From: Kan Liang Date: Tue, 20 May 2025 18:16:30 +0000 (-0700) Subject: perf: Only dump the throttle log for the leader X-Git-Tag: v6.16-rc1~196^2~17 X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=e800ac51202f053018f3d6acb1819ecec4d75a2c;p=thirdparty%2Flinux.git perf: Only dump the throttle log for the leader The PERF_RECORD_THROTTLE records are dumped for all throttled events. It's not necessary for group events, which are throttled altogether. Optimize it by only dump the throttle log for the leader. The sample right after the THROTTLE record must be generated by the actual target event. It is good enough for the perf tool to locate the actual target event. Suggested-by: Namhyung Kim Signed-off-by: Kan Liang Signed-off-by: Peter Zijlstra (Intel) Acked-by: Namhyung Kim Link: https://lore.kernel.org/r/20250520181644.2673067-3-kan.liang@linux.intel.com --- diff --git a/kernel/events/core.c b/kernel/events/core.c index 8327ab0ee641c..f34c99f8ce8f4 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -2650,14 +2650,16 @@ static void perf_event_unthrottle(struct perf_event *event, bool start) event->hw.interrupts = 0; if (start) event->pmu->start(event, 0); - perf_log_throttle(event, 1); + if (event == event->group_leader) + perf_log_throttle(event, 1); } static void perf_event_throttle(struct perf_event *event) { event->pmu->stop(event, 0); event->hw.interrupts = MAX_INTERRUPTS; - perf_log_throttle(event, 0); + if (event == event->group_leader) + perf_log_throttle(event, 0); } static void perf_event_unthrottle_group(struct perf_event *event, bool skip_start_event)