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* Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2009-10-05
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf tools: Run generate-cmdlist.sh properly perf_event: Clean up perf_event_init_task() perf_event: Fix event group handling in __perf_event_sched_*() perf timechart: Add a power-only mode perf top: Add poll_idle to the skip list
| * perf_event: Clean up perf_event_init_task()Xiao Guangrong2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While at it: we can traverse ctx->group_list to get all group leader, it should be safe since we hold ctx->mutex. Changlog v1->v2: - remove WARN_ON_ONCE() according to Peter Zijlstra's suggestion Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4ABC5AF9.6060808@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf_event: Fix event group handling in __perf_event_sched_*()Xiao Guangrong2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Paul Mackerras says: "Actually, looking at this more closely, it has to be a group leader anyway since it's at the top level of ctx->group_list. In fact I see four places where we do: list_for_each_entry(event, &ctx->group_list, group_entry) { if (event == event->group_leader) ... or the equivalent, three of which appear to have been introduced by afedadf2 ("perf_counter: Optimize sched in/out of counters") back in May by Peter Z. As far as I can see the if () is superfluous in each case (a singleton event will be a group of 1 and will have its group_leader pointing to itself)." [ See: http://marc.info/?l=linux-kernel&m=125361238901442&w=2 ] And Peter Zijlstra points out this is a bugfix: "The intent was to call event_sched_{in,out}() for single event groups because that's cheaper than group_sched_{in,out}(), however.. - as you noticed, I got the condition wrong, it should have read: list_empty(&event->sibling_list) - it failed to call group_can_go_on() which deals with ->exclusive. - it also doesn't call hw_perf_group_sched_in() which might break power." [ See: http://marc.info/?l=linux-kernel&m=125369523318583&w=2 ] Changelog v1->v2: - Fix the title name according to Peter Zijlstra's suggestion - Remove the comments and WARN_ON_ONCE() as Peter Zijlstra's suggestion Signed-off-by: Xiao Guangrong <xiaoguangrong@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Paul Mackerras <paulus@samba.org> LKML-Reference: <4ABC5A55.7000208@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2009-10-05
|\ \ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: hrtimer: Remove overly verbose "switch to high res mode" message
| * | hrtimer: Remove overly verbose "switch to high res mode" messageRoland Dreier2009-09-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On big systems, printing <number of CPUs> copies of Switched to high resolution mode on CPU nnn clutters up the kernel log for minimal gain. Just get rid of them. Signed-off-by: Roland Dreier <rolandd@cisco.com> LKML-Reference: <ada1vlw126s.fsf_-_@cisco.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-10-05
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: kmemtrace: Fix up tracer registration tracing: Fix infinite recursion in ftrace_update_pid_func()
| * | | kmemtrace: Fix up tracer registrationPaul Mundt2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit ddc1637af217dbd8bc51f30e6d24e84476a869a6 ("kmemtrace: Print binary output only if 'bin' option is set") ended up inverting the error detection logic. register_tracer() returns 0 on success, which this change caused to treat as an error, resulting in: [ 0.132000] Warning: could not register the kmem tracer as well as bailing out of the initcall with an error value. This restores the old logic. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Pekka Enberg <penberg@cs.helsinki.fi> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Li Zefan <lizf@cn.fujitsu.com> LKML-Reference: <20090928075540.GD6668@linux-sh.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | tracing: Fix infinite recursion in ftrace_update_pid_func()Matt Fleming2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When CONFIG_HAVE_FUNCTION_TRACE_MCOUNT_TEST is enabled __ftrace_trace_function contains the current trace function, not ftrace_trace_function. In ftrace_update_pid_func() we currently incorrectly assign the value of ftrace_trace_function to __ftrace_trace_funcion before returning. Without this patch it is possible to execute an infinite recursion whereby ftrace_test_stop_func() calls __ftrace_trace_function, which was assigned ftrace_test_stop_func() in ftrace_update_pid_func(). Signed-off-by: Matt Fleming <matthew.fleming@imgtec.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <1254152581-18347-1-git-send-email-matt@console-pimps.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-blockLinus Torvalds2009-10-04
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.kernel.dk/linux-2.6-block: (41 commits) Revert "Seperate read and write statistics of in_flight requests" cfq-iosched: don't delay async queue if it hasn't dispatched at all block: Topology ioctls cfq-iosched: use assigned slice sync value, not default cfq-iosched: rename 'desktop' sysfs entry to 'low_latency' cfq-iosched: implement slower async initiate and queue ramp up cfq-iosched: delay async IO dispatch, if sync IO was just done cfq-iosched: add a knob for desktop interactiveness Add a tracepoint for block request remapping block: allow large discard requests block: use normal I/O path for discard requests swapfile: avoid NULL pointer dereference in swapon when s_bdev is NULL fs/bio.c: move EXPORT* macros to line after function Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs cciss: fix build when !PROC_FS block: Do not clamp max_hw_sectors for stacking devices block: Set max_sectors correctly for stacking devices cciss: cciss_host_attr_groups should be const cciss: Dynamically allocate the drive_info_struct for each logical drive. cciss: Add usage_count attribute to each logical drive in /sys ...
| * | | | Add a tracepoint for block request remappingJun'ichi Nomura2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Since 2.6.31 now has request-based device-mapper, it's useful to have a tracepoint for request-remapping as well as bio-remapping. This patch adds a tracepoint for request-remapping, trace_block_rq_remap(). Signed-off-by: Kiyoshi Ueda <k-ueda@ct.jp.nec.com> Signed-off-by: Jun'ichi Nomura <j-nomura@ce.jp.nec.com> Cc: Alasdair G Kergon <agk@redhat.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
| * | | | Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfsZdenek Kabelac2009-10-01
| | |_|/ | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add missing blk_trace_remove_sysfs to be in pair with blk_trace_init_sysfs introduced in commit 1d54ad6da9192fed5dd3b60224d9f2dfea0dcd82. Release kobject also in case the request_fn is NULL. Problem was noticed via kmemleak backtrace when some sysfs entries were note properly destroyed during device removal: unreferenced object 0xffff88001aa76640 (size 80): comm "lvcreate", pid 2120, jiffies 4294885144 hex dump (first 32 bytes): 01 00 00 00 00 00 00 00 f0 65 a7 1a 00 88 ff ff .........e...... 90 66 a7 1a 00 88 ff ff 86 1d 53 81 ff ff ff ff .f........S..... backtrace: [<ffffffff813f9cc6>] kmemleak_alloc+0x26/0x60 [<ffffffff8111d693>] kmem_cache_alloc+0x133/0x1c0 [<ffffffff81195891>] sysfs_new_dirent+0x41/0x120 [<ffffffff81194b0c>] sysfs_add_file_mode+0x3c/0xb0 [<ffffffff81197c81>] internal_create_group+0xc1/0x1a0 [<ffffffff81197d93>] sysfs_create_group+0x13/0x20 [<ffffffff810d8004>] blk_trace_init_sysfs+0x14/0x20 [<ffffffff8123f45c>] blk_register_queue+0x3c/0xf0 [<ffffffff812447e4>] add_disk+0x94/0x160 [<ffffffffa00d8b08>] dm_create+0x598/0x6e0 [dm_mod] [<ffffffffa00de951>] dev_create+0x51/0x350 [dm_mod] [<ffffffffa00de823>] ctl_ioctl+0x1a3/0x240 [dm_mod] [<ffffffffa00de8f2>] dm_compat_ctl_ioctl+0x12/0x20 [dm_mod] [<ffffffff81177bfd>] compat_sys_ioctl+0xcd/0x4f0 [<ffffffff81036ed8>] sysenter_dispatch+0x7/0x2c [<ffffffffffffffff>] 0xffffffffffffffff Signed-off-by: Zdenek Kabelac <zkabelac@redhat.com> Reviewed-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
* | | | memcg: some modification to softlimit under hierarchical memory reclaim.KAMEZAWA Hiroyuki2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch clean up/fixes for memcg's uncharge soft limit path. Problems: Now, res_counter_charge()/uncharge() handles softlimit information at charge/uncharge and softlimit-check is done when event counter per memcg goes over limit. Now, event counter per memcg is updated only when memory usage is over soft limit. Here, considering hierarchical memcg management, ancesotors should be taken care of. Now, ancerstors(hierarchy) are handled in charge() but not in uncharge(). This is not good. Prolems: 1. memcg's event counter incremented only when softlimit hits. That's bad. It makes event counter hard to be reused for other purpose. 2. At uncharge, only the lowest level rescounter is handled. This is bug. Because ancesotor's event counter is not incremented, children should take care of them. 3. res_counter_uncharge()'s 3rd argument is NULL in most case. ops under res_counter->lock should be small. No "if" sentense is better. Fixes: * Removed soft_limit_xx poitner and checks in charge and uncharge. Do-check-only-when-necessary scheme works enough well without them. * make event-counter of memcg incremented at every charge/uncharge. (per-cpu area will be accessed soon anyway) * All ancestors are checked at soft-limit-check. This is necessary because ancesotor's event counter may never be modified. Then, they should be checked at the same time. Reviewed-by: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | cgroup: catch bad css refcnt at css_putKAMEZAWA Hiroyuki2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | __css_put() doesn't check a bug as refcnt goes to minus. I think it should be caught. This patch adds a check for it. Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Paul Menage <menage@google.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Balbir Singh <balbir@in.ibm.com> Cc: Daisuke Nishimura <nishimura@mxp.nes.nec.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | const: constify remaining file_operationsAlexey Dobriyan2009-10-01
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [akpm@linux-foundation.org: fix KVM] Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | | module: fix up CONFIG_KALLSYMS=n build.Paul Mundt2009-10-01
| |/ / |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Starting from commit 4a4962263f07d14660849ec134ee42b63e95ea9a "reduce symbol table for loaded modules (v2)", the kernel/module.c build is broken with CONFIG_KALLSYMS disabled. CC kernel/module.o kernel/module.c:1995: warning: type defaults to 'int' in declaration of 'Elf_Hdr' kernel/module.c:1995: error: expected ';', ',' or ')' before '*' token kernel/module.c: In function 'load_module': kernel/module.c:2203: error: 'strmap' undeclared (first use in this function) kernel/module.c:2203: error: (Each undeclared identifier is reported only once kernel/module.c:2203: error: for each function it appears in.) kernel/module.c:2239: error: 'symoffs' undeclared (first use in this function) kernel/module.c:2239: error: implicit declaration of function 'layout_symtab' kernel/module.c:2240: error: 'stroffs' undeclared (first use in this function) make[1]: *** [kernel/module.o] Error 1 make: *** [kernel/module.o] Error 2 There are three different issues: - layout_symtab() takes a const Elf_Ehdr - layout_symtab() needs to return a value - symoffs/stroffs/strmap are referenced by the load_module() code despite being ifdefed out, which seems unnecessary given the noop behaviour of layout_symtab()/add_kallsyms() in the case of CONFIG_KALLSYMS=n. Signed-off-by: Paul Mundt <lethal@linux-sh.org> Acked-by: Jan Beulich <jbeulich@novell.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | | sched_clock: Fix atomicity/continuity bug by using cmpxchg64()Eric Dumazet2009-09-30
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit def0a9b2573 (sched_clock: Make it NMI safe) assumed cmpxchg() of 64bit values was available on X86_32. That is not so - and causes some subtle scheduler misbehavior due to incorrect timestamps off to up by ~4 seconds. Two symptoms are known right now: - interactivity problems seen by Arjan: up to 600 msecs latencies instead of the expected 20-40 msecs. These latencies are very visible on the desktop. - incorrect CPU stats: occasionally too high percentages in 'top', and crazy CPU usage stats. Reported-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Cc: John Stultz <johnstul@us.ibm.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20090930170754.0886ff2e@infradead.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | const: mark struct vm_struct_operationsAlexey Dobriyan2009-09-27
| | | | | | | | | | | | | | | | | | | | | | * mark struct vm_area_struct::vm_ops as const * mark vm_ops in AGP code But leave TTM code alone, something is fishy there with global vm_ops being used. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* | Merge branch 'timers-for-linus' of ↵Linus Torvalds2009-09-27
|\ \ | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: hrtimer: Eliminate needless reprogramming of clock events device
| * | hrtimer: Eliminate needless reprogramming of clock events deviceAshwin Chaugule2009-09-15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On NOHZ systems the following timers, - tick_nohz_restart_sched_tick (tick_sched_timer) - hrtimer_start (tick_sched_timer) are reprogramming the clock events device far more often than needed. No specific test case was required to observe this effect. This occurres because there was no check to see if the currently removed or restarted hrtimer was: 1) the one which previously armed the clock events device. 2) going to be replaced by another timer which has the same expiry time. Avoid the reprogramming in hrtimer_force_reprogram when the new expiry value which is evaluated from the clock bases is equal to cpu_base->expires_next. This results in faster application startup time by ~4%. [ tglx: simplified initial solution ] Signed-off-by: Ashwin Chaugule <ashwinc@quicinc.com> LKML-Reference: <4AA00165.90609@codeaurora.org> Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
* | | Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds2009-09-26
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: futex: Add memory barrier commentary to futex_wait_queue_me() futex: Fix wakeup race by setting TASK_INTERRUPTIBLE before queue_me() futex: Correct futex_q woken state commentary futex: Make function kernel-doc commentary consistent futex: Correct queue_me and unqueue_me commentary futex: Correct futex_wait_requeue_pi() commentary
| * | | futex: Add memory barrier commentary to futex_wait_queue_me()Darren Hart2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The memory barrier semantics of futex_wait_queue_me() are non-obvious. Add some commentary to try and clarify it. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090924185447.694.38948.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | futex: Fix wakeup race by setting TASK_INTERRUPTIBLE before queue_me()Darren Hart2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PI futexes do not use the same plist_node_empty() test for wakeup. It was possible for the waiter (in futex_wait_requeue_pi()) to set TASK_INTERRUPTIBLE after the waker assigned the rtmutex to the waiter. The waiter would then note the plist was not empty and call schedule(). The task would not be found by any subsequeuent futex wakeups, resulting in a userspace hang. By moving the setting of TASK_INTERRUPTIBLE to before the call to queue_me(), the race with the waker is eliminated. Since we no longer call get_user() from within queue_me(), there is no need to delay the setting of TASK_INTERRUPTIBLE until after the call to queue_me(). The FUTEX_LOCK_PI operation is not affected as futex_lock_pi() relies entirely on the rtmutex code to handle schedule() and wakeup. The requeue PI code is affected because the waiter starts as a non-PI waiter and is woken on a PI futex. Remove the crusty old comment about holding spinlocks() across get_user() as we no longer do that. Correct the locking statement with a description of why the test is performed. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090922053038.8717.97838.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | futex: Correct futex_q woken state commentaryDarren Hart2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use kernel-doc format to describe struct futex_q. Correct the wakeup definition to eliminate the statement about waking the waiter between the plist_del() and the q->lock_ptr = 0. Note in the comment that PI futexes have a different definition of the woken state. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090922053029.8717.62798.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | futex: Make function kernel-doc commentary consistentDarren Hart2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Make the existing function kernel-doc consistent throughout futex.c, following Documentation/kernel-doc-nano-howto.txt as closely as possible. When unsure, at least be consistent within futex.c. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090922053022.8717.13339.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | futex: Correct queue_me and unqueue_me commentaryDarren Hart2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The queue_me/unqueue_me commentary is oddly placed and out of date. Clean it up and correct the inaccurate bits. Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090922053015.8717.71713.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | futex: Correct futex_wait_requeue_pi() commentaryDarren Hart2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Correct various typos and formatting inconsistencies in the commentary of futex_wait_requeue_pi(). Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090922052958.8717.21932.stgit@Aeon> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'timers-fixes-for-linus' of ↵Linus Torvalds2009-09-26
|\ \ \ \ | | |_|/ | |/| | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'timers-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: clocksource: Resume clocksource without taking the clocksource mutex
| * | | clocksource: Resume clocksource without taking the clocksource mutexMartin Schwidefsky2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git commit 75c5158f70c065b9 converted the clocksource spinlock to a mutex. This causes the following BUG: BUG: sleeping function called from invalid context at kernel/mutex.c:280 in_atomic(): 0, irqs_disabled(): 1, pid: 2473, name: pm-suspend 2 locks held by pm-suspend/2473: #0: (&buffer->mutex){......}, at: [<ffffffff8115ab13>] sysfs_write_file+0x3c/0x137 #1: (pm_mutex){......}, at: [<ffffffff810865b5>] enter_state+0x39/0x130 Pid: 2473, comm: pm-suspend Not tainted 2.6.31 #1 Call Trace: [<ffffffff810792f0>] ? __debug_show_held_locks+0x22/0x24 [<ffffffff8104a2ef>] __might_sleep+0x107/0x10b [<ffffffff8141fca9>] mutex_lock_nested+0x25/0x43 [<ffffffff81073537>] clocksource_resume+0x1c/0x60 [<ffffffff81072902>] timekeeping_resume+0x1e/0x1c8 [<ffffffff812aee62>] __sysdev_resume+0x25/0xcf [<ffffffff812aef79>] sysdev_resume+0x6d/0xae [<ffffffff810864f8>] suspend_devices_and_enter+0x12b/0x1af [<ffffffff8108665b>] enter_state+0xdf/0x130 [<ffffffff81085dc3>] state_store+0xb6/0xd3 [<ffffffff81204c73>] kobj_attr_store+0x17/0x19 [<ffffffff8115abd2>] sysfs_write_file+0xfb/0x137 [<ffffffff811057d2>] vfs_write+0xae/0x10b [<ffffffff81208392>] ? __up_read+0x1a/0x7f [<ffffffff811058ef>] sys_write+0x4a/0x6e [<ffffffff81011b82>] system_call_fastpath+0x16/0x1b clocksource_resume is called early in the resume process, there is only one cpu, no processes are running and the interrupts are disabled. It is therefore possible to resume the clocksources without taking the clocksource mutex. Reported-by: Xiaotian Feng <xtfeng@gmail.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Tested-by: Michal Schmidt <mschmidt@redhat.com> Cc: Xiaotian Feng <xtfeng@gmail.com> Cc: John Stultz <johnstul@us.ibm.com> LKML-Reference: <20090924172952.49697825@mschwide.boeblingen.de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds2009-09-26
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'tracing-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: modules, tracing: Remove stale struct marker signature from module_layout() tracing/workqueue: Use %pf in workqueue trace events tracing: Fix a comment and a trivial format issue in tracepoint.h tracing: Fix failure path in ftrace_regex_open() tracing: Fix failure path in ftrace_graph_write() tracing: Check the return value of trace_get_user() tracing: Fix off-by-one in trace_get_user()
| * | | | modules, tracing: Remove stale struct marker signature from module_layout()Ingo Molnar2009-09-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus reported this new build warning: kernel/module.c:2951: warning: ?struct marker? declared inside parameter list kernel/module.c:2951: warning: its scope is only this definition or declaration, which is probably not what you want Caused by: fc53776: tracing: Remove markers module_layout() is an artificial symbol with 'significant' symbols listed in its argument list so that it gets a proper argument types signature that modversions can pick up to decide whether a module is version-compatible or not. If these dont match then we wont even look at a module. Remove the stale marker symbol. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> LKML-Reference: <alpine.LFD.2.01.0909210908020.4950@localhost.localdomain> Cc: Christoph Hellwig <hch@lst.de> Cc: Mathieu Desnoyers <mathieu.desnoyers@polymtl.ca> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | tracing: Fix failure path in ftrace_regex_open()Li Zefan2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't forget to free trace_parser if seq_open() returned failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4AB86694.4040803@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | tracing: Fix failure path in ftrace_graph_write()Li Zefan2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't call trace_parser_put() on uninitialized trace_parser. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4AB86639.3000003@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | tracing: Check the return value of trace_get_user()Li Zefan2009-09-22
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Return immediately if trace_get_user() returned failure. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4AB86614.7020803@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | | | tracing: Fix off-by-one in trace_get_user()Li Zefan2009-09-22
| | |/ / | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Leave the last slot for the tailing '\0'. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <4AB865FA.5080801@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | | Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller2009-09-24
|\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: drivers/staging/Kconfig drivers/staging/Makefile drivers/staging/cpc-usb/TODO drivers/staging/cpc-usb/cpc-usb_drv.c drivers/staging/cpc-usb/cpc.h drivers/staging/cpc-usb/cpc_int.h drivers/staging/cpc-usb/cpcusb.h
| * \ \ \ Merge branch 'for-linus' of git://git.monstr.eu/linux-2.6-microblazeLinus Torvalds2009-09-24
| |\ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 'for-linus' of git://git.monstr.eu/linux-2.6-microblaze: (24 commits) microblaze: Disable heartbeat/enable emaclite in defconfigs microblaze: Support simpleImage.dts make target microblaze: Fix _start symbol to physical address microblaze: Use LOAD_OFFSET macro to get correct LMA for all sections microblaze: Create the LOAD_OFFSET macro used to compute VMA vs LMA offsets microblaze: Copy ppc asm-compat.h for clean handling of constants in asm and C microblaze: Actually show KiB rather than pages in "Freeing initrd memory:" microblaze: Support ptrace syscall tracing. microblaze: Updated CPU version and FPGA family codes in PVR microblaze: Generate correct signal and siginfo for integer div-by-zero microblaze: Don't be noisy when userspace causes hardware exceptions microblaze: Remove ipc.h file which points to non-existing asm-generic file microblaze: Clear sticky FSR register after generating exception signals microblaze: Ensure CPU usermode is set on new userspace processes microblaze: Use correct kbuild variable KBUILD_CFLAGS microblaze: Save and restore msr in hw exception microblaze: Add architectural support for USB EHCI host controllers microblaze: Implement include/asm/syscall.h. microblaze: Improve checking mechanism for MSR instruction microblaze: Add checking mechanism for MSR instruction ...
| | * | | | microblaze: Enable GCOV_PROFILE_ALLMichal Simek2009-09-21
| | | | | | | | | | | | | | | | | | | | | | | | Signed-off-by: Michal Simek <monstr@monstr.eu>
| * | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linusLinus Torvalds2009-09-24
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/rusty/linux-2.6-for-linus: module: don't call percpu_modfree on NULL pointer. module: fix memory leak when load fails after srcversion/version allocated module: preferred way to use MODULE_AUTHOR param: allow whitespace as kernel parameter separator module: reduce string table for loaded modules (v2) module: reduce symbol table for loaded modules (v2)
| | * | | | | module: don't call percpu_modfree on NULL pointer.Rusty Russell2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The general one handles NULL, the static obsolescent (CONFIG_HAVE_LEGACY_PER_CPU_AREA) one in module.c doesn't; Eric's commit 720eba31 assumed it did, and various frobbings since then kept that assumption. All other callers in module.c all protect it with an if; this effectively does the same as free_init is only goto if we fail percpu_modalloc(). Reported-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Eric Dumazet <dada1@cosmosbay.com> Cc: Masami Hiramatsu <mhiramat@redhat.com> Cc: Américo Wang <xiyou.wangcong@gmail.com> Tested-by: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
| | * | | | | module: fix memory leak when load fails after srcversion/version allocatedRusty Russell2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Normally the twisty paths of sysfs will free the attributes, but not if we fail before we hook it into sysfs (which is the last thing we do in load_module). (This sysfs code is a turd, no doubt there are other issues lurking too). Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: Catalin Marinas <catalin.marinas@arm.com> Tested-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp>
| | * | | | | param: allow whitespace as kernel parameter separatorPeter Oberparleiter2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some boot mechanisms require that kernel parameters are stored in a separate file which is loaded to memory without further processing (e.g. the "Load from FTP" method on s390). When such a file contains newline characters, the kernel parameter preceding the newline might not be correctly parsed (due to the newline being stuck to the end of the actual parameter value) which can lead to boot failures. This patch improves kernel command line usability in such a situation by allowing generic whitespace characters as separators between kernel parameters. Signed-off-by: Peter Oberparleiter <oberpar@linux.vnet.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| | * | | | | module: reduce string table for loaded modules (v2)Jan Beulich2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Also remove all parts of the string table (referenced by the symbol table) that are not needed for kallsyms use (i.e. which were only referenced by symbols discarded by the previous patch, or not referenced at all for whatever reason). Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| | * | | | | module: reduce symbol table for loaded modules (v2)Jan Beulich2009-09-24
| | | |_|/ / | | |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Discard all symbols not interesting for kallsyms use: absolute, section, and in the common case (!KALLSYMS_ALL) data ones. Signed-off-by: Jan Beulich <jbeulich@novell.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
| * | | | | Merge git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-currentLinus Torvalds2009-09-24
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/viro/audit-current: lsm: Use a compressed IPv6 string format in audit events Audit: send signal info if selinux is disabled Audit: rearrange audit_context to save 16 bytes per struct Audit: reorganize struct audit_watch to save 8 bytes
| | * | | | | Audit: send signal info if selinux is disabledEric Paris2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Audit will not respond to signal requests if selinux is disabled since it is unable to translate the 0 sid from the sending process to a context. This patch just doesn't send the context info if there isn't any. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | | | Audit: rearrange audit_context to save 16 bytes per structEric Paris2009-09-24
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pahole pointed out that on x86_64 struct audit_context can be rearrainged to save 16 bytes per struct. Since we have an audit_context per task this can acually be a pretty significant gain. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| | * | | | | Audit: reorganize struct audit_watch to save 8 bytesEric Paris2009-09-24
| | |/ / / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | pahole showed that struct audit_watch had two holes: struct audit_watch { atomic_t count; /* 0 4 */ /* XXX 4 bytes hole, try to pack */ char * path; /* 8 8 */ dev_t dev; /* 16 4 */ /* XXX 4 bytes hole, try to pack */ long unsigned int ino; /* 24 8 */ struct audit_parent * parent; /* 32 8 */ struct list_head wlist; /* 40 16 */ struct list_head rules; /* 56 16 */ /* --- cacheline 1 boundary (64 bytes) was 8 bytes ago --- */ /* size: 72, cachelines: 2, members: 7 */ /* sum members: 64, holes: 2, sum holes: 8 */ /* last cacheline: 8 bytes */ }; /* definitions: 1 */ by moving dev after count we save 8 bytes, actually improving cacheline usage. There are typically very few of these in the kernel so it won't be a large savings, but it's a good thing no matter what. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | | | | Merge branch 'hwpoison' of ↵Linus Torvalds2009-09-24
| |\ \ \ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6 * 'hwpoison' of git://git.kernel.org/pub/scm/linux/kernel/git/ak/linux-mce-2.6: (21 commits) HWPOISON: Enable error_remove_page on btrfs HWPOISON: Add simple debugfs interface to inject hwpoison on arbitary PFNs HWPOISON: Add madvise() based injector for hardware poisoned pages v4 HWPOISON: Enable error_remove_page for NFS HWPOISON: Enable .remove_error_page for migration aware file systems HWPOISON: The high level memory error handler in the VM v7 HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per process HWPOISON: shmem: call set_page_dirty() with locked page HWPOISON: Define a new error_remove_page address space op for async truncation HWPOISON: Add invalidate_inode_page HWPOISON: Refactor truncate to allow direct truncating of page v2 HWPOISON: check and isolate corrupted free pages v2 HWPOISON: Handle hardware poisoned pages in try_to_unmap HWPOISON: Use bitmask/action code for try_to_unmap behaviour HWPOISON: x86: Add VM_FAULT_HWPOISON handling to x86 page fault handler v2 HWPOISON: Add poison check to page fault handling HWPOISON: Add basic support for poisoned pages in fault handler v3 HWPOISON: Add new SIGBUS error codes for hardware poison signals HWPOISON: Add support for poison swap entries v2 HWPOISON: Export some rmap vma locking to outside world ...
