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2010-05-11Revert "perf: Fix exit() vs PERF_FORMAT_GROUP"Ingo Molnar1-1/+0
This reverts commit 4fd38e4595e2f6c9d27732c042a0e16b2753049c. It causes various crashes and hangs when events are activated. The cause is not fully understood yet but we need to revert it because the effects are severe. Reported-by: Stephane Eranian <eranian@google.com> Reported-by: Lin Ming <ming.m.lin@intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07perf: Add group scheduling transactional APIsLin Ming1-3/+12
Add group scheduling transactional APIs to struct pmu. These APIs will be implemented in arch code, based on Peter's idea as below. > the idea behind hw_perf_group_sched_in() is to not perform > schedulability tests on each event in the group, but to add the group > as a whole and then perform one test. > > Of course, when that test fails, you'll have to roll-back the whole > group again. > > So start_txn (or a better name) would simply toggle a flag in the pmu > implementation that will make pmu::enable() not perform the > schedulablilty test. > > Then commit_txn() will perform the schedulability test (so note the > method has to have a !void return value. > > This will allow us to use the regular > kernel/perf_event.c::group_sched_in() and all the rollback code. > Currently each hw_perf_group_sched_in() implementation duplicates all > the rolllback code (with various bugs). ->start_txn: Start group events scheduling transaction, set a flag to make pmu::enable() not perform the schedulability test, it will be performed at commit time. ->commit_txn: Commit group events scheduling transaction, perform the group schedulability as a whole ->cancel_txn: Stop group events scheduling transaction, clear the flag so pmu::enable() will perform the schedulability test. Reviewed-by: Stephane Eranian <eranian@google.com> Reviewed-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Lin Ming <ming.m.lin@intel.com> Cc: David Miller <davem@davemloft.net> Cc: Paul Mackerras <paulus@samba.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1272002160.5707.60.camel@minggr.sh.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07perf, x86: Improve the PEBS ABIPeter Zijlstra1-4/+19
Rename perf_event_attr::precise to perf_event_attr::precise_ip and widen it to 2 bits. This new field describes the required precision of the PERF_SAMPLE_IP field: 0 - SAMPLE_IP can have arbitrary skid 1 - SAMPLE_IP must have constant skid 2 - SAMPLE_IP requested to have 0 skid 3 - SAMPLE_IP must have 0 skid And modify the Intel PEBS code accordingly. The PEBS implementation now supports up to precise_ip == 2, where we perform the IP fixup. Also s/PERF_RECORD_MISC_EXACT/&_IP/ to clarify its meaning, this bit should be set for each PERF_SAMPLE_IP field known to match the actual instruction triggering the event. This new scheme allows for a PEBS mode that uses the buffer for more than a single event. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07Merge branch 'perf/urgent' into perf/coreIngo Molnar3-3/+18
Merge reason: Resolve patch dependency Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-07perf: Fix exit() vs PERF_FORMAT_GROUPPeter Zijlstra1-0/+1
Both Stephane and Corey reported that PERF_FORMAT_GROUP didn't work as expected if the task the counters were attached to quit before the read() call. The cause is that we unconditionally destroy the grouping when we remove counters from their context. Fix this by only doing this when we free the counter itself. Reported-by: Corey Ashford <cjashfor@linux.vnet.ibm.com> Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1273160566.5605.404.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-05-04i2c-core: Use per-adapter userspace device listsJean Delvare1-0/+2
Using a single list for all userspace devices leads to a dead lock on multiplexed buses in some circumstances (mux chip instantiated from userspace). This is solved by using a separate list for each bus segment. Signed-off-by: Jean Delvare <khali@linux-fr.org> Acked-by: Michael Lawnick <ml.lawnick@gmx.de>
2010-05-01hw-breakpoints: Get the number of available registers on boot dynamicallyFrederic Weisbecker1-0/+10
The breakpoint generic layer assumes that archs always know in advance the static number of address registers available to host breakpoints through the HBP_NUM macro. However this is not true for every archs. For example Arm needs to get this information dynamically to handle the compatiblity between different versions. To solve this, this patch proposes to drop the static HBP_NUM macro and let the arch provide the number of available slots through a new hw_breakpoint_slots() function. For archs that have CONFIG_HAVE_MIXED_BREAKPOINTS_REGS selected, it will be called once as the number of registers fits for instruction and data breakpoints together. For the others it will be called first to get the number of instruction breakpoint registers and another time to get the data breakpoint registers, the targeted type is given as a parameter of hw_breakpoint_slots(). Reported-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: K. Prasad <prasad@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-05-01hw-breakpoints: Separate constraint space for data and instruction breakpointsFrederic Weisbecker1-3/+6
