summaryrefslogtreecommitdiff
path: root/kernel
AgeCommit message (Collapse)Author
2009-10-29param: fix lots of bugs with writing charp params from sysfs, by leaking mem.Rusty Russell
e180a6b7759a "param: fix charp parameters set via sysfs" fixed the case where charp parameters written via sysfs were freed, leaving drivers accessing random memory. Unfortunately, storing a flag in the kparam struct was a bad idea: it's rodata so setting it causes an oops on some archs. But that's not all: 1) module_param_array() on charp doesn't work reliably, since we use an uninitialized temporary struct kernel_param. 2) there's a fundamental race if a module uses this parameter and then it's changed: they will still access the old, freed, memory. The simplest fix (ie. for 2.6.32) is to never free the memory. This prevents all these problems, at cost of a memory leak. In practice, there are only 18 places where a charp is writable via sysfs, and all are root-only writable. Reported-by: Takashi Iwai <tiwai@suse.de> Cc: Sitsofe Wheeler <sitsofe@yahoo.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christof Schmitt <christof.schmitt@de.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Cc: stable@kernel.org
2009-10-28PM / freezer: Don't get over-anxious while waitingTejun Heo
Freezing isn't exactly the most latency sensitive operation and there's no reason to burn cpu cycles and power waiting for it to complete. msleep(10) instead of yield(). This should improve reliability of emergency hibernation. [rjw: Modified the comment next to the msleep(10).] Signed-off-by: Tejun Heo <tj@kernel.org> Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
2009-10-28futex: Fix spurious wakeup for requeue_pi reallyThomas Gleixner
The requeue_pi path doesn't use unqueue_me() (and the racy lock_ptr == NULL test) nor does it use the wake_list of futex_wake() which where the reason for commit 41890f2 (futex: Handle spurious wake up) See debugging discussing on LKML Message-ID: <4AD4080C.20703@us.ibm.com> The changes in this fix to the wait_requeue_pi path were considered to be a likely unecessary, but harmless safety net. But it turns out that due to the fact that for unknown $@#!*( reasons EWOULDBLOCK is defined as EAGAIN we built an endless loop in the code path which returns correctly EWOULDBLOCK. Spurious wakeups in wait_requeue_pi code path are unlikely so we do the easy solution and return EWOULDBLOCK^WEAGAIN to user space and let it deal with the spurious wakeup. Cc: Darren Hart <dvhltc@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: John Stultz <johnstul@linux.vnet.ibm.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> LKML-Reference: <4AE23C74.1090502@us.ibm.com> Cc: stable@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2009-10-28kmemleak: Scan the _ftrace_events section in modulesCatalin Marinas
This section contains pointers to allocated objects and not scanning it leads to false positives. Reported-by: Zdenek Kabelac <zdenek.kabelac@gmail.com> Acked-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2009-10-29sched: move rq_weight data array out of .percpuJiri Kosina
Commit 34d76c41 introduced percpu array update_shares_data, size of which being proportional to NR_CPUS. Unfortunately this blows up ia64 for large NR_CPUS configuration, as ia64 allows only 64k for .percpu section. Fix this by allocating this array dynamically and keep only pointer to it percpu. The per-cpu handling doesn't impose significant performance penalty on potentially contented path in tg_shares_up(). ... ffffffff8104337c: 65 48 8b 14 25 20 cd mov %gs:0xcd20,%rdx ffffffff81043383: 00 00 ffffffff81043385: 48 c7 c0 00 e1 00 00 mov $0xe100,%rax ffffffff8104338c: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp) ffffffff81043393: 00 ffffffff81043394: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp) ffffffff8104339b: 00 ffffffff8104339c: 48 01 d0 add %rdx,%rax ffffffff8104339f: 49 8d 94 24 08 01 00 lea 0x108(%r12),%rdx ffffffff810433a6: 00 ffffffff810433a7: b9 ff ff ff ff mov $0xffffffff,%ecx ffffffff810433ac: 48 89 45 b0 mov %rax,-0x50(%rbp) ffffffff810433b0: bb 00 04 00 00 mov $0x400,%ebx ffffffff810433b5: 48 89 55 c0 mov %rdx,-0x40(%rbp) ... After: ... ffffffff8104337c: 65 8b 04 25 28 cd 00 mov %gs:0xcd28,%eax ffffffff81043383: 00 ffffffff81043384: 48 98 cltq ffffffff81043386: 49 8d bc 24 08 01 00 lea 0x108(%r12),%rdi ffffffff8104338d: 00 ffffffff8104338e: 48 8b 15 d3 7f 76 00 mov 0x767fd3(%rip),%rdx # ffffffff817ab368 <update_shares_data> ffffffff81043395: 48 8b 34 c5 00 ee 6d mov -0x7e921200(,%rax,8),%rsi ffffffff8104339c: 81 ffffffff8104339d: 48 c7 45 a0 00 00 00 movq $0x0,-0x60(%rbp) ffffffff810433a4: 00 ffffffff810433a5: b9 ff ff ff ff mov $0xffffffff,%ecx ffffffff810433aa: 48 89 7d c0 mov %rdi,-0x40(%rbp) ffffffff810433ae: 48 c7 45 a8 00 00 00 movq $0x0,-0x58(%rbp) ffffffff810433b5: 00 ffffffff810433b6: bb 00 04 00 00 mov $0x400,%ebx ffffffff810433bb: 48 01 f2 add %rsi,%rdx ffffffff810433be: 48 89 55 b0 mov %rdx,-0x50(%rbp) ... Signed-off-by: Jiri Kosina <jkosina@suse.cz> Acked-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Tejun Heo <tj@kernel.org>
