From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267660AbUGWL6o (ORCPT ); Fri, 23 Jul 2004 07:58:44 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267661AbUGWL6o (ORCPT ); Fri, 23 Jul 2004 07:58:44 -0400 Received: from mx1.elte.hu ([157.181.1.137]:20676 "EHLO mx1.elte.hu") by vger.kernel.org with ESMTP id S267660AbUGWL6m (ORCPT ); Fri, 23 Jul 2004 07:58:42 -0400 Date: Fri, 23 Jul 2004 14:00:14 +0200 From: Ingo Molnar To: Paolo Ciarrocchi Cc: linux-kernel@vger.kernel.org, Rudo Thomas , Matt Heler Subject: Re: [patch] voluntary-preempt-2.6.8-rc2-I3 Message-ID: <20040723120014.GA5573@elte.hu> References: <20040722161941.GA23972@elte.hu> <20040722172428.GA5632@ss1000.ms.mff.cuni.cz> <20040722175457.GA5855@ss1000.ms.mff.cuni.cz> <20040722180142.GC30059@elte.hu> <20040722180821.GA377@elte.hu> <20040722181426.GA892@elte.hu> <20040723104246.GA2752@elte.hu> <4d8e3fd30407230358141e0e58@mail.gmail.com> <20040723110430.GA3787@elte.hu> <4d8e3fd30407230442afe80c1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4d8e3fd30407230442afe80c1@mail.gmail.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 * Paolo Ciarrocchi wrote: > Hi Ingo, > thanks for the clarification. > > What about performance of vanilla vs voluntary-preempt-2.6.8-rc2-I3 ? > Do you have numbers available ? Can we, somehow, support you ? All known performance problems have been fixed in -I4. The focus is mainly on latency. You can best support this patch by trying it out and doing measurements - both latency and throughput measurements are welcome. Latency measurement can be done via the latencytest tool: http://www.alsa-project.org/~iwai/latencytest-0.5.4.tar.gz If you enable both CONFIG_PREEMPT_VOLUNTARY and CONFIG_PREEMPT then you can use the /proc/sys/kernel/voluntary_preemption|kernel_preemption sysctl knobs to turn the preemption features on/off. The following flag combinations can be used to do comparisons: vanilla: vp:0 kp:0 CONFIG_PREEMPT: vp:0 kp:1 voluntary-preempt: vp:1 kp:0 voluntary-preempt + CONFIG_PREEMPT: vp:1 kp:1 voluntary-preempt + softirq defer: vp:2 kp:0 [default] voluntary-preempt + softirq defer + CONFIG_PREEMPT: vp:2 kp:1 each of the above combinations should work and should pretty exactly represent that particular kernel (i.e. you can get vanilla non-preemptible 2.6.8-rc2 kernel behavior by switching both flags on) - but i typically use the default one for testing. Ingo