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perf: Fix cgroup vs jump_label problem

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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>
This commit is contained in:
Peter Zijlstra 2011-03-03 11:31:20 +01:00 committed by Ingo Molnar
parent 2d0f25201e
commit 08309379b7
1 changed files with 13 additions and 13 deletions
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26
kernel/perf_event.c
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@ -820,16 +820,8 @@ list_add_event(struct perf_event *event, struct perf_event_context *ctx)
list_add_tail(&event->group_entry, list);
}
if (is_cgroup_event(event)) {
if (is_cgroup_event(event))
ctx->nr_cgroups++;
/*
* one more event:
* - that has cgroup constraint on event->cpu
* - that may need work on context switch
*/
atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
jump_label_inc(&perf_sched_events);
}
list_add_rcu(&event->event_entry, &ctx->event_list);
if (!ctx->nr_events)
@ -957,11 +949,8 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
event->attach_state &= ~PERF_ATTACH_CONTEXT;
if (is_cgroup_event(event)) {
if (is_cgroup_event(event))
ctx->nr_cgroups--;
atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
jump_label_dec(&perf_sched_events);
}
ctx->nr_events--;
if (event->attr.inherit_stat)
@ -2903,6 +2892,10 @@ static void free_event(struct perf_event *event)
atomic_dec(&nr_task_events);
if (event->attr.sample_type & PERF_SAMPLE_CALLCHAIN)
put_callchain_buffers();
if (is_cgroup_event(event)) {
atomic_dec(&per_cpu(perf_cgroup_events, event->cpu));
jump_label_dec(&perf_sched_events);
}
}
if (event->buffer) {
@ -6478,6 +6471,13 @@ SYSCALL_DEFINE5(perf_event_open,
err = perf_cgroup_connect(pid, event, &attr, group_leader);
if (err)
goto err_alloc;
/*
* one more event:
* - that has cgroup constraint on event->cpu
* - that may need work on context switch
*/
atomic_inc(&per_cpu(perf_cgroup_events, event->cpu));
jump_label_inc(&perf_sched_events);
}
/*