux-list +There is a mailing list: linux-media@vger.kernel.org +http://vger.kernel.org/vger-lists.html#linux-media If you have trouble with some specific TV card, try to ask there instead of mailing me directly. The chance that someone with the diff --git a/Documentation/video4linux/cx2341x/README.hm12 b/Documentation/video4linux/cx2341x/README.hm12 index 0e213ed095e6..b36148ea0750 100644 --- a/Documentation/video4linux/cx2341x/README.hm12 +++ b/Documentation/video4linux/cx2341x/README.hm12 @@ -32,6 +32,10 @@ Y, U and V planes. This code assumes frames of 720x576 (PAL) pixels. The width of a frame is always 720 pixels, regardless of the actual specified width. +If the height is not a multiple of 32 lines, then the captured video is +missing macroblocks at the end and is unusable. So the height must be a +multiple of 32. + -------------------------------------------------------------------------- #include <stdio.h> diff --git a/Documentation/video4linux/gspca.txt b/Documentation/video4linux/gspca.txt index 1c58a7630146..98529e03a46e 100644 --- a/Documentation/video4linux/gspca.txt +++ b/Documentation/video4linux/gspca.txt @@ -32,6 +32,7 @@ spca561 041e:403b Creative Webcam Vista (VF0010) zc3xx 041e:4051 Creative Live!Cam Notebook Pro (VF0250) ov519 041e:4052 Creative Live! VISTA IM zc3xx 041e:4053 Creative Live!Cam Video IM +vc032x 041e:405b Creative Live! Cam Notebook Ultra (VC0130) ov519 041e:405f Creative Live! VISTA VF0330 ov519 041e:4060 Creative Live! VISTA VF0350 ov519 041e:4061 Creative Live! VISTA VF0400 @@ -193,6 +194,7 @@ spca500 084d:0003 D-Link DSC-350 spca500 08ca:0103 Aiptek PocketDV sunplus 08ca:0104 Aiptek PocketDVII 1.3 sunplus 08ca:0106 Aiptek Pocket DV3100+ +mr97310a 08ca:0111 Aiptek PenCam VGA+ sunplus 08ca:2008 Aiptek Mini PenCam 2 M sunplus 08ca:2010 Aiptek PocketCam 3M sunplus 08ca:2016 Aiptek PocketCam 2 Mega @@ -215,6 +217,7 @@ pac207 093a:2468 PAC207 pac207 093a:2470 Genius GF112 pac207 093a:2471 Genius VideoCam ge111 pac207 093a:2472 Genius VideoCam ge110 +pac207 093a:2474 Genius iLook 111 pac207 093a:2476 Genius e-Messenger 112 pac7311 093a:2600 PAC7311 Typhoon pac7311 093a:2601 Philips SPC 610 NC @@ -279,6 +282,7 @@ spca561 10fd:7e50 FlyCam Usb 100 zc3xx 10fd:8050 Typhoon Webshot II USB 300k ov534 1415:2000 Sony HD Eye for PS3 (SLEH 00201) pac207 145f:013a Trust WB-1300N +vc032x 15b8:6001 HP 2.0 Megapixel vc032x 15b8:6002 HP 2.0 Megapixel rz406aa spca501 1776:501c Arowana 300K CMOS Camera t613 17a1:0128 TASCORP JPEG Webcam, NGS Cyclops diff --git a/Documentation/video4linux/pxa_camera.txt b/Documentation/video4linux/pxa_camera.txt new file mode 100644 index 000000000000..b1137f9a53eb --- /dev/null +++ b/Documentation/video4linux/pxa_camera.txt @@ -0,0 +1,125 @@ + PXA-Camera Host Driver + ====================== + +Constraints +----------- + a) Image size for YUV422P format + All YUV422P images are enforced to have width x height % 16 = 0. + This is due to DMA constraints, which transfers only planes of 8 byte + multiples. + + +Global video workflow +--------------------- + a) QCI stopped + Initialy, the QCI interface is stopped. + When a buffer is queued (pxa_videobuf_ops->buf_queue), the QCI starts. + + b) QCI started + More buffers can be queued while the QCI is started without halting the + capture. The new buffers are "appended" at the tail of the DMA chain, and + smoothly captured one frame after the other. + + Once a buffer is filled in the QCI interface, it is marked as "DONE" and + removed from the active buffers list. It can be then requeud or dequeued by + userland application. + + Once the last buffer is filled in, the QCI interface stops. + + +DMA usage +--------- + a) DMA flow + - first buffer queued for capture + Once a first buffer is queued for capture, the QCI is started, but data + transfer is not started. On "End Of Frame" interrupt, the irq handler + starts the DMA chain. + - capture of one videobuffer + The DMA chain starts transfering data into videobuffer RAM pages. + When all pages are transfered, the DMA irq is raised on "ENDINTR" status + - finishing one videobuffer + The DMA irq handler marks the videobuffer as "done", and removes it from + the active running queue + Meanwhile, the next videobuffer (if there is one), is transfered by DMA + - finishing the last videobuffer + On the DMA irq of the last videobuffer, the QCI is stopped. + + b) DMA prepared buffer will have this structure + + +------------+-----+---------------+-----------------+ + | desc-sg[0] | ... | desc-sg[last] | finisher/linker | + +------------+-----+---------------+-----------------+ + + This structure is pointed by dma->sg_cpu. + The descriptors are used as follows : + - desc-sg[i]: i-th descriptor, transfering the i-th sg + element to the video buffer scatter gather + - finisher: has ddadr=DADDR_STOP, dcmd=ENDIRQEN + - linker: has ddadr= desc-sg[0] of next video buffer, dcmd=0 + + For the next schema, let's assume d0=desc-sg[0] .. dN=desc-sg[N], + "f" stands for finisher and "l" for linker. + A typical running chain is : + + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+---+ + | | + +----+ + + After the chaining is finished, the chain looks like : + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + + c) DMA hot chaining timeslice issue + + As DMA chaining is done while DMA _is_ running, the linking may be done + while the DMA jumps from one Videobuffer to another. On the schema, that + would be a problem if the following sequence is encountered : + + - DMA chain is Videobuffer1 + Videobuffer2 + - pxa_videobuf_queue() is called to queue Videobuffer3 + - DMA controller finishes Videobuffer2, and DMA stops + => + Videobuffer 1 Videobuffer 2 + +---------+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-^-+ + | | | + +----+ +-- DMA DDADR loads DDADR_STOP + + - pxa_dma_add_tail_buf() is called, the Videobuffer2 "finisher" is + replaced by a "linker" to Videobuffer3 (creation of new_link) + - pxa_videobuf_queue() finishes + - the DMA irq handler is called, which terminates Videobuffer2 + - Videobuffer3 capture is not scheduled on DMA chain (as it stopped !!!) + + Videobuffer 1 Videobuffer 2 Videobuffer 3 + +---------+----+---+ +----+----+----+---+ +----+----+----+---+ + | d0 | .. | dN | l | | d0 | .. | dN | l | | d0 | .. | dN | f | + +---------+----+-|-+ ^----+----+----+-|-+ ^----+----+----+---+ + | | | | + +----+ +----+ + new_link + DMA DDADR still is DDADR_STOP + + - pxa_camera_check_link_miss() is called + This checks if the DMA is finished and a buffer is still on the + pcdev->capture list. If that's the case, the capture will be restarted, + and Videobuffer3 is scheduled on DMA chain. + - the DMA irq handler finishes + + Note: if DMA stops just after pxa_camera_check_link_miss() reads DDADR() + value, we have the guarantee that the DMA irq handler will be called back + when the DMA will finish the buffer, and pxa_camera_check_link_miss() will + be called again, to reschedule Videobuffer3. + +-- +Author: Robert Jarzmik <robert.jarzmik@free.fr> diff --git a/Documentation/video4linux/si470x.txt b/Documentation/video4linux/si470x.txt index 49679e6aaa76..3a7823e01b4d 100644 --- a/Documentation/video4linux/si470x.txt +++ b/Documentation/video4linux/si470x.txt @@ -1,6 +1,6 @@ Driver for USB radios for the Silicon Labs Si470x FM Radio Receivers -Copyright (c) 2008 Tobias Lorenz <tobias.lorenz@gmx.net> +Copyright (c) 2009 Tobias Lorenz <tobias.lorenz@gmx.net> Information from Silicon Labs @@ -41,7 +41,7 @@ chips are known to work: - 10c4:818a: Silicon Labs USB FM Radio Reference Design - 06e1:a155: ADS/Tech FM Radio Receiver (formerly Instant FM Music) (RDX-155-EF) - 1b80:d700: KWorld USB FM Radio SnapMusic Mobile 700 (FM700) -- 10c5:819a: DealExtreme USB Radio +- 10c5:819a: Sanei Electric, Inc. FM USB Radio (sold as DealExtreme.com PCear) Software @@ -52,6 +52,7 @@ Testing is usually done with most application under Debian/testing: - gradio - GTK FM radio tuner - kradio - Comfortable Radio Application for KDE - radio - ncurses-based radio application +- mplayer - The Ultimate Movie Player For Linux There is also a library libv4l, which can be used. It's going to have a function for frequency seeking, either by using hardware functionality as in radio-si470x @@ -69,7 +70,7 @@ Audio Listing USB Audio is provided by the ALSA snd_usb_audio module. It is recommended to also select SND_USB_AUDIO, as this is required to get sound from the radio. For listing you have to redirect the sound, for example using one of the following -commands. +commands. Please adjust the audio devices to your needs (/dev/dsp* and hw:x,x). If you just want to test audio (very poor quality): cat /dev/dsp1 > /dev/dsp @@ -80,6 +81,10 @@ sox -2 --endian little -r 96000 -t oss /dev/dsp1 -t oss /dev/dsp If you use arts try: arecord -D hw:1,0 -r96000 -c2 -f S16_LE | artsdsp aplay -B - +If you use mplayer try: +mplayer -radio adevice=hw=1.0:arate=96000 \ + -rawaudio rate=96000 \ + radio://<frequency>/capture Module Parameters ================= diff --git a/Documentation/video4linux/v4l2-framework.txt b/Documentation/video4linux/v4l2-framework.txt index ff124374e9ba..854808b67fae 100644 --- a/Documentation/video4linux/v4l2-framework.txt +++ b/Documentation/video4linux/v4l2-framework.txt @@ -47,7 +47,9 @@ All drivers have the following structure: 3) Creating V4L2 device nodes (/dev/videoX, /dev/vbiX, /dev/radioX and /dev/vtxX) and keeping track of device-node specific data. -4) Filehandle-specific structs containing per-filehandle data. +4) Filehandle-specific structs containing per-filehandle data; + +5) video buffer handling. This is a rough schematic of how it all relates: @@ -82,12 +84,20 @@ You must register the device instance: v4l2_device_register(struct device *dev, struct v4l2_device *v4l2_dev); Registration will initialize the v4l2_device struct and link dev->driver_data -to v4l2_dev. Registration will also set v4l2_dev->name to a value derived from -dev (driver name followed by the bus_id, to be precise). You may change the -name after registration if you want. +to v4l2_dev. If v4l2_dev->name is empty then it will be set to a value derived +from dev (driver name followed by the bus_id, to be precise). If you set it +up before calling v4l2_device_register then it will be untouched. If dev is +NULL, then you *must* setup v4l2_dev->name before calling v4l2_device_register. The first 'dev' argument is normally the struct device pointer of a pci_dev, -usb_device or platform_device. +usb_interface or platform_device. It is rare for dev to be NULL, but it happens +with ISA devices or when one device creates multiple PCI devices, thus making +it impossible to associate v4l2_dev with a particular parent. + +You can also supply a notify() callback that can be called by sub-devices to +notify you of events. Whether you need to set this depends on the sub-device. +Any notifications a sub-device supports must be defined in a header in +include/media/<subdevice>.h. You unregister with: @@ -95,6 +105,17 @@ You unregister with: Unregistering will also automatically unregister all subdevs from the device. +If you have a hotpluggable device (e.g. a USB device), then when a disconnect +happens the parent device becomes invalid. Since v4l2_device has a pointer to +that parent device it has to be cleared as well to mark that the parent is +gone. To do this call: + + v4l2_device_disconnect(struct v4l2_device *v4l2_dev); + +This does *not* unregister the subdevs, so you still need to call the +v4l2_device_unregister() function for that. If your driver is not hotpluggable, +then there is no need to call v4l2_device_disconnect(). + Sometimes you need to iterate over all devices registered by a specific driver. This is usually the case if multiple device drivers use the same hardware. E.g. the ivtvfb driver is a framebuffer driver that uses the ivtv @@ -134,7 +155,7 @@ The recommended approach is as follows: static atomic_t drv_instance = ATOMIC_INIT(0); -static int __devinit drv_probe(struct pci_dev *dev, +static int __devinit drv_probe(struct pci_dev *pdev, const struct pci_device_id *pci_id) { ... @@ -218,7 +239,7 @@ to add new ops and categories. A sub-device driver initializes the v4l2_subdev struct using: - v4l2_subdev_init(subdev, &ops); + v4l2_subdev_init(sd, &ops); Afterwards you need to initialize subdev->name with a unique name and set the module owner. This is done for you if you use the i2c helper functions. @@ -226,7 +247,7 @@ module owner. This is done for you if you use the i2c helper functions. A device (bridge) driver needs to register the v4l2_subdev with the v4l2_device: - int err = v4l2_device_register_subdev(device, subdev); + int err = v4l2_device_register_subdev(v4l2_dev, sd); This can fail if the subdev module disappeared before it could be registered. After this function was called successfully the subdev->dev field points to @@ -234,17 +255,17 @@ the v4l2_device. You can unregister a sub-device using: - v4l2_device_unregister_subdev(subdev); + v4l2_device_unregister_subdev(sd); -Afterwards the subdev module can be unloaded and subdev->dev == NULL. +Afterwards the subdev module can be unloaded and sd->dev == NULL. You can call an ops function either directly: - err = subdev->ops->core->g_chip_ident(subdev, &chip); + err = sd->ops->core->g_chip_ident(sd, &chip); but it is better and easier to use this macro: - err = v4l2_subdev_call(subdev, core, g_chip_ident, &chip); + err = v4l2_subdev_call(sd, core, g_chip_ident, &chip); The macro will to the right NULL pointer checks and returns -ENODEV if subdev is NULL, -ENOIOCTLCMD if either subdev->core or subdev->core->g_chip_ident is @@ -252,19 +273,19 @@ NULL, or the actual result of the subdev->ops->core->g_chip_ident ops. It is also possible to call all or a subset of the sub-devices: - v4l2_device_call_all(dev, 0, core, g_chip_ident, &chip); + v4l2_device_call_all(v4l2_dev, 0, core, g_chip_ident, &chip); Any subdev that does not support this ops is skipped and error results are ignored. If you want to check for errors use this: - err = v4l2_device_call_until_err(dev, 0, core, g_chip_ident, &chip); + err = v4l2_device_call_until_err(v4l2_dev, 0, core, g_chip_ident, &chip); Any error except -ENOIOCTLCMD will exit the loop with that error. If no errors (except -ENOIOCTLCMD) occured, then 0 is returned. The second argument to both calls is a group ID. If 0, then all subdevs are called. If non-zero, then only those whose group ID match that value will -be called. Before a bridge driver registers a subdev it can set subdev->grp_id +be called. Before a bridge driver registers a subdev it can set sd->grp_id to whatever value it wants (it's 0 by default). This value is owned by the bridge driver and the sub-device driver will never modify or use it. @@ -276,6 +297,11 @@ e.g. AUDIO_CONTROLLER and specify that as the group ID value when calling v4l2_device_call_all(). That ensures that it will only go to the subdev that needs it. +If the sub-device needs to notify its v4l2_device parent of an event, then +it can call v4l2_subdev_notify(sd, notification, arg). This macro checks +whether there is a notify() callback defined and returns -ENODEV if not. +Otherwise the result of the notify() call is returned. + The advantage of using v4l2_subdev is that it is a generic struct and does not contain any knowledge about the underlying hardware. So a driver might contain several subdevs that use an I2C bus, but also a subdev that is @@ -325,32 +351,25 @@ And this to go from an i2c_client to a v4l2_subdev struct: struct v4l2_subdev *sd = i2c_get_clientdata(client); -Finally you need to make a command function to make driver->command() -call the right subdev_ops functions: - -static int subdev_command(struct i2c_client *client, unsigned cmd, void *arg) -{ - return v4l2_subdev_command(i2c_get_clientdata(client), cmd, arg); -} - -If driver->command is never used then you can leave this out. Eventually the -driver->command usage should be removed from v4l. - Make sure to call v4l2_device_unregister_subdev(sd) when the remove() callback is called. This will unregister the sub-device from the bridge driver. It is safe to call this even if the sub-device was never registered. +You need to do this because when the bridge driver destroys the i2c adapter +the remove() callbacks are called of the i2c devices on that adapter. +After that the corresponding v4l2_subdev structures are invalid, so they +have to be unregistered first. Calling v4l2_device_unregister_subdev(sd) +from the remove() callback ensures that this is always done correctly. + The bridge driver also has some helper functions it can use: -struct v4l2_subdev *sd = v4l2_i2c_new_subdev(adapter, "module_foo", "chipid", 0x36); +struct v4l2_subdev *sd = v4l2_i2c_new_subdev(v4l2_dev, adapter, + "module_foo", "chipid", 0x36); This loads the given module (can be NULL if no module needs to be loaded) and calls i2c_new_device() with the given i2c_adapter and chip/address arguments. -If all goes well, then it registers the subdev with the v4l2_device. It gets -the v4l2_device by calling i2c_get_adapdata(adapter), so you should make sure -that adapdata is set to v4l2_device when you setup the i2c_adapter in your -driver. +If all goes well, then it registers the subdev with the v4l2_device. You can also use v4l2_i2c_new_probed_subdev() which is very similar to v4l2_i2c_new_subdev(), except that it has an array of possible I2C addresses @@ -358,6 +377,14 @@ that it should probe. Internally it calls i2c_new_probed_device(). Both functions return NULL if something went wrong. +Note that the chipid you pass to v4l2_i2c_new_(probed_)subdev() is usually +the same as the module name. It allows you to specify a chip variant, e.g. +"saa7114" or "saa7115". In general though the i2c driver autodetects this. +The use of chipid is something that needs to be looked at more closely at a +later date. It differs between i2c drivers and as such can be confusing. +To see which chip variants are supported you can look in the i2c driver code +for the i2c_device_id table. This lists all the possibilities. + struct video_device ------------------- @@ -396,6 +423,15 @@ You should also set these fields: - ioctl_ops: if you use the v4l2_ioctl_ops to simplify ioctl maintenance (highly recommended to use this and it might become compulsory in the future!), then set this to your v4l2_ioctl_ops struct. +- parent: you only set this if v4l2_device was registered with NULL as + the parent device struct. This only happens in cases where one hardware + device has multiple PCI devices that all share the same v4l2_device core. + + The cx88 driver is an example of this: one core v4l2_device struct, but + it is used by both an raw video PCI device (cx8800) and a MPEG PCI device + (cx8802). Since the v4l2_device cannot be associated with a particular + PCI device it is setup without a parent device. But when the struct + video_device is setup you do know which parent PCI device to use. If you use v4l2_ioctl_ops, then you should set either .unlocked_ioctl or .ioctl to video_ioctl2 in your v4l2_file_operations struct. @@ -499,8 +535,8 @@ There are a few useful helper functions: You can set/get driver private data in the video_device struct using: -void *video_get_drvdata(struct video_device *dev); -void video_set_drvdata(struct video_device *dev, void *data); +void *video_get_drvdata(struct video_device *vdev); +void video_set_drvdata(struct video_device *vdev, void *data); Note that you can safely call video_set_drvdata() before calling video_register_device(). @@ -519,3 +555,103 @@ void *video_drvdata(struct file *file); You can go from a video_device struct to the v4l2_device struct using: struct v4l2_device *v4l2_dev = vdev->v4l2_dev; + +video buffer helper functions +----------------------------- + +The v4l2 core API provides a standard method for dealing with video +buffers. Those methods allow a driver to implement read(), mmap() and +overlay() on a consistent way. + +There are currently methods for using video buffers on devices that +supports DMA with scatter/gather method (videobuf-dma-sg), DMA with +linear access (videobuf-dma-contig), and vmalloced buffers, mostly +used on USB drivers (videobuf-vmalloc). + +Any driver using videobuf should provide operations (callbacks) for +four handlers: + +ops->buf_setup - calculates the size of the video buffers and avoid they + to waste more than some maximum limit of RAM; +ops->buf_prepare - fills the video buffer structs and calls + videobuf_iolock() to alloc and prepare mmaped memory; +ops->buf_queue - advices the driver that another buffer were + requested (by read() or by QBUF); +ops->buf_release - frees any buffer that were allocated. + +In order to use it, the driver need to have a code (generally called at +interrupt context) that will properly handle the buffer request lists, +announcing that a new buffer were filled. + +The irq handling code should handle the videobuf task lists, in order +to advice videobuf that a new frame were filled, in order to honor to a +request. The code is generally like this one: + if (list_empty(&dma_q->active)) + return; + + buf = list_entry(dma_q->active.next, struct vbuffer, vb.queue); + + if (!waitqueue_active(&buf->vb.done)) + return; + + /* Some logic to handle the buf may be needed here */ + + list_del(&buf->vb.queue); + do_gettimeofday(&buf->vb.ts); + wake_up(&buf->vb.done); + +Those are the videobuffer functions used on drivers, implemented on +videobuf-core: + +- Videobuf init functions + videobuf_queue_sg_init() + Initializes the videobuf infrastructure. This function should be + called before any other videobuf function on drivers that uses DMA + Scatter/Gather buffers. + + videobuf_queue_dma_contig_init + Initializes the videobuf infrastructure. This function should be + called before any other videobuf function on drivers that need DMA + contiguous buffers. + + videobuf_queue_vmalloc_init() + Initializes the videobuf infrastructure. This function should be + called before any other videobuf function on USB (and other drivers) + that need a vmalloced type of videobuf. + +- videobuf_iolock() + Prepares the videobuf memory for the proper method (read, mmap, overlay). + +- videobuf_queue_is_busy() + Checks if a videobuf is streaming. + +- videobuf_queue_cancel() + Stops video handling. + +- videobuf_mmap_free() + frees mmap buffers. + +- videobuf_stop() + Stops video handling, ends mmap and frees mmap and other buffers. + +- V4L2 api functions. Those functions correspond to VIDIOC_foo ioctls: + videobuf_reqbufs(), videobuf_querybuf(), videobuf_qbuf(), + videobuf_dqbuf(), videobuf_streamon(), videobuf_streamoff(). + +- V4L1 api function (corresponds to VIDIOCMBUF ioctl): + videobuf_cgmbuf() + This function is used to provide backward compatibility with V4L1 + API. + +- Some help functions for read()/poll() operations: + videobuf_read_stream() + For continuous stream read() + videobuf_read_one() + For snapshot read() + videobuf_poll_stream() + polling help function + +The better way to understand it is to take a look at vivi driver. One +of the main reasons for vivi is to be a videobuf usage example. the +vivi_thread_tick() does the task that the IRQ callback would do on PCI +drivers (or the irq callback on USB). diff --git a/Documentation/video4linux/v4lgrab.c b/Documentation/video4linux/v4lgrab.c index d6e70bef8ad0..05769cff1009 100644 --- a/Documentation/video4linux/v4lgrab.c +++ b/Documentation/video4linux/v4lgrab.c @@ -105,8 +105,8 @@ int main(int argc, char ** argv) struct video_picture vpic; unsigned char *buffer, *src; - int bpp = 24, r, g, b; - unsigned int i, src_depth; + int bpp = 24, r = 0, g = 0, b = 0; + unsigned int i, src_depth = 16; if (fd < 0) { perror(VIDEO_DEV); diff --git a/Documentation/video4linux/zr364xx.txt b/Documentation/video4linux/zr364xx.txt index 5c81e3ae6458..7f3d1955d214 100644 --- a/Documentation/video4linux/zr364xx.txt +++ b/Documentation/video4linux/zr364xx.txt @@ -65,3 +65,4 @@ Vendor Product Distributor Model 0x06d6 0x003b Trust Powerc@m 970Z 0x0a17 0x004e Pentax Optio 50 0x041e 0x405d Creative DiVi CAM 516 +0x08ca 0x2102 Aiptek DV T300 diff --git a/Documentation/vm/00-INDEX b/Documentation/vm/00-INDEX index 2131b00b63f6..2f77ced35df7 100644 --- a/Documentation/vm/00-INDEX +++ b/Documentation/vm/00-INDEX @@ -1,5 +1,7 @@ 00-INDEX - this file. +active_mm.txt + - An explanation from Linus about tsk->active_mm vs tsk->mm. balance - various information on memory balancing. hugetlbpage.txt diff --git a/Documentation/vm/active_mm.txt b/Documentation/vm/active_mm.txt new file mode 100644 index 000000000000..4ee1f643d897 --- /dev/null +++ b/Documentation/vm/active_mm.txt @@ -0,0 +1,83 @@ +List: linux-kernel +Subject: Re: active_mm +From: Linus Torvalds <torvalds () transmeta ! com> +Date: 1999-07-30 21:36:24 + +Cc'd to linux-kernel, because I don't write explanations all that often, +and when I do I feel better about more people reading them. + +On Fri, 30 Jul 1999, David Mosberger wrote: +> +> Is there a brief description someplace