Re: [PATCH 1/2] perf sched: Introduce timehist command - v2

[David Ahern <dsahern@gmail.com>]

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On 12/2/13, 2:33 AM, Pekka Enberg wrote:
> I'm seeing rather large "sch delay" numbers on Fedora 19's default
> kernel that seem like a data error of some sort:
>
>      4500.663117 [02] fix_client[7216]         0.007
> 18446744073708.033     1.786


Does this address the large numbers for you?

David

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diff --git a/tools/perf/builtin-sched.c b/tools/perf/builtin-sched.c
index abcb40a44151..ae71782064ac 100644
--- a/tools/perf/builtin-sched.c
+++ b/tools/perf/builtin-sched.c
@@ -1751,8 +1751,12 @@ static void timehist_update_runtime_stats(struct thread_runtime *r,
 	r->dt_between = 0;
 	if (tprev) {
 		r->dt_run = t - tprev;
-		if (r->ready_to_run)
-			r->dt_delay = tprev - r->ready_to_run;
+		if (r->ready_to_run) {
+			if (r->ready_to_run > tprev)
+				pr_debug("time travel: wakeup time for task > previous sched_switch event\n");
+			else
+				r->dt_delay = tprev - r->ready_to_run;
+		}
 
 		if (r->last_time > tprev)
 			pr_debug("time travel: last sched out time for task > previous sched_switch event\n");