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2009-03-28Merge branch 'percpu-cpumask-x86-for-linus-2' of ↵Linus Torvalds1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'percpu-cpumask-x86-for-linus-2' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (682 commits) percpu: fix spurious alignment WARN in legacy SMP percpu allocator percpu: generalize embedding first chunk setup helper percpu: more flexibility for @dyn_size of pcpu_setup_first_chunk() percpu: make x86 addr <-> pcpu ptr conversion macros generic linker script: define __per_cpu_load on all SMP capable archs x86: UV: remove uv_flush_tlb_others() WARN_ON percpu: finer grained locking to break deadlock and allow atomic free percpu: move fully free chunk reclamation into a work percpu: move chunk area map extension out of area allocation percpu: replace pcpu_realloc() with pcpu_mem_alloc() and pcpu_mem_free() x86, percpu: setup reserved percpu area for x86_64 percpu, module: implement reserved allocation and use it for module percpu variables percpu: add an indirection ptr for chunk page map access x86: make embedding percpu allocator return excessive free space percpu: use negative for auto for pcpu_setup_first_chunk() arguments percpu: improve first chunk initial area map handling percpu: cosmetic renames in pcpu_setup_first_chunk() percpu: clean up percpu constants x86: un-__init fill_pud/pmd/pte x86: remove vestigial fix_ioremap prototypes ... Manually merge conflicts in arch/ia64/kernel/irq_ia64.c
2009-03-28Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds1-0/+1
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (119 commits) [SCSI] scsi_dh_rdac: Retry for NOT_READY check condition [SCSI] mpt2sas: make global symbols unique [SCSI] sd: Make revalidate less chatty [SCSI] sd: Try READ CAPACITY 16 first for SBC-2 devices [SCSI] sd: Refactor sd_read_capacity() [SCSI] mpt2sas v00.100.11.15 [SCSI] mpt2sas: add MPT2SAS_MINOR(221) to miscdevice.h [SCSI] ch: Add scsi type modalias [SCSI] 3w-9xxx: add power management support [SCSI] bsg: add linux/types.h include to bsg.h [SCSI] cxgb3i: fix function descriptions [SCSI] libiscsi: fix possbile null ptr session command cleanup [SCSI] iscsi class: remove host no argument from session creation callout [SCSI] libiscsi: pass session failure a session struct [SCSI] iscsi lib: remove qdepth param from iscsi host allocation [SCSI] iscsi lib: have lib create work queue for transmitting IO [SCSI] iscsi class: fix lock dep warning on logout [SCSI] libiscsi: don't cap queue depth in iscsi modules [SCSI] iscsi_tcp: replace scsi_debug/tcp_debug logging with iscsi conn logging [SCSI] libiscsi_tcp: replace tcp_debug/scsi_debug logging with session/conn logging ...
2009-03-27Merge branch 'core/percpu' into percpu-cpumask-x86-for-linus-2Ingo Molnar1-1/+1
Conflicts: arch/parisc/kernel/irq.c arch/x86/include/asm/fixmap_64.h arch/x86/include/asm/setup.h kernel/irq/handle.c Semantic merge: arch/x86/include/asm/fixmap.h Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-03-26bsg: Remove bogus check against request_queue->max_sectorsBoaz Harrosh1-3/+0
bsg submits REQ_TYPE_BLOCK_PC so the right check is max_hw_sectors. But I've removed this check because right after, bsg proceeds with calling blk_rq_map_user() which does all the right checks. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-26block: WARN in __blk_put_request() for potential bio leakBoaz Harrosh3-17/+9
Put a WARN_ON in __blk_put_request if it is about to leak bio(s). This is a serious bug that can happen in error handling code paths. For this to work I have fixed a couple of places in block/ where request->bio != NULL ownership was not honored. And a small cleanup at sg_io() while at it. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-24bsg: add support for tail queuingBoaz Harrosh1-2/+7