| | * | | | | HWPOISON: The high level memory error handler in the VM v7Andi Kleen2009-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add the high level memory handler that poisons pages that got corrupted by hardware (typically by a two bit flip in a DIMM or a cache) on the Linux level. The goal is to prevent everyone from accessing these pages in the future. This done at the VM level by marking a page hwpoisoned and doing the appropriate action based on the type of page it is. The code that does this is portable and lives in mm/memory-failure.c To quote the overview comment: High level machine check handler. Handles pages reported by the hardware as being corrupted usually due to a 2bit ECC memory or cache failure. This focuses on pages detected as corrupted in the background. When the current CPU tries to consume corruption the currently running process can just be killed directly instead. This implies that if the error cannot be handled for some reason it's safe to just ignore it because no corruption has been consumed yet. Instead when that happens another machine check will happen. Handles page cache pages in various states. The tricky part here is that we can access any page asynchronous to other VM users, because memory failures could happen anytime and anywhere, possibly violating some of their assumptions. This is why this code has to be extremely careful. Generally it tries to use normal locking rules, as in get the standard locks, even if that means the error handling takes potentially a long time. Some of the operations here are somewhat inefficient and have non linear algorithmic complexity, because the data structures have not been optimized for this case. This is in particular the case for the mapping from a vma to a process. Since this case is expected to be rare we hope we can get away with this. There are in principle two strategies to kill processes on poison: - just unmap the data and wait for an actual reference before killing - kill as soon as corruption is detected. Both have advantages and disadvantages and should be used in different situations. Right now both are implemented and can be switched with a new sysctl vm.memory_failure_early_kill The default is early kill. The patch does some rmap data structure walking on its own to collect processes to kill. This is unusual because normally all rmap data structure knowledge is in rmap.c only. I put it here for now to keep everything together and rmap knowledge has been seeping out anyways Includes contributions from Johannes Weiner, Chris Mason, Fengguang Wu, Nick Piggin (who did a lot of great work) and others. Cc: npiggin@suse.de Cc: riel@redhat.com Signed-off-by: Andi Kleen <ak@linux.intel.com> Acked-by: Rik van Riel <riel@redhat.com> Reviewed-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com>
| | * | | | | HWPOISON: Add PR_MCE_KILL prctl to control early kill behaviour per processAndi Kleen2009-09-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This allows processes to override their early/late kill behaviour on hardware memory errors. Typically applications which are memory error aware is better of with early kill (see the error as soon as possible), all others with late kill (only see the error when the error is really impacting execution) There's a global sysctl, but this way an application can set its specific policy. We're using two bits, one to signify that the process stated its intention and that I also made the prctl future proof by enforcing the unused arguments are 0. The state is inherited to children. Note this makes us officially run out of process flags on 32bit, but the next patch can easily add another field. Manpage patch will be supplied separately. Signed-off-by: Andi Kleen <ak@linux.intel.com>