perf/core: Update ctx time before detaching events

We should make sure the ctx time is updated before we detach events;
which will want to update event times.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@kernel.org>

kernel/events/core.c

@@ -11129,6 +11129,7 @@ static void __perf_event_exit_context(void *__info)
 	struct perf_event *event;
 
 	raw_spin_lock(&ctx->lock);
+	ctx_sched_out(ctx, cpuctx, EVENT_TIME);
 	list_for_each_entry(event, &ctx->event_list, event_entry)
 		__perf_remove_from_context(event, cpuctx, ctx, (void *)DETACH_GROUP);
 	raw_spin_unlock(&ctx->lock);