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* Merge branch 'sched-core-for-linus' of ↵Linus Torvalds2013-02-1983-507/+1105
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull scheduler changes from Ingo Molnar: "Main changes: - scheduler side full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker. - Initial sched.h split-up changes, by Clark Williams - select_idle_sibling() performance improvement by Mike Galbraith: " 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs " - sched_rr_get_interval() ABI fix/change. We think this detail is not used by apps (so it's not an ABI in practice), but lets keep it under observation. - misc RT scheduling cleanups, optimizations" * 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (24 commits) sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h> cputime: Remove irqsave from seqlock readers sched, powerpc: Fix sched.h split-up build failure cputime: Restore CPU_ACCOUNTING config defaults for PPC64 sched/rt: Move rt specific bits into new header file sched/rt: Add a tuning knob to allow changing SCHED_RR timeslice sched: Move sched.h sysctl bits into separate header sched: Fix signedness bug in yield_to() sched: Fix select_idle_sibling() bouncing cow syndrome sched/rt: Further simplify pick_rt_task() sched/rt: Do not account zero delta_exec in update_curr_rt() cputime: Safely read cputime of full dynticks CPUs kvm: Prepare to add generic guest entry/exit callbacks cputime: Use accessors to read task cputime stats cputime: Allow dynamic switch between tick/virtual based cputime accounting cputime: Generic on-demand virtual cputime accounting cputime: Move default nsecs_to_cputime() to jiffies based cputime file cputime: Librarize per nsecs resolution cputime definitions cputime: Avoid multiplication overflow on utime scaling context_tracking: Export context state for generic vtime ... Fix up conflict in kernel/context_tracking.c due to comment additions.
| * sched/rt: Add <linux/sched/rt.h> header to <linux/init_task.h>Ingo Molnar2013-02-191-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | IA64 relied on it through sched.h inclusion: arch/ia64/kernel/init_task.c:38:11: error: 'MAX_PRIO' undeclared here (not in a function) arch/ia64/kernel/init_task.c:38:11: error: 'RR_TIMESLICE' undeclared here (not in a function) Reported-by: kbuild test robot <fengguang.wu@intel.com> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/n/tip-xaan1twswggedMR0airtpjui@git.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * cputime: Remove irqsave from seqlock readersThomas Gleixner2013-02-191-6/+4
| | | | | | | | | | | | | | | | | | The reader side code has no requirement to disable interrupts while sampling data. The sequence counter is enough to ensure consistency. Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched, powerpc: Fix sched.h split-up build failureIngo Molnar2013-02-111-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | Fix PowerPC/Cell build fallout from: 8bd75c77b7c6 sched/rt: Move rt specific bits into new header file Reported-by: Michael Ellerman <michael@ellerman.id.au> Cc: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * cputime: Restore CPU_ACCOUNTING config defaults for PPC64Stephen Rothwell2013-02-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit abf917cd91cb ("cputime: Generic on-demand virtual cputime accounting") inadvertantly changed the default CPU_ACCOUNTING config for PPC64. Repair that. Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: ppc-dev <linuxppc-dev@lists.ozlabs.org> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Link: http://lkml.kernel.org/r/20130208141938.f31b7b9e1acac5bbe769ee4c@canb.auug.org.au Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/rt: Move rt specific bits into new header fileClark Williams2013-02-0722-57/+81
| | | | | | | | | | | | | | | | | | | | | | Move rt scheduler definitions out of include/linux/sched.h into new file include/linux/sched/rt.h Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094707.7b9f825f@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched/rt: Add a tuning knob to allow changing SCHED_RR timesliceClark Williams2013-02-074-3/+44
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Add a /proc/sys/kernel scheduler knob named sched_rr_timeslice_ms that allows global changing of the SCHED_RR timeslice value. User visable value is in milliseconds but is stored as jiffies. Setting to 0 (zero) resets to the default (currently 100ms). Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094704.13751796@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * sched: Move sched.h sysctl bits into separate headerClark Williams2013-02-0711-91/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | Move the sysctl-related bits from include/linux/sched.h into a new file: include/linux/sched/sysctl.h. Then update source files requiring access to those bits by including the new header file. Signed-off-by: Clark Williams <williams@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Link: http://lkml.kernel.org/r/20130207094659.06dced96@riff.lan Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * Merge tag 'full-dynticks-cputime-for-mingo' of ↵Ingo Molnar2013-02-0552-322/+842
