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 LKML-Reference: --- include/linux/perf_event.h | 1 + kernel/perf_event.c | 4 ++-- 2 files changed, 3 insertions(+), 2 deletions(-) Index: linux-2.6/include/linux/perf_event.h =================================================================== --- linux-2.6.orig/include/linux/perf_event.h +++ linux-2.6/include/linux/perf_event.h @@ -648,6 +648,7 @@ struct perf_event { enum perf_event_active_state state; atomic64_t count; + atomic64_t child_count; /* * These are the total time in nanoseconds that the event Index: linux-2.6/kernel/perf_event.c =================================================================== --- linux-2.6.orig/kernel/perf_event.c +++ linux-2.6/kernel/perf_event.c @@ -1703,7 +1703,7 @@ 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) @@ -5282,7 +5282,7 @@ static void sync_child_event(struct perf /* * 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, -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/