From: Jens Axboe <axboe@kernel.dk>
To: David Howells <dhowells@redhat.com>
Cc: Imre Deak <imre.deak@intel.com>,
Daniel Vetter <daniel.vetter@ffwll.ch>,
"Paul E. McKenney" <paulmck@linux.vnet.ibm.com>,
Dave Jones <davej@redhat.com>,
Lukas Czerner <lczerner@redhat.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] wait: fix false timeouts when using wait_event_timeout()
Date: Thu, 2 May 2013 14:35:17 +0200 [thread overview]
Message-ID: <20130502123517.GL7800@kernel.dk> (raw)
In-Reply-To: <3633.1367497784@warthog.procyon.org.uk>
On Thu, May 02 2013, David Howells wrote:
> Imre Deak <imre.deak@intel.com> wrote:
>
> > Many callers of the wait_event_timeout() and
> > wait_event_interruptible_timeout() expect that the return value will be
> > positive if the specified condition becomes true before the timeout
> > elapses. However, at the moment this isn't guaranteed. If the wake-up
> > handler is delayed enough, the time remaining until timeout will be
> > calculated as 0 - and passed back as a return value - even if the
> > condition became true before the timeout has passed.
> >
> > Fix this by returning at least 1 if the condition becomes true. This
> > semantic is in line with what wait_for_condition_timeout() does; see
> > commit bb10ed09 - "sched: fix wait_for_completion_timeout() spurious
> > failure under heavy load".
> >
> > Signed-off-by: Imre Deak <imre.deak@intel.com>
>
> Acked-by: David Howells <dhowells@redhat.com>
You can add mine, too:
Acked-by: Jens Axboe <axboe@kernel.dk>
--
Jens Axboe
next prev parent reply other threads:[~2013-05-02 12:35 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-05-02 8:58 [PATCH] wait: fix false timeouts when using wait_event_timeout() Imre Deak
2013-05-02 9:36 ` Daniel Vetter
2013-05-07 23:12 ` Andrew Morton
2013-05-08 9:49 ` Imre Deak
2013-05-02 10:29 ` David Howells
2013-05-02 12:02 ` Imre Deak
2013-05-02 12:13 ` Daniel Vetter
2013-05-02 12:23 ` Jens Axboe
2013-05-02 12:29 ` David Howells
2013-05-02 12:34 ` Imre Deak
2013-05-02 12:54 ` Jens Axboe
2013-05-02 13:56 ` Imre Deak
2013-05-02 14:04 ` Daniel Vetter
2013-05-02 12:29 ` David Howells
2013-05-02 12:35 ` Jens Axboe [this message]
2013-05-02 19:56 ` Imre Deak
-- strict thread matches above, loose matches on Subject: below --
2013-06-04 19:28 Oleg Nesterov
2013-06-04 21:35 ` Imre Deak
2013-06-04 21:40 ` Imre Deak
2013-06-05 16:37 ` Oleg Nesterov
2013-06-05 19:07 ` Oleg Nesterov
2013-06-06 1:45 ` Tejun Heo
2013-06-06 18:47 ` Oleg Nesterov
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