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* perf_event: Fix cgrp event scheduling bug in perf_enable_on_exec()Stephane Eranian2011-04-11
| | | | | | | | | | | | | | | | | | | There is a bug in perf_event_enable_on_exec() when cgroup events are active on a CPU: the cgroup events may be scheduled twice causing event state corruptions which eventually may lead to kernel panics. The reason is that the function needs to first schedule out the cgroup events, just like for the per-thread events. The cgroup event are scheduled back in automatically from the perf_event_context_sched_in() function. The patch also adds a WARN_ON_ONCE() is perf_cgroup_switch() to catch any bogus state. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Link: http://lkml.kernel.org/r/20110406005454.GA1062@quad Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix task_struct reference leakPeter Zijlstra2011-03-31
| | | | | | | | | | | | sys_perf_event_open() had an imbalance in the number of task refs it took causing memory leakage Cc: Jiri Olsa <jolsa@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: stable@kernel.org # .37+ Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Rebase max unprivileged mlock threshold on top of page sizeFrederic Weisbecker2011-03-31
| | | | | | | | | | | | | | | Ensure we allow 512 kiB + 1 page for user control without assuming a 4096 bytes page size. Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: <stable@kernel.org> LKML-Reference: <1301535209-9679-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Better fit max unprivileged mlock pages for tools needsFrederic Weisbecker2011-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The maximum kilobytes of locked memory that an unprivileged user can reserve is of 512 kB = 128 pages by default, scaled to the number of onlined CPUs, which fits well with the tools that use 128 data pages by default. However tools actually use 129 pages, because they need one more for the user control page. Thus the default mlock threshold is not sufficient for the default tools needs and we always end up to evaluate the constant mlock rlimit policy, which doesn't have this scaling with the number of online CPUs. Hence, on systems that have more than 16 CPUs, we overlap the rlimit threshold and fail to mmap: $ perf record ls Error: failed to mmap with 1 (Operation not permitted) Just increase the max unprivileged mlock threshold by one page so that it supports well perf tools even after 16 CPUs. Reported-by: Han Pingtian <phan@redhat.com> Reported-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Reported-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Stephane Eranian <eranian@google.com> Cc: Stable <stable@kernel.org> LKML-Reference: <1300904979-5508-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_events: Fix stale ->cgrp pointer in update_cgrp_time_from_cpuctx()Stephane Eranian2011-03-23
| | | | | | | | | | | | | | | | | | | | | | | | | | | This patch solves a stale pointer problem in update_cgrp_time_from_cpuctx(). The cpuctx->cgrp was not cleared on all possible event exit paths, including: close() perf_release() perf_release_kernel() list_del_event() This patch fixes list_del_event() to clear cpuctx->cgrp when there are no cgroup events left in the context. [ This second version makes the code compile when CONFIG_CGROUP_PERF is not enabled. We unconditionally define perf_cpu_context->cgrp. ] Signed-off-by: Stephane Eranian <eranian@google.com> Cc: peterz@infradead.org Cc: perfmon2-devel@lists.sf.net Cc: paulus@samba.org Cc: davem@davemloft.net LKML-Reference: <20110323150306.GA1580@quad> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix tear-down of inherited group eventsPeter Zijlstra2011-03-16
| | | | | | | | | | | | When destroying inherited events, we need to destroy groups too, otherwise the event iteration in perf_event_exit_task_context() will miss group siblings and we leak events with all the consequences. Reported-and-tested-by: Vince Weaver <vweaver1@eecs.utk.edu> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: <stable@kernel.org> # .35+ LKML-Reference: <1300196470.2203.61.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Handle stopped state with tracepointsFrederic Weisbecker2011-03-16
| | | | | | | | | | | | | | | We toggle the state from start and stop callbacks but actually don't check it when the event triggers. Do it so that these callbacks actually work. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1299529629-18280-2-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix the software events state checkFrederic Weisbecker2011-03-16
| | | | | | | | | | | | | Fix the mistakenly inverted check of events state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: <stable@kernel.org> LKML-Reference: <1299529629-18280-1-git-send-email-fweisbec@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix cgroup vs jump_label problemPeter Zijlstra2011-03-04