on how "mm" vs. "active_mm" in +> the task_struct are supposed to be used? (My apologies if this was +> discussed on the mailing lists---I just returned from vacation and +> wasn't able to follow linux-kernel for a while). + +Basically, the new setup is: + + - we have "real address spaces" and "anonymous address spaces". The + difference is that an anonymous address space doesn't care about the + user-level page tables at all, so when we do a context switch into an + anonymous address space we just leave the previous address space + active. + + The obvious use for a "anonymous address space" is any thread that + doesn't need any user mappings - all kernel threads basically fall into + this category, but even "real" threads can temporarily say that for + some amount of time they are not going to be interested in user space, + and that the scheduler might as well try to avoid wasting time on + switching the VM state around. Currently only the old-style bdflush + sync does that. + + - "tsk->mm" points to the "real address space". For an anonymous process, + tsk->mm will be NULL, for the logical reason that an anonymous process + really doesn't _have_ a real address space at all. + + - however, we obviously need to keep track of which address space we + "stole" for such an anonymous user. For that, we have "tsk->active_mm", + which shows what the currently active address space is. + + The rule is that for a process with a real address space (ie tsk->mm is + non-NULL) the active_mm obviously always has to be the same as the real + one. + + For a anonymous process, tsk->mm == NULL, and tsk->active_mm is the + "borrowed" mm while the anonymous process is running. When the + anonymous process gets scheduled away, the borrowed address space is + returned and cleared. + +To support all that, the "struct mm_struct" now has two counters: a +"mm_users" counter that is how many "real address space users" there are, +and a "mm_count" counter that is the number of "lazy" users (ie anonymous +users) plus one if there are any real users. + +Usually there is at least one real user, but it could be that the real +user exited on another CPU while a lazy user was still active, so you do +actually get cases where you have a address space that is _only_ used by +lazy users. That is often a short-lived state, because once that thread +gets scheduled away in favour of a real thread, the "zombie" mm gets +released because "mm_users" becomes zero. + +Also, a new rule is that _nobody_ ever has "init_mm" as a real MM any +more. "init_mm" should be considered just a "lazy context when no other +context is available", and in fact it is mainly used just at bootup when +no real VM has yet been created. So code that used to check + + if (current->mm == &init_mm) + +should generally just do + + if (!current->mm) + +instead (which makes more sense anyway - the test is basically one of "do +we have a user context", and is generally done by the page fault handler +and things like that). + +Anyway, I put a pre-patch-2.3.13-1 on ftp.kernel.org just a moment ago, +because it slightly changes the interfaces to accomodate the alpha (who +would have thought it, but the alpha actually ends up having one of the +ugliest context switch codes - unlike the other architectures where the MM +and register state is separate, the alpha PALcode joins the two, and you +need to switch both together). + +(From http://marc.info/?l=linux-kernel&m=93337278602211&w=2) diff --git a/Documentation/vm/numa_memory_policy.txt b/Documentation/vm/numa_memory_policy.txt index 6aaaeb38730c..be45dbb9d7f2 100644 --- a/Documentation/vm/numa_memory_policy.txt +++ b/Documentation/vm/numa_memory_policy.txt @@ -8,7 +8,8 @@ The current memory policy support was added to Linux 2.6 around May 2004. This document attempts to describe the concepts and APIs of the 2.6 memory policy support. -Memory policies should not be confused with cpusets (Documentation/cpusets.txt) +Memory policies should not be confused with cpusets +(Documentation/cgroups/cpusets.txt) which is an administrative mechanism for restricting the nodes from which memory may be allocated by a set of processes. Memory policies are a programming interface that a NUMA-aware application can take advantage of. When diff --git a/Documentation/vm/page_migration b/Documentation/vm/page_migration index d5fdfd34bbaf..6513fe2d90b8 100644 --- a/Documentation/vm/page_migration +++ b/Documentation/vm/page_migration @@ -37,7 +37,8 @@ locations. Larger installations usually partition the system using cpusets into sections of nodes. Paul Jackson has equipped cpusets with the ability to -move pages when a task is moved to another cpuset (See ../cpusets.txt). +move pages when a task is moved to another cpuset (See +Documentation/cgroups/cpusets.txt). Cpusets allows the automation of process locality. If a task is moved to a new cpuset then also all its pages are moved with it so that the performance of the process does not sink dramatically. Also the pages diff --git a/Documentation/vm/unevictable-lru.txt b/Documentation/vm/unevictable-lru.txt index 0706a7282a8c..2d70d0d95108 100644 --- a/Documentation/vm/unevictable-lru.txt +++ b/Documentation/vm/unevictable-lru.txt @@ -1,588 +1,691 @@ - -This document describes the Linux memory management "Unevictable LRU" -infrastructure and the use of this infrastructure to manage several types -of "unevictable" pages. The document attempts to provide the overall -rationale behind this mechanism and the rationale for some of the design -decisions that drove the implementation. The latter design rationale is -discussed in the context of an implementation description. Admittedly, one -can obtain the implementation details--the "what does it do?"--by reading the -code. One hopes that the descriptions below add value by provide the answer -to "why does it do that?". - -Unevictable LRU Infrastructure: - -The Unevictable LRU adds an additional LRU list to track unevictable pages -and to hide these pages from vmscan. This mechanism is based on a patch by -Larry Woodman of Red Hat to address several scalability problems with page + ============================== + UNEVICTABLE LRU INFRASTRUCTURE + ============================== + +======== +CONTENTS +======== + + (*) The Unevictable LRU + + - The unevictable page list. + - Memory control group interaction. + - Marking address spaces unevictable. + - Detecting Unevictable Pages. + - vmscan's handling of unevictable pages. + + (*) mlock()'d pages. + + - History. + - Basic management. + - mlock()/mlockall() system call handling. + - Filtering special vmas. + - munlock()/munlockall() system call handling. + - Migrating mlocked pages. + - mmap(MAP_LOCKED) system call handling. + - munmap()/exit()/exec() system call handling. + - try_to_unmap(). + - try_to_munlock() reverse map scan. + - Page reclaim in shrink_*_list(). + + +============ +INTRODUCTION +============ + +This document describes the Linux memory manager's "Unevictable LRU" +infrastructure and the use of this to manage several types of "unevictable" +pages. + +The document attempts to provide the overall rationale behind this mechanism +and the rationale for some of the design decisions that drove the +implementation. The latter design rationale is discussed in the context of an +implementation description. Admittedly, one can obtain the implementation +details - the "what does it do?" - by reading the code. One hopes that the +descriptions below add value by provide the answer to "why does it do that?". + + +=================== +THE UNEVICTABLE LRU +=================== + +The Unevictable LRU facility adds an additional LRU list to track unevictable +pages and to hide these pages from vmscan. This mechanism is based on a patch +by Larry Woodman of Red Hat to address several scalability problems with page reclaim in Linux. The problems have been observed at customer sites on large -memory x86_64 systems. For example, a non-numal x86_64 platform with 128GB -of main memory will have over 32 million 4k pages in a single zone. When a -large fraction of these pages are not evictable for any reason [see below], -vmscan will spend a lot of time scanning the LRU lists looking for the small -fraction of pages that are evictable. This can result in a situation where -all cpus are spending 100% of their time in vmscan for hours or days on end, -with the system completely unresponsive. - -The Unevictable LRU infrastructure addresses the following classes of -unevictable pages: - -+ page owned by ramfs -+ page mapped into SHM_LOCKed shared memory regions -+ page mapped into VM_LOCKED [mlock()ed] vmas - -The infrastructure might be able to handle other conditions that make pages +memory x86_64 systems. + +To illustrate this with an example, a non-NUMA x86_64 platform with 128GB of +main memory will have over 32 million 4k pages in a single zone. When a large +fraction of these pages are not evictable for any reason [see below], vmscan +will spend a lot of time scanning the LRU lists looking for the small fraction +of pages that are evictable. This can result in a situation where all CPUs are +spending 100% of their time in vmscan for hours or days on end, with the system +completely unresponsive. + +The unevictable list addresses the following classes of unevictable pages: + + (*) Those owned by ramfs. + + (*) Those mapped into SHM_LOCK'd shared memory regions. + + (*) Those mapped into VM_LOCKED [mlock()ed] VMAs. + +The infrastructure may also be able to handle other conditions that make pages unevictable, either by definition or by circumstance, in the future. -The Unevictable LRU List +THE UNEVICTABLE PAGE LIST +------------------------- The Unevictable LRU infrastructure consists of an additional, per-zone, LRU list called the "unevictable" list and an associated page flag, PG_unevictable, to -indicate that the page is being managed on the unevictable list. The -PG_unevictable flag is analogous to, and mutually exclusive with, the PG_active -flag in that it indicates on which LRU list a page resides when PG_lru is set. -The unevictable LRU list is source configurable based on the UNEVICTABLE_LRU -Kconfig option. +indicate that the page is being managed on the unevictable list. + +The PG_unevictable flag is analogous to, and mutually exclusive with, the +PG_active flag in that it indicates on which LRU list a page resides when +PG_lru is set. The unevictable list is compile-time configurable based on the +UNEVICTABLE_LRU Kconfig option. The Unevictable LRU infrastructure maintains unevictable pages on an additional LRU list for a few reasons: -1) We get to "treat unevictable pages just like we treat other pages in the - system, which means we get to use the same code to manipulate them, the - same code to isolate them (for migrate, etc.), the same code to keep track - of the statistics, etc..." [Rik van Riel] + (1) We get to "treat unevictable pages just like we treat other pages in the + system - which means we get to use the same code to manipulate them, the + same code to isolate them (for migrate, etc.), the same code to keep track + of the statistics, etc..." [Rik van Riel] + + (2) We want to be able to migrate unevictable pages between nodes for memory + defragmentation, workload management and memory hotplug. The linux kernel + can only migrate pages that it can successfully isolate from the LRU + lists. If we were to maintain pages elsewhere than on an LRU-like list, + where they can be found by isolate_lru_page(), we would prevent their + migration, unless we reworked migration code to find the unevictable pages + itself. -2) We want to be able to migrate unevictable pages between nodes--for memory - defragmentation, workload management and memory hotplug. The linux kernel - can only migrate pages that it can successfully isolate from the lru lists. - If we were to maintain pages elsewise than on an lru-like list, where they - can be found by isolate_lru_page(), we would prevent their migration, unless - we reworked migration code to find the unevictable pages. +The unevictable list does not differentiate between file-backed and anonymous, +swap-backed pages. This differentiation is only important while the pages are, +in fact, evictable. -The unevictable LRU list does not differentiate between file backed and swap -backed [anon] pages. This differentiation is only important while the pages -are, in fact, evictable. +The unevictable list benefits from the "arrayification" of the per-zone LRU +lists