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author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2009-11-20 22:19:54 +0100 |
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committer | Ingo Molnar <mingo@elte.hu> | 2009-11-21 14:11:39 +0100 |
commit | 2b8988c9f7defe319cffe0cd362a7cd356c86f62 (patch) | |
tree | 0b9dde7d4c4304eaa1b701897609b1918d72e0f3 /kernel/perf_event.c | |
parent | 58e5ad1de3d6ad931c84f0cc8ef0655c922f30ad (diff) | |
download | linux-stable-2b8988c9f7defe319cffe0cd362a7cd356c86f62.tar.gz linux-stable-2b8988c9f7defe319cffe0cd362a7cd356c86f62.tar.bz2 linux-stable-2b8988c9f7defe319cffe0cd362a7cd356c86f62.zip |
perf: Fix time locking
Most sites updating ctx->time and event times do so under
ctx->lock, make sure they all do.
This was made possible by removing the __perf_event_read() call
from __perf_event_sync_stat(), which already had this lock
taken.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
LKML-Reference: <20091120212509.102316434@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r-- | kernel/perf_event.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 028619dd6d0e..fdfae888a67c 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1526,8 +1526,11 @@ static void __perf_event_read(void *info) if (ctx->task && cpuctx->task_ctx != ctx) return; + spin_lock(&ctx->lock); update_context_time(ctx); update_event_times(event); + spin_unlock(&ctx->lock); + event->pmu->read(event); } @@ -1541,7 +1544,13 @@ static u64 perf_event_read(struct perf_event *event) smp_call_function_single(event->oncpu, __perf_event_read, event, 1); } else if (event->state == PERF_EVENT_STATE_INACTIVE) { + struct perf_event_context *ctx = event->ctx; + unsigned long flags; + + spin_lock_irqsave(&ctx->lock, flags); + update_context_time(ctx); update_event_times(event); + spin_unlock_irqrestore(&ctx->lock, flags); } return atomic64_read(&event->count); |