From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264433AbTL0Oo7 (ORCPT ); Sat, 27 Dec 2003 09:44:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264479AbTL0Oo7 (ORCPT ); Sat, 27 Dec 2003 09:44:59 -0500 Received: from fep03.swip.net ([130.244.199.131]:12030 "EHLO fep03-svc.swip.net") by vger.kernel.org with ESMTP id S264433AbTL0Oo5 (ORCPT ); Sat, 27 Dec 2003 09:44:57 -0500 Message-ID: <3FED9A87.4020209@free.fr> Date: Sat, 27 Dec 2003 15:43:19 +0100 From: Jean-Luc Fontaine User-Agent: Mozilla/5.0 (X11; U; Linux i586; en-US; rv:1.6b) Gecko/20031210 X-Accept-Language: en-us, ja MIME-Version: 1.0 To: linux-kernel@vger.kernel.org CC: kernel@pacrimopen.com Subject: Re: IDE performance drop between 2.4.23 and 2.6.0 X-Enigmail-Version: 0.82.5.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I solved the problem in a very strange way. Note that the (b) disk performance only improves after readahead has been increased on another (c) drive! (the (c) drive performance was also increased by to 2.4 levels but is not shown here). I could reliably repeat this behavior after rebooting. Can any IDE expert explain it? # hdparm /dev/hdb ~ multcount = 0 (off) ~ IO_support = 1 (32-bit) ~ unmