From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S265141AbUEZEnX (ORCPT ); Wed, 26 May 2004 00:43:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S265147AbUEZEnX (ORCPT ); Wed, 26 May 2004 00:43:23 -0400 Received: from [213.171.41.46] ([213.171.41.46]:44292 "EHLO kaamos.homelinux.net") by vger.kernel.org with ESMTP id S265141AbUEZEnU (ORCPT ); Wed, 26 May 2004 00:43:20 -0400 From: Alexey Kopytov Organization: MySQL AB To: Andrew Morton Subject: Re: Random file I/O regressions in 2.6 [patch+results] Date: Wed, 26 May 2004 08:43:17 +0400 User-Agent: KMail/1.6.2 Cc: linuxram@us.ibm.com, nickpiggin@yahoo.com.au, peter@mysql.com, linux-kernel@vger.kernel.org, axboe@suse.de References: <200405022357.59415.alexeyk@mysql.com> <20040520145902.27647dee.akpm@osdl.org> <200405220113.31136.alexeyk@mysql.com> In-Reply-To: <200405220113.31136.alexeyk@mysql.com> MIME-Version: 1.0 Content-Disposition: inline Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <200405260843.17682.alexeyk@mysql.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Saturday 22 May 2004 01:13, Alexey Kopytov wrote: >I ran the tests with a configuration as close to yours as possible. Here are >the results for mem=256M, 2G total file size (ext3): > >2.4.25: > Time spent for test: 79.4146s > 0.20user 16.08system 3:20.29elapsed 8%CPU > Time spent for test: 78.9797s > 0.11user 15.84system 3:19.76elapsed 7%CPU > >2.6.6-bk, AS: > Time spent for test: 81.2208s > 0.13user 17.97system 3:13.30elapsed 9%CPU > Time spent for test: 82.5538s > 0.14user 18.00system 3:14.88elapsed 9%CPU > >This correlates very well your results. But when I returned back to my >original configuration (mem=640M, 3G total file size), I got the following: > >2.4.25: > Time spent for test: 77.5377s > >2.6.6-bk, AS: > Time spent for test: 83.1929s > >It seems like the smaller file size just hides the regression, but I have to >run some more tests to ensure this. > The assumption appears to be true. I tried to vary the total file size and got the following results (tests were done on another IDE disk): 2.4.27-pre3: 2 GB: 58.2707s 4 GB: 72.3313s 8 GB: 83.082s 2.6.7-rc1, AS: 2 GB: 60.6792s 4 GB: 82.8023s 8 GB: 99.4398s Varying the number of files while keeping the total file size constant also gives some interesting results: 2.4.27-pre3, 4 GB total file size: 1 file: 71.7288s 128 files: 72.3313s 256 files: 73.9268 2.6.7-rc1, AS, 4 GB total file size: 1 file: 76.443 128 files: 82.8023 256 files: 81.9618 -- Alexey Kopytov, Software Developer MySQL AB, www.mysql.com Are you MySQL certified? www.mysql.com/certification