From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S266449AbUHBKjL (ORCPT ); Mon, 2 Aug 2004 06:39:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S266453AbUHBKjK (ORCPT ); Mon, 2 Aug 2004 06:39:10 -0400 Received: from mx1.elte.hu ([157.181.1.137]:37072 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S266449AbUHBKeO (ORCPT ); Mon, 2 Aug 2004 06:34:14 -0400 Date: Mon, 2 Aug 2004 12:35:16 +0200 From: Ingo Molnar To: William Lee Irwin III , Lee Revell , linux-kernel Subject: Re: [patch] preempt-timing-on-2.6.8-rc2-O2 Message-ID: <20040802103516.GA20584@elte.hu> References: <1091228074.805.6.camel@mindpipe> <1091234100.1677.41.camel@mindpipe> <1091403477.862.4.camel@mindpipe> <1091407585.862.40.camel@mindpipe> <20040802073938.GA8332@elte.hu> <1091435237.3024.9.camel@mindpipe> <20040802092855.GA15894@elte.hu> <20040802100815.GA18349@elte.hu> <20040802101840.GB2334@holomorphy.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040802101840.GB2334@holomorphy.com> 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 * William Lee Irwin III wrote: > On Mon, Aug 02, 2004 at 12:08:15PM +0200, Ingo Molnar wrote: > > i've uploaded a new version of the patch, this solves a problem when > > using a smaller than 1000 usecs threshold: idle time got accounted as > > delay too which flooded the log. The new patch makes idle=poll the > > default and that function calls touch_preempt_timing(). > > Sorry about not updating things, but there's also another bug, which > is that touch_preempt_timing() forgets to check if the threshold has > been violated in the interim. i've re-uploaded the -O2 patch with this fixed: http://redhat.com/~mingo/voluntary-preempt/preempt-timing-on-2.6.8-rc2-O2 but i'm still seeing some latencies: (kjournald/189): 997us non-preemptible critical section violated 100 us preempt threshold starting at journal_commit_transaction+0x642/0x2b10 and ending at journal_commit_transaction+0x24ce/0x2b10 [] dump_stack+0x1e/0x30 [] dec_preempt_count+0x3f/0x50 [] journal_commit_transaction+0x24ce/0x2b10 [] kjournald+0x1a4/0x710 [] kernel_thread_helper+0x5/0x10 these should not happen with vp=3 and max_sectors=16. Could you double-check the patch above, does it have any other timing thinko? Ingo