There are two outstanding fashions for archs to implement hardware breakpoints. The first is to separate breakpoint address pattern definition space between data and instruction breakpoints. We then have typically distinct instruction address breakpoint registers and data address breakpoint registers, delivered with separate control registers for data and instruction breakpoints as well. This is the case of PowerPc and ARM for example. The second consists in having merged breakpoint address space definition between data and instruction breakpoint. Address registers can host either instruction or data address and the access mode for the breakpoint is defined in a control register. This is the case of x86 and Super H. This patch adds a new CONFIG_HAVE_MIXED_BREAKPOINTS_REGS config that archs can select if they belong to the second case. Those will have their slot allocation merged for instructions and data breakpoints. The others will have a separate slot tracking between data and instruction breakpoints. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: K. Prasad <prasad@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu>
2010-05-01hw-breakpoints: Tag ptrace breakpoint as exclude_kernelFrederic Weisbecker1-0/+6
Tag ptrace breakpoints with the exclude_kernel attribute set. This will make it easier to set generic policies on breakpoints, when it comes to ensure nobody unpriviliged try to breakpoint on the kernel. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Cc: Will Deacon <will.deacon@arm.com> Cc: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Cc: K. Prasad <prasad@linux.vnet.ibm.com> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu>
2010-04-30USB: rename usb_buffer_alloc() and usb_buffer_free()Daniel Mack1-3/+15
For more clearance what the functions actually do, usb_buffer_alloc() is renamed to usb_alloc_coherent() usb_buffer_free() is renamed to usb_free_coherent() They should only be used in code which really needs DMA coherency. [added compatibility macros so we can convert things easier - gregkh] Signed-off-by: Daniel Mack <daniel@caiaq.de> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Pedro Ribeiro <pedrib@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-04-30Merge commit 'v2.6.34-rc6' into perf/coreIngo Molnar7-2/+23
Merge reason: update to the latest -rc. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-29Merge branch 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6Linus Torvalds1-0/+1
* 'bugfixes' of git://git.linux-nfs.org/projects/trondmy/nfs-2.6: nfs: fix memory leak in nfs_get_sb with CONFIG_NFS_V4 nfs: fix some issues in nfs41_proc_reclaim_complete() NFS: Ensure that nfs_wb_page() waits for Pg_writeback to clear NFS: Fix an unstable write data integrity race nfs: testing for null instead of ERR_PTR() NFS: rsize and wsize settings ignored on v4 mounts NFSv4: Don't attempt an atomic open if the file is a mountpoint SUNRPC: Fix a bug in rpcauth_prune_expired
2010-04-28Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds4-0/+10
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: coda: move backing-dev.h kernel include inside __KERNEL__ mtd: ensure that bdi entries are properly initialized and registered Move mtd_bdi_*mappable to mtdcore.c btrfs: convert to using bdi_setup_and_register() Catch filesystems lacking s_bdi drbd: Terminate a connection early if sending the protocol fails drbd: fix memory leak Fix JFFS2 sync silent failure smbfs: add bdi backing to mount session ncpfs: add bdi backing to mount session exofs: add bdi backing to mount session ecryptfs: add bdi backing to mount session coda: add bdi backing to mount session cifs: add bdi backing to mount session afs: add bdi backing to mount session. 9p: add bdi backing to mount session bdi: add helper function for doing init and register of a bdi for a file system block: ensure jiffies wrap is handled correctly in blk_rq_timed_out_timer
2010-04-28coda: move backing-dev.h kernel include inside __KERNEL__Jens Axboe1-1/+2
Otherwise we must export backing-dev.h as well, which doesn't make any sense. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-25Catch filesystems lacking s_bdiJörn Engel1-0/+1
noop_backing_dev_info is used only as a flag to mark filesystems that don't have any backing store, like tmpfs, procfs, spufs, etc. Signed-off-by: Joern Engel <joern@logfs.org> Changed the BUG_ON() to a WARN_ON(). Note that adding dirty inodes to the noop_backing_dev_info is not legal and will not result in them being flushed, but we already catch this condition in __mark_inode_dirty() when checking for a registered bdi. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-24hugetlb: fix infinite loop in get_futex_key() when backed by huge pagesMel Gorman1-0/+9
