From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267232AbUGMX3s (ORCPT ); Tue, 13 Jul 2004 19:29:48 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267233AbUGMX3s (ORCPT ); Tue, 13 Jul 2004 19:29:48 -0400 Received: from fw.osdl.org ([65.172.181.6]:38123 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S267232AbUGMX3o (ORCPT ); Tue, 13 Jul 2004 19:29:44 -0400 Date: Tue, 13 Jul 2004 16:32:36 -0700 From: Andrew Morton To: Andrea Arcangeli Cc: paul@linuxaudiosystems.com, rlrevell@joe-job.com, linux-audio-dev@music.columbia.edu, mingo@elte.hu, arjanv@redhat.com, linux-kernel@vger.kernel.org Subject: Re: [linux-audio-dev] Re: [announce] [patch] Voluntary Kernel Preemption Patch Message-Id: <20040713163236.0dbf3872.akpm@osdl.org> In-Reply-To: <20040713231803.GP974@dualathlon.random> References: <20040713162539.GD974@dualathlon.random> <20040713114829.705b9607.akpm@osdl.org> <20040713213847.GH974@dualathlon.random> <20040713145424.1217b67f.akpm@osdl.org> <20040713220103.GJ974@dualathlon.random> <20040713152532.6df4a163.akpm@osdl.org> <20040713223701.GM974@dualathlon.random> <20040713154448.4d29e004.akpm@osdl.org> <20040713225305.GO974@dualathlon.random> <20040713160628.596b96a3.akpm@osdl.org> <20040713231803.GP974@dualathlon.random> X-Mailer: Sylpheed version 0.9.7 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Andrea Arcangeli wrote: > > > And it's currently OK to add a might_sleep() to (say) an inline path which > > is expended a zillion times because we know it'll go away for production > > builds. If those things become cond_resched() calls instead, the code > > increase will be permanent. > > this is exactly why I'm making this change: so you can still add > might_sleep in a inline path expected to run a zillion times. With > Ingo's change you would be doing cond_sched internally to might_sleep, I > do the other way around so might_sleep remains a debugging statement. OK. cond_resched() is usually a waste of space with CONFIG_PREEMPT. It might make sense to define a cond_resched_if_not_preempt thingy, which only does things if !CONFIG_PREEMPT. We'd still need to use cond_resched() inside lock_kernel(). > > > I've yet to go through Arjan's patch - I suspect a lot of it is not needed. > > Arjan's or Ingo's? I've seen Ingo's patch but maybe I missed Arjan's one. I think Ingo's patch includes Arjan's one. Ingo's patch apparently breaks ext3. I have a bunch of ext3 and other fixes here, but there's still an occasional problem on SMP.