2009-10-28kmemleak: Simplify the kmemleak_scan_area() function prototypeCatalin Marinas
This function was taking non-necessary arguments which can be determined by kmemleak. The patch also modifies the calling sites. Signed-off-by: Catalin Marinas <catalin.marinas@arm.com> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
2009-10-28perf_event: Add alignment-faults and emulation-faults software eventsAnton Blanchard
Add two more software events that are common to many cpus. Alignment faults: When a load or store is not aligned properly. Emulation faults: When an instruction is emulated in software. Both cause a very significant slowdown (100x or worse), so identifying and fixing them is very important. Signed-off-by: Anton Blanchard <anton@samba.org> Signed-off-by: Paul Mackerras <paulus@samba.org>
2009-10-26rcu: Simplify creating of lockdep class for root rcu_nodePeter Zijlstra
Use lockdep_set_class() to simplify the code and to avoid any additional overhead in the !LOCKDEP case. Also move the definition of rcu_root_class into kernel/rcutree.c, as suggested by Lai Jiangshan. Signed-off-by: Peter Zijlstra <peterz@infradead.org> 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: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: dhowells@redhat.com LKML-Reference: <1256577871443-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Do tiny cleanups in rcutinyIngo Molnar
No change in functionality - just straighten out a few small stylistic details. Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: laijs@cn.fujitsu.com Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351355-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Improve rcutorture diagnostics when bad torture_type specifiedPaul E. McKenney
Make rcutorture list the available torture_type values when it doesn't like the one specified. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca 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: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351868-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Add synchronize_srcu_expedited() to the rcutorture test suitePaul E. McKenney
Adds the "srcu_expedited" torture type, and also renames sched_ops_sync to sched_sync_ops for consistency while we are in this file. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca 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: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226353636-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: Add synchronize_srcu_expedited()Paul E. McKenney
This patch creates a synchronize_srcu_expedited() that uses synchronize_sched_expedited() where synchronize_srcu() uses synchronize_sched(). The synchronize_srcu() and synchronize_srcu_expedited() functions become one-liners that pass synchronize_sched() or synchronize_sched_expedited(), repectively, to a new __synchronize_srcu() function. While in the file, move the EXPORT_SYMBOL_GPL()s to immediately follow the corresponding functions. Requested-by: Avi Kivity <avi@redhat.com> Tested-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca 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: avi@redhat.com LKML-Reference: <12565226354038-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-26rcu: "Tiny RCU", The Bloatwatch EditionPaul E. McKenney
