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| author | Peter Zijlstra <peterz@infradead.org> | 2015-01-23 11:19:48 +0100 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2015-01-28 13:17:35 +0100 |
| commit | c3c87e770458aa004bd7ed3f29945ff436fd6511 (patch) | |
| tree | 79074706175f54d333daf61cc0794aa9d76b1909 /include | |
| parent | ef454caeb740ee4e1b89aeb7f7692d5ddffb6830 (diff) | |
| download | lwn-c3c87e770458aa004bd7ed3f29945ff436fd6511.tar.gz lwn-c3c87e770458aa004bd7ed3f29945ff436fd6511.zip | |
perf: Tighten (and fix) the grouping condition
The fix from 9fc81d87420d ("perf: Fix events installation during
moving group") was incomplete in that it failed to recognise that
creating a group with events for different CPUs is semantically
broken -- they cannot be co-scheduled.
Furthermore, it leads to real breakage where, when we create an event
for CPU Y and then migrate it to form a group on CPU X, the code gets
confused where the counter is programmed -- triggered in practice
as well by me via the perf fuzzer.
Fix this by tightening the rules for creating groups. Only allow
grouping of counters that can be co-scheduled in the same context.
This means for the same task and/or the same cpu.
Fixes: 9fc81d87420d ("perf: Fix events installation during moving group")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Arnaldo Carvalho de Melo <acme@kernel.org>
Cc: Jiri Olsa <jolsa@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/20150123125834.090683288@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/perf_event.h | 6 |
1 files changed, 0 insertions, 6 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 4f7a61ca4b39..664de5a4ec46 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -450,11 +450,6 @@ struct perf_event { #endif /* CONFIG_PERF_EVENTS */ }; -enum perf_event_context_type { - task_context, - cpu_context, -}; - /** * struct perf_event_context - event context structure * @@ -462,7 +457,6 @@ enum perf_event_context_type { */ struct perf_event_context { struct pmu *pmu; - enum perf_event_context_type type; /* * Protect the states of the events in the list, * nr_active, and the list: |