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/frederic/linux-dynticks into sched/core Pull full-dynticks (user-space execution is undisturbed and receives no timer IRQs) preparation changes that convert the cputime accounting code to be full-dynticks ready, from Frederic Weisbecker: "This implements the cputime accounting on full dynticks CPUs. Typical cputime stats infrastructure relies on the timer tick and its periodic polling on the CPU to account the amount of time spent by the CPUs and the tasks per high level domains such as userspace, kernelspace, guest, ... Now we are preparing to implement full dynticks capability on Linux for Real Time and HPC users who want full CPU isolation. This feature requires a cputime accounting that doesn't depend on the timer tick. To implement it, this new cputime infrastructure plugs into kernel/user/guest boundaries to take snapshots of cputime and flush these to the stats when needed. This performs pretty much like CONFIG_VIRT_CPU_ACCOUNTING except that context location and cputime snaphots are synchronized between write and read side such that the latter can safely retrieve the pending tickless cputime of a task and add it to its latest cputime snapshot to return the correct result to the user." Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * cputime: Safely read cputime of full dynticks CPUsFrederic Weisbecker2013-01-2711-52/+290
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | While remotely reading the cputime of a task running in a full dynticks CPU, the values stored in utime/stime fields of struct task_struct may be stale. Its values may be those of the last kernel <-> user transition time snapshot and we need to add the tickless time spent since this snapshot. To fix this, flush the cputime of the dynticks CPUs on kernel <-> user transition and record the time / context where we did this. Then on top of this snapshot and the current time, perform the fixup on the reader side from task_times() accessors. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> [fixed kvm module related build errors] Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
| | * kvm: Prepare to add generic guest entry/exit callbacksFrederic Weisbecker2013-01-275-21/+32
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Do some ground preparatory work before adding guest_enter() and guest_exit() context tracking callbacks. Those will be later used to read the guest cputime safely when we run in full dynticks mode. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Gleb Natapov <gleb@redhat.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Marcelo Tosatti <mtosatti@redhat.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| | * cputime: Use accessors to read task cputime statsFrederic Weisbecker2013-01-2716-49/+144
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is in preparation for the full dynticks feature. While remotely reading the cputime of a task running in a full dynticks CPU, we'll need to do some extra-computation. This way we can account the time it spent tickless in userspace since its last cputime snapshot. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| | * cputime: Allow dynamic switch between tick/virtual based cputime accountingFrederic Weisbecker2013-01-273-11/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Allow to dynamically switch between tick and virtual based cputime accounting. This way we can provide a kind of "on-demand" virtual based cputime accounting. In this mode, the kernel relies on the context tracking subsystem to dynamically probe on kernel boundaries. This is in preparation for being able to stop the timer tick in more places than just the idle state. Doing so will depend on CONFIG_VIRT_CPU_ACCOUNTING_GEN which makes it possible to account the cputime without the tick by hooking on kernel/user boundaries. Depending whether the tick is stopped or not, we can switch between tick and vtime based accounting anytime in order to minimize the overhead associated to user hooks. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| | * cputime: Generic on-demand virtual cputime accountingFrederic Weisbecker2013-01-2727-54/+160
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If we want to stop the tick further idle, we need to be able to account the cputime without using the tick. Virtual based cputime accounting solves that problem by hooking into kernel/user boundaries. However implementing CONFIG_VIRT_CPU_ACCOUNTING require low level hooks and involves more overhead. But we already have a generic context tracking subsystem that is required for RCU needs by archs which plan to shut down the tick outside idle. This patch implements a generic virtual based cputime accounting that relies on these generic kernel/user hooks. There are some upsides of doing this: - This requires no arch code to implement CONFIG_VIRT_CPU_ACCOUNTING if context tracking is already built (already necessary for RCU in full tickless mode). - We can rely on the generic context tracking subsystem to dynamically (de)activate the hooks, so that we can switch anytime between virtual and tick based accounting. This way we don't have the overhead of the virtual accounting when the tick is running periodically. And one downside: - There is probably more overhead than a native virtual based cputime accounting. But this relies on hooks that are already set anyway. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| | * cputime: Move default nsecs_to_cputime() to jiffies based cputime fileFrederic Weisbecker2013-01-272-6/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the architecture doesn't provide an implementation of nsecs_to_cputime(), the cputime accounting core uses a default one that converts the nanoseconds to jiffies. However this only makes sense if we use the jiffies based cputime. For now it doesn't matter much because this API is only called on code that uses jiffies based cputime accounting. But the code may evolve and this API may be used more broadly in the future. Keeping this default implementation around is very error prone as it may introduce a bug and hide it on architectures that don't override this API. Fix this by moving this definition to the jiffies based cputime headers as it is the only place where it belongs to. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| | * cputime: Librarize per nsecs resolution cputime definitionsFrederic Weisbecker2013-01-274-145/+167