This patch is a version of RCU designed for !SMP provided for a small-footprint RCU implementation. In particular, the implementation of synchronize_rcu() is extremely lightweight and high performance. It passes rcutorture testing in each of the four relevant configurations (combinations of NO_HZ and PREEMPT) on x86. This saves about 1K bytes compared to old Classic RCU (which is no longer in mainline), and more than three kilobytes compared to Hierarchical RCU (updated to 2.6.30): CONFIG_TREE_RCU: text data bss dec filename 183 4 0 187 kernel/rcupdate.o 2783 520 36 3339 kernel/rcutree.o 3526 Total (vs 4565 for v7) CONFIG_TREE_PREEMPT_RCU: text data bss dec filename 263 4 0 267 kernel/rcupdate.o 4594 776 52 5422 kernel/rcutree.o 5689 Total (6155 for v7) CONFIG_TINY_RCU: text data bss dec filename 96 4 0 100 kernel/rcupdate.o 734 24 0 758 kernel/rcutiny.o 858 Total (vs 848 for v7) The above is for x86. Your mileage may vary on other platforms. Further compression is possible, but is being procrastinated. Changes from v7 (http://lkml.org/lkml/2009/10/9/388) o Apply Lai Jiangshan's review comments (aside from might_sleep() in synchronize_sched(), which is covered by SMP builds). o Fix up expedited primitives. Changes from v6 (http://lkml.org/lkml/2009/9/23/293). o Forward ported to put it into the 2.6.33 stream. o Added lockdep support. o Make lightweight rcu_barrier. Changes from v5 (http://lkml.org/lkml/2009/6/23/12). o Ported to latest pre-2.6.32 merge window kernel. - Renamed rcu_qsctr_inc() to rcu_sched_qs(). - Renamed rcu_bh_qsctr_inc() to rcu_bh_qs(). - Provided trivial rcu_cpu_notify(). - Provided trivial exit_rcu(). - Provided trivial rcu_needs_cpu(). - Fixed up the rcu_*_enter/exit() functions in linux/hardirq.h. o Removed the dependence on EMBEDDED, with a view to making TINY_RCU default for !SMP at some time in the future. o Added (trivial) support for expedited grace periods. Changes from v4 (http://lkml.org/lkml/2009/5/2/91) include: o Squeeze the size down a bit further by removing the ->completed field from struct rcu_ctrlblk. o This permits synchronize_rcu() to become the empty function. Previous concerns about rcutorture were unfounded, as rcutorture correctly handles a constant value from rcu_batches_completed() and rcu_batches_completed_bh(). Changes from v3 (http://lkml.org/lkml/2009/3/29/221) include: o Changed rcu_batches_completed(), rcu_batches_completed_bh() rcu_enter_nohz(), rcu_exit_nohz(), rcu_nmi_enter(), and rcu_nmi_exit(), to be static inlines, as suggested by David Howells. Doing this saves about 100 bytes from rcutiny.o. (The numbers between v3 and this v4 of the patch are not directly comparable, since they are against different versions of Linux.) Changes from v2 (http://lkml.org/lkml/2009/2/3/333) include: o Fix whitespace issues. o Change short-circuit "||" operator to instead be "+" in order to fix performance bug noted by "kraai" on LWN. (http://lwn.net/Articles/324348/) Changes from v1 (http://lkml.org/lkml/2009/1/13/440) include: o This version depends on EMBEDDED as well as !SMP, as suggested by Ingo. o Updated rcu_needs_cpu() to unconditionally return zero, permitting the CPU to enter dynticks-idle mode at any time. This works because callbacks can be invoked upon entry to dynticks-idle mode. o Paul is now OK with this being included, based on a poll at the Kernel Miniconf at linux.conf.au, where about ten people said that they cared about saving 900 bytes on single-CPU systems. o Applies to both mainline and tip/core/rcu. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Josh Triplett <josh@joshtriplett.org> Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com> Cc: dipankar@in.ibm.com Cc: mathieu.desnoyers@polymtl.ca Cc: dvhltc@us.ibm.com Cc: niv@us.ibm.com Cc: peterz@infradead.org Cc: rostedt@goodmis.org Cc: Valdis.Kletnieks@vt.edu Cc: avi@redhat.com Cc: mtosatti@redhat.com LKML-Reference: <12565226351355-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-25x86: Fix user return notifier buildAvi Kivity
When CONFIG_USER_RETURN_NOTIFIER is set, we need to link kernel/user-return-notifier.o. Signed-off-by: Avi Kivity <avi@redhat.com> LKML-Reference: <1256473485-23109-1-git-send-email-avi@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-25sched, cpuacct: Fix niced guest time accountingRyota Ozaki
CPU time of a guest is always accounted in 'user' time without concern for the nice value of its counterpart process although the guest is scheduled under the nice value. This patch fixes the defect and accounts cpu time of a niced guest in 'nice' time as same as a niced process. And also the patch adds 'guest_nice' to cpuacct. The value provides niced guest cpu time which is like 'nice' to 'user'. The original discussions can be found here: http://www.mail-archive.com/kvm@vger.kernel.org/msg23982.html http://www.mail-archive.com/kvm@vger.kernel.org/msg23860.html Signed-off-by: Ryota Ozaki <ozaki.ryota@gmail.com> Acked-by: Avi Kivity <avi@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1256314810-7897-1-git-send-email-ozaki.ryota@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-25Merge branch 'linus' into sched/coreIngo Molnar
