---

yaml
---
r: 218637
b: refs/heads/master
c: d7842da
h: refs/heads/master
i:
  218635: 8ee6340
v: v3

[refs]

@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 9ffcfa6f1f63eeac15555b745c292eb9f59130f6
+refs/heads/master: d7842da470f244d258f21c5f72cd8388b3541d04

trunk/kernel/perf_event.c

@@ -691,6 +691,8 @@ group_sched_in(struct perf_event *group_event,
 {
 	struct perf_event *event, *partial_group = NULL;
 	struct pmu *pmu = group_event->pmu;
+	u64 now = ctx->time;
+	bool simulate = false;
 
 	if (group_event->state == PERF_EVENT_STATE_OFF)
 		return 0;
@@ -719,11 +721,27 @@ group_sched_in(struct perf_event *group_event,
 	/*
 	 * Groups can be scheduled in as one unit only, so undo any
 	 * partial group before returning:
+	 * The events up to the failed event are scheduled out normally,
+	 * tstamp_stopped will be updated.
+	 *
+	 * The failed events and the remaining siblings need to have
+	 * their timings updated as if they had gone thru event_sched_in()
+	 * and event_sched_out(). This is required to get consistent timings
+	 * across the group. This also takes care of the case where the group
+	 * could never be scheduled by ensuring tstamp_stopped is set to mark
+	 * the time the event was actually stopped, such that time delta
+	 * calculation in update_event_times() is correct.
 	 */
 	list_for_each_entry(event, &group_event->sibling_list, group_entry) {
 		if (event == partial_group)
-			break;
-		event_sched_out(event, cpuctx, ctx);
+			simulate = true;
+
+		if (simulate) {
+			event->tstamp_running += now - event->tstamp_stopped;
+			event->tstamp_stopped = now;
+		} else {
+			event_sched_out(event, cpuctx, ctx);
+		}
 	}
 	event_sched_out(group_event, cpuctx, ctx);