1 files changed, 20 insertions, 2 deletions

diff --git a/kernel/perf_event.c b/kernel/perf_event.c
index 39afdb07d758..517d827f4982 100644
--- a/kernel/perf_event.c
+++ b/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_error:
         /*
          * 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);