Messages in this thread Patch in this message | | | From | Jiri Olsa <> | Subject | [PATCH 03/11] perf: Do not get values from disabled counters in group format read | Date | Mon, 4 Feb 2013 13:32:57 +0100 |
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From: "jolsa@redhat.com" <jolsa@redhat.com>
It's possible some of the counters in the group could be disabled when sampling member of the event group is reading the rest via PERF_SAMPLE_READ sample type processing. Disabled counters could then produce wrong numbers.
Fixing that by reading only enabled counters for PERF_SAMPLE_READ sample type processing.
Signed-off-by: Jiri Olsa <jolsa@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@ghostprotocols.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@elte.hu> Cc: Paul Mackerras <paulus@samba.org> Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Namhyung Kim <namhyung@kernel.org> --- kernel/events/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/kernel/events/core.c b/kernel/events/core.c index 4081261..e2ea1b9 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -4018,7 +4018,8 @@ static void perf_output_read_group(struct perf_output_handle *handle, list_for_each_entry(sub, &leader->sibling_list, group_entry) { n = 0; - if (sub != event) + if ((sub != event) && + (sub->state == PERF_EVENT_STATE_ACTIVE)) sub->pmu->read(sub); values[n++] = perf_event_count(sub); -- 1.7.11.7
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