and statistics originally proposed and posted by Christoph Lameter. -The unevictable LRU list benefits from the "arrayification" of the per-zone -LRU lists and statistics originally proposed and posted by Christoph Lameter. +The unevictable list does not use the LRU pagevec mechanism. Rather, +unevictable pages are placed directly on the page's zone's unevictable list +under the zone lru_lock. This allows us to prevent the stranding of pages on +the unevictable list when one task has the page isolated from the LRU and other +tasks are changing the "evictability" state of the page. -The unevictable list does not use the lru pagevec mechanism. Rather, -unevictable pages are placed directly on the page's zone's unevictable -list under the zone lru_lock. The reason for this is to prevent stranding -of pages on the unevictable list when one task has the page isolated from the -lru and other tasks are changing the "evictability" state of the page. +MEMORY CONTROL GROUP INTERACTION +-------------------------------- -Unevictable LRU and Memory Controller Interaction +The unevictable LRU facility interacts with the memory control group [aka +memory controller; see Documentation/cgroups/memory.txt] by extending the +lru_list enum. + +The memory controller data structure automatically gets a per-zone unevictable +list as a result of the "arrayification" of the per-zone LRU lists (one per +lru_list enum element). The memory controller tracks the movement of pages to +and from the unevictable list. -The memory controller data structure automatically gets a per zone unevictable -lru list as a result of the "arrayification" of the per-zone LRU lists. The -memory controller tracks the movement of pages to and from the unevictable list. When a memory control group comes under memory pressure, the controller will not attempt to reclaim pages on the unevictable list. This has a couple of -effects. Because the pages are "hidden" from reclaim on the unevictable list, -the reclaim process can be more efficient, dealing only with pages that have -a chance of being reclaimed. On the other hand, if too many of the pages -charged to the control group are unevictable, the evictable portion of the -working set of the tasks in the control group may not fit into the available -memory. This can cause the control group to thrash or to oom-kill tasks. - - -Unevictable LRU: Detecting Unevictable Pages - -The function page_evictable(page, vma) in vmscan.c determines whether a -page is evictable or not. For ramfs pages and pages in SHM_LOCKed regions, -page_evictable() tests a new address space flag, AS_UNEVICTABLE, in the page's -address space using a wrapper function. Wrapper functions are used to set, -clear and test the flag to reduce the requirement for #ifdef's throughout the -source code. AS_UNEVICTABLE is set on ramfs inode/mapping when it is created. -This flag remains for the life of the inode. - -For shared memory regions, AS_UNEVICTABLE is set when an application -successfully SHM_LOCKs the region and is removed when the region is -SHM_UNLOCKed. Note that shmctl(SHM_LOCK, ...) does not populate the page -tables for the region as does, for example, mlock(). So, we make no special -effort to push any pages in the SHM_LOCKed region to the unevictable list. -Vmscan will do this when/if it encounters the pages during reclaim. On -SHM_UNLOCK, shmctl() scans the pages in the region and "rescues" them from the -unevictable list if no other condition keeps them unevictable. If a SHM_LOCKed -region is destroyed, the pages are also "rescued" from the unevictable list in -the process of freeing them. - -page_evictable() detects mlock()ed pages by testing an additional page flag, -PG_mlocked via the PageMlocked() wrapper. If the page is NOT mlocked, and a -non-NULL vma is supplied, page_evictable() will check whether the vma is +effects: + + (1) Because the pages are "hidden" from reclaim on the unevictable list, the + reclaim process can be more efficient, dealing only with pages that have a + chance of being reclaimed. + + (2) On the other hand, if too many of the pages charged to the control group + are unevictable, the evictable portion of the working set of the tasks in + the control group may not fit into the available memory. This can cause + the control group to thrash or to OOM-kill tasks. + + +MARKING ADDRESS SPACES UNEVICTABLE +---------------------------------- + +For facilities such as ramfs none of the pages attached to the address space +may be evicted. To prevent eviction of any such pages, the AS_UNEVICTABLE +address space flag is provided, and this can be manipulated by a filesystem +using a number of wrapper functions: + + (*) void mapping_set_unevictable(struct address_space *mapping); + + Mark the address space as being completely unevictable. + + (*) void mapping_clear_unevictable(struct address_space *mapping); + + Mark the address space as being evictable. + + (*) int mapping_unevictable(struct address_space *mapping); + + Query the address space, and return true if it is completely + unevictable. + +These are currently used in two places in the kernel: + + (1) By ramfs to mark the address spaces of its inodes when they are created, + and this mark remains for the life of the inode. + + (2) By SYSV SHM to mark SHM_LOCK'd address spaces until SHM_UNLOCK is called. + + Note that SHM_LOCK is not required to page in the locked pages if they're + swapped out; the application must touch the pages manually if it wants to + ensure they're in memory. + + +DETECTING UNEVICTABLE PAGES +--------------------------- + +The function page_evictable() in vmscan.c determines whether a page is +evictable or not using the query function outlined above [see section "Marking +address spaces unevictable"] to check the AS_UNEVICTABLE flag. + +For address spaces that are so marked after being populated (as SHM regions +might be), the lock action (eg: SHM_LOCK) can be lazy, and need not populate +the page tables for the region as does, for example, mlock(), nor need it make +any special effort to push any pages in the SHM_LOCK'd area to the unevictable +list. Instead, vmscan will do this if and when it encounters the pages during +a reclamation scan. + +On an unlock action (such as SHM_UNLOCK), the unlocker (eg: shmctl()) must scan +the pages in the region and "rescue" them from the unevictable list if no other +condition is keeping them unevictable. If an unevictable region is destroyed, +the pages are also "rescued" from the unevictable list in the process of +freeing them. + +page_evictable() also checks for mlocked pages by testing an additional page +flag, PG_mlocked (as wrapped by PageMlocked()). If the page is NOT mlocked, +and a non-NULL VMA is supplied, page_evictable() will check whether the VMA is VM_LOCKED via is_mlocked_vma(). is_mlocked_vma() will SetPageMlocked() and update the appropriate statistics if the vma is VM_LOCKED. This method allows efficient "culling" of pages in the fault path that are being faulted in to -VM_LOCKED vmas. +VM_LOCKED VMAs. -Unevictable Pages and Vmscan [shrink_*_list()] +VMSCAN'S HANDLING OF UNEVICTABLE PAGES +-------------------------------------- If unevictable pages are culled in the fault path, or moved to the unevictable -list at mlock() or mmap() time, vmscan will never encounter the pages until -they have become evictable again, for example, via munlock() and have been -"rescued" from the unevictable list. However, there may be situations where we -decide, for the sake of expediency, to leave a unevictable page on one of the -regular active/inactive LRU lists for vmscan to deal with. Vmscan checks for -such pages in all of the shrink_{active|inactive|page}_list() functions and -will "cull" such pages that it encounters--that is, it diverts those pages to -the unevictable list for the zone being scanned. - -There may be situations where a page is mapped into a VM_LOCKED vma, but the -page is not marked as PageMlocked. Such pages will make it all the way to +list at mlock() or mmap() time, vmscan will not encounter the pages until they +have become evictable again (via munlock() for example) and have been "rescued" +from the unevictable list. However, there may be situations where we decide, +for the sake of expediency, to leave a unevictable page on one of the regular +active/inactive LRU lists for vmscan to deal with. vmscan checks for such +pages in all of the shrink_{active|inactive|page}_list() functions and will +"cull" such pages that it encounters: that is, it diverts those pages to the +unevictable list for the zone being scanned. + +There may be situations where a page is mapped into a VM_LOCKED VMA, but the +page is not marked as PG_mlocked. Such pages will make it all the way to shrink_page_list() where they will be detected when vmscan walks the reverse -map in try_to_unmap(). If try_to_unmap() returns SWAP_MLOCK, shrink_page_list() -will cull the page at that point. +map in try_to_unmap(). If try_to_unmap() returns SWAP_MLOCK, +shrink_page_list() will cull the page at that point. -To "cull" an unevictable page, vmscan simply puts the page back on the lru -list using putback_lru_page()--the inverse operation to isolate_lru_page()-- -after dropping the page lock. Because the condition which makes the page -unevictable may change once the page is unlocked, putback_lru_page() will -recheck the unevictable state of a page that it places on the unevictable lru -list. If the page has become unevictable, putback_lru_page() removes it from -the list and retries, including the page_unevictable() test. Because such a -race is a rare event and movement of pages onto the unevictable list should be -rare, these extra evictabilty checks should not occur in the majority of calls -to putback_lru_page(). +To "cull" an unevictable page, vmscan simply puts the page back on the LRU list +using putback_lru_page() - the inverse operation to isolate_lru_page() - after +dropping the page lock. Because the condition which makes the page unevictable +may change once the page is unlocked, putback_lru_page() will recheck the +unevictable state of a page that it places on the unevictable list. If the +page has become unevictable, putback_lru_page() removes it from the list and +retries, including the page_unevictable() test. Because such a race is a rare +event and movement of pages onto the unevictable list should be rare, these +extra evictabilty checks should not occur in the majority of calls to +putback_lru_page(). -Mlocked Page: Prior Work +============= +MLOCKED PAGES +============= -The "Unevictable Mlocked Pages" infrastructure is based on work originally +The unevictable page list is also useful for mlock(), in addition to ramfs and +SYSV SHM. Note that mlock() is only available in CONFIG_MMU=y situations; in +NOMMU situations, all mappings are effectively mlocked. + + +HISTORY +------- + +The "Unevictable mlocked Pages" infrastructure is based on work originally posted by Nick Piggin in an RFC patch entitled "mm: mlocked pages off LRU". -Nick posted his patch as an alternative to a patch posted by Christoph -Lameter to achieve the same objective--hiding mlocked pages from vmscan. -In Nick's patch, he used one of the struct page lru list link fields as a count -of VM_LOCKED vmas that map the page. This use of the link field for a count -prevented the management of the pages on an LRU list. Thus, mlocked pages were -not migratable as isolate_lru_page() could not find them and the lru list link -field was not available to the migration subsystem. Nick resolved this by -putting mlocked pages back on the lru list before attempting to isolate them, -thus abandoning the count of VM_LOCKED vmas. When Nick's patch was integrated -with the Unevictable LRU work, the count was replaced by walking the reverse -map to determine whether any VM_LOCKED vmas mapped the page. More on this -below. - - -Mlocked Pages: Basic Management - -Mlocked pages--pages mapped into a VM_LOCKED vma--represent one class of -unevictable pages. When such a page has been "noticed" by the memory -management subsystem, the page is marked with the PG_mlocked [PageMlocked()] -flag. A PageMlocked() page will be placed on the unevictable LRU list when -it is added to the LRU. Pages can be "noticed" by memory management in -several places: - -1) in the mlock()/mlockall() system call handlers. -2) in the mmap() system call handler when mmap()ing a region with the - MAP_LOCKED flag, or mmap()ing a region in a task that has called - mlockall() with the MCL_FUTURE flag. Both of these conditions result - in the VM_LOCKED flag being set for the vma. -3) in the fault path, if mlocked pages are "culled" in the fault path, - and when a VM_LOCKED stack segment is expanded. -4) as mentioned above, in vmscan:shrink_page_list() when attempting to - reclaim a page in a VM_LOCKED vma via try_to_unmap(). - -Mlocked pages become unlocked and rescued from the unevictable list when: - -1) mapped in a range unlocked via the munlock()/munlockall() system calls. -2) munmapped() out of the last VM_LOCKED vma that maps the page, including - unmapping at task exit. -3) when the page is truncated from the last VM_LOCKED vma of an mmap()ed file. -4) before a page is COWed in a VM_LOCKED vma. - - -Mlocked Pages: mlock()/mlockall() System Call Handling +Nick posted his patch as an alternative to a patch posted by Christoph Lameter +to achieve the same objective: hiding mlocked pages from vmscan. + +In Nick's patch, he used one of the struct page LRU list link fields as a count +of VM_LOCKED VMAs that map the page. This use of the link field for a count +prevented the management of the pages on an LRU list, and thus mlocked pages +were not migratable as isolate_lru_page() could not find them, and the LRU list +link field was not available to the migration subsystem. + +Nick resolved this by putting mlocked pages back on the lru list before +attempting to isolate them, thus abandoning the count of VM_LOCKED VMAs. When +Nick's patch was integrated with the Unevictable LRU work, the count was +replaced by walking the reverse map to determine whether any VM_LOCKED VMAs +mapped the page. More on this below. + + +BASIC MANAGEMENT +---------------- + +mlocked pages - pages mapped into a VM_LOCKED VMA - are a class of unevictable +pages. When such a page has been "noticed" by the memory management subsystem, +the page is marked with the PG_mlocked flag. This can be manipulated using the +PageMlocked() functions. + +A PG_mlocked page will be placed on the unevictable list when it is added to +the LRU. Such pages can be "noticed" by memory management in several places: + + (1) in the mlock()/mlockall() system call handlers; + + (2) in the mmap() system call handler when mmapping a region with the + MAP_LOCKED flag; + + (3) mmapping a region in a task that has called mlockall() with the MCL_FUTURE + flag + + (4) in the fault path, if mlocked pages are "culled" in the fault path, + and when a VM_LOCKED stack segment is expanded; or + + (5) as mentioned above, in vmscan:shrink_page_list() when attempting to + reclaim a page in a VM_LOCKED VMA via try_to_unmap() + +all of which result in the VM_LOCKED flag being set for the VMA if it doesn't +already have it set. + +mlocked pages become unlocked and rescued from the unevictable list when: + + (1) mapped in a range unlocked via the munlock()/munlockall() system calls; + + (2) munmap()'d out of the last VM_LOCKED VMA that maps the page, including + unmapping at task exit; + + (3) when the page is truncated from the last VM_LOCKED VMA of an mmapped file; + or + + (4) before a page is COW'd in a VM_LOCKED VMA. + + +mlock()/mlockall() SYSTEM CALL HANDLING +--------------------------------------- Both [do_]mlock() and [do_]mlockall() system call handlers call mlock_fixup() -for each vma in the range specified by the call. In the case of mlockall(), +for each VMA in the range specified by the call. In the case of mlockall(), this is the entire active address space of the task. Note that mlock_fixup() -is used for both mlock()ing and munlock()ing a range of memory. A call to -mlock() an already VM_LOCKED vma, or to munlock() a vma that is not VM_LOCKED -is treated as a no-op--mlock_fixup() simply returns. - -If the vma passes some filtering described in "Mlocked Pages: Filtering Vmas" -below, mlock_fixup() will attempt to merge the vma with its neighbors or split -off a subset of the vma if the range does not cover the entire vma. Once the -vma has been merged or split or neither, mlock_fixup() will call -__mlock_vma_pages_range() to fault in the pages via get_user_pages() and -to mark the pages as mlocked via mlock_vma_page(). - -Note that the vma being mlocked might be mapped with PROT_NONE. In this case, -get_user_pages() will be unable to fault in the pages. That's OK. If pages -do end up getting faulted into this VM_LOCKED vma, we'll handle them in the +is used for both mlocking and munlocking a range of memory. A call to mlock() +an already VM_LOCKED VMA, or to munlock() a VMA that is not VM_LOCKED is +treated as a no-op, and mlock_fixup() simply returns. + +If the VMA passes some filtering as described in "Filtering Special Vmas" +below, mlock_fixup() will attempt to merge the VMA with its neighbors or split +off a subset of the VMA if the range does not cover the entire VMA. Once the +VMA has been merged or split or neither, mlock_fixup() will call +__mlock_vma_pages_range() to fault in the pages via get_user_pages() and to +mark the pages as mlocked via mlock_vma_page(). + +Note that the VMA being mlocked might be mapped with PROT_NONE. In this case, +get_user_pages() will be unable to fault in the pages. That's okay. If pages +do end up getting faulted into this VM_LOCKED VMA, we'll handle them in the fault path or in vmscan. Also note that a page returned by get_user_pages() could be truncated or -migrated out from under us, while we're trying to mlock it. To detect -this, __mlock_vma_pages_range() tests the page_mapping after acquiring -the page lock. If the page is still associated with its mapping, we'll -go ahead and call mlock_vma_page(). If the mapping is gone, we just -unlock the page and move on. Worse case, this results in page mapped -in a VM_LOCKED vma remaining on a normal LRU list without being -PageMlocked(). Again, vmscan will detect and cull such pages. - -mlock_vma_page(), called with the page locked [N.B., not "mlocked"], will -TestSetPageMlocked() for each page returned by get_user_pages(). We use -TestSetPageMlocked() because the page might already be mlocked by another -task/vma and we don't want to do extra work. We especially do not want to -count an mlocked page more than once in the statistics. If the page was -already mlocked, mlock_vma_page() is done. +migrated out from under us, while we're trying to mlock it. To detect this, +__mlock_vma_pages_range() checks page_mapping() after acquiring the page lock. +If the page is still associated with its mapping, we'll go ahead and call +mlock_vma_page(). If the mapping is gone, we just unlock the page and move on. +In the worst case, this will result in a page mapped in a VM_LOCKED VMA +remaining on a normal LRU list without being PageMlocked(). Again, vmscan will +detect and cull such pages. + +mlock_vma_page() will call TestSetPageMlocked() for each page returned by +get_user_pages(). We use TestSetPageMlocked() because the page might already +be mlocked by another task/VMA and we don't want to do extra work. We +especially do not want to count an mlocked page more than once in the +statistics. If the page was already mlocked, mlock_vma_page() need do nothing +more. If the page was NOT already mlocked, mlock_vma_page() attempts to isolate the page from the LRU, as it is likely on the appropriate active or inactive list -at that time. If the isolate_lru_page() succeeds, mlock_vma_page() will -putback the page--putback_lru_page()--which will notice that the page is now -mlocked and divert the page to the zone's unevictable LRU list. If +at that time. If the isolate_lru_page() succeeds, mlock_vma_page() will put +back the page - by calling putback_lru_page() - which will notice that the page +is now mlocked and divert the page to the zone's unevictable list. If mlock_vma_page() is unable to isolate the page from the LRU, vmscan will handle -it later if/when it attempts to reclaim the page. +it later if and when it attempts to reclaim the page. -Mlocked Pages: Filtering Special Vmas +FILTERING SPECIAL VMAS +---------------------- -mlock_fixup() filters several classes of "special" vmas: +mlock_fixup() filters several classes of "special" VMAs: -1) vmas with VM_IO|VM_PFNMAP set are skipped entirely. The pages behind +1) VMAs with VM_IO or VM_PFNMAP set are skipped entirely. The pages behind these mappings are inherently pinned, so we don't need to mark them as - mlocked. In any case, most of the pages have no struct page in which to - so mark the page. Because of this, get_user_pages() will fail for these - vmas, so there is no sense in attempting to visit them. - -2) vmas mapping hugetlbfs page are already effectively pinned into memory. - We don't need nor want to mlock() these pages. However, to preserve the - prior behavior of mlock()--before the unevictable/mlock changes-- - mlock_fixup() will call make_pages_present() in the hugetlbfs vma range - to allocate the huge pages and populate the ptes. - -3) vmas with VM_DONTEXPAND|VM_RESERVED are generally user space mappings of - kernel pages, such as the vdso page, relay channel pages, etc. These pages + mlocked. In any case, most of the pages have no struct page in which to so + mark the page. Because of this, get_user_pages() will fail for these VMAs, + so there is no sense in attempting to visit them. + +2) VMAs mapping hugetlbfs page are already effectively pinned into memory. We + neither need nor want to mlock() these pages. However, to preserve the + prior behavior of mlock() - before the unevictable/mlock changes - + mlock_fixup() will call make_pages_present() in the hugetlbfs VMA range to + allocate the huge pages and populate the ptes. + +3) VMAs with VM_DONTEXPAND or VM_RESERVED are generally userspace mappings of + kernel pages, such as the VDSO page, relay channel pages, etc. These pages are inherently unevictable and are not managed on the LRU lists. - mlock_fixup() treats these vmas the same as hugetlbfs vmas. It calls + mlock_fixup() treats these VMAs the same as hugetlbfs VMAs. It calls make_pages_present() to populate the ptes. -Note that for all of these special vmas, mlock_fixup() does not set the +Note that for all of these special VMAs, mlock_fixup() does not set the VM_LOCKED flag. Therefore, we won't have to deal with them later during -munlock() or munmap()--for example, at task exit. Neither does mlock_fixup() -account these vmas against the task's "locked_vm". - -Mlocked Pages: Downgrading the Mmap Semaphore. - -mlock_fixup() must be called with the mmap semaphore held for write, because -it may have to merge or split vmas. However, mlocking a large region of -memory can take a long time--especially if vmscan must reclaim pages to -satisfy the regions requirements. Faulting in a large region with the mmap -semaphore held for write can hold off other faults on the address space, in -the case of a multi-threaded task. It can also hold off scans of the task's -address space via /proc. While testing under heavy load, it was observed that -the ps(1) command could be held off for many minutes while a large segment was -mlock()ed down. - -To address this issue, and to make the system more responsive during mlock()ing -of large segments, mlock_fixup() downgrades the mmap semaphore to read mode -during the call to __mlock_vma_pages_range(). This works fine. However, the -callers of mlock_fixup() expect the semaphore to be returned in write mode. -So, mlock_fixup() "upgrades" the semphore to write mode. Linux does not -support an atomic upgrade_sem() call, so mlock_fixup() must drop the semaphore -and reacquire it in write mode. In a multi-threaded task, it is possible for -the task memory map to change while the semaphore is dropped. Therefore, -mlock_fixup() looks up the vma at the range start address after reacquiring -the semaphore in write mode and verifies that it still covers the original -range. If not, mlock_fixup() returns an error [-EAGAIN]. All callers of -mlock_fixup() have been changed to deal with this new error condition. - -Note: when munlocking a region, all of the pages should already be resident-- -unless we have racing threads mlocking() and munlocking() regions. So, -unlocking should not have to wait for page allocations nor faults of any kind. -Therefore mlock_fixup() does not downgrade the semaphore for munlock(). - - -Mlocked Pages: munlock()/munlockall() System Call Handling - -The munlock() and munlockall() system calls are handled by the same functions-- -do_mlock[all]()--as the mlock() and mlockall() system calls with the unlock -vs lock operation