diff options
| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2010-05-27 17:47:49 +0400 |
|---|---|---|
| committer | Paul Gortmaker <paul.gortmaker@windriver.com> | 2013-01-17 01:45:07 +0400 |
| commit | e732ebc42aea321ee84514330eb3a675307fcc83 (patch) | |
| tree | b81a93b56e3c75e284504cf542c4c916e45ec789 /include | |
| parent | 9cb08e9f1df7113af1cf28534d73ef3adb419017 (diff) | |
| download | linux-e732ebc42aea321ee84514330eb3a675307fcc83.tar.xz | |
perf_events: Fix races in group composition
commit 8a49542c0554af7d0073aac0ee73ee65b807ef34 upstream.
Group siblings don't pin each-other or the parent, so when we destroy
events we must make sure to clean up all cross referencing pointers.
In particular, for destruction of a group leader we must be able to
find all its siblings and remove their reference to it.
This means that detaching an event from its context must not detach it
from the group, otherwise we can end up failing to clear all pointers.
Solve this by clearly separating the attachment to a context and
attachment to a group, and keep the group composed until we destroy
the events.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/perf_event.h | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index eea91881fe24..c6e14329b656 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -571,6 +571,9 @@ enum perf_group_flag { PERF_GROUP_SOFTWARE = 0x1, }; +#define PERF_ATTACH_CONTEXT 0x01 +#define PERF_ATTACH_GROUP 0x02 + /** * struct perf_event - performance event kernel representation: */ @@ -585,6 +588,7 @@ struct perf_event { const struct pmu *pmu; enum perf_event_active_state state; + unsigned int attach_state; atomic64_t count; /* |