If a futex key happens to be located within a huge page mapped MAP_PRIVATE, get_futex_key() can go into an infinite loop waiting for a page->mapping that will never exist. See https://bugzilla.redhat.com/show_bug.cgi?id=552257 for more details about the problem. This patch makes page->mapping a poisoned value that includes PAGE_MAPPING_ANON mapped MAP_PRIVATE. This is enough for futex to continue but because of PAGE_MAPPING_ANON, the poisoned value is not dereferenced or used by futex. No other part of the VM should be dereferencing the page->mapping of a hugetlbfs page as its page cache is not on the LRU. This patch fixes the problem with the test case described in the bugzilla. [akpm@linux-foundation.org: mel cant spel] Signed-off-by: Mel Gorman <mel@csn.ul.ie> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Darren Hart <darren@dvhart.com> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23Cleanup generic block based fiemapJosef Bacik1-2/+3
This cleans up a few of the complaints of __generic_block_fiemap. I've fixed all the typing stuff, used inline functions instead of macros, gotten rid of a couple of variables, and made sure the size and block requests are all block aligned. It also fixes a problem where sometimes FIEMAP_EXTENT_LAST wasn't being set properly. Signed-off-by: Josef Bacik <josef@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-23Merge branch 'linus' into perf/coreIngo Molnar18-72/+185
Merge reason: merge the latest fixes, update to latest -rc. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-22Merge branch 'for-linus' of ↵Linus Torvalds2-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: ohci: wait for local CSR lock access to finish firewire: ohci: prevent aliasing of locally handled register addresses firewire: core: fw_iso_resource_manage: return -EBUSY when out of resources firewire: core: fix retries calculation in iso manage_channel() firewire: cdev: fix cut+paste mistake in disclaimer
2010-04-22NFS: Fix an unstable write data integrity raceTrond Myklebust1-0/+1
Commit 2c61be0a9478258f77b66208a0c4b1f5f8161c3c (NFS: Ensure that the WRITE and COMMIT RPC calls are always uninterruptible) exposed a race on file close. In order to ensure correct close-to-open behaviour, we want to wait for all outstanding background commit operations to complete. This patch adds an inode flag that indicates if a commit operation is under way, and provides a mechanism to allow ->write_inode() to wait for its completion if this is a data integrity flush. Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2010-04-22smbfs: add bdi backing to mount sessionJens Axboe1-0/+3
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22ncpfs: add bdi backing to mount sessionJens Axboe1-0/+2
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22coda: add bdi backing to mount sessionJens Axboe1-0/+2
This ensures that dirty data gets flushed properly. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-22bdi: add helper function for doing init and register of a bdi for a file systemJens Axboe1-0/+1
Pretty trivial helper, just sets up the bdi and registers it. An atomic sequence count is used to ensure that the registered sysfs names are unique. Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
2010-04-21Merge branch 'for-linus' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/lrg/voltage-2.6: mc13783-regulator: fix a memory leak in mc13783_regulator_remove regulator: Let drivers know when they use the stub API
2010-04-20KVM: Increase NR_IOBUS_DEVS limit to 200Sridhar Samudrala1-1/+1
This patch increases the current hardcoded limit of NR_IOBUS_DEVS from 6 to 200. We are hitting this limit when creating a guest with more than 1 virtio-net device using vhost-net backend. Each virtio-net device requires 2 such devices to service notifications from rx/tx queues. Signed-off-by: Sridhar Samudrala <sri@us.ibm.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-20KVM: fix the handling of dirty bitmaps to avoid overflowsTakuya Yoshikawa1-0/+5
Int is not long enough to store the size of a dirty bitmap. This patch fixes this problem with the introduction of a wrapper function to calculate the sizes of dirty bitmaps. Note: in mark_page_dirty(), we have to consider the fact that __set_bit() takes the offset as int, not long. Signed-off-by: Takuya Yoshikawa <yoshikawa.takuya@oss.ntt.co.jp> Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
2010-04-20perf & kvm: Clean up some of the guest profiling callback API detailsZhang, Yanmin1-6/+4
Fix some build bug and programming style issues: - use valid C - fix up various style details Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Cc: Avi Kivity <avi@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Sheng Yang <sheng@linux.intel.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: oerg Roedel <joro@8bytes.org> Cc: Jes Sorensen <Jes.Sorensen@redhat.com> Cc: Gleb Natapov <gleb@redhat.com> Cc: Zachary Amsden <zamsden@redhat.com> Cc: zhiteng.huang@intel.com Cc: tim.c.chen@intel.com Cc: Arnaldo Carvalho de Melo <acme@infradead.org> LKML-Reference: <1271729638.2078.624.camel@ymzhang.sh.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-19Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds1-9/+56
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'core-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: rcu: Make RCU lockdep check the lockdep_recursion variable rcu: Update docs for rcu_access_pointer and rcu_dereference_protected rcu: Better explain the condition parameter of rcu_dereference_check() rcu: Add rcu_access_pointer and rcu_dereference_protected
2010-04-19regulator: Let drivers know when they use the stub APIJean Delvare1-2/+6
Have the stub variant of regulator_get() return NULL, so that drivers can (but still don't have to) handle this case specifically. Signed-off-by: Jean Delvare <khali@linux-fr.org> Cc: Mark Brown <broonie@opensource.wolfsonmicro.com> Cc: Jerome Oufella <jerome.oufella@savoirfairelinux.com> Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com> Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>
2010-04-19perf: Enhance perf to allow for guest statistic collection from hostZhang, Yanmin1-1/+20
Below patch introduces perf_guest_info_callbacks and related register/unregister functions. Add more PERF_RECORD_MISC_XXX bits meaning guest kernel and guest user space. Signed-off-by: Zhang Yanmin <yanmin_zhang@linux.intel.com> Signed-off-by: Avi Kivity <avi@redhat.com>
2010-04-19rcu: Make RCU lockdep check the lockdep_recursion variablePaul E. McKenney1-4/+1
The lockdep facility temporarily disables lockdep checking by incrementing the current->lockdep_recursion variable. Such disabling happens in NMIs and in other situations where lockdep might expect to recurse on itself. This patch therefore checks current->lockdep_recursion, disabling RCU lockdep splats when this variable is non-zero. In addition, this patch removes the "likely()", as suggested by Lai Jiangshan. Reported-by: Frederic Weisbecker <fweisbec@gmail.com> Reported-by: David Miller <davem@davemloft.net> Tested-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: eric.dumazet@gmail.com LKML-Reference: <20100415195039.GA22623@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-16firewire: cdev: fix cut+paste mistake in disclaimerStefan Richter2-2/+2
This was supposed to be generic "authors or copyright holders"; I mistakenly picked up text from a wrong file. Reported-by: Daniel K. <dk@uw.no> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-15Merge branch 'for-linus' of ↵Linus Torvalds2-25/+82
git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ieee1394/linux1394-2.6: firewire: cdev: change license of exported header files to MIT license firewire: cdev: comment fixlet firewire: cdev: iso packet documentation firewire: cdev: fix information leak firewire: cdev: require quadlet-aligned headers for transmit packets firewire: cdev: disallow receive packets without header
2010-04-15Merge branch 'for-linus' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/dtor/input: Input: wacom - switch mode upon system resume Revert "Input: wacom - merge out and in prox events" Input: matrix_keypad - allow platform to disable key autorepeat Input: ALPS - add signature for HP Pavilion dm3 laptops Input: i8042 - spelling fix Input: sparse-keymap - implement safer freeing of the keymap Input: update the status of the Multitouch X driver project Input: clarify the no-finger event in multitouch protocol Input: bcm5974 - retract efi-broken suspend_resume Input: sparse-keymap - free the right keymap on error
2010-04-15firewire: cdev: change license of exported header files to MIT licenseStefan Richter2-17/+47
Among else, this allows projects like libdc1394 to carry copies of the ABI related header files without them or distributors having to worry about effects on the project's overall license terms. Switch to MIT license as suggested by Kristian. Also update the year in the copyright statement according to source history. Cc: Jay Fenlason <fenlason@redhat.com> Acked-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> Signed-off-by: Kristian Høgsberg <krh@bitplanet.net>
2010-04-14perf: Store active software events in a hashlistFrederic Weisbecker1-0/+12
