Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759351Ab3EBMfj (ORCPT ); Thu, 2 May 2013 08:35:39 -0400 Received: from merlin.infradead.org ([205.233.59.134]:48306 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759266Ab3EBMfi (ORCPT ); Thu, 2 May 2013 08:35:38 -0400 Date: Thu, 2 May 2013 14:35:17 +0200 From: Jens Axboe To: David Howells Cc: Imre Deak , Daniel Vetter , "Paul E. McKenney" , Dave Jones , Lukas Czerner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] wait: fix false timeouts when using wait_event_timeout() Message-ID: <20130502123517.GL7800@kernel.dk> References: <1367485129-4423-1-git-send-email-imre.deak@intel.com> <3633.1367497784@warthog.procyon.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3633.1367497784@warthog.procyon.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1244 Lines: 32 On Thu, May 02 2013, David Howells wrote: > Imre Deak 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 > > Acked-by: David Howells You can add mine, too: Acked-by: Jens Axboe -- Jens Axboe -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/