Conflicts: fs/proc/array.c Merge reason: resolve conflict and queue up dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-24tracing: Remove cpu arg from the rb_time_stamp() functionJiri Olsa
The cpu argument is not used inside the rb_time_stamp() function. Plus fix a typo. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233647.118547500@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-24tracing: Fix comment typo and documentation exampleJiri Olsa
Trivial patch to fix a documentation example and to fix a comment. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.871719877@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-24tracing: Fix trace_seq_printf() return valueJiri Olsa
trace_seq_printf() return value is a little ambiguous. It currently returns the length of the space available in the buffer. printf usually returns the amount written. This is not adequate here, because: trace_seq_printf(s, ""); is perfectly legal, and returning 0 would indicate that it failed. We can always see the amount written by looking at the before and after values of s->len. This is not quite the same use as printf. We only care if the string was successfully written to the buffer or not. Make trace_seq_printf() return 0 if the trace oversizes the buffer's free space, 1 otherwise. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.631787612@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-24tracing: Update *ppos instead of filp->f_posJiri Olsa
Instead of directly updating filp->f_pos we should update the *ppos argument. The filp->f_pos gets updated within the file_pos_write() function called from sys_write(). Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> LKML-Reference: <20091023233646.399670810@goodmis.org> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23sched: Strengthen buddies and mitigate buddy induced latenciesMike Galbraith
This patch restores the effectiveness of LAST_BUDDY in preventing pgsql+oltp from collapsing due to wakeup preemption. It also switches LAST_BUDDY to exclusively do what it does best, namely mitigate the effects of aggressive wakeup preemption, which improves vmark throughput markedly, and restores mysql+oltp scalability. Since buddies are about scalability, enable them beginning at the point where we begin expanding sched_latency, namely sched_nr_latency. Previously, buddies were cleared aggressively, which seriously reduced their effectiveness. Not clearing aggressively however, produces a small drop in mysql+oltp throughput immediately after peak, indicating that LAST_BUDDY is actually doing some harm. This is right at the point where X on the desktop in competition with another load wants low latency service. Ergo, do not enable until we need to scale. To mitigate latency induced by buddies, or by a task just missing wakeup preemption, check latency at tick time. Last hunk prevents buddies from stymieing BALANCE_NEWIDLE via CACHE_HOT_BUDDY. Supporting performance tests: tip = v2.6.32-rc5-1497-ga525b32 tipx = NO_GENTLE_FAIR_SLEEPERS NEXT_BUDDY granularity knobs = 31 knobs + 31 buddies tip+x = NO_GENTLE_FAIR_SLEEPERS granularity knobs = 31 knobs (Three run averages except where noted.) vmark: ------ tip 108466 messages per second tip+ 125307 messages per second tip+x 125335 messages per second tipx 117781 messages per second 2.6.31.3 122729 messages per second mysql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 9949.89 18690.20 34801.24 34460.04 32682.88 30765.97 28305.27 25059.64 19548.08 tip+ 10013.90 18526.84 34900.38 34420.14 33069.83 32083.40 30578.30 28010.71 25605.47 tipx 9698.71 18002.70 34477.56 33420.01 32634.30 31657.27 29932.67 26827.52 21487.18 2.6.31.3 8243.11 18784.20 34404.83 33148.38 31900.32 31161.90 29663.81 25995.94 18058.86 pgsql+oltp: ----------- clients 1 2 4 8 16 32 64 128 256 .......................................................................................... tip 13686.37 26609.25 51934.28 51347.81 49479.51 45312.65 36691.91 26851.57 24145.35 tip+ (1x) 13907.85 27135.87 52951.98 52514.04 51742.52 50705.43 49947.97 48374.19 46227.94 tip+x 13906.78 27065.81 52951.19 52542.59 52176.11 51815.94 50838.90 49439.46 46891.00 tipx 13742.46 26769.81 52351.99 51891.73 51320.79 50938.98 50248.65 48908.70 46553.84 2.6.31.3 13815.35 26906.46 52683.34 52061.31 51937.10 51376.80 50474.28 49394.47 47003.25 Signed-off-by: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23ratelimit: Make suppressed output messages more usefulChristian Borntraeger
