From: Jayson King <dev@jaysonking.com>
To: arjan@linux.intel.com
Cc: linux-kernel@vger.kernel.org, mingo@elte.hu,
torvalds@linux-foundation.org, a.p.zijlstra@chello.nl,
shaggy@linux.vnet.ibm.com, rjw@sisk.pl, fabio.comolli@gmail.com
Subject: Re: large intermittent latency spike 2.6.28 (and 2.6.27.10), bisect commit ca7e716c7833aeaeb8fedd6d004c5f5d5e14d325 -> Revert "sched_clock: prevent scd->clock from moving backwards"
Date: Wed, 31 Dec 2008 16:27:09 -0600 [thread overview]
Message-ID: <495BF1BD.1070408@jaysonking.com> (raw)
In-Reply-To: <495A96FF.1000200@jaysonking.com>
Arjan van de Ven wrote:
> Jayson King <dev@jaysonking.com> wrote:
>> Please disregard this. ...
>
> can you run latencytop to see if it can pinpoint a cause of latency?
Like I said in my other reply I was running the wrong kernel when I
wrote that (oops)... So now I am still sure it is ca7e716.
Ingo's patch makes the same change that reverting ca7e716 does here:
- max_clock = scd->tick_gtod + TICK_NSEC;
+ max_clock = wrap_max(scd->clock, scd->tick_gtod + TICK_NSEC);
And with that change (I'm using Ingo's patch now) I can't trigger the
hang anymore. And before, I could reliably trigger it in a short time.
Jayson
next prev parent reply other threads:[~2008-12-31 22:25 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-12-30 21:47 large intermittent latency spike 2.6.28 (and 2.6.27.10), bisect commit ca7e716c7833aeaeb8fedd6d004c5f5d5e14d325 -> Revert "sched_clock: prevent scd->clock from moving backwards" Jayson King
2008-12-31 8:54 ` [PATCH] sched_clock: prevent scd->clock from moving backwards, take #2 Ingo Molnar
2008-12-31 18:49 ` Jayson King
2008-12-31 9:52 ` Disregard: was Re: large intermittent latency spike 2.6.28 (and 2.6.27.10), bisect commit ca7e716c7833aeaeb8fedd6d004c5f5d5e14d325 -> Revert "sched_clock: prevent scd->clock from moving backwards" Jayson King
2008-12-31 10:41 ` Jayson King
2008-12-31 11:00 ` Arjan van de Ven
2008-12-31 22:27 ` Jayson King [this message]
2008-12-31 22:38 ` Fabio Comolli
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