From: Peter Zijlstra <peterz@infradead.org>
To: NeilBrown <neilb@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>,
Ingo Molnar <mingo@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
lkml <linux-kernel@vger.kernel.org>,
"Dr. H. Nikolaus Schaller" <hns@goldelico.com>,
Marek Belisko <marek@goldelico.com>,
Mark Brown <broonie@kernel.org>
Subject: Re: [PATCH/RFC] wait_for_completion_timeout() considered harmful.
Date: Tue, 19 Nov 2013 09:25:48 +0100 [thread overview]
Message-ID: <20131119082548.GD10022@twins.programming.kicks-ass.net> (raw)
In-Reply-To: <20131119104438.6d45828b@notabene.brown>
On Tue, Nov 19, 2013 at 10:44:38AM +1100, NeilBrown wrote:
> We have loops that have
> timeout = schedule_timeout(timeout)
> in the middle and if we change the semantics of schedule_timeout() to round
> up, those loops could wait quite a bit longer than expected.
Depends on what you expect; most of these functions have documentation
that says they will sleep at least timeout amount of time.
schedule_timeout()'s version looks like:
* Make the current task sleep until @timeout jiffies have
* elapsed.
Clearly it doesn't do that currently, so adding 1 will actually make it
do what it says on the tin.
next prev parent reply other threads:[~2013-11-19 8:25 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-16 21:06 NeilBrown
2013-11-18 23:27 ` Andrew Morton
2013-11-18 23:42 ` Peter Zijlstra
2013-11-19 0:49 ` Jonathan Corbet
2013-11-19 7:05 ` Ingo Molnar
2013-11-19 8:29 ` Peter Zijlstra
2013-11-18 23:44 ` NeilBrown
2013-11-19 8:25 ` Peter Zijlstra [this message]
2013-11-19 8:58 ` NeilBrown
2013-11-19 12:23 ` Peter Zijlstra
2013-11-19 14:39 ` Thomas Gleixner
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