Today I got: [39648.224782] Registered led device: iwl-phy0::TX [40676.545099] __ratelimit: 246 callbacks suppressed [40676.545103] abcdef[23675]: segfault at 0 ... as you can see the ratelimit message contains a function prefix. Since this is always __ratelimit, this wont help much. This patch changes __ratelimit and printk_ratelimit to print the function name that calls ratelimit. This will pinpoint the responsible function, as long as not several different places call ratelimit with the same ratelimit state at the same time. In that case we catch only one random function that calls ratelimit after the wait period. Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Cc: Dave Young <hidave.darkstar@gmail.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> CC: Andrew Morton <akpm@linux-foundation.org> LKML-Reference: <200910231458.11832.borntraeger@de.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23generic-ipi: Fix misleading smp_call_function*() descriptionSheng Yang
After commit:8969a5ede0f9e17da4b943712429aef2c9bcd82b "generic-ipi: remove kmalloc()", wait = 0 can be guaranteed. Signed-off-by: Sheng Yang <sheng@linux.intel.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Jens Axboe <jens.axboe@oracle.com> Cc: Nick Piggin <npiggin@suse.de> LKML-Reference: <1256210374-25354-1-git-send-email-sheng@linux.intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23perf events: Don't generate events for the idle task when exclude_idle is setSoeren Sandmann
Getting samples for the idle task is often not interesting, so don't generate them when exclude_idle is set for the event in question. Signed-off-by: Søren Sandmann Pedersen <sandmann@redhat.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> 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> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <ye8pr8fmlq7.fsf@camel16.daimi.au.dk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23perf events: Fix swevent hrtimer sampling by keeping track of remaining time ↵Soeren Sandmann
when enabling/disabling swevent hrtimers Make the hrtimer based events work for sysprof. Whenever a swevent is scheduled out, the hrtimer is canceled. When it is scheduled back in, the timer is restarted. This happens every scheduler tick, which means the timer never expired because it was getting repeatedly restarted over and over with the same period. To fix that, save the remaining time when disabling; when reenabling, use that saved time as the period instead of the user-specified sampling period. Also, move the starting and stopping of the hrtimers to helper functions instead of duplicating the code. Signed-off-by: Søren Sandmann Pedersen <sandmann@redhat.com> LKML-Reference: <ye8vdi7mluz.fsf@camel16.daimi.au.dk> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-23Merge branch 'perf/core' into perf/probesIngo Molnar
Conflicts: tools/perf/Makefile Merge reason: - fix the conflict - pick up the pr_*() infrastructure to queue up dependent patch Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-22PM: Make warning in suspend_test_finish() less likely to happenRafael J. Wysocki
Increase TEST_SUSPEND_SECONDS to 10 so the warning in suspend_test_finish() doesn't annoy the users of slower systems so much. Also, make the warning print the suspend-resume cycle time, so that we know why the warning actually triggered. Patch prepared during the hacking session at the Kernel Summit in Tokyo. Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-10-20Merge branch 'perf/urgent' into perf/coreIngo Molnar
Merge reason: Queue up dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-19HWPOISON: Allow schedule_on_each_cpu() from keventdAndi Kleen
Right now when calling schedule_on_each_cpu() from keventd there is a deadlock because it tries to schedule a work item on the current CPU too. This happens via lru_add_drain_all() in hwpoison. Just call the function for the current CPU in this case. This is actually faster too. Debugging with Fengguang Wu & Max Asbock Signed-off-by: Andi Kleen <ak@linux.intel.com>
2009-10-18Merge commit 'perf/core' into perf/hw-breakpointFrederic Weisbecker
Conflicts: kernel/Makefile kernel/trace/Makefile kernel/trace/trace.h samples/Makefile Merge reason: We need to be uptodate with the perf events development branch because we plan to rewrite the breakpoints API on top of perf events.