| | | | | | | | | | Li Zefan reported that the jump label code sleeps and we're calling it under a spinlock, *fail* ;-) Reported-by: Li Zefan <lizf@cn.fujitsu.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf cgroup: Clean up perf_cgroup_create()Li Zefan2011-03-04
| | | | | | | | | | | | | - Use kzalloc() to replace kmalloc() + memset(). - Remove redundant initialization, since alloc_percpu() returns zero-filled percpu memory. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4D6F347E.2010806@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf cgroup: Fix unmatched call to perf_detach_cgroup()Li Zefan2011-03-04
| | | | | | | | | | | In the failure path, we call perf_detach_cgroup(), but we didn't call perf_get_cgroup() prio to it. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4D6F346E.9070606@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf cgroup: Fix leak of file reference countLi Zefan2011-03-04
| | | | | | | | | | In perf_cgroup_connect(), fput_light() is missing in a failure path. Signed-off-by: Li Zefan <lizf@cn.fujitsu.com> Acked-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4D6F3461.6060406@cn.fujitsu.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix the missing event initialization when pmu is found in idrLin Ming2011-03-04
| | | | | | | | | | | Currently, the event is not initialized if pmu is found in idr. This never causes bug just because now no pmu is associated with the idr id. Signed-off-by: Lin Ming <ming.m.lin@intel.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1298812411.2699.9.camel@localhost> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Simplify task_clock_event_read()Peter Zijlstra2011-02-23
| | | | | | | | | | There is no point in us having different code paths for nmi and !nmi here, so remove the !nmi one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf_events: Fix rcu and locking issues with cgroup supportStephane Eranian2011-02-23
| | | | | | | | | | | | | | | | | | | | | | This patches ensures that we do not end up calling perf_cgroup_from_task() when there is no cgroup event. This avoids potential RCU and locking issues. The change in perf_cgroup_set_timestamp() ensures we check against ctx->nr_cgroups. It also avoids calling perf_clock() tiwce in a row. It also ensures we do need to grab ctx->lock before calling the function. We drop update_cgrp_time() from task_clock_event_read() because it is not needed. This also avoids having to deal with perf_cgroup_from_task(). Thanks to Peter Zijlstra for his help on this. Signed-off-by: Stephane Eranian <eranian@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d5e76b8.815bdf0a.7ac3.774f@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Optimize hrtimer eventsPeter Zijlstra2011-02-16
| | | | | | | | | | | | There is no need to re-initialize the hrtimer every time we start it, so don't do that (shaves a few cycles). Also, since we know hrtimers run at a fixed rate (nanoseconds) we can pre-compute the desired frequency at which they tick. This avoids us having to go through the whole adaptive frequency feedback logic (shaves another few cycles). Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1297448589.5226.47.camel@laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Optimize throttling codePeter Zijlstra2011-02-16
| | | | | | | | | | By pre-computing the maximum number of samples per tick we can avoid a multiplication and a conditional since MAX_INTERRUPTS > max_samples_per_tick. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Add cgroup supportStephane Eranian2011-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | This kernel patch adds the ability to filter monitoring based on container groups (cgroups). This is for use in per-cpu mode only. The cgroup to monitor is passed as a file descriptor in the pid argument to the syscall. The file descriptor must be opened to the cgroup name in the cgroup filesystem. For instance, if the cgroup name is foo and cgroupfs is mounted in /cgroup, then the file descriptor is opened to /cgroup/foo. Cgroup mode is activated by passing PERF_FLAG_PID_CGROUP in the flags argument to the syscall. For instance to measure in cgroup foo on CPU1 assuming cgroupfs is mounted under /cgroup: struct perf_event_attr attr; int cgroup_fd, fd; cgroup_fd = open("/cgroup/foo", O_RDONLY); fd = perf_event_open(&attr, cgroup_fd, 1, -1, PERF_FLAG_PID_CGROUP); close(cgroup_fd); Signed-off-by: Stephane Eranian <eranian@google.com> [ added perf_cgroup_{exit,attach} ] Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d590250.114ddf0a.689e.4482@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'perf/urgent' into perf/coreIngo Molnar2011-02-16
