From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265517AbUGITvJ (ORCPT ); Fri, 9 Jul 2004 15:51:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265812AbUGITvJ (ORCPT ); Fri, 9 Jul 2004 15:51:09 -0400 Received: from [213.146.154.40] ([213.146.154.40]:34992 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S265517AbUGITvG (ORCPT ); Fri, 9 Jul 2004 15:51:06 -0400 Date: Fri, 9 Jul 2004 20:51:05 +0100 From: Christoph Hellwig To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Arjan van de Ven Subject: Re: [announce] [patch] Voluntary Kernel Preemption Patch Message-ID: <20040709195105.GA4807@infradead.org> Mail-Followup-To: Christoph Hellwig , Ingo Molnar , linux-kernel@vger.kernel.org, Arjan van de Ven References: <20040709182638.GA11310@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040709182638.GA11310@elte.hu> User-Agent: Mutt/1.4.1i X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > unlike the lowlatency patches, this patch doesn't add a lot of new > scheduling points to the source code, it rather reuses a rich but > currently inactive set of scheduling points that already exist in the > 2.6 tree: the might_sleep() debugging checks. Any code point that does > might_sleep() is in fact ready to sleep at that point. So the patch > activates these debugging checks to be scheduling points. This reduces > complexity and impact quite significantly. I don't think this is a good idea. Just because a function might sleep it doesn't mean it should sleep. I'd rather add the might_sleep() to cond_resched() and replace the former with the latter in the cases where it makes sense.