From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161077AbWAHT15 (ORCPT ); Sun, 8 Jan 2006 14:27:57 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161102AbWAHT15 (ORCPT ); Sun, 8 Jan 2006 14:27:57 -0500 Received: from relay02.mail-hub.dodo.com.au ([202.136.32.45]:24993 "EHLO relay02.mail-hub.dodo.com.au") by vger.kernel.org with ESMTP id S1161077AbWAHT14 (ORCPT ); Sun, 8 Jan 2006 14:27:56 -0500 From: Grant Coady To: Octavio Alvarez Piza Cc: linux-kernel@vger.kernel.org, Willy Tarreau , Markus Rechberger , linux-kernel@vger.kernel.org Subject: Re: Why is 2.4.32 four times faster than 2.6.14.6?? Date: Mon, 09 Jan 2006 06:27:52 +1100 Organization: http://bugsplatter.mine.nu/ Reply-To: gcoady@gmail.com Message-ID: References: <20060108095741.GH7142@w.ods.org> <20060108102101.770a395f@octavio.alvarezp.pri> In-Reply-To: <20060108102101.770a395f@octavio.alvarezp.pri> X-Mailer: Forte Agent 2.0/32.652 MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 8 Jan 2006 10:21:01 -0800, Octavio Alvarez Piza wrote: >On Sun, 08 Jan 2006 22:05:43 +1100 >Grant Coady wrote: > >> On Sun, 8 Jan 2006 10:57:41 +0100, Willy Tarreau wrote: >> >> > Could you please retest : >> > - without the pipe (remove '| cut ...') to avoid inter-process >> > communications >> >> I thought it made a difference, then delay back again, I'll try >> again tomorrow when I'm more awake. >> >> >You should be able to find one simple pattern which makes the problem >> >appear/disappear on 2.6. At least, 'cat x.log >/dev/null' should not >> >take time or that time should be spent in I/O. >> >> Yes, done that and the time went down by ~five seconds. > >Just make sure you first read all the file with cat (I'd retry all from >the initial tests) so you don't add hd-read time to the first command. I do notice occasional pauses (just a slight jerkiness) in output from log file, perhaps when it is appended to. As I wrote earlier, this one liner is something I do fairly often to see what is hitting the web server, the 'cut -c -96' is because I run 96 character wide ssh terminals. Grant.