|\ | | | | | | | | | | Merge reason: we need to queue up dependent patch Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Fix throttle logicPeter Zijlstra2011-02-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It was possible to call pmu::start() on an already running event. In particular this lead so some wreckage as the hrtimer events would re-initialize active timers. This was due to throttled events being activated again by scheduling. Scheduling in a context would add and force start events, resulting in running events with a possible throttle status. The next tick to hit that task will then try to unthrottle the event and call ->start() on an already running event. Reported-by: Jeff Moyer <jmoyer@redhat.com> Cc: <stable@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'linus' into perf/coreIngo Molnar2011-02-07
|\| | | | | | | | | | | Merge reason: Pick up perf fixes that are now upstream Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Fix reading in perf_event_read()Peter Zijlstra2011-02-03
| | | | | | | | | | | | | | | | | | | | | | It is quite possible for the event to have been disabled between perf_event_read() sending the IPI and the CPU servicing the IPI and calling __perf_event_read(), hence revalidate the state. Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Fix alloc_callchain_buffers()Eric Dumazet2011-01-27
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 927c7a9e92c4 ("perf: Fix race in callchains") introduced a mismatch in the sizing of struct callchain_cpus_entries. nr_cpu_ids must be used instead of num_possible_cpus(), or we might get out of bound memory accesses on some machines. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Miller <davem@davemloft.net> Cc: Stephane Eranian <eranian@google.com> CC: stable@kernel.org LKML-Reference: <1295980851.3588.351.camel@edumazet-laptop> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | perf: Cure task_oncpu_function_call() racesPeter Zijlstra2011-02-03
|/ | | | | | | | | | | | | | | | | | | | Oleg reported that on architectures with __ARCH_WANT_INTERRUPTS_ON_CTXSW the IPI from task_oncpu_function_call() can land before perf_event_task_sched_in() and cause interesting situations for eg. perf_install_in_context(). This patch reworks the task_oncpu_function_call() interface to give a more usable primitive as well as rework all its users to hopefully be more obvious as well as remove the races. While looking at the code I also found a number of races against perf_event_task_sched_out() which can flip contexts between tasks so plug those too. Reported-and-reviewed-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: perf_event_exit_task_context: s/rcu_dereference/rcu_dereference_raw/Oleg Nesterov2011-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | In theory, almost every user of task->child->perf_event_ctxp[] is wrong. find_get_context() can install the new context at any moment, we need read_barrier_depends(). dbe08d82ce3967ccdf459f7951d02589cf967300 "perf: Fix find_get_context() vs perf_event_exit_task() race" added rcu_dereference() into perf_event_exit_task_context() to make the precedent, but this makes __rcu_dereference_check() unhappy. Use rcu_dereference_raw() to shut up the warning. Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: acme@redhat.com Cc: paulus@samba.org Cc: stern@rowland.harvard.edu Cc: a.p.zijlstra@chello.nl Cc: fweisbec@gmail.com Cc: roland@redhat.com Cc: prasad@linux.vnet.ibm.com Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> LKML-Reference: <20110121174547.GA8796@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Annotate cpuctx->ctx.mutex to avoid a lockdep splatPeter Zijlstra2011-01-21
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Lockdep spotted: loop_1b_instruc/1899 is trying to acquire lock: (event_mutex){+.+.+.}, at: [<ffffffff810e1908>] perf_trace_init+0x3b/0x2f7 but task is already holding lock: (&ctx->mutex){+.+.+.}, at: [<ffffffff810eb45b>] perf_event_init_context+0xc0/0x218 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&ctx->mutex){+.+.+.}: -> #2 (cpu_hotplug.lock){+.+.+.}: -> #1 (module_mutex){+.+...}: -> #0 (event_mutex){+.+.+.}: But because the deadlock would be cpuhotplug (cpu-event) vs fork (task-event) it cannot, in fact, happen. We can annotate this by giving the perf_event_context used for the cpuctx a different lock class from those used by tasks. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix perf_event_init_task()/perf_event_free_task() interactionOleg Nesterov2011-01-19
