From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760286AbXKNRSo (ORCPT ); Wed, 14 Nov 2007 12:18:44 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755356AbXKNRSg (ORCPT ); Wed, 14 Nov 2007 12:18:36 -0500 Received: from mx3.mail.elte.hu ([157.181.1.138]:44992 "EHLO mx3.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754926AbXKNRSf (ORCPT ); Wed, 14 Nov 2007 12:18:35 -0500 Date: Wed, 14 Nov 2007 18:18:05 +0100 From: Ingo Molnar To: Andrew Morton Cc: "Alan D. Brunelle" , Rik van Riel , arjan@infradead.org, jens.axboe@oracle.com, linux-kernel@vger.kernel.org Subject: Re: [patch] Give kjournald a IOPRIO_CLASS_RT io priority Message-ID: <20071114171805.GA20959@elte.hu> References: <20071015104647.14e60bc5@laptopd505.fenrus.org> <20071015114738.6b5a25c7.akpm@linux-foundation.org> <20071015161315.4fe18e07@bree.surriel.com> <20071015141236.62b075c6.akpm@linux-foundation.org> <473B18BA.5000709@hp.com> <20071114091451.d4b110db.akpm@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071114091451.d4b110db.akpm@linux-foundation.org> User-Agent: Mutt/1.5.17 (2007-11-01) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.1.7-deb -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org * Andrew Morton wrote: > ooh, more performance testing. Thanks > > > * The overwriter task (on an 8GiB file), average over 10 runs: > > o 2.6.24 - 300.88226 seconds > > o 2.6.24 + Arjan's patch - 403.85505 seconds > > > > * The read-a-different-kernel-tree task, average over 10 runs: > > o 2.6.24 - 46.8145945549 seconds > > o 2.6.24 + Arjan's patch - 39.6430601119 seconds > > > > * The large-linear-read task (on an 8GiB file), average over 10 runs: > > o 2.6.24 - 290.32522 seconds > > o 2.6.24 + Arjan's patch - 386.34860 seconds > > These are *large* differences, making this a very signifcant patch. > Much care is needed now. and the numbers suggest it's mostly a severe performance regression. That's not what i have expected - ho hum. Apologies for my earlier "please merge it already!" whining. Ingo