From: Arjan van de Ven <arjanv@redhat.com>
To: Andrew Morton <akpm@osdl.org>
Cc: Con Kolivas <kernel@kolivas.org>, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Instrumenting high latency
Date: Mon, 12 Jul 2004 10:29:40 +0200 [thread overview]
Message-ID: <1089620980.2806.8.camel@laptop.fenrus.com> (raw)
In-Reply-To: <20040712003418.02997a12.akpm@osdl.org>
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On Mon, 2004-07-12 at 09:34, Andrew Morton wrote:
> Con Kolivas <kernel@kolivas.org> wrote:
> >
> > He hacked
> > together this simple patch which times periods according to the preempt
> > count.
>
> OK, small problem. We have code which does, effectively,
>
> if (need_resched()) {
> drop_the_lock();
> schedule();
> grab_the_lock();
> }
>
> so if need_resched() stays false then this will hold the lock for a long
> time and bogus reports are generated:
... or reset the time(r) in need_resched() under the assumption that all
need_resched() callers will yield when it returns true...
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next prev parent reply other threads:[~2004-07-12 8:29 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-07-12 6:29 [PATCH] Instrumenting high latency Con Kolivas
2004-07-12 6:37 ` Andrew Morton
2004-07-12 6:43 ` Con Kolivas
2004-07-12 6:58 ` Andrew Morton
2004-07-12 7:00 ` [PATCH] " William Lee Irwin III
2004-07-12 7:34 ` Andrew Morton
2004-07-12 8:02 ` William Lee Irwin III
2004-07-12 8:38 ` William Lee Irwin III
2004-07-12 11:31 ` William Lee Irwin III
2004-07-12 14:32 ` William Lee Irwin III
2004-07-12 17:09 ` Martin Josefsson
2004-07-12 8:29 ` Arjan van de Ven [this message]
2004-07-12 8:42 ` William Lee Irwin III
2004-07-12 8:47 ` William Lee Irwin III
2004-07-12 10:41 ` Rajput
2004-07-12 10:44 ` William Lee Irwin III
2004-07-12 14:24 ` Martin J. Bligh
2004-07-12 14:27 ` Con Kolivas
2004-07-12 14:33 ` Martin J. Bligh
2004-07-12 14:42 ` Con Kolivas
2004-07-12 14:47 ` Martin J. Bligh
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