2009-10-17Merge commit 'v2.6.32-rc5' into perf/probesIngo Molnar
Conflicts: kernel/trace/trace_event_profile.c Merge reason: update to -rc5 and resolve conflict. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-17tracing/kprobes: Add failure messages for debuggingMasami Hiramatsu
Add verbose failure messages to kprobe-tracer for debugging. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20091017000728.16556.16713.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-17tracing/kprobes: Update kprobe-tracer selftest against new syntaxMasami Hiramatsu
Update kprobe-tracer selftest since command syntax has been changed. Signed-off-by: Masami Hiramatsu <mhiramat@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20091017000720.16556.26343.stgit@dhcp-100-2-132.bos.redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-16futex: Move drop_futex_key_refs out of spinlock'ed regionDarren Hart
When requeuing tasks from one futex to another, the reference held by the requeued task to the original futex location needs to be dropped eventually. Dropping the reference may ultimately lead to a call to "iput_final" and subsequently call into filesystem- specific code - which may be non-atomic. It is therefore safer to defer this drop operation until after the futex_hash_bucket spinlock has been dropped. Originally-From: Helge Bahmann <hcb@chaoticmind.net> Signed-off-by: Darren Hart <dvhltc@us.ibm.com> Cc: <stable@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Dinakar Guniguntala <dino@in.ibm.com> Cc: John Stultz <johnstul@linux.vnet.ibm.com> Cc: Sven-Thorsten Dietrich <sdietrich@novell.com> Cc: John Kacur <jkacur@redhat.com> LKML-Reference: <4AD7A298.5040802@us.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15Merge the right tty-fixes branchLinus Torvalds
* branch 'tty-fixes' tty: use the new 'flush_delayed_work()' helper to do ldisc flush workqueue: add 'flush_delayed_work()' to run and wait for delayed work tty: Make flush_to_ldisc() locking more robust
2009-10-15rcu: Fix TREE_PREEMPT_RCU CPU_HOTPLUG bad-luck hangPaul E. McKenney
If the following sequence of events occurs, then TREE_PREEMPT_RCU will hang waiting for a grace period to complete, eventually OOMing the system: o A TREE_PREEMPT_RCU build of the kernel is booted on a system with more than 64 physical CPUs present (32 on a 32-bit system). Alternatively, a TREE_PREEMPT_RCU build of the kernel is booted with RCU_FANOUT set to a sufficiently small value that the physical CPUs populate two or more leaf rcu_node structures. o A task is preempted in an RCU read-side critical section while running on a CPU corresponding to a given leaf rcu_node structure. o All CPUs corresponding to this same leaf rcu_node structure record quiescent states for the current grace period. o All of these same CPUs go offline (hence the need for enough physical CPUs to populate more than one leaf rcu_node structure). This causes the preempted task to be moved to the root rcu_node structure. At this point, there is nothing left to cause the quiescent state to be propagated up the rcu_node tree, so the current grace period never completes. The simplest fix, especially after considering the deadlock possibilities, is to detect this situation when the last CPU is offlined, and to set that CPU's ->qsmask bit in its leaf rcu_node structure. This will cause the next invocation of force_quiescent_state() to end the grace period. Without this fix, this hang can be triggered in an hour or so on some machines with rcutorture and random CPU onlining/offlining. With this fix, these same machines pass a full 10 hours of this sort of abuse. 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 LKML-Reference: <20091015162614.GA19131@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15tracing/events: Fix locking imbalance in the filter codeIngo Molnar
Américo Wang noticed that we have a locking imbalance in the error paths of ftrace_profile_set_filter(), causing potential leakage of event_mutex. Also clean up other error codepaths related to event_mutex while at it. Plus fix an initialized variable in the subsystem filter code. Reported-by: Américo Wang <xiyou.wangcong@gmail.com> Cc: Li Zefan <lizf@cn.fujitsu.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <2375c9f90910150247u5ccb8e2at58c764e385ffa490@mail.gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15tracing/profile: Add filter supportLi Zefan