| | | | | | | | | | | | | | | | | | | | | | | perf_event_init_task() should clear child->perf_event_ctxp[] before anything else. Otherwise, if perf_event_init_context(perf_hw_context) fails, perf_event_free_task() can free perf_event_ctxp[perf_sw_context] copied from parent->perf_event_ctxp[] by dup_task_struct(). Also move the initialization of perf_event_mutex and perf_event_list from perf_event_init_context() to perf_event_init_context(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> LKML-Reference: <20110119182228.GC12183@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* perf: Fix find_get_context() vs perf_event_exit_task() raceOleg Nesterov2011-01-19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | find_get_context() must not install the new perf_event_context if the task has already passed perf_event_exit_task(). If nothing else, this means the memory leak. Initially ctx->refcount == 2, it is supposed that perf_event_exit_task_context() should participate and do the necessary put_ctx(). find_lively_task_by_vpid() checks PF_EXITING but this buys nothing, by the time we call find_get_context() this task can be already dead. To the point, cmpxchg() can succeed when the task has already done the last schedule(). Change find_get_context() to populate task->perf_event_ctxp[] under task->perf_event_mutex, this way we can trust PF_EXITING because perf_event_exit_task() takes the same mutex. Also, change perf_event_exit_task_context() to use rcu_dereference(). Probably this is not strictly needed, but with or without this change find_get_context() can race with setup_new_exec()->perf_event_exit_task(), rcu_dereference() looks better. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> LKML-Reference: <20110119182207.GB12183@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* Merge branch 'perf-fixes-for-linus' of ↵Linus Torvalds2011-01-18
|\ | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip * 'perf-fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: perf: Validate cpu early in perf_event_alloc() perf: Find_get_context: fix the per-cpu-counter check perf: Fix contexted inheritance
| * perf: Validate cpu early in perf_event_alloc()Oleg Nesterov2011-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Starting from perf_event_alloc()->perf_init_event(), the kernel assumes that event->cpu is either -1 or the valid CPU number. Change perf_event_alloc() to validate this argument early. This also means we can remove the similar check in find_get_context(). Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: gregkh@suse.de Cc: stable@kernel.org LKML-Reference: <20110118161032.GC693@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Find_get_context: fix the per-cpu-counter checkOleg Nesterov2011-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If task == NULL, find_get_context() should always check that cpu is correct. Afaics, the bug was introduced by 38a81da2 "perf events: Clean up pid passing", but even before that commit "&& cpu != -1" was not exactly right, -ESRCH from find_task_by_vpid() is not accurate. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Prasad <prasad@linux.vnet.ibm.com> Cc: Roland McGrath <roland@redhat.com> Cc: gregkh@suse.de Cc: stable@kernel.org LKML-Reference: <20110118161008.GB693@redhat.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * perf: Fix contexted inheritancePeter Zijlstra2011-01-18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linus reported that the RCU lockdep annotation bits triggered for this rcu_dereference() because we're not holding rcu_read_lock(). Going over the code I cannot convince myself its correct: - holding a ref on the parent_ctx, doesn't avoid it being uncloned concurrently (as the comment says), so we can race with a free. - holding parent_ctx->mutex doesn't avoid the above free from taking place either, it would at best avoid parent_ctx from being freed. I.e. the warning is correct. To fix the bug, serialize against the unclone_ctx() call by extending the reach of the parent_ctx->lock. Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | Merge branch 'for-next' of ↵Linus Torvalds2011-01-13
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (43 commits) Documentation/trace/events.txt: Remove obsolete sched_signal_send. writeback: fix global_dirty_limits comment runtime -> real-time ppc: fix comment typo singal -> signal drivers: fix comment typo diable -> disable. m68k: fix comment typo diable -> disable. wireless: comment typo fix diable -> disable. media: comment typo fix diable -> disable. remove doc for obsolete dynamic-printk kernel-parameter remove extraneous 'is' from Documentation/iostats.txt Fix spelling milisec -> ms in snd_ps3 module parameter description Fix spelling mistakes in comments Revert conflicting V4L changes i7core_edac: fix typos in comments mm/rmap.c: fix comment sound, ca0106: Fix assignment to 'channel'. hrtimer: fix a typo in comment init/Kconfig: fix typo anon_inodes: fix wrong function name in comment fix comment typos concerning "consistent" poll: fix a typo in comment ... Fix up trivial conflicts in: - drivers/net/wireless/iwlwifi/iwl-core.c (moved to iwl-legacy.c) - fs/ext4/ext4.h Also fix missed 'diabled' typo in drivers/net/bnx2x/bnx2x.h while at it.
