Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261277AbVEXO4z (ORCPT ); Tue, 24 May 2005 10:56:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261266AbVEXO4y (ORCPT ); Tue, 24 May 2005 10:56:54 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:13206 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S261277AbVEXO4j (ORCPT ); Tue, 24 May 2005 10:56:39 -0400 Date: Tue, 24 May 2005 15:56:36 +0100 From: Christoph Hellwig To: Ingo Molnar Cc: Andrew Morton , Arjan van de Ven , Nick Piggin , Christoph Hellwig , linux-kernel@vger.kernel.org Subject: Re: [patch] Voluntary Kernel Preemption, 2.6.12-rc4-mm2 Message-ID: <20050524145636.GA15943@infradead.org> Mail-Followup-To: Christoph Hellwig , Ingo Molnar , Andrew Morton , Arjan van de Ven , Nick Piggin , linux-kernel@vger.kernel.org References: <20050524121541.GA17049@elte.hu> <20050524132105.GA29477@elte.hu> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050524132105.GA29477@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 Content-Length: 1102 Lines: 25 On Tue, May 24, 2005 at 03:21:05PM +0200, Ingo Molnar wrote: > > this patch (ontop of the current -mm scheduler patchset plus the > previous 2 patches from me) adds a new preemption model: 'Voluntary > Kernel Preemption'. The 3 models can be selected from a new menu: > > (X) No Forced Preemption (Server) > ( ) Voluntary Kernel Preemption (Desktop) > ( ) Preemptible Kernel (Low-Latency Desktop) > > we still default to the stock (Server) preemption model. > > Voluntary preemption works by adding a cond_resched() > (reschedule-if-needed) call to every might_sleep() check. I still disagree with this one violently. If you want a cond_resched() add it where nessecary, but don't hide it behind might_sleep - there could be quite a lot might_sleeps in common codepathes and they should stay purely a debug aid. - 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/