- Add an ioctl to allocate a filter for a perf event. - Free the filter when the associated perf event is to be freed. - Do the filtering in perf_swevent_match(). Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4AD69546.8050401@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15tracing/filters: Use a different op for glob matchLi Zefan
"==" will always do a full match, and "~" will do a glob match. In the future, we may add "=~" for regex match. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4AD69528.3050309@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15tracing/filters: Refactor subsystem filter codeLi Zefan
Change: for_each_pred for_each_subsystem To: for_each_subsystem for_each_pred This change also prepares for later patches. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Peter Zijlstra <peterz@infradead.org> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Tom Zanussi <tzanussi@gmail.com> LKML-Reference: <4AD69502.8060903@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15Merge branch 'tracing/core' into perf/coreIngo Molnar
Merge reason: to add event filter support we need the following commits from the tracing tree: 3f6fe06: tracing/filters: Unify the regex parsing helpers 1889d20: tracing/filters: Provide basic regex support 737f453: tracing/filters: Cleanup useless headers Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15rcu: Add rnp->blocked_tasks to tracingPaul E. McKenney
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: 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: npiggin@suse.de Cc: jens.axboe@oracle.com Cc: Josh Triplett <josh@joshtriplett.org> LKML-Reference: <20091014233638.GE6763@linux.vnet.ibm.com> Signed-off-by: Ingo Molnar <mingo@elte.hu> kernel/rcutree_trace.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)
2009-10-15rcu: Stopgap fix for synchronize_rcu_expedited() for TREE_PREEMPT_RCUPaul E. McKenney
For the short term, map synchronize_rcu_expedited() to synchronize_rcu() for TREE_PREEMPT_RCU and to synchronize_sched_expedited() for TREE_RCU. Longer term, there needs to be a real expedited grace period for TREE_PREEMPT_RCU, but candidate patches to date are considerably more complex and intrusive. 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: npiggin@suse.de Cc: jens.axboe@oracle.com LKML-Reference: <12555405592331-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15rcu: Prevent RCU IPI storms in presence of high call_rcu() loadPaul E. McKenney
As the number of callbacks on a given CPU rises, invoke force_quiescent_state() only every blimit number of callbacks (defaults to 10,000), and even then only if no other CPU has invoked force_quiescent_state() in the meantime. This should fix the performance regression reported by Nick. Reported-by: Nick Piggin <npiggin@suse.de> 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: jens.axboe@oracle.com LKML-Reference: <12555405592133-git-send-email-> Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-15Merge branch 'linus' into perf/coreIngo Molnar
Merge reason: pick up tools/perf/ changes from upstream. Signed-off-by: Ingo Molnar <mingo@elte.hu>
2009-10-14Merge branch 'tty-fixes'Linus Torvalds
* branch 'tty-fixes': tty: use the new 'flush_delayed_work()' helper to do ldisc flush workqueue: add 'flush_delayed_work()' to run and wait for delayed work Make flush_to_ldisc properly handle parallel calls
2009-10-14Merge branch 'core-fixes-for-linus' of ↵Linus Torvalds
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: oprofile: warn on freeing event buffer too early oprofile: fix race condition in event_buffer free lockdep: Use cpu_clock() for lockstat
2009-10-14Merge branch 'sched-fixes-for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'sched-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: sched: Fix missing kernel-doc notation Revert "x86, timers: Check for pending timers after (device) interrupts" sched: Update the clock of runqueue select_task_rq() selected
2009-10-14Merge branch 'tracing-fixes-for-linus' of ↵Linus Torvalds
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: tracing/filters: Fix memory leak when setting a filter tracing: fix trace_vprintk call
2009-10-14workqueue: add 'flush_delayed_work()' to run and wait for delayed workLinus Torvalds
It basically turns a delayed work into an immediate work, and then waits for it to finish, thus allowing you to force (and wait for) an immediate flush of a delayed work. We'll want to use this in the tty layer to clean up tty_flush_to_ldisc(). Acked-by: Oleg Nesterov <oleg@redhat.com> [ Fixed to use 'del_timer_sync()' as noted by Oleg ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>