From: David Ahern <dsahern@gmail.com>
To: Pekka Enberg <penberg@iki.fi>,
acme@ghostprotocols.net, linux-kernel@vger.kernel.org
Cc: namhyung@kernel.org, Ingo Molnar <mingo@kernel.org>,
Frederic Weisbecker <fweisbec@gmail.com>,
Peter Zijlstra <a.p.zijlstra@chello.nl>,
Mike Galbraith <efault@gmx.de>, Jiri Olsa <jolsa@redhat.com>,
Stephane Eranian <eranian@google.com>,
Pekka Enberg <penberg@kernel.org>
Subject: Re: [PATCH 1/2] perf sched: Introduce timehist command - v2
Date: Mon, 02 Dec 2013 09:19:22 -0700 [thread overview]
Message-ID: <529CB30A.1030306@gmail.com> (raw)
In-Reply-To: <529C53D2.8020203@iki.fi>
[-- Attachment #1: Type: text/plain, Size: 303 bytes --]
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
[-- Attachment #2: timehist-check-ready-time.patch --]
[-- Type: text/plain, Size: 718 bytes --]
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");
next prev parent reply other threads:[~2013-12-02 16:19 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-12-02 0:23 [PATCH 0/2] perf: sched timehist command - v2 David Ahern
2013-12-02 0:23 ` [PATCH 1/2] perf sched: Introduce " David Ahern
2013-12-02 7:58 ` Namhyung Kim
2013-12-02 14:28 ` David Ahern
2013-12-02 9:33 ` Pekka Enberg
2013-12-02 14:33 ` David Ahern
2013-12-02 16:19 ` David Ahern [this message]
2013-12-02 0:23 ` [PATCH 2/2] perf sched: Add documentation for timehist options David Ahern
2013-12-02 6:07 ` Srikar Dronamraju
2013-12-02 12:38 ` Ingo Molnar
2013-12-02 7:41 ` Namhyung Kim
2013-12-02 14:37 ` David Ahern
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