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The full dynticks cputime accounting that we'll soon introduce will rely on sched_clock(). And its clock can have a per nanosecond granularity. To prepare for this, we need to have a cputime_t implementation that has this precision. ia64 virtual cputime accounting already uses that granularity so all we need is to librarize its implementation in the asm generic headers. Also librarize the default per jiffy granularity cputime_t as well so that we can easily pick either implementation depending on the cputime accounting config we choose. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com>
| | * context_tracking: Export context state for generic vtimeFrederic Weisbecker2013-01-262-15/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Export the context state: whether we run in user / kernel from the context tracking subsystem point of view. This is going to be used by the generic virtual cputime accounting subsystem that is needed to implement the full dynticks. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Li Zhong <zhong@linux.vnet.ibm.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul Gortmaker <paul.gortmaker@windriver.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Thomas Gleixner <tglx@linutronix.de>
| * | sched: Fix signedness bug in yield_to()Dan Carpenter2013-02-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In 7b270f6099 "sched: Bail out of yield_to when source and target runqueue has one task" we changed this to store -ESRCH so it needs to be signed. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: kbuild@01.org Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Mike Galbraith <efault@gmx.de> Link: http://lkml.kernel.org/r/20130205113751.GA20521@elgon.mountain Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched: Fix select_idle_sibling() bouncing cow syndromeMike Galbraith2013-02-041-14/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If the previous CPU is cache affine and idle, select it. The current implementation simply traverses the sd_llc domain, taking the first idle CPU encountered, which walks buddy pairs hand in hand over the package, inflicting excruciating pain. 1 tbench pair (worst case) in a 10 core + SMT package: pre 15.22 MB/sec 1 procs post 252.01 MB/sec 1 procs Signed-off-by: Mike Galbraith <bitbucket@online.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1359371965.5783.127.camel@marge.simpson.net Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/rt: Further simplify pick_rt_task()Kirill Tkhai2013-02-031-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Function next_prio() has been removed and pull_rt_task() is the only user of pick_next_highest_task_rt() at the moment. pull_rt_task is not interested in p->nr_cpus_allowed, its only interest is the fact that cpu is allowed to execute p. If nr_cpus_allowed == 1, cpu != task_cpu(p) and cpu is allowed then it means that task p is in the middle of the migration techniques; the task waits until it is moved by migration thread. So, lets pull it earlier. Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> CC: linux-rt-users <linux-rt-users@vger.kernel.org> Link: http://lkml.kernel.org/r/70871359644177@web16d.yandex.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/rt: Do not account zero delta_exec in update_curr_rt()Kirill Tkhai2013-01-311-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are several places of consecutive calls of dequeue_task_rt() and put_prev_task_rt() in the scheduler. For example, function rt_mutex_setprio() does it. The both calls lead to update_curr_rt(), the second of it receives zeroed delta_exec. The only effective action in this case is call of sched_rt_avg_update(), which can change rq->age_stamp and rq->rt_avg. But it is possible in case of ""floating"" rq->clock. This fact is not reasonable to be accounted. Another actions do nothing. Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> CC: linux-rt-users <linux-rt-users@vger.kernel.org> Link: http://lkml.kernel.org/r/931541359550236@web1g.yandex.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | cputime: Avoid multiplication overflow on utime scalingFrederic Weisbecker2013-01-271-9/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We scale stime, utime values based on rtime (sum_exec_runtime converted to jiffies). During scaling we multiple rtime * utime, which seems to be fine, since both values are converted to u64, but it's not. Let assume HZ is 1000 - 1ms tick. Process consist of 64 threads, run for 1 day, threads utilize 100% cpu on user space. Machine has 64 cpus. Process rtime = utime will be 64 * 24 * 60 * 60 * 1000 jiffies, which is 0x149970000. Multiplication rtime * utime result is 0x1a855771100000000, which can not be covered in 64 bits. Result of overflow is stall of utime values visible in user space (prev_utime in kernel), even if application still consume lot of CPU time. A solution to solve this is to perform the multiplication on stime instead of utime. It's easy to grow the utime value fast with a CPU bound thread in userspace for example. Now we assume that doing so with stime is much harder. In most cases a