| * Merge branch 'master' into for-nextJiri Kosina2010-12-22
| |\ | | | | | | | | | | | | | | | | | | | | | | | | | | | Conflicts: MAINTAINERS arch/arm/mach-omap2/pm24xx.c drivers/scsi/bfa/bfa_fcpim.c Needed to update to apply fixes for which the old branch was too outdated.
| * | Kill off a bunch of warning: ‘inline’ is not at beginning of declarationJesper Juhl2010-11-28
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | These warnings are spewed during a build of a 'allnoconfig' kernel (especially the ones from u64_stats_sync.h show up a lot) when building with -Wextra (which I often do).. They are a) annoying b) easy to get rid of. This patch kills them off. include/linux/u64_stats_sync.h:70:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:77:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:84:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:96:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:115:1: warning: ‘inline’ is not at beginning of declaration include/linux/u64_stats_sync.h:127:1: warning: ‘inline’ is not at beginning of declaration kernel/time.c:241:1: warning: ‘inline’ is not at beginning of declaration kernel/time.c:257:1: warning: ‘inline’ is not at beginning of declaration kernel/perf_event.c:4513:1: warning: ‘inline’ is not at beginning of declaration mm/page_alloc.c:4012:1: warning: ‘inline’ is not at beginning of declaration Signed-off-by: Jesper Juhl <jj@chaosbits.net> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* | | perf_events: Add perf_event_time()Stephane Eranian2011-01-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Adds perf_event_time() to try and centralize access to event timing and in particular ctx->time. Prepares for cgroup support. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d22059c.122ae30a.5e0e.ffff8b8b@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf_events: Generalize use of event_filter_match()Stephane Eranian2011-01-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace all occurrences of: event->cpu != -1 && event->cpu == smp_processor_id() by a call to: event_filter_match(event) This makes the code more consistent and will make the cgroup patch smaller. Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d220593.2308e30a.48c5.ffff8ae9@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf_events: Move code around to prepare for cgroupStephane Eranian2011-01-07
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In particular this patch move perf_event_exit_task() before cgroup_exit() to allow for cgroup support. The cgroup_exit() function detaches the cgroups attached to a task. Other movements include hoisting some definitions and inlines at the top of perf_event.c Signed-off-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <4d22058b.cdace30a.4657.ffff95b1@mx.google.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf: Sysfs enumerationPeter Zijlstra2010-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Simple sysfs emumeration of the PMUs. Use a "event_source" bus, and add PMU devices using their name. Each PMU device has a type attribute which contrains the value needed for perf_event_attr::type to identify this PMU. This is the minimal stub needed to start using this interface, we'll consider extending the sysfs usage later. Cc: Kay Sievers <kay.sievers@vrfy.org> Cc: Greg KH <gregkh@suse.de> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101117222056.316982569@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf: Dynamic pmu typesPeter Zijlstra2010-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Extend the perf_pmu_register() interface to allow for named and dynamic pmu types. Because we need to support the existing static types we cannot use dynamic types for everything, hence provide a type argument. If we want to enumerate the PMUs they need a name, provide one. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101117222056.259707703@chello.nl> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | Merge branch 'perf/urgent' into perf/coreIngo Molnar2010-12-16
|\ \ \ | | |/ | |/| | | | | | | | | | Merge reason: We want to apply a dependent patch. Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | perf: Fix off by one in perf_swevent_init()Dan Carpenter2010-12-16
| | | | | | | | | | | | | | | | | | | | | | | | | | | The perf_swevent_enabled[] array has PERF_COUNT_SW_MAX elements. Signed-off-by: Dan Carpenter <error27@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <20101024195041.GT5985@bicker> Signed-off-by: Ingo Molnar <mingo@elte.hu>