indicated by an argument. So, these system calls are also -handled by mlock_fixup(). Again, if called for an already munlock()ed vma, -mlock_fixup() simply returns. Because of the vma filtering discussed above, -VM_LOCKED will not be set in any "special" vmas. So, these vmas will be +munlock(), munmap() or task exit. Neither does mlock_fixup() account these +VMAs against the task's "locked_vm". + + +munlock()/munlockall() SYSTEM CALL HANDLING +------------------------------------------- + +The munlock() and munlockall() system calls are handled by the same functions - +do_mlock[all]() - as the mlock() and mlockall() system calls with the unlock vs +lock operation indicated by an argument. So, these system calls are also +handled by mlock_fixup(). Again, if called for an already munlocked VMA, +mlock_fixup() simply returns. Because of the VMA filtering discussed above, +VM_LOCKED will not be set in any "special" VMAs. So, these VMAs will be ignored for munlock. -If the vma is VM_LOCKED, mlock_fixup() again attempts to merge or split off -the specified range. The range is then munlocked via the function -__mlock_vma_pages_range()--the same function used to mlock a vma range-- +If the VMA is VM_LOCKED, mlock_fixup() again attempts to merge or split off the +specified range. The range is then munlocked via the function +__mlock_vma_pages_range() - the same function used to mlock a VMA range - passing a flag to indicate that munlock() is being performed. -Because the vma access protections could have been changed to PROT_NONE after +Because the VMA access protections could have been changed to PROT_NONE after faulting in and mlocking pages, get_user_pages() was unreliable for visiting -these pages for munlocking. Because we don't want to leave pages mlocked(), +these pages for munlocking. Because we don't want to leave pages mlocked, get_user_pages() was enhanced to accept a flag to ignore the permissions when -fetching the pages--all of which should be resident as a result of previous -mlock()ing. +fetching the pages - all of which should be resident as a result of previous +mlocking. For munlock(), __mlock_vma_pages_range() unlocks individual pages by calling munlock_vma_page(). munlock_vma_page() unconditionally clears the PG_mlocked -flag using TestClearPageMlocked(). As with mlock_vma_page(), munlock_vma_page() -use the Test*PageMlocked() function to handle the case where the page might -have already been unlocked by another task. If the page was mlocked, -munlock_vma_page() updates that zone statistics for the number of mlocked -pages. Note, however, that at this point we haven't checked whether the page -is mapped by other VM_LOCKED vmas. - -We can't call try_to_munlock(), the function that walks the reverse map to check -for other VM_LOCKED vmas, without first isolating the page from the LRU. +flag using TestClearPageMlocked(). As with mlock_vma_page(), +munlock_vma_page() use the Test*PageMlocked() function to handle the case where +the page might have already been unlocked by another task. If the page was +mlocked, munlock_vma_page() updates that zone statistics for the number of +mlocked pages. Note, however, that at this point we haven't checked whether +the page is mapped by other VM_LOCKED VMAs. + +We can't call try_to_munlock(), the function that walks the reverse map to +check for other VM_LOCKED VMAs, without first isolating the page from the LRU. try_to_munlock() is a variant of try_to_unmap() and thus requires that the page -not be on an lru list. [More on these below.] However, the call to -isolate_lru_page() could fail, in which case we couldn't try_to_munlock(). -So, we go ahead and clear PG_mlocked up front, as this might be the only chance -we have. If we can successfully isolate the page, we go ahead and +not be on an LRU list [more on these below]. However, the call to +isolate_lru_page() could fail, in which case we couldn't try_to_munlock(). So, +we go ahead and clear PG_mlocked up front, as this might be the only chance we +have. If we can successfully isolate the page, we go ahead and try_to_munlock(), which will restore the PG_mlocked flag and update the zone -page statistics if it finds another vma holding the page mlocked. If we fail +page statistics if it finds another VMA holding the page mlocked. If we fail to isolate the page, we'll have left a potentially mlocked page on the LRU. -This is fine, because we'll catch it later when/if vmscan tries to reclaim the -page. This should be relatively rare. - -Mlocked Pages: Migrating Them... - -A page that is being migrated has been isolated from the lru lists and is -held locked across unmapping of the page, updating the page's mapping -[address_space] entry and copying the contents and state, until the -page table entry has been replaced with an entry that refers to the new -page. Linux supports migration of mlocked pages and other unevictable -pages. This involves simply moving the PageMlocked and PageUnevictable states -from the old page to the new page. - -Note that page migration can race with mlocking or munlocking of the same -page. This has been discussed from the mlock/munlock perspective in the -respective sections above. Both processes [migration, m[un]locking], hold -the page locked. This provides the first level of synchronization. Page -migration zeros out the page_mapping of the old page before unlocking it, -so m[un]lock can skip these pages by testing the page mapping under page -lock. - -When completing page migration, we place the new and old pages back onto the -lru after dropping the page lock. The "unneeded" page--old page on success, -new page on failure--will be freed when the reference count held by the -migration process is released. To ensure that we don't strand pages on the -unevictable list because of a race between munlock and migration, page -migration uses the putback_lru_page() function to add migrated pages back to -the lru. - - -Mlocked Pages: mmap(MAP_LOCKED) System Call Handling +This is fine, because we'll catch it later if and if vmscan tries to reclaim +the page. This should be relatively rare. + + +MIGRATING MLOCKED PAGES +----------------------- + +A page that is being migrated has been isolated from the LRU lists and is held +locked across unmapping of the page, updating the page's address space entry +and copying the contents and state, until the page table entry has been +replaced with an entry that refers to the new page. Linux supports migration +of mlocked pages and other unevictable pages. This involves simply moving the +PG_mlocked and PG_unevictable states from the old page to the new page. + +Note that page migration can race with mlocking or munlocking of the same page. +This has been discussed from the mlock/munlock perspective in the respective +sections above. Both processes (migration and m[un]locking) hold the page +locked. This provides the first level of synchronization. Page migration +zeros out the page_mapping of the old page before unlocking it, so m[un]lock +can skip these pages by testing the page mapping under page lock. + +To complete page migration, we place the new and old pages back onto the LRU +after dropping the page lock. The "unneeded" page - old page on success, new +page on failure - will be freed when the reference count held by the migration +process is released. To ensure that we don't strand pages on the unevictable +list because of a race between munlock and migration, page migration uses the +putback_lru_page() function to add migrated pages back to the LRU. + + +mmap(MAP_LOCKED) SYSTEM CALL HANDLING +------------------------------------- In addition the the mlock()/mlockall() system calls, an application can request -that a region of memory be mlocked using the MAP_LOCKED flag with the mmap() +that a region of memory be mlocked supplying the MAP_LOCKED flag to the mmap() call. Furthermore, any mmap() call or brk() call that expands the heap by a task that has previously called mlockall() with the MCL_FUTURE flag will result -in the newly mapped memory being mlocked. Before the unevictable/mlock changes, -the kernel simply called make_pages_present() to allocate pages and populate -the page table. +in the newly mapped memory being mlocked. Before the unevictable/mlock +changes, the kernel simply called make_pages_present() to allocate pages and +populate the page table. To mlock a range of memory under the unevictable/mlock infrastructure, the mmap() handler and task address space expansion functions call mlock_vma_pages_range() specifying the vma and the address range to mlock. -mlock_vma_pages_range() filters vmas like mlock_fixup(), as described above in -"Mlocked Pages: Filtering Vmas". It will clear the VM_LOCKED flag, which will -have already been set by the caller, in filtered vmas. Thus these vma's need -not be visited for munlock when the region is unmapped. +mlock_vma_pages_range() filters VMAs like mlock_fixup(), as described above in +"Filtering Special VMAs". It will clear the VM_LOCKED flag, which will have +already been set by the caller, in filtered VMAs. Thus these VMA's need not be +visited for munlock when the region is unmapped. -For "normal" vmas, mlock_vma_pages_range() calls __mlock_vma_pages_range() to +For "normal" VMAs, mlock_vma_pages_range() calls __mlock_vma_pages_range() to fault/allocate the pages and mlock them. Again, like mlock_fixup(), mlock_vma_pages_range() downgrades the mmap semaphore to read mode before -attempting to fault/allocate and mlock the pages; and "upgrades" the semaphore +attempting to fault/allocate and mlock the pages and "upgrades" the semaphore back to write mode before returning. -The callers of mlock_vma_pages_range() will have already added the memory -range to be mlocked to the task's "locked_vm". To account for filtered vmas, +The callers of mlock_vma_pages_range() will have already added the memory range +to be mlocked to the task's "locked_vm". To account for filtered VMAs, mlock_vma_pages_range() returns the number of pages NOT mlocked. All of the -callers then subtract a non-negative return value from the task's locked_vm. -A negative return value represent an error--for example, from get_user_pages() -attempting to fault in a vma with PROT_NONE access. In this case, we leave -the memory range accounted as locked_vm, as the protections could be changed -later and pages allocated into that region. +callers then subtract a non-negative return value from the task's locked_vm. A +negative return value represent an error - for example, from get_user_pages() +attempting to fault in a VMA with PROT_NONE access. In this case, we leave the +memory range accounted as locked_vm, as the protections could be changed later +and pages allocated into that region. -Mlocked Pages: munmap()/exit()/exec() System Call Handling +munmap()/exit()/exec() SYSTEM CALL HANDLING +------------------------------------------- When unmapping an mlocked region of memory, whether by an explicit call to munmap() or via an internal unmap from exit() or exec() processing, we must -munlock the pages if we're removing the last VM_LOCKED vma that maps the pages. +munlock the pages if we're removing the last VM_LOCKED VMA that maps the pages. Before the unevictable/mlock changes, mlocking did not mark the pages in any way, so unmapping them required no processing. To munlock a range of memory under the unevictable/mlock infrastructure, the -munmap() hander and task address space tear down function call +munmap() handler and task address space call tear down function munlock_vma_pages_all(). The name reflects the observation that one always -specifies the entire vma range when munlock()ing during unmap of a region. -Because of the vma filtering when mlocking() regions, only "normal" vmas that +specifies the entire VMA range when munlock()ing during unmap of a region. +Because of the VMA filtering when mlocking() regions, only "normal" VMAs that actually contain mlocked pages will be passed to munlock_vma_pages_all(). -munlock_vma_pages_all() clears the VM_LOCKED vma flag and, like mlock_fixup() +munlock_vma_pages_all() clears the VM_LOCKED VMA flag and, like mlock_fixup() for the munlock case, calls __munlock_vma_pages_range() to walk the page table -for the vma's memory range and munlock_vma_page() each resident page mapped by -the vma. This effectively munlocks the page, only if this is the last -VM_LOCKED vma that maps the page. - +for the VMA's memory range and munlock_vma_page() each resident page mapped by +the