task shouldn't ever spend much time in kernel space as it tends to sleep waiting for jobs completion when they take long to achieve. IO is the typical example of that. Hence scaling the cputime by performing the multiplication on stime instead of utime should considerably reduce the chances of an overflow on most workloads. This is largely inspired by a patch from Stanislaw Gruszka: http://lkml.kernel.org/r/20130107113144.GA7544@redhat.com Inspired-by: Stanislaw Gruszka <sgruszka@redhat.com> Reported-by: Stanislaw Gruszka <sgruszka@redhat.com> Acked-by: Stanislaw Gruszka <sgruszka@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Link: http://lkml.kernel.org/r/1359217182-25184-1-git-send-email-fweisbec@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/rt: Avoid updating RT entry timeout twice within one tick periodYing Xue2013-01-252-1/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The issue below was found in 2.6.34-rt rather than mainline rt kernel, but the issue still exists upstream as well. So please let me describe how it was noticed on 2.6.34-rt: On this version, each softirq has its own thread, it means there is at least one RT FIFO task per cpu. The priority of these tasks is set to 49 by default. If user launches an RT FIFO task with priority lower than 49 of softirq RT tasks, it's possible there are two RT FIFO tasks enqueued one cpu runqueue at one moment. By current strategy of balancing RT tasks, when it comes to RT tasks, we really need to put them off to a CPU that they can run on as soon as possible. Even if it means a bit of cache line flushing, we want RT tasks to be run with the least latency. When the user RT FIFO task which just launched before is running, the sched timer tick of the current cpu happens. In this tick period, the timeout value of the user RT task will be updated once. Subsequently, we try to wake up one softirq RT task on its local cpu. As the priority of current user RT task is lower than the softirq RT task, the current task will be preempted by the higher priority softirq RT task. Before preemption, we check to see if current can readily move to a different cpu. If so, we will reschedule to allow the RT push logic to try to move current somewhere else. Whenever the woken softirq RT task runs, it first tries to migrate the user FIFO RT task over to a cpu that is running a task of lesser priority. If migration is done, it will send a reschedule request to the found cpu by IPI interrupt. Once the target cpu responds the IPI interrupt, it will pick the migrated user RT task to preempt its current task. When the user RT task is running on the new cpu, the sched timer tick of the cpu fires. So it will tick the user RT task again. This also means the RT task timeout value will be updated again. As the migration may be done in one tick period, it means the user RT task timeout value will be updated twice within one tick. If we set a limit on the amount of cpu time for the user RT task by setrlimit(RLIMIT_RTTIME), the SIGXCPU signal should be posted upon reaching the soft limit. But exactly when the SIGXCPU signal should be sent depends on the RT task timeout value. In fact the timeout mechanism of sending the SIGXCPU signal assumes the RT task timeout is increased once every tick. However, currently the timeout value may be added twice per tick. So it results in the SIGXCPU signal being sent earlier than expected. To solve this issue, we prevent the timeout value from increasing twice within one tick time by remembering the jiffies value of last updating the timeout. As long as the RT task's jiffies is different with the global jiffies value, we allow its timeout to be updated. Signed-off-by: Ying Xue <ying.xue@windriver.com> Signed-off-by: Fan Du <fan.du@windriver.com> Reviewed-by: Yong Zhang <yong.zhang0@gmail.com> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: <peterz@infradead.org> Link: http://lkml.kernel.org/r/1342508623-2887-1-git-send-email-ying.xue@windriver.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/fair: Set se->vruntime directly in place_entity()Viresh Kumar2013-01-241-3/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We are first storing the new vruntime in a variable and then storing it in se->vruntime. Simply update se->vruntime directly. Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org> Cc: linaro-dev@lists.linaro.org Cc: patches@linaro.org Cc: peterz@infradead.org Link: http://lkml.kernel.org/r/ae59db1945518d6f6250920d46eb1f1a9cc0024e.1352361704.git.viresh.kumar@linaro.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched/rt: Add reschedule check to switched_from_rt()Kirill Tkhai2013-01-241-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reschedule rq->curr if the first RT task has just been pulled to the rq. Signed-off-by: Kirill V Tkhai <tkhai@yandex.ru> Acked-by: Steven Rostedt <rostedt@goodmis.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Tkhai Kirill <tkhai@yandex.ru> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/118761353614535@web28f.yandex.ru Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | sched: Fix the broken sched_rr_get_interval()Zhu Yanhai2013-01-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The caller of sched_sliced() should pass se.cfs_rq and se as the arguments, however in sched_rr_get_interval() we gave it rq.cfs_rq and se, which made the following computation obviously wrong. The change was introduced by commit: 77034937dc45 sched: fix crash in sys_sched_rr_get_interval() ... 5 years ago, while it had been the correct 'cfs_rq_of' before the commit. The change seems to be irrelevant to the commit msg, which was to return a 0 timeslice for tasks that are on an idle runqueue. So I believe that was just a plain typo. Signed-off-by: Zhu Yanhai <gaoyang.zyh@taobao.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul Turner <pjt@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/1357621012-15039-1-git-send-email-gaoyang.zyh@taobao.com [ Since this is an ABI and an old bug, we'll test this via a slow upstream route, to hopefully discover any app breakage. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