| * | perf: Fix duplicate events with multiple-pmu vs software eventsPeter Zijlstra2010-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Because the multi-pmu bits can share contexts between struct pmu instances we could get duplicate events by iterating the pmu list. Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf: Stop all counters on rebootPeter Zijlstra2010-12-08
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Use the reboot notifier to detach all running counters on reboot, this solves a problem with kexec where the new kernel doesn't expect running counters (rightly so). It will however decrease the coverage of the NMI watchdog. Making a kexec specific reboot notifier callback would be best, however that would require touching all notifier callback handlers as they are not properly structured to deal with new state. As a compromise, place the perf reboot notifier at the very last position in the list. Reported-by: Yinghai Lu <yinghai@kernel.org> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: Jason Wessel <jason.wessel@windriver.com> Cc: Don Zickus <dzickus@redhat.com> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf events: Make sample_type identity fields available in all PERF_RECORD_ ↵Arnaldo Carvalho de Melo2010-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | events If perf_event_attr.sample_id_all is set it will add the PERF_SAMPLE_ identity info: TID, TIME, ID, CPU, STREAM_ID As a trailer, so that older perf tools can process new files, just ignoring the extra payload. With this its possible to do further analysis on problems in the event stream, like detecting reordering of MMAP and FORK events, etc. V2: Fixup header size in comm, mmap and task processing, as we have to take into account different sample_types for each matching event, noticed by Thomas Gleixner. Thomas also noticed a problem in v2 where if we didn't had space in the buffer we wouldn't restore the header size. Tested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | perf events: Separate the routines handling the PERF_SAMPLE_ identity fieldsArnaldo Carvalho de Melo2010-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Those will be made available in sample like events like MMAP, EXEC, etc in a followup patch. So precalculate the extra id header space and have a separate routine to fill them up. V2: Thomas noticed that the id header needs to be precalculated at inherit_events too: LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6> Tested-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Ian Munsie <imunsie@au1.ibm.com> Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Acked-by: Thomas Gleixner <tglx@linutronix.de> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> LKML-Reference: <1291318772-30880-2-git-send-email-acme@infradead.org> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | perf events: Fix event inherit fallout of precalculated headersThomas Gleixner2010-12-04
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The precalculated header size is not updated when an event is inherited. That results in bogus sample entries for all child events. Bug introduced in c320c7b. Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Mike Galbraith <efault@gmx.de> Cc: Paul Mackerras <paulus@samba.org> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Stephane Eranian <eranian@google.com> LKML-Reference: <alpine.LFD.2.00.1012031245220.2653@localhost6.localdomain6> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | perf events: Precalculate the header space for PERF_SAMPLE_ fieldsArnaldo Carvalho de Melo2010-11-30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | PERF_SAMPLE_{CALLCHAIN,RAW} have variable lenghts per sample, but the others can be precalculated, reducing a bit the per sample cost. Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Frédéric Weisbecker <fweisbec@gmail.com> Cc: Ian Munsie <imunsie@au1.ibm.com> Cc: Mike Galbraith <efault@gmx.de> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Paul Mackerras <paulus@samba.org> Cc: Stephane Eranian <eranian@google.com> LKML-Reference: <new-submission> Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
* | | perf: Ignore non-sampling overflowsPeter Zijlstra2010-11-26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some arch implementations call perf_event_overflow() by 'accident', ignore this. Reported-by: Francis Moreau <francis.moro@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu>
* | | perf: Don't bother to init the hrtimer for no SW sampling countersFranck Bui-Huu2010-11-26
| | | | | | | | | | | | | | | | | | | | | Signed-off-by: Franck Bui-Huu <fbuihuu@gmail.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1290525705-6265-3-git-send-email-fbuihuu@gmail.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
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