From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161727AbXDYM46 (ORCPT ); Wed, 25 Apr 2007 08:56:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161861AbXDYM46 (ORCPT ); Wed, 25 Apr 2007 08:56:58 -0400 Received: from mx2.go2.pl ([193.17.41.42]:52649 "EHLO poczta.o2.pl" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1161727AbXDYM45 (ORCPT ); Wed, 25 Apr 2007 08:56:57 -0400 Date: Wed, 25 Apr 2007 15:02:46 +0200 From: Jarek Poplawski To: Oleg Nesterov Cc: Andrew Morton , David Howells , David Miller , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [PATCH] cancel_delayed_work: use del_timer() instead of del_timer_sync() Message-ID: <20070425130246.GA4086@ff.dom.local> References: <20070424215034.GA5985@tv-sign.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070424215034.GA5985@tv-sign.ru> User-Agent: Mutt/1.4.2.2i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 25, 2007 at 01:50:34AM +0400, Oleg Nesterov wrote: > del_timer_sync() buys nothing for cancel_delayed_work(), but it is less > efficient since it locks the timer unconditionally, and may wait for the > completion of the delayed_work_timer_fn(). I'm not sure what is the main aim of this patch. It seems this change cannot do any harm, but anyway it could change a few things, e.g. with current version of cancel_rearming_delayed_work some flush_workqueue could be done needlessly, before the work is queued from timer. It's not a big deal here, but if anybody did something like this without loop - it could matter. So, probably a lot of current code should be checked, before applying and I doubt the gain is worth of this. Maybe, for safety, make this with new name as an alternative and deprecate the current version? Regards, Jarek P.