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>
This commit is contained in:
Peter Zijlstra 2010-05-21 14:27:58 +02:00 committed by Ingo Molnar
parent b5e58793c7
commit a6e6dea68c
2 changed files with 3 additions and 2 deletions

View File

@ -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

View File

@ -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,