* | | Merge branch 'perf-core-for-linus' of ↵Linus Torvalds2013-02-19195-4097/+8995
|\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf changes from Ingo Molnar: "There are lots of improvements, the biggest changes are: Main kernel side changes: - Improve uprobes performance by adding 'pre-filtering' support, by Oleg Nesterov. - Make some POWER7 events available in sysfs, equivalent to what was done on x86, from Sukadev Bhattiprolu. - tracing updates by Steve Rostedt - mostly misc fixes and smaller improvements. - Use perf/event tracing to report PCI Express advanced errors, by Tony Luck. - Enable northbridge performance counters on AMD family 15h, by Jacob Shin. - This tracing commit: tracing: Remove the extra 4 bytes of padding in events changes the ABI. All involved parties (PowerTop in particular) seem to agree that it's safe to do now with the introduction of libtraceevent, but the devil is in the details ... Main tooling side changes: - Add 'event group view', from Namyung Kim: To use it, 'perf record' should group events when recording. And then perf report parses the saved group relation from file header and prints them together if --group option is provided. You can use the 'perf evlist' command to see event group information: $ perf record -e '{ref-cycles,cycles}' noploop 1 [ perf record: Woken up 2 times to write data ] [ perf record: Captured and wrote 0.385 MB perf.data (~16807 samples) ] $ perf evlist --group {ref-cycles,cycles} With this example, default perf report will show you each event separately. You can use --group option to enable event group view: $ perf report --group ... # group: {ref-cycles,cycles} # ======== # Samples: 7K of event 'anon group { ref-cycles, cycles }' # Event count (approx.): 6876107743 # # Overhead Command Shared Object Symbol # ................ ....... ................. .......................... 99.84% 99.76% noploop noploop [.] main 0.07% 0.00% noploop ld-2.15.so [.] strcmp 0.03% 0.00% noploop [kernel.kallsyms] [k] timerqueue_del 0.03% 0.03% noploop [kernel.kallsyms] [k] sched_clock_cpu 0.02% 0.00% noploop [kernel.kallsyms] [k] account_user_time 0.01% 0.00% noploop [kernel.kallsyms] [k] __alloc_pages_nodemask 0.00% 0.00% noploop [kernel.kallsyms] [k] native_write_msr_safe 0.00% 0.11% noploop [kernel.kallsyms] [k] _raw_spin_lock 0.00% 0.06% noploop [kernel.kallsyms] [k] find_get_page 0.00% 0.02% noploop [kernel.kallsyms] [k] rcu_check_callbacks 0.00% 0.02% noploop [kernel.kallsyms] [k] __current_kernel_time As you can see the Overhead column now contains both of ref-cycles and cycles and header line shows group information also - 'anon group { ref-cycles, cycles }'. The output is sorted by period of group leader first. - Initial GTK+ annotate browser, from Namhyung Kim. - Add option for runtime switching perf data file in perf report, just press 's' and a menu with the valid files found in the current directory will be presented, from Feng Tang. - Add support to display whole group data for raw columns, from Jiri Olsa. - Add per processor socket count aggregation in perf stat, from Stephane Eranian. - Add interval printing in 'perf stat', from Stephane Eranian. - 'perf test' improvements - Add support for wildcards in tracepoint system name, from Jiri Olsa. - Add anonymous huge page recognition, from Joshua Zhu. - perf build-id cache now can show DSOs present in a perf.data file that are not in the cache, to integrate with build-id servers being put in place by organizations such as Fedora. - perf top now shares more of the evsel config/creation routines with 'record', paving the way for further integration like 'top' snapshots, etc. - perf top now supports DWARF callchains. - Fix mmap limitations on 32-bit, fix from David Miller. - 'perf bench numa mem' NUMA performance measurement suite - ... and lots of fixes, performance improvements, cleanups and other improvements I failed to list - see the shortlog and git log for details." * 'perf-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (270 commits) perf/x86/amd: Enable northbridge performance counters on AMD family 15h perf/hwbp: Fix cleanup in case of kzalloc failure perf tools: Fix build with bison 2.3 and older. perf tools: Limit unwind support to x86 archs perf annotate: Make it to be able to skip unannotatable symbols perf gtk/annotate: Fail early if it can't annotate perf gtk/annotate: Show source lines with gray color perf gtk/annotate: Support multiple event annotation perf ui/gtk: Implement basic GTK2 annotation browser perf annotate: Fix warning message on a missing vmlinux perf buildid-cache: Add --update option uprobes/perf: Avoid uprobe_apply() whenever possible uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVE uprobes/perf: Teach trace_uprobe/perf code to pre-filter uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event's uprobes: Introduce uprobe_apply() perf: Introduce hw_perf_event->tp_target and ->tp_list uprobes/perf: Always increment trace_uprobe->nhit uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into trace_uprobe uprobes/tracing: Introduce is_trace_uprobe_enabled() ...