Each time a software event triggers, we need to walk through the entire list of events from the current cpu and task contexts to retrieve a running perf event that matches. We also need to check a matching perf event is actually counting. This walk is wasteful and makes the event fast path scaling down with a growing number of events running on the same contexts. To solve this, we store the running perf events in a hashlist to get an immediate access to them against their type:event_id when they trigger. v2: - Fix SWEVENT_HLIST_SIZE definition (and re-learn some basic maths along the way) - Only allocate hlist for online cpus, but keep track of the refcount on offline possible cpus too, so that we allocate it if needed when it becomes online. - Drop the kref use as it's not adapted to our tricks anymore. v3: - Fix bad refcount check (address instead of value). Thanks to Eric Dumazet who spotted this. - While exiting cpu, move the hlist release out of the IPI path to lock the hlist mutex sanely. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Ingo Molnar <mingo@elte.hu>
2010-04-14rcu: Better explain the condition parameter of rcu_dereference_check()David Howells1-5/+23
Better explain the condition parameter of rcu_dereference_check() that describes the conditions under which the dereference is permitted to take place (and incorporate Yong Zhang's suggestion). This condition is only checked under lockdep proving. Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: eric.dumazet@gmail.com LKML-Reference: <1270852752-25278-2-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-14rcu: Add rcu_access_pointer and rcu_dereference_protectedPaul E. McKenney1-0/+32
This patch adds variants of rcu_dereference() that handle situations where the RCU-protected data structure cannot change, perhaps due to our holding the update-side lock, or where the RCU-protected pointer is only to be fetched, not dereferenced. These are needed due to some performance concerns with using rcu_dereference() where it is not required, aside from the need for lockdep/sparse checking. The new rcu_access_pointer() primitive is for the case where the pointer is be fetch and not dereferenced. This primitive may be used without protection, RCU or otherwise, due to the fact that it uses ACCESS_ONCE(). The new rcu_dereference_protected() primitive is for the case where updates are prevented, for example, due to holding the update-side lock. This primitive does neither ACCESS_ONCE() nor smp_read_barrier_depends(), so can only be used when updates are somehow prevented. Suggested-by: David Howells <dhowells@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: josh@joshtriplett.org Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com Cc: eric.dumazet@gmail.com LKML-Reference: <1270852752-25278-1-git-send-email-paulmck@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-12NFSv4: fix delegated lockingTrond Myklebust1-0/+1
Arnaud Giersch reports that NFSv4 locking is broken when we hold a delegation since commit 8e469ebd6dc32cbaf620e134d79f740bf0ebab79 (NFSv4: Don't allow posix locking against servers that don't support it). According to Arnaud, the lock succeeds the first time he opens the file (since we cannot do a delegated open) but then fails after we start using delegated opens. The following patch fixes it by ensuring that locking behaviour is governed by a per-filesystem capability flag that is initially set, but gets cleared if the server ever returns an OPEN without the NFS4_OPEN_RESULT_LOCKTYPE_POSIX flag being set. Reported-by: Arnaud Giersch <arnaud.giersch@iut-bm.univ-fcomte.fr> Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com> Cc: stable@kernel.org
2010-04-10firewire: cdev: comment fixletStefan Richter1-2/+2
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-10firewire: cdev: iso packet documentationClemens Ladisch1-6/+33
Add the missing documentation for iso packets. Signed-off-by: Clemens Ladisch <clemens@ladisch.de> Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
2010-04-09Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds7-33/+21
* 'for-linus' of git://git.kernel.dk/linux-2.6-block: (34 commits) cfq-iosched: Fix the incorrect timeslice accounting with forced_dispatch loop: Update mtime when writing using aops block: expose the statistics in blkio.time and blkio.sectors for the root cgroup backing-dev: Handle class_create() failure Block: Fix block/elevator.c elevator_get() off-by-one error drbd: lc_element_by_index() never returns NULL cciss: unlock on error path cfq-iosched: Do not merge queues of BE and IDLE classes cfq-iosched: Add additional blktrace log messages in CFQ for easier debugging i2o: Remove the dangerous kobj_to_i2o_device macro block: remove 16 bytes of padding from struct request on 64bits cfq-iosched: fix a kbuild regression block: make CONFIG_BLK_CGROUP visible Remove GENHD_FL_DRIVERFS block: Export max number of segments and max segment size in sysfs block: Finalize conversion of block limits functions block: Fix overrun in lcm() and move it to lib vfs: improve writeback_inodes_wb() paride: fix off-by-one test drbd: fix al-to-on-disk-bitmap for 4k logical_block_size ...