Currently inherited from sg.c bsg will submit asynchronous request at the head-of-the-queue, (using "at_head" set in the call to blk_execute_rq_nowait()). This is bad in situation where the queues are full, requests will execute out of order, and can cause starvation of the first submitted requests. The sg_io_v4->flags member is used and a bit is allocated to denote the Q_AT_TAIL. Zero is to queue at_head as before, to be compatible with old code at the write/read path. SG_IO code path behavior was changed so to be the same as write/read behavior. SG_IO was very rarely used and breaking compatibility with it is OK at this stage. sg_io_hdr at sg.h also has a flags member and uses 3 bits from the first nibble and one bit from the last nibble. Even though none of these bits are supported by bsg, The second nibble is allocated for use by bsg. Just in case. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> CC: Douglas Gilbert <dgilbert@interlog.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-24block: get rid of unused blkdev_free_rq() defineJens Axboe1-1/+0
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-24block: remove various blk_queue_*() setting functions in blk_init_queue_node()Jens Axboe1-6/+3
It calls blk_queue_make_request(), which sets the identical set of limits. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-12[SCSI] Make scsi.h independent of the rest of the scsi includesJames Bottomley1-0/+1
This allows it to compile and be used on the ps3 platform that wants to use the #define values in scsi.h without actually having CONFIG_SCSI set. Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-03-06block: fix missing bio back/front segment size setting in blk_recount_segments()Jens Axboe1-16/+9
Commit 1e42807918d17e8c93bf14fbb74be84b141334c1 introduced a bug where we don't get front/back segment sizes in the bio in blk_recount_segments(). Fix this by tracking the back bio as well as the front bio in __blk_recalc_rq_segments(), this also cleans up the interface by getting rid of the segment size pointer passing. Tested-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-03-04Merge branch 'x86/core' into core/percpuIngo Molnar2-41/+69
2009-02-26block: reduce stack footprint of blk_recount_segments()Jens Axboe1-41/+53
blk_recalc_rq_segments() requires a request structure passed in, which we don't have from blk_recount_segments(). So the latter allocates one on the stack, using > 400 bytes of stack for that. This can cause us to spill over one page of stack from ext4 at least: 0) 4560 400 blk_recount_segments+0x43/0x62 1) 4160 32 bio_phys_segments+0x1c/0x24 2) 4128 32 blk_rq_bio_prep+0x2a/0xf9 3) 4096 32 init_request_from_bio+0xf9/0xfe 4) 4064 112 __make_request+0x33c/0x3f6 5) 3952 144 generic_make_request+0x2d1/0x321 6) 3808 64 submit_bio+0xb9/0xc3 7) 3744 48 submit_bh+0xea/0x10e 8) 3696 368 ext4_mb_init_cache+0x257/0xa6a [ext4] 9) 3328 288 ext4_mb_regular_allocator+0x421/0xcd9 [ext4] 10) 3040 160 ext4_mb_new_blocks+0x211/0x4b4 [ext4] 11) 2880 336 ext4_ext_get_blocks+0xb61/0xd45 [ext4] 12) 2544 96 ext4_get_blocks_wrap+0xf2/0x200 [ext4] 13) 2448 80 ext4_da_get_block_write+0x6e/0x16b [ext4] 14) 2368 352 mpage_da_map_blocks+0x7e/0x4b3 [ext4] 15) 2016 352 ext4_da_writepages+0x2ce/0x43c [ext4] 16) 1664 32 do_writepages+0x2d/0x3c 17) 1632 144 __writeback_single_inode+0x162/0x2cd 18) 1488 96 generic_sync_sb_inodes+0x1e3/0x32b 19) 1392 16 sync_sb_inodes+0xe/0x10 20) 1376 48 writeback_inodes+0x69/0xb3 21) 1328 208 balance_dirty_pages_ratelimited_nr+0x187/0x2f9 22) 1120 224 generic_file_buffered_write+0x1d4/0x2c4 23) 896 176 __generic_file_aio_write_nolock+0x35f/0x393 24) 720 80 generic_file_aio_write+0x6c/0xc8 25) 640 80 ext4_file_write+0xa9/0x137 [ext4] 26) 560 320 do_sync_write+0xf0/0x137 27) 240 48 vfs_write+0xb3/0x13c 28) 192 64 sys_write+0x4c/0x74 29) 128 128 system_call_fastpath+0x16/0x1b Split the segment counting out into a __blk_recalc_rq_segments() helper to avoid allocating an onstack request just for checking the physical segment count. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-26block: add documentation for register_blkdev()Márton Németh1-0/+16
Add documentation for register_blkdev() function and for the parameters. Signed-off-by: Márton Németh <nm127@freemail.hu> Cc: Greg Kroah-Hartman <gregkh@suse.de> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-24Merge branch 'tj-percpu' of ↵Ingo Molnar1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tj/misc into core/percpu Conflicts: arch/x86/include/asm/pgtable.h
2009-02-20alloc_percpu: add align argument to __alloc_percpu.Rusty Russell1-1/+1
This prepares for a real __alloc_percpu, by adding an alignment argument. Only one place uses __alloc_percpu directly, and that's for a string. tj: af_inet also uses __alloc_percpu(), update it. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Jens Axboe <axboe@kernel.dk>