| * | | perf/x86/amd: Enable northbridge performance counters on AMD family 15hJacob Shin2013-02-164-20/+164
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | On AMD family 15h processors, there are 4 new performance counters (in addition to 6 core performance counters) that can be used for counting northbridge events (i.e. DRAM accesses). Their bit fields are almost identical to the core performance counters. However, unlike the core performance counters, these MSRs are shared between multiple cores (that share the same northbridge). We will reuse the same code path as existing family 10h northbridge event constraints handler logic to enforce this sharing. Signed-off-by: Jacob Shin <jacob.shin@amd.com> Acked-by: Stephane Eranian <eranian@google.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Jacob Shin <jacob.shin@amd.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360171589-6381-7-git-send-email-jacob.shin@amd.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
| * | | Merge tag 'perf-core-for-mingo' of ↵Ingo Molnar2013-02-1513-11/+349
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/core Pull perf/core improvements and fixes from Arnaldo Carvalho de Melo: * Fix cleanup in case of kzalloc failure, from Daniel Baluta. * Limit unwind support to x86 archs, fix from Jiri Olsa. * Initial GTK+ annotate browser, from Namhyung Kim. * Fix build with bison 2.3 and older, from Vinson Lee. Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | perf/hwbp: Fix cleanup in case of kzalloc failureDaniel Baluta2013-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Obviously this is a typo and could result in memory leaks if kzalloc fails on a given cpu. Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com> Acked-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360186160-7566-1-git-send-email-dbaluta@ixiacom.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf tools: Fix build with bison 2.3 and older.Vinson Lee2013-02-143-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The %name-prefix "prefix" syntax is not available on bison 2.3 and older. Substitute with the -p "prefix" command-line option for compatibility with older versions of bison. This patch fixes this build error with older versions of bison. CC util/sysfs.o BISON util/pmu-bison.c util/pmu.y:2.14-24: syntax error, unexpected string, expecting = make: *** [util/pmu-bison.c] Error 1 Signed-off-by: Vinson Lee <vlee@twitter.com> Tested-by: Li Zefan <lizefan@huawei.com> Cc: stable@vger.kernel.org # 3.4+ Cc: Ingo Molnar <mingo@redhat.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Namhyung Kim <namhyung@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Link: http://lkml.kernel.org/r/1360792138-29186-1-git-send-email-vlee@twitter.com Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf tools: Limit unwind support to x86 archsJiri Olsa2013-02-141-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There's DWARF unwind support only for x86 archs, so limit the unwind.o object to them only. Without this building for other archs (e.g. cross compiling for ARM) is broken. Signed-off-by: Jiri Olsa <jolsa@redhat.com> Signed-off-by: Dirk Behme <dirk.behme@de.bosch.com> Link: http://lkml.kernel.org/n/tip-viqtvd6hppqgt68zz4wlqm20@git.kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf annotate: Make it to be able to skip unannotatable symbolsNamhyung Kim2013-02-142-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add --skip-missing option for skipping symbols that cannot be used for annotation. It's the case of kernel symbols that user doesn't have a vmlinux image file. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-8-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf gtk/annotate: Fail early if it can't annotateNamhyung Kim2013-02-141-8/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Don't need to setup a browser window if annotate cannot work. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-7-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf gtk/annotate: Show source lines with gray colorNamhyung Kim2013-02-141-3/+27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to differentiate source lines from asm line, print them with gray color. To do this, it needs to be escaped since sometimes it contains "<" and/or ">" characters so that it should not be considered as a markup tags. Use glib's g_markup_escape_text() for this. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-4-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf gtk/annotate: Support multiple event annotationNamhyung Kim2013-02-144-27/+56
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Show multiple annotation result for each evsel. Each result represents the most frquently sampled symbol/function for the evsel and it will be shown in a tab window. For this add a reference to main container (notebook) to the pgctx. At the first call to annotate browser, hist_entry__find_annotations() will setup a new browser, and next calls will add new tabs to the browser. But it requires final perf_gtk__show_annotations() to start processing GUI events. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-3-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf ui/gtk: Implement basic GTK2 annotation browserNamhyung Kim2013-02-146-4/+218