VMA. This effectively munlocks the page, only if this is the last +VM_LOCKED VMA that maps the page. -Mlocked Page: try_to_unmap() -[Note: the code changes represented by this section are really quite small -compared to the text to describe what happening and why, and to discuss the -implications.] +try_to_unmap() +-------------- -Pages can, of course, be mapped into multiple vmas. Some of these vmas may +Pages can, of course, be mapped into multiple VMAs. Some of these VMAs may have VM_LOCKED flag set. It is possible for a page mapped into one or more -VM_LOCKED vmas not to have the PG_mlocked flag set and therefore reside on one -of the active or inactive LRU lists. This could happen if, for example, a -task in the process of munlock()ing the page could not isolate the page from -the LRU. As a result, vmscan/shrink_page_list() might encounter such a page -as described in "Unevictable Pages and Vmscan [shrink_*_list()]". To -handle this situation, try_to_unmap() has been enhanced to check for VM_LOCKED -vmas while it is walking a page's reverse map. +VM_LOCKED VMAs not to have the PG_mlocked flag set and therefore reside on one +of the active or inactive LRU lists. This could happen if, for example, a task +in the process of munlocking the page could not isolate the page from the LRU. +As a result, vmscan/shrink_page_list() might encounter such a page as described +in section "vmscan's handling of unevictable pages". To handle this situation, +try_to_unmap() checks for VM_LOCKED VMAs while it is walking a page's reverse +map. try_to_unmap() is always called, by either vmscan for reclaim or for page -migration, with the argument page locked and isolated from the LRU. BUG_ON() -assertions enforce this requirement. Separate functions handle anonymous and -mapped file pages, as these types of pages have different reverse map -mechanisms. - - try_to_unmap_anon() - -To unmap anonymous pages, each vma in the list anchored in the anon_vma must be -visited--at least until a VM_LOCKED vma is encountered. If the page is being -unmapped for migration, VM_LOCKED vmas do not stop the process because mlocked -pages are migratable. However, for reclaim, if the page is mapped into a -VM_LOCKED vma, the scan stops. try_to_unmap() attempts to acquire the mmap -semphore of the mm_struct to which the vma belongs in read mode. If this is -successful, try_to_unmap() will mlock the page via mlock_vma_page()--we -wouldn't have gotten to try_to_unmap() if the page were already mlocked--and -will return SWAP_MLOCK, indicating that the page is unevictable. If the -mmap semaphore cannot be acquired, we are not sure whether the page is really -unevictable or not. In this case, try_to_unmap() will return SWAP_AGAIN. - - try_to_unmap_file() -- linear mappings - -Unmapping of a mapped file page works the same, except that the scan visits -all vmas that maps the page's index/page offset in the page's mapping's -reverse map priority search tree. It must also visit each vma in the page's -mapping's non-linear list, if the list is non-empty. As for anonymous pages, -on encountering a VM_LOCKED vma for a mapped file page, try_to_unmap() will -attempt to acquire the associated mm_struct's mmap semaphore to mlock the page, -returning SWAP_MLOCK if this is successful, and SWAP_AGAIN, if not. - - try_to_unmap_file() -- non-linear mappings - -If a page's mapping contains a non-empty non-linear mapping vma list, then -try_to_un{map|lock}() must also visit each vma in that list to determine -whether the page is mapped in a VM_LOCKED vma. Again, the scan must visit -all vmas in the non-linear list to ensure that the pages is not/should not be -mlocked. If a VM_LOCKED vma is found in the list, the scan could terminate. -However, there is no easy way to determine whether the page is actually mapped -in a given vma--either for unmapping or testing whether the VM_LOCKED vma -actually pins the page. - -So, try_to_unmap_file() handles non-linear mappings by scanning a certain -number of pages--a "cluster"--in each non-linear vma associated with the page's -mapping, for each file mapped page that vmscan tries to unmap. If this happens -to unmap the page we're trying to unmap, try_to_unmap() will notice this on -return--(page_mapcount(page) == 0)--and return SWAP_SUCCESS. Otherwise, it -will return SWAP_AGAIN, causing vmscan to recirculate this page. We take -advantage of the cluster scan in try_to_unmap_cluster() as follows: - -For each non-linear vma, try_to_unmap_cluster() attempts to acquire the mmap -semaphore of the associated mm_struct for read without blocking. If this -attempt is successful and the vma is VM_LOCKED, try_to_unmap_cluster() will -retain the mmap semaphore for the scan; otherwise it drops it here. Then, -for each page in the cluster, if we're holding the mmap semaphore for a locked -vma, try_to_unmap_cluster() calls mlock_vma_page() to mlock the page. This -call is a no-op if the page is already locked, but will mlock any pages in -the non-linear mapping that happen to be unlocked. If one of the pages so -mlocked is the page passed in to try_to_unmap(), try_to_unmap_cluster() will -return SWAP_MLOCK, rather than the default SWAP_AGAIN. This will allow vmscan -to cull the page, rather than recirculating it on the inactive list. Again, -if try_to_unmap_cluster() cannot acquire the vma's mmap sem, it returns -SWAP_AGAIN, indicating that the page is mapped by a VM_LOCKED vma, but -couldn't be mlocked. - - -Mlocked pages: try_to_munlock() Reverse Map Scan - -TODO/FIXME: a better name might be page_mlocked()--analogous to the -page_referenced() reverse map walker. - -When munlock_vma_page()--see "Mlocked Pages: munlock()/munlockall() -System Call Handling" above--tries to munlock a page, it needs to -determine whether or not the page is mapped by any VM_LOCKED vma, without -actually attempting to unmap all ptes from the page. For this purpose, the -unevictable/mlock infrastructure introduced a variant of try_to_unmap() called -try_to_munlock(). +migration, with the argument page locked and isolated from the LRU. Separate +functions handle anonymous and mapped file pages, as these types of pages have +different reverse map mechanisms. + + (*) try_to_unmap_anon() + + To unmap anonymous pages, each VMA in the list anchored in the anon_vma + must be visited - at least until a VM_LOCKED VMA is encountered. If the + page is being unmapped for migration, VM_LOCKED VMAs do not stop the + process because mlocked pages are migratable. However, for reclaim, if + the page is mapped into a VM_LOCKED VMA, the scan stops. + + try_to_unmap_anon() attempts to acquire in read mode the mmap semphore of + the mm_struct to which the VMA belongs. If this is successful, it will + mlock the page via mlock_vma_page() - we wouldn't have gotten to + try_to_unmap_anon() if the page were already mlocked - and will return + SWAP_MLOCK, indicating that the page is unevictable. + + If the mmap semaphore cannot be acquired, we are not sure whether the page + is really unevictable or not. In this case, try_to_unmap_anon() will + return SWAP_AGAIN. + + (*) try_to_unmap_file() - linear mappings + + Unmapping of a mapped file page works the same as for anonymous mappings, + except that the scan visits all VMAs that map the page's index/page offset + in the page's mapping's reverse map priority search tree. It also visits + each VMA in the page's mapping's non-linear list, if the list is + non-empty. + + As for anonymous pages, on encountering a VM_LOCKED VMA for a mapped file + page, try_to_unmap_file() will attempt to acquire the associated + mm_struct's mmap semaphore to mlock the page, returning SWAP_MLOCK if this + is successful, and SWAP_AGAIN, if not. + + (*) try_to_unmap_file() - non-linear mappings + + If a page's mapping contains a non-empty non-linear mapping VMA list, then + try_to_un{map|lock}() must also visit each VMA in that list to determine + whether the page is mapped in a VM_LOCKED VMA. Again, the scan must visit + all VMAs in the non-linear list to ensure that the pages is not/should not + be mlocked. + + If a VM_LOCKED VMA is found in the list, the scan could terminate. + However, there is no easy way to determine whether the page is actually + mapped in a given VMA - either for unmapping or testing whether the + VM_LOCKED VMA actually pins the page. + + try_to_unmap_file() handles non-linear mappings by scanning a certain + number of pages - a "cluster" - in each non-linear VMA associated with the + page's mapping, for each file mapped page that vmscan tries to unmap. If + this happens to unmap the page we're trying to unmap, try_to_unmap() will + notice this on return (page_mapcount(page) will be 0) and return + SWAP_SUCCESS. Otherwise, it will return SWAP_AGAIN, causing vmscan to + recirculate this page. We take advantage of the cluster scan in + try_to_unmap_cluster() as follows: + + For each non-linear VMA, try_to_unmap_cluster() attempts to acquire the + mmap semaphore of the associated mm_struct for read without blocking. + + If this attempt is successful and the VMA is VM_LOCKED, + try_to_unmap_cluster() will retain the mmap semaphore for the scan; + otherwise it drops it here. + + Then, for each page in the cluster, if we're holding the mmap semaphore + for a locked VMA, try_to_unmap_cluster() calls mlock_vma_page() to + mlock the page. This call is a no-op if the page is already locked, + but will mlock any pages in the non-linear mapping that happen to be + unlocked. + + If one of the pages so mlocked is the page passed in to try_to_unmap(), + try_to_unmap_cluster() will return SWAP_MLOCK, rather than the default + SWAP_AGAIN. This will allow vmscan to cull the page, rather than + recirculating it on the inactive list. + + Again, if try_to_unmap_cluster() cannot acquire the VMA's mmap sem, it + returns SWAP_AGAIN, indicating that the page is mapped by a VM_LOCKED + VMA, but couldn't be mlocked. + + +try_to_munlock() REVERSE MAP SCAN +--------------------------------- + + [!] TODO/FIXME: a better name might be page_mlocked() - analogous to the + page_referenced() reverse map walker. + +When munlock_vma_page() [see section "munlock()/munlockall() System Call +Handling" above] tries to munlock a page, it needs to determine whether or not +the page is mapped by any VM_LOCKED VMA without actually attempting to unmap +all PTEs from the page. For this purpose, the unevictable/mlock infrastructure +introduced a variant of try_to_unmap() called try_to_munlock(). try_to_munlock() calls the same functions as try_to_unmap() for anonymous and mapped file pages with an additional argument specifing unlock versus unmap processing. Again, these functions walk the respective reverse maps looking -for VM_LOCKED vmas. When such a vma is found for anonymous pages and file +for VM_LOCKED VMAs. When such a VMA is found for anonymous pages and file pages mapped in linear VMAs, as in the try_to_unmap() case, the functions attempt to acquire the associated mmap semphore, mlock the page via mlock_vma_page() and return SWAP_MLOCK. This effectively undoes the pre-clearing of the page's PG_mlocked done by munlock_vma_page. -If try_to_unmap() is unable to acquire a VM_LOCKED vma's associated mmap -semaphore, it will return SWAP_AGAIN. This will allow shrink_page_list() -to recycle the page on the inactive list and hope that it has better luck -with the page next time. - -For file pages mapped into non-linear vmas, the try_to_munlock() logic works -slightly differently. On encountering a VM_LOCKED non-linear vma that might -map the page, try_to_munlock() returns SWAP_AGAIN without actually mlocking -the page. munlock_vma_page() will just leave the page unlocked and let -vmscan deal with it--the usual fallback position. - -Note that try_to_munlock()'s reverse map walk must visit every vma in a pages' -reverse map to determine that a page is NOT mapped into any VM_LOCKED vma. -However, the scan can terminate when it encounters a VM_LOCKED vma and can -successfully acquire the vma's mmap semphore for read and mlock the page. -Although try_to_munlock() can be called many [very many!] times when -munlock()ing a large region or tearing down a large address space that has been -mlocked via mlockall(), overall this is a fairly rare event. - -Mlocked Page: Page Reclaim in shrink_*_list() - -shrink_active_list() culls any obviously unevictable pages--i.e., -!page_evictable(page, NULL)--diverting these to the unevictable lru -list. However, shrink_active_list() only sees