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authorPeter Zijlstra <a.p.zijlstra@chello.nl>2010-05-21 14:27:58 +0200
committerIngo Molnar <mingo@elte.hu>2010-06-09 11:12:37 +0200
commita6e6dea68c18f705957573ee5596097c7e82d0e5 (patch)
tree2e8d302800fa4c57cc6604d856e6d680d3ee120f
parentb5e58793c7a8ec35e72ea6ec6c353499dd189809 (diff)
downloadlinux-a6e6dea68c18f705957573ee5596097c7e82d0e5.tar.bz2
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>
-rw-r--r--include/linux/perf_event.h1
-rw-r--r--kernel/perf_event.c4
2 files changed, 3 insertions, 2 deletions
diff --git a/include/linux/perf_event.h b/include/linux/perf_event.h
index 441992a9775c..f34dab9b275e 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 ab4c0ffc271c..a395fda2d94c 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,