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Basic implementation of perf annotate on GTK2. Currently only shows first symbol. Add a new --gtk option to use it. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Namhyung Kim <namhyung.kim@lge.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-2-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf annotate: Fix warning message on a missing vmlinuxNamhyung Kim2013-02-141-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When perf annotate runs with no vmlinux file it cannot annotate kernel symbols because the kallsyms only provides symbol addresses. So it recommends to run perf buildid-cache to install proper vmlinux image. But running perf buildid-cache -av vmlinux as the message gives me a following error: $ perf buildid-cache -av /home/namhyung/build/kernel/vmlinux Couldn't add v: No such file or directory Since the -a option receives a parameter, 'v' should not be after the option. In addition -a option is not work for this case since the build-id cache already has a kallsyms with same build-id so it'll fail with EEXIST. Use recently added -u (--update) option for it. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-6-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| | * | | perf buildid-cache: Add --update optionNamhyung Kim2013-02-142-1/+53
| |/ / / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When adding vmlinux file to build-id cache, it'd be fail since kallsyms dso with a same build-id was already added by perf record. So one needs to remove the kallsyms first to add vmlinux into the cache. Add --update option for doing it at once. Signed-off-by: Namhyung Kim <namhyung@kernel.org> Cc: Andi Kleen <andi@firstfloor.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Ingo Molnar <mingo@kernel.org> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Pekka Enberg <penberg@kernel.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/1360227734-375-5-git-send-email-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
| * | | Merge branch 'uprobes/core' of ↵Ingo Molnar2013-02-118-274/+456
| |\ \ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/oleg/misc into perf/core Improve uprobes performance by adding 'pre-filtering' support, by Oleg Nesterov: # time perl -e 'syscall -1 for 1..100_000' real 0m0.040s user 0m0.027s sys 0m0.010s # perf probe -x /lib/libc.so.6 syscall # perf record -e probe_libc:syscall sleep 100 & Before this series: # time perl -e 'syscall -1 for 1..100_000' real 0m1.714s user 0m0.103s sys 0m1.607s After: # time perl -e 'syscall -1 for 1..100_000' real 0m0.037s user 0m0.013s sys 0m0.023s Signed-off-by: Ingo Molnar <mingo@kernel.org>
| | * | | uprobes/perf: Avoid uprobe_apply() whenever possibleOleg Nesterov2013-02-081-6/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | uprobe_perf_open/close call the costly uprobe_apply() every time, we can avoid it if: - "nr_systemwide != 0" is not changed. - There is another process/thread with the same ->mm. - copy_proccess() does inherit_event(). dup_mmap() preserves the inserted breakpoints. - event->attr.enable_on_exec == T, we can rely on uprobe_mmap() called by exec/mmap paths. - tp_target is exiting. Only _close() checks PF_EXITING, I don't think TRACE_REG_PERF_OPEN can hit the dying task too often. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes/perf: Teach trace_uprobe/perf code to use UPROBE_HANDLER_REMOVEOleg Nesterov2013-02-081-7/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Change uprobe_trace_func() and uprobe_perf_func() to return "int". Change uprobe_dispatcher() to return "trace_ret | perf_ret" although this is not needed, currently TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive. The only functional change is that uprobe_perf_func() checks the filtering too and returns UPROBE_HANDLER_REMOVE if nobody wants to trace current. Testing: # perf probe -x /lib/libc.so.6 syscall # perf record -e probe_libc:syscall -i perl -e 'fork; syscall -1 for 1..10; wait' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 20 A child process doesn't have a counter, but still it hits this breakoint "copied" by dup_mmap(). After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 11 The child process hits this int3 only once and does unapply_uprobe(). Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes/perf: Teach trace_uprobe/perf code to pre-filterOleg Nesterov2013-02-081-3/+43
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Finally implement uprobe_perf_filter() which checks ->nr_systemwide or ->perf_events to figure out whether we need to insert the breakpoint. uprobe_perf_open/close are changed to do uprobe_apply(true/false) when the new perf event comes or goes away. Note that currently this is very suboptimal: - uprobe_register() called by TRACE_REG_PERF_REGISTER becomes a heavy nop, consumer->filter() always returns F at this stage. As it was already discussed we need uprobe_register_only() to avoid the costly register_for_each_vma() when possible. - uprobe_apply() is oftenly overkill. Unless "nr_systemwide != 0" changes we need uprobe_apply_mm(), unapply_uprobe() is almost what we need. - uprobe_apply() can be simply avoided sometimes, see the next changes. Testing: # perf probe -x /lib/libc.so.6 syscall # perl -e 'syscall -1 while 1' & [1] 530 # perf record -e probe_libc:syscall perl -e 'syscall -1 for 1..10; sleep 1' # perf report --show-total-period 100.00% 10 perl libc-2.8.so [.] syscall Before this patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 79291 A huge ->nrhit == 79291 reflects the fact that the background process 530 constantly hits this breakpoint too, even if doesn't contribute to the output. After the patch: # cat /sys/kernel/debug/tracing/uprobe_profile /lib/libc.so.6 syscall 10 This shows that only the target process was punished by int3. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes/perf: Teach trace_uprobe/perf code to track the active perf_event'sOleg Nesterov2013-02-081-0/+55