unevictable pages that -made it onto the active/inactive lru lists. Note that these pages do not -have PageUnevictable set--otherwise, they would be on the unevictable list and -shrink_active_list would never see them. +If try_to_unmap() is unable to acquire a VM_LOCKED VMA's associated mmap +semaphore, it will return SWAP_AGAIN. This will allow shrink_page_list() to +recycle the page on the inactive list and hope that it has better luck with the +page next time. + +For file pages mapped into non-linear VMAs, the try_to_munlock() logic works +slightly differently. On encountering a VM_LOCKED non-linear VMA that might +map the page, try_to_munlock() returns SWAP_AGAIN without actually mlocking the +page. munlock_vma_page() will just leave the page unlocked and let vmscan deal +with it - the usual fallback position. + +Note that try_to_munlock()'s reverse map walk must visit every VMA in a page's +reverse map to determine that a page is NOT mapped into any VM_LOCKED VMA. +However, the scan can terminate when it encounters a VM_LOCKED VMA and can +successfully acquire the VMA's mmap semphore for read and mlock the page. +Although try_to_munlock() might be called a great many times when munlocking a +large region or tearing down a large address space that has been mlocked via +mlockall(), overall this is a fairly rare event. + + +PAGE RECLAIM IN shrink_*_list() +------------------------------- + +shrink_active_list() culls any obviously unevictable pages - i.e. +!page_evictable(page, NULL) - diverting these to the unevictable list. +However, shrink_active_list() only sees unevictable pages that made it onto the +active/inactive lru lists. Note that these pages do not have PageUnevictable +set - otherwise they would be on the unevictable list and shrink_active_list +would never see them. Some examples of these unevictable pages on the LRU lists are: -1) ramfs pages that have been placed on the lru lists when first allocated. + (1) ramfs pages that have been placed on the LRU lists when first allocated. + + (2) SHM_LOCK'd shared memory pages. shmctl(SHM_LOCK) does not attempt to + allocate or fault in the pages in the shared memory region. This happens + when an application accesses the page the first time after SHM_LOCK'ing + the segment. -2) SHM_LOCKed shared memory pages. shmctl(SHM_LOCK) does not attempt to - allocate or fault in the pages in the shared memory region. This happens - when an application accesses the page the first time after SHM_LOCKing - the segment. + (3) mlocked pages that could not be isolated from the LRU and moved to the + unevictable list in mlock_vma_page(). -3) Mlocked pages that could not be isolated from the lru and moved to the - unevictable list in mlock_vma_page(). + (4) Pages mapped into multiple VM_LOCKED VMAs, but try_to_munlock() couldn't + acquire the VMA's mmap semaphore to test the flags and set PageMlocked. + munlock_vma_page() was forced to let the page back on to the normal LRU + list for vmscan to handle. -3) Pages mapped into multiple VM_LOCKED vmas, but try_to_munlock() couldn't - acquire the vma's mmap semaphore to test the flags and set PageMlocked. - munlock_vma_page() was forced to let the page back on to the normal - LRU list for vmscan to handle. +shrink_inactive_list() also diverts any unevictable pages that it finds on the +inactive lists to the appropriate zone's unevictable list. -shrink_inactive_list() also culls any unevictable pages that it finds on -the inactive lists, again diverting them to the appropriate zone's unevictable -lru list. shrink_inactive_list() should only see SHM_LOCKed pages that became -SHM_LOCKed after shrink_active_list() had moved them to the inactive list, or -pages mapped into VM_LOCKED vmas that munlock_vma_page() couldn't isolate from -the lru to recheck via try_to_munlock(). shrink_inactive_list() won't notice -the latter, but will pass on to shrink_page_list(). +shrink_inactive_list() should only see SHM_LOCK'd pages that became SHM_LOCK'd +after shrink_active_list() had moved them to the inactive list, or pages mapped +into VM_LOCKED VMAs that munlock_vma_page() couldn't isolate from the LRU to +recheck via try_to_munlock(). shrink_inactive_list() won't notice the latter, +but will pass on to shrink_page_list(). shrink_page_list() again culls obviously unevictable pages that it could encounter for similar reason to shrink_inactive_list(). Pages mapped into -VM_LOCKED vmas but without PG_mlocked set will make it all the way to +VM_LOCKED VMAs but without PG_mlocked set will make it all the way to try_to_unmap(). shrink_page_list() will divert them to the unevictable list when try_to_unmap() returns SWAP_MLOCK, as discussed above. diff --git a/Documentation/x86/boot.txt b/Documentation/x86/boot.txt index 7b4596ac4120..e0203662f9e9 100644 --- a/Documentation/x86/boot.txt +++ b/Documentation/x86/boot.txt @@ -158,7 +158,7 @@ Offset Proto Name Meaning 0202/4 2.00+ header Magic signature "HdrS" 0206/2 2.00+ version Boot protocol version supported 0208/4 2.00+ realmode_swtch Boot loader hook (see below) -020C/2 2.00+ start_sys The load-low segment (0x1000) (obsolete) +020C/2 2.00+ start_sys_seg The load-low segment (0x1000) (obsolete) 020E/2 2.00+ kernel_version Pointer to kernel version string 0210/1 2.00+ type_of_loader Boot loader identifier 0211/1 2.00+ loadflags Boot protocol option flags @@ -170,10 +170,11 @@ Offset Proto Name Meaning 0224/2 2.01+ heap_end_ptr Free memory after setup end 0226/2 N/A pad1 Unused 0228/4 2.02+ cmd_line_ptr 32-bit pointer to the kernel command line -022C/4 2.03+ initrd_addr_max Highest legal initrd address +022C/4 2.03+ ramdisk_max Highest legal initrd address 0230/4 2.05+ kernel_alignment Physical addr alignment required for kernel 0234/1 2.05+ relocatable_kernel Whether kernel is relocatable or not -0235/3 N/A pad2 Unused +0235/1 N/A pad2 Unused +0236/2 N/A pad3 Unused 0238/4 2.06+ cmdline_size Maximum size of the kernel command line 023C/4 2.07+ hardware_subarch Hardware subarchitecture 0240/8 2.07+ hardware_subarch_data Subarchitecture-specific data @@ -299,14 +300,14 @@ Protocol: 2.00+ e.g. 0x0204 for version 2.04, and 0x0a11 for a hypothetical version 10.17. -Field name: readmode_swtch +Field name: realmode_swtch Type: modify (optional) Offset/size: 0x208/4 Protocol: 2.00+ Boot loader hook (see ADVANCED BOOT LOADER HOOKS below.) -Field name: start_sys +Field name: start_sys_seg Type: read Offset/size: 0x20c/2 Protocol: 2.00+ @@ -468,7 +469,7 @@ Protocol: 2.02+ zero, the kernel will assume that your boot loader does not support the 2.02+ protocol. -Field name: initrd_addr_max +Field name: ramdisk_max Type: read Offset/size: 0x22c/4 Protocol: 2.03+ @@ -542,7 +543,10 @@ Protocol: 2.08+ The payload may be compressed. The format of both the compressed and uncompressed data should be determined using the standard magic - numbers. Currently only gzip compressed ELF is used. + numbers. The currently supported compression formats are gzip + (magic numbers 1F 8B or 1F 9E), bzip2 (magic number 42 5A) and LZMA + (magic number 5D 00). The uncompressed payload is currently always ELF + (magic number 7F 45 4C 46). Field name: payload_length Type: read diff --git a/Documentation/x86/earlyprintk.txt b/Documentation/x86/earlyprintk.txt new file mode 100644 index 000000000000..607b1a016064 --- /dev/null +++ b/Documentation/x86/earlyprintk.txt @@ -0,0 +1,101 @@ + +Mini-HOWTO for using the earlyprintk=dbgp boot option with a +USB2 Debug port key and a debug cable, on x86 systems. + +You need two computers, the 'USB debug key' special gadget and +and two USB cables, connected like this: + + [host/target] <-------> [USB debug key] <-------> [client/console] + +1. There are three specific hardware requirements: + + a.) Host/target system needs to have USB debug port capability. + + You can check this capability by looking at a 'Debug port' bit in + the lspci -vvv output: + + # lspci -vvv + ... + 00:1d.7 USB Controller: Intel Corporation 82801H (ICH8 Family) USB2 EHCI Controller #1 (rev 03) (prog-if 20 [EHCI]) + Subsystem: Lenovo ThinkPad T61 + Control: I/O- Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR+ FastB2B- DisINTx- + Status: Cap+ 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- <TAbort- <MAbort- >SERR- <PERR- INTx- + Latency: 0 + Interrupt: pin D routed to IRQ 19 + Region 0: Memory at fe227000 (32-bit, non-prefetchable) [size=1K] + Capabilities: [50] Power Management version 2 + Flags: PMEClk- DSI- D1- D2- AuxCurrent=375mA PME(D0+,D1-,D2-,D3hot+,D3cold+) + Status: D0 PME-Enable- DSel=0 DScale=0 PME+ + Capabilities: [58] Debug port: BAR=1 offset=00a0 + ^^^^^^^^^^^ <==================== [ HERE ] + Kernel driver in use: ehci_hcd + Kernel modules: ehci-hcd + ... + +( If your system does not list a debug port capability then you probably + wont be able to use the USB debug key. ) + + b.) You also need a Netchip USB debug cable/key: + + http://www.plxtech.com/products/NET2000/NET20DC/default.asp + + This is a small blue plastic connector with two USB connections, + it draws power from its USB connections. + + c.) Thirdly, you need a second client/console system with a regular USB port. + +2. Software requirements: + + a.) On the host/target system: + + You need to enable the following kernel config option: + + CONFIG_EARLY_PRINTK_DBGP=y + + And you need to add the boot command line: "earlyprintk=dbgp". + (If you are using Grub, append it to the 'kernel' line in + /etc/grub.conf) + + NOTE: normally earlyprintk console gets turned off once the + regular console is alive - use "earlyprintk=dbgp,keep" to keep + this channel open beyond early bootup. This can be useful for + debugging crashes under Xorg, etc. + + b.) On the client/console system: + + You should enable the following kernel config option: + + CONFIG_USB_SERIAL_DEBUG=y + + On the next bootup with the modified kernel you should + get a /dev/ttyUSBx device(s). + + Now this channel of kernel messages is ready to be used: start + your favorite terminal emulator (minicom, etc.) and set + it up to use /dev/ttyUSB0 - or use a raw 'cat /dev/ttyUSBx' to + see the raw output. + + c.) On Nvidia Southbridge based systems: the kernel will try to probe + and find out which port has debug device connected. + +3. Testing that it works fine: + + You can test the output by using earlyprintk=dbgp,keep and provoking + kernel messages on the host/target system. You can provoke a harmless + kernel message by for example doing: + + echo h > /proc/sysrq-trigger + + On the host/target system you should see this help line in "dmesg" output: + + SysRq : HELP : loglevel(0-9) reBoot Crashdump terminate-all-tasks(E) memory-full-oom-kill(F) kill-all-tasks(I) saK show-backtrace-all-active-cpus(L) show-memory-usage(M) nice-all-RT-tasks(N) powerOff show-registers(P) show-all-timers(Q) unRaw Sync show-task-states(T) Unmount show-blocked-tasks(W) dump-ftrace-buffer(Z) + + On the client/console system do: + + cat /dev/ttyUSB0 + + And you should see the help line above displayed shortly after you've + provoked it on the host system. + +If it does not work then please ask about it on the linux-kernel@vger.kernel.org +mailing list or contact the x86 maintainers. diff --git a/Documentation/x86/x86_64/fake-numa-for-cpusets b/Documentation/x86/x86_64/fake-numa-for-cpusets index 33bb56655991..0f11d9becb0b 100644 --- a/Documentation/x86/x86_64/fake-numa-for-cpusets +++ b/Documentation/x86/x86_64/fake-numa-for-cpusets @@ -7,7 +7,8 @@ you can create fake NUMA nodes that represent contiguous chunks of memory and assign them to cpusets and their attached tasks. This is a way of limiting the amount of system memory that are available to a certain class of tasks. -For more information on the features of cpusets, see Documentation/cpusets.txt. +For more information on the features of cpusets, see +Documentation/cgroups/cpusets.txt. There are a number of different configurations you can use for your needs. For more information on the numa=fake command line option and its various ways of configuring fake nodes, see Documentation/x86/x86_64/boot-options.txt. @@ -32,7 +33,7 @@ A machine may be split as follows with "numa=fake=4*512," as reported by dmesg: On node 3 totalpages: 131072 Now following the instructions for mounting the cpusets filesystem from -Documentation/cpusets.txt, you can assign fake nodes (i.e. contiguous memory +Documentation/cgroups/cpusets.txt, you can assign fake nodes (i.e. contiguous memory address spaces) to individual cpusets: [root@xroads /]# mkdir exampleset |