Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758743Ab3EBM3v (ORCPT ); Thu, 2 May 2013 08:29:51 -0400 Received: from mx1.redhat.com ([209.132.183.28]:32637 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758558Ab3EBM3u (ORCPT ); Thu, 2 May 2013 08:29:50 -0400 Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <1367485129-4423-1-git-send-email-imre.deak@intel.com> References: <1367485129-4423-1-git-send-email-imre.deak@intel.com> To: Imre Deak Cc: dhowells@redhat.com, Daniel Vetter , "Paul E. McKenney" , Dave Jones , Jens Axboe , Lukas Czerner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] wait: fix false timeouts when using wait_event_timeout() Date: Thu, 02 May 2013 13:29:44 +0100 Message-ID: <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: 1085 Lines: 23 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 -- 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/