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce "struct trace_uprobe_filter" which records the "active" perf_event's attached to ftrace_event_call. For the start we simply use list_head, we can optimize this later if needed. For example, we do not really need to record an event with ->parent != NULL, we can rely on parent->child_list. And we can certainly do some optimizations for the case when 2 events have the same ->tp_target or tp_target->mm. Change trace_uprobe_register() to process TRACE_REG_PERF_OPEN/CLOSE and add/del this perf_event to the list. We can probably avoid any locking, but lets start with the "obvioulsy correct" trace_uprobe_filter->rwlock which protects everything. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes: Introduce uprobe_apply()Oleg Nesterov2013-02-082-4/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently it is not possible to change the filtering constraints after uprobe_register(), so a consumer can not, say, start to trace a task/mm which was previously filtered out, or remove the no longer needed bp's. Introduce uprobe_apply() which simply does register_for_each_vma() again to consult uprobe_consumer->filter() and install/remove the breakpoints. The only complication is that register_for_each_vma() can no longer assume that uprobe->consumers should be consulter if is_register == T, so we change it to accept "struct uprobe_consumer *new" instead. Unlike uprobe_register(), uprobe_apply(true) doesn't do "unregister" if register_for_each_vma() fails, it is up to caller to handle the error. Note: we probably need to cleanup the current interface, it is strange that uprobe_apply/unregister need inode/offset. We should either change uprobe_register() to return "struct uprobe *", or add a private ->uprobe member in uprobe_consumer. And in the long term uprobe_apply() should take a single argument, uprobe or consumer, even "bool add" should go away. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | perf: Introduce hw_perf_event->tp_target and ->tp_listOleg Nesterov2013-02-082-3/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | sys_perf_event_open()->perf_init_event(event) is called before find_get_context(event), this means that event->ctx == NULL when class->reg(TRACE_REG_PERF_REGISTER/OPEN) is called and thus it can't know if this event is per-task or system-wide. This patch adds hw_perf_event->tp_target for PERF_TYPE_TRACEPOINT, this is analogous to PERF_TYPE_BREAKPOINT/bp_target we already have. The patch also moves ->bp_target up so that it can overlap with the new member, this can help the compiler to generate the better code. trace_uprobe_register() will use it for prefiltering to avoid the unnecessary breakpoints in mm's we do not want to trace. ->tp_target doesn't have its own reference, but we can rely on the fact that either sys_perf_event_open() holds a reference, or it is equal to event->ctx->task. So this pointer is always valid until free_event(). Also add the "struct list_head tp_list" into this union. It is not strictly necessary, but it can simplify the next changes and we can add it for free. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes/perf: Always increment trace_uprobe->nhitOleg Nesterov2013-02-081-2/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move tu->nhit++ from uprobe_trace_func() to uprobe_dispatcher(). ->nhit counts how many time we hit the breakpoint inserted by this uprobe, we do not want to loose this info if uprobe was enabled by sys_perf_event_open(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| | * | | uprobes/tracing: Kill uprobe_trace_consumer, embed uprobe_consumer into ↵Oleg Nesterov2013-02-081-29/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | trace_uprobe trace_uprobe->consumer and "struct uprobe_trace_consumer" add the unnecessary indirection and complicate the code for no reason. This patch simply embeds uprobe_consumer into "struct trace_uprobe", all other changes only fix the compilation errors. Signed-off-by: Oleg Nesterov <oleg@redhat.com>
| | * | | uprobes/tracing: Introduce is_trace_uprobe_enabled()Oleg Nesterov2013-02-082-3/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probe_event_enable/disable() check tu->consumer != NULL to avoid the wrong uprobe_register/unregister(). We are going to kill this pointer and "struct uprobe_trace_consumer", so we add the new helper, is_trace_uprobe_enabled(), which can rely on TP_FLAG_TRACE/TP_FLAG_PROFILE instead. Note: the current logic doesn't look optimal, it is not clear why TP_FLAG_TRACE/TP_FLAG_PROFILE are mutually exclusive, we will probably change this later. Also kill the unused TP_FLAG_UPROBE. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
| | * | | uprobes/tracing: Ensure inode != NULL in create_trace_uprobe()Oleg Nesterov2013-02-081-3/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | probe_event_enable/disable() check tu->inode != NULL at the start. This is ugly, if igrab() can fail create_trace_uprobe() should not succeed and "postpone" the failure. And S_ISREG(inode->i_mode) check added by d24d7dbf is not safe. Note: alloc_uprobe() should probably check igrab() != NULL as well. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-07 16:04:45 +0000