2010-04-09radix_tree_tag_get() is not as safe as the docs make out [ver #2]David Howells1-0/+7
radix_tree_tag_get() is not safe to use concurrently with radix_tree_tag_set() or radix_tree_tag_clear(). The problem is that the double tag_get() in radix_tree_tag_get(): if (!tag_get(node, tag, offset)) saw_unset_tag = 1; if (height == 1) { int ret = tag_get(node, tag, offset); may see the value change due to the action of set/clear. RCU is no protection against this as no pointers are being changed, no nodes are being replaced according to a COW protocol - set/clear alter the node directly. The documentation in linux/radix-tree.h, however, says that radix_tree_tag_get() is an exception to the rule that "any function modifying the tree or tags (...) must exclude other modifications, and exclude any functions reading the tree". The problem is that the next statement in radix_tree_tag_get() checks that the tag doesn't vary over time: BUG_ON(ret && saw_unset_tag); This has been seen happening in FS-Cache: https://www.redhat.com/archives/linux-cachefs/2010-April/msg00013.html To this end, remove the BUG_ON() from radix_tree_tag_get() and note in various comments that the value of the tag may change whilst the RCU read lock is held, and thus that the return value of radix_tree_tag_get() may not be relied upon unless radix_tree_tag_set/clear() and radix_tree_delete() are excluded from running concurrently with it. Reported-by: Romain DEGEZ <romain.degez@smartjog.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Nick Piggin <npiggin@suse.de> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-09slab: Generify kernel pointer validationPekka Enberg1-0/+1
As suggested by Linus, introduce a kern_ptr_validate() helper that does some sanity checks to make sure a pointer is a valid kernel pointer. This is a preparational step for fixing SLUB kmem_ptr_validate(). Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: David Rientjes <rientjes@google.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Matt Mackall <mpm@selenic.com> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-04-08libata: Fix accesses at LBA28 boundary (old bug, but nasty) (v2)Mark Lord1-2/+2
Most drives from Seagate, Hitachi, and possibly other brands, do not allow LBA28 access to sector number 0x0fffffff (2^28 - 1). So instead use LBA48 for such accesses. This bug could bite a lot of systems, especially when the user has taken care to align partitions to 4KB boundaries. On misaligned systems, it is less likely to be encountered, since a 4KB read would end at 0x10000000 rather than at 0x0fffffff. Signed-off-by: Mark Lord <mlord@pobox.com> Signed-off-by: Jeff Garzik <jgarzik@redhat.com>
2010-04-08Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6Linus Torvalds1-0/+1
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/ide-2.6: ide: Fix IDE taskfile with cfq scheduler ide: Must hold queue lock when requeueing ide: Requeue request after DMA timeout
2010-04-08Merge branch 'linus' into perf/coreIngo Molnar25-65/+67
Semantic conflict: arch/x86/kernel/cpu/perf_event_intel_ds.c Merge reason: pick up latest fixes, fix the conflict Signed-off-by: Ingo Molnar <mingo@elte.hu>
2010-04-08virtio: disable multiport console support.Michael S. Tsirkin1-23/+0
Move MULTIPORT feature and related config changes out of exported headers, and disable the feature at runtime. At this point, it seems less risky to keep code around until we can enable it than rip it out completely. Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
2010-04-07Merge branch 'x86-fixes-for-linus' of ↵Linus Torvalds1-2/+6
git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip * 'x86-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/x86/linux-2.6-tip: x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards x86: Increase CONFIG_NODES_SHIFT max to 10 ibft, x86: Change reserve_ibft_region() to find_ibft_region() x86, hpet: Fix bug in RTC emulation x86, hpet: Erratum workaround for read after write of HPET comparator bootmem, x86: Fix 32bit numa system without RAM on node 0 nobootmem, x86: Fix 32bit numa system without RAM on node 0 x86: Handle overlapping mptables x86: Make e820_remove_range to handle all covered case x86-32, resume: do a global tlb flush in S4 resume