From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262547AbUHJIq6 (ORCPT ); Tue, 10 Aug 2004 04:46:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262927AbUHJIp4 (ORCPT ); Tue, 10 Aug 2004 04:45:56 -0400 Received: from mx2.elte.hu ([157.181.151.9]:10222 "EHLO mx2.elte.hu") by vger.kernel.org with ESMTP id S262450AbUHJIoO (ORCPT ); Tue, 10 Aug 2004 04:44:14 -0400 Date: Tue, 10 Aug 2004 09:51:30 +0200 From: Ingo Molnar To: Lee Revell Cc: Florian Schmidt , linux-kernel , Felipe Alfaro Solana Subject: Re: [patch] voluntary-preempt-2.6.8-rc3-O4 Message-ID: <20040810075130.GA25238@elte.hu> References: <20040726083537.GA24948@elte.hu> <1090832436.6936.105.camel@mindpipe> <20040726124059.GA14005@elte.hu> <20040726204720.GA26561@elte.hu> <20040729222657.GA10449@elte.hu> <20040801193043.GA20277@elte.hu> <20040809104649.GA13299@elte.hu> <20040809130558.GA17725@elte.hu> <20040809190201.64dab6ea@mango.fruits.de> <1092071169.13668.23.camel@mindpipe> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1092071169.13668.23.camel@mindpipe> User-Agent: Mutt/1.4.1i X-ELTE-SpamVersion: MailScanner 4.31.6-itk1 (ELTE 1.2) SpamAssassin 2.63 ClamAV 0.73 X-ELTE-VirusStatus: clean X-ELTE-SpamCheck: no X-ELTE-SpamCheck-Details: score=-4.9, required 5.9, autolearn=not spam, BAYES_00 -4.90 X-ELTE-SpamLevel: X-ELTE-SpamScore: -4 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Lee Revell wrote: > Ingo, do you plan to maintain the voluntary preempt patch against the > -mm series? From looking at Andrew's announcement yesterday it looks > like many latency issues fixed in the voluntary preemption patches are > also fixed in -mm, so it seems like the patch would be much smaller. yeah, and in addition we've already pushed 99% of our might_sleep() additions to -mm too so that reduces the patch size too, quite significantly. time is the only limiting factor. Due to these partial merges (we are trying to get all uncontroversial bits into -mm, hence into upstream) the merge to -mm is hard. Especially for lock-breaks that i've done differently than Andrew. I sent a consolidation patch yesterday but this is still work in progress. So i'll do an -mm merge very time i get to do it, but the primary testing still remains on the vanilla kernel (which most people use). > One thing that might be useful is breaking out the irq threading code > as a patch against -mm. Judging from all the -mm latency fixes it > seems like this would work as well as the vanilla kernel+voluntary > preempt. both softirq threading and hardirq threading will be done separately, yes. Also, most of the switches and source-level distinctions between cond_resched and voluntary_resched variants can go away too. The '-clean' patch in the voluntary-preempt directory shows how it would look like in the end. > This would also make it easier to identify which are the important > latency fixes from -mm enabling them to be pushed into mainline > sooner. On some of my tests I got 10-20% better results using > vol-preempt+mm vs vol-preempt+vanilla, it would be nice to identify > what changes are responsible. the plan right now is to push all the known-good stuff into 2.6.9 once 2.6.8 is out. That will unify all the improvements in a natural way. The latest update kernel of FC2 also includes an earlier version of the voluntary-preempt patch (sans any irq threading bits) - and it worked out fine so far. Ingo