2009-02-18block: fix deadlock in blk_abort_queue() for drivers that readd to timeout listHannes Reinecke1-1/+8
blk_abort_queue() iterates the timeout list and aborts each request on the list, but if the driver error handling readds a request to the timeout list during this processing, we could be looping forever. Fix this by splicing current entries to a local list and run over that list instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18block: fix booting from partitioned md arrayNeil Brown1-0/+8
Hi Tejun, it looks like your commit: block: don't depend on consecutive minor space f331c0296f2a9fee0d396a70598b954062603015 broke a particular case for booting from partitioned md/raid devices. That is the second time this has been broken recently. The previous time was fixed by block: do_mounts - accept root=<non-existant partition> 30f2f0eb4bd2c43d10a8b0d872c6e5ad8f31c9a0 Because the data isn't available when an md device is first created (we add disks and set it up after creation), the initial partition scan finds nothing. It is not until the device is opened that another partition scan happens and finds something. So at the point where the kernel parameter "root=/dev/md_d0p1" is being parsed, md_d0 exists, but md_d0p1 does not. However if we let blk_lookup_devt return the correct device number even though the device doesn't exist, then the attempt to mount it will successfully find the partition. I have tried in the past to find a way to get the partition table to be read as soon as the array is assembled but that proved impossible (at the time). I don't remember the details, and could possibly revisit it. However it would be really nice if blk_lookup_devt could be adjusted to again accept non existant partitions. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18block: fix bad definition of BIO_RW_SYNCJens Axboe1-1/+1
We can't OR shift values, so get rid of BIO_RW_SYNC and use BIO_RW_SYNCIO and BIO_RW_UNPLUG explicitly. This brings back the behaviour from before 213d9417fec62ef4c3675621b9364a667954d4dd. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-18bsg: Fix sense buffer bug in SG_IOBoaz Harrosh1-7/+10
When submitting requests via SG_IO, which does a sync io, a bsg_command is not allocated. So an in-Kernel sense_buffer was not set. However when calling blk_execute_rq() with no sense buffer one is provided from the stack. Now bsg at blk_complete_sgv4_hdr_rq() would check if rq->sense_len and a sense was requested by sg_io_v4 the rq->sense was copy_user() back, but by now it is already mangled stack memory. I have fixed that by forcing a sense_buffer when calling bsg_map_hdr(). The bsg_command->sense is provided in the write/read path like before, and on-the-stack buffer is provided when doing SG_IO. I have also fixed a dprintk message to print rq->errors in hex because of the scsi bit-field use of this member. For other block devices it does not matter anyway. Signed-off-by: Boaz Harrosh <bharrosh@panasas.com> Acked-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-02-02block: fix oops in blk_queue_io_stat()Jens Axboe2-3/+11
Some initial probe requests don't have disk->queue mapped yet, so we can't rely on a non-NULL queue in blk_queue_io_stat(). Wrap it in blk_do_io_stat(). Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30cfq-iosched: Allow RT requests to pre-empt ongoing BE timesliceDivyesh Shah1-1/+38
This patch adds the ability to pre-empt an ongoing BE timeslice when a RT request is waiting for the current timeslice to complete. This reduces the wait time to disk for RT requests from an upper bound of 4 (current value of cfq_quantum) to 1 disk request. Applied Jens' suggeested changes to avoid the rb lookup and use !cfq_class_rt() and retested. Latency(secs) for the RT task when doing sequential reads from 10G file. | only RT | RT + BE | RT + BE + this patch small (512 byte) reads | 143 | 163 | 145 large (1Mb) reads | 142 | 158 | 146 Signed-off-by: Divyesh Shah <dpshah@google.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: add sysfs file for controlling io stats accountingJens Axboe2-36/+82
This allows us to turn off disk stat accounting completely, for the cases where the 0.5-1% reduction in system time is important. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: silently error an unsupported barrier bioJens Axboe1-0/+5
