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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-05-06 17:31:38 +0200
committerIngo Molnar <mingo@elte.hu>2010-05-07 11:30:17 +0200
commit4fd38e4595e2f6c9d27732c042a0e16b2753049c (patch)
treebb18024a183691b81062f97fbc3de4938a1d6086 /kernel/perf_event.c
parent722154e4cacf015161efe60009ae9be23d492296 (diff)
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perf: Fix exit() vs PERF_FORMAT_GROUP
Both Stephane and Corey reported that PERF_FORMAT_GROUP didn't work as expected if the task the counters were attached to quit before the read() call. The cause is that we unconditionally destroy the grouping when we remove counters from their context. Fix this by only doing this when we free the counter itself. Reported-by: Corey Ashford <cjashfor@linux.vnet.ibm.com> Reported-by: Stephane Eranian <eranian@google.com> Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> LKML-Reference: <1273160566.5605.404.camel@twins> Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel/perf_event.c')
-rw-r--r--kernel/perf_event.c5
1 files changed, 5 insertions, 0 deletions
diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 3d1552d3c12b..f13c3db765f4 100644
--- a/kernel/perf_event.c
+++ b/kernel/perf_event.c
@@ -341,6 +341,9 @@ list_del_event(struct perf_event *event, struct perf_event_context *ctx)
if (event->state > PERF_EVENT_STATE_OFF)
event->state = PERF_EVENT_STATE_OFF;
+ if (event->state > PERF_EVENT_STATE_FREE)
+ return;
+
/*
* If this was a group event with sibling events then
* upgrade the siblings to singleton events by adding them
@@ -1856,6 +1859,8 @@ int perf_event_release_kernel(struct perf_event *event)
{
struct perf_event_context *ctx = event->ctx;
+ event->state = PERF_EVENT_STATE_FREE;
+
WARN_ON_ONCE(ctx->parent_ctx);
mutex_lock(&ctx->mutex);
perf_event_remove_from_context(event);