Messages in this thread Patch in this message | | | Date | Wed, 9 Jun 2010 10:17:42 GMT | From | tip-bot for Peter Zijlstra <> | Subject | [tip:perf/core] perf: Add perf_event::child_count |
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Commit-ID: a6e6dea68c18f705957573ee5596097c7e82d0e5 Gitweb: http://git.kernel.org/tip/a6e6dea68c18f705957573ee5596097c7e82d0e5 Author: Peter Zijlstra <a.p.zijlstra@chello.nl> AuthorDate: Fri, 21 May 2010 14:27:58 +0200 Committer: Ingo Molnar <mingo@elte.hu> CommitDate: Wed, 9 Jun 2010 11:12:37 +0200
perf: Add perf_event::child_count
Only child counters adding back their values into the parent counter are responsible for cross-cpu updates to event->count.
So if we pull that out into a new child_count variable, we get an event->count that is only modified locally.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Paul Mackerras <paulus@samba.org> Cc: Mike Galbraith <efault@gmx.de> Cc: Steven Rostedt <rostedt@goodmis.org> LKML-Reference: <new-submission> Signed-off-by: Ingo Molnar <mingo@elte.hu> --- include/linux/perf_event.h | 1 + kernel/perf_event.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-)
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h index 441992a..f34dab9 100644 --- a/include/linux/perf_event.h +++ b/include/linux/perf_event.h @@ -671,6 +671,7 @@ struct perf_event { enum perf_event_active_state state; unsigned int attach_state; atomic64_t count; + atomic64_t child_count; /* * These are the total time in nanoseconds that the event diff --git a/kernel/perf_event.c b/kernel/perf_event.c index ab4c0ff..a395fda 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1738,7 +1738,7 @@ static void __perf_event_read(void *info) static inline u64 perf_event_count(struct perf_event *event) { - return atomic64_read(&event->count); + return atomic64_read(&event->count) + atomic64_read(&event->child_count); } static u64 perf_event_read(struct perf_event *event) @@ -5379,7 +5379,7 @@ static void sync_child_event(struct perf_event *child_event, /* * Add back the child's count to the parent's count: */ - atomic64_add(child_val, &parent_event->count); + atomic64_add(child_val, &parent_event->child_count); atomic64_add(child_event->total_time_enabled, &parent_event->child_total_time_enabled); atomic64_add(child_event->total_time_running,
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