This fixes a "regression" from 2.6.28, where the barrier probes that file systems may do would trigger additional end request warnings in dmesg. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: Fix documentation for blkdev_issue_flush()Theodore Ts'o1-1/+1
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: seperate bio/request unplug and sync bitsJens Axboe1-1/+4
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: export SSD/non-rotational queue flag through sysfsBartlomiej Zolnierkiewicz1-1/+29
For some devices (i.e. CFA ATA) we can't reliably detect whether the device is of rotational or non-rotational type so we need to leave the final decision about this setting to the user-space. As a bonus do a minor CodingStyle fixup in queue_nomerges_store(). Suggested-by: Alan Cox <alan@lxorguk.ukuu.org.uk> Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: get rid of the manual directory counting in blktraceJens Axboe1-51/+21
It can result in a stuck blktrace system, if --kill is used. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-30block: Allow empty integrity profileMartin K. Petersen1-11/+14
Allow a block device to allocate and register an integrity profile without providing a template. This allows DM to preallocate a profile to avoid deadlocks during table reconfiguration. Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2009-01-09Merge branch 'for_linus' of ↵Linus Torvalds1-0/+6
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 * 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (57 commits) jbd2: Fix oops in jbd2_journal_init_inode() on corrupted fs ext4: Remove "extents" mount option block: Add Kconfig help which notes that ext4 needs CONFIG_LBD ext4: Make printk's consistently prefixed with "EXT4-fs: " ext4: Add sanity checks for the superblock before mounting the filesystem ext4: Add mount option to set kjournald's I/O priority jbd2: Submit writes to the journal using WRITE_SYNC jbd2: Add pid and journal device name to the "kjournald2 starting" message ext4: Add markers for better debuggability ext4: Remove code to create the journal inode ext4: provide function to release metadata pages under memory pressure ext3: provide function to release metadata pages under memory pressure add releasepage hooks to block devices which can be used by file systems ext4: Fix s_dirty_blocks_counter if block allocation failed with nodelalloc ext4: Init the complete page while building buddy cache ext4: Don't allow new groups to be added during block allocation ext4: mark the blocks/inode bitmap beyond end of group as used ext4: Use new buffer_head flag to check uninit group bitmaps initialization ext4: Fix the race between read_inode_bitmap() and ext4_new_inode() ext4: code cleanup ...
2009-01-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6Linus Torvalds1-9/+10
* git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi-misc-2.6: (45 commits) [SCSI] qla2xxx: Update version number to 8.03.00-k1. [SCSI] qla2xxx: Add ISP81XX support. [SCSI] qla2xxx: Use proper request/response queues with MQ instantiations. [SCSI] qla2xxx: Correct MQ-chain information retrieval during a firmware dump. [SCSI] qla2xxx: Collapse EFT/FCE copy procedures during a firmware dump. [SCSI] qla2xxx: Don't pollute kernel logs with ZIO/RIO status messages. [SCSI] qla2xxx: Don't fallback to interrupt-polling during re-initialization with MSI-X enabled. [SCSI] qla2xxx: Remove support for reading/writing HW-event-log. [SCSI] cxgb3i: add missing include [SCSI] scsi_lib: fix DID_RESET status problems [SCSI] fc transport: restore missing dev_loss_tmo callback to LLDD [SCSI] aha152x_cs: Fix regression that keeps driver from using shared interrupts [SCSI] sd: Correctly handle 6-byte commands with DIX [SCSI] sd: DIF: Fix tagging on platforms with signed char [SCSI] sd: DIF: Show app tag on error [SCSI] Fix error handling for DIF/DIX [SCSI] scsi_lib: don't decrement busy counters when inserting commands [SCSI] libsas: fix test for negative unsigned and typos [SCSI] a2091, gvp11: kill warn_unused_result warnings [SCSI] fusion: Move a dereference below a NULL test ... Fixed up trivial conflict due to moving the async part of sd_probe around in the async probes vs using dev_set_name() in naming.
2009-01-06block: Add Kconfig help which notes that ext4 needs CONFIG_LBDTheodore Ts'o1-0/+6
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu> Cc: Jens Axboe <jens.axboe@oracle.com>
2009-01-06block: struct device - replace bus_id with dev_name(), dev_set_name()Kay Sievers2-4/+4
Cc: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-01-02[SCSI] block: make blk_rq_map_user take a NULL user-space buffer for WRITEFUJITA Tomonori1-9/+7
The commit 818827669d85b84241696ffef2de485db46b0b5e (block: make blk_rq_map_user take a NULL user-space buffer) extended blk_rq_map_user to accept a NULL user-space buffer with a READ command. It was necessary to convert sg to use the block layer mapping API. This patch extends blk_rq_map_user again for a WRITE command. It is necessary to convert st and osst drivers to use the block layer apping API. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2009-01-02[SCSI] block: fix the partial mappings with struct rq_map_dataFUJITA Tomonori1-0/+3
This fixes bio_copy_user_iov to properly handle the partial mappings with struct rq_map_data (which only sg uses for now but st and osst will shortly). It adds the offset member to struct rq_map_data and changes blk_rq_map_user to update it so that bio_copy_user_iov can add an appropriate page frame via bio_add_pc_page(). Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Acked-by: Jens Axboe <jens.axboe@oracle.com> Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2008-12-31Merge branch 'master' of ↵Rusty Russell17-195/+196
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 Conflicts: arch/x86/kernel/io_apic.c
2008-12-30Merge branch 'master' of ↵Rusty Russell4-25/+366
git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
2008-12-29cfq-iosched: fix race between exiting queue and exiting taskJens Axboe1-1/+9
Original patch from Nikanth Karthikesan <knikanth@suse.de> When a queue exits the queue lock is taken and cfq_exit_queue() would free all the cic's associated with the queue. But when a task exits, cfq_exit_io_context() gets cic one by one and then locks the associated queue to call __cfq_exit_single_io_context. It looks like between getting a cic from the ioc and locking the queue, the queue might have exited on another cpu. Fix this by rechecking the cfq_io_context queue key inside the queue lock again, and not calling into __cfq_exit_single_io_context() if somebody beat us to it. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29Get rid of CONFIG_LSFJens Axboe1-18/+5
We have two seperate config entries for large devices/files. One is CONFIG_LBD that guards just the devices, the other is CONFIG_LSF that handles large files. This doesn't make a lot of sense, you typically want both or none. So get rid of CONFIG_LSF and change CONFIG_LBD wording to indicate that it covers both. Acked-by: Jean Delvare <khali@linux-fr.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make blk_softirq_init() staticRoel Kluin1-1/+1
Sparse asked whether these could be static. Signed-off-by: Roel Kluin <roel.kluin@gmail.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: use min_not_zero in blk_queue_stack_limitsFUJITA Tomonori1-3/+3
zero is invalid for max_phys_segments, max_hw_segments, and max_segment_size. It's better to use use min_not_zero instead of min. min() works though (because the commit 0e435ac makes sure that these values are set to the default values, non zero, if a queue is initialized properly). With this patch, blk_queue_stack_limits does the almost same thing that dm's combine_restrictions_low() does. I think that it's easy to remove dm's combine_restrictions_low. Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: add one-hit cache for disk partition lookupJens Axboe1-4/+19
disk_map_sector_rcu() returns a partition from a sector offset, which we use for IO statistics on a per-partition basis. The lookup itself is an O(N) list lookup, where N is the number of partitions. This actually hurts performance quite a bit, even on the lower end partitions. On higher numbered partitions, it can get pretty bad. Solve this by adding a one-hit cache for partition lookup. This makes the lookup O(1) for the case where we do most IO to one partition. Even for mixed partition workloads, amortized cost is pretty close to O(1) since the natural IO batching makes the one-hit cache last for lots of IOs. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29cfq-iosched: remove limit of dispatch depth of max 4 times quantumJens Axboe1-6/+2
This basically limits the hardware queue depth to 4*quantum at any point in time, which is 16 with the default settings. As CFQ uses other means to shrink the hardware queue when necessary in the first place, there's really no need for this extra heuristic. Additionally, it ends up hurting performance in some cases. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: get rid of elevator_t typedefJens Axboe5-37/+40
Just use struct elevator_queue everywhere instead. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: don't use plugging on SSD devicesJens Axboe1-4/+3
We just want to hand the first bits of IO to the device as fast as possible. Gains a few percent on the IOPS rate. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: fix empty barrier on write-through w/ ordered tagTejun Heo1-1/+13
Empty barrier on write-through (or no cache) w/ ordered tag has no command to execute and without any command to execute ordered tag is never issued to the device and the ordering is never achieved. Force draining for such cases. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: simplify empty barrier implementationTejun Heo2-14/+10
Empty barrier required special handling in __elv_next_request() to complete it without letting the low level driver see it. With previous changes, barrier code is now flexible enough to skip the BAR step using the same barrier sequence selection mechanism. Drop the special handling and mask off q->ordered from start_ordered(). Remove blk_empty_barrier() test which now has no user. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make barrier completion more robustTejun Heo2-21/+34
Barrier completion had the following assumptions. * start_ordered() couldn't finish the whole sequence properly. If all actions are to be skipped, q->ordseq is set correctly but the actual completion was never triggered thus hanging the barrier request. * Drain completion in elv_complete_request() assumed that there's always at least one request in the queue when drain completes. Both assumptions are true but these assumptions need to be removed to improve empty barrier implementation. This patch makes the following changes. * Make start_ordered() use blk_ordered_complete_seq() to mark skipped steps complete and notify __elv_next_request() that it should fetch the next request if the whole barrier has completed inside start_ordered(). * Make drain completion path in elv_complete_request() check whether the queue is empty. Empty queue also indicates drain completion. * While at it, convert 0/1 return from blk_do_ordered() to false/true. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: make every barrier action optionalTejun Heo1-17/+24
In all barrier sequences, the barrier write itself was always assumed to be issued and thus didn't have corresponding control flag. This patch adds QUEUE_ORDERED_DO_BAR and unify action mask handling in start_ordered() such that any barrier action can be skipped. This patch doesn't introduce any visible behavior changes. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: remove duplicate or unused barrier/discard error pathsTejun Heo2-35/+13
* Because barrier mode can be changed dynamically, whether barrier is supported or not can be determined only when actually issuing the barrier and there is no point in checking it earlier. Drop barrier support check in generic_make_request() and __make_request(), and update comment around the support check in blk_do_ordered(). * There is no reason to check discard support in both generic_make_request() and __make_request(). Drop the check in __make_request(). While at it, move error action block to the end of the function and add unlikely() to q existence test. * Barrier request, be it empty or not, is never passed to low level driver and thus it's meaningless to try to copy back req->sector to bio->bi_sector on error. In addition, the notion of failed sector doesn't make any sense for empty barrier to begin with. Drop the code block from __end_that_request_first(). Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2008-12-29block: reorganize QUEUE_ORDERED_* constantsTejun Heo1-10/+10
Separate out ordering type (drain,) and action masks (preflush, postflush, fua) from visible ordering mode selectors (QUEUE_ORDERED_*). Ordering types are now named QUEUE_ORDERED_BY_* while action masks are named QUEUE_ORDERED_DO_*. This change is necessary to add QUEUE_ORDERED_DO_BAR and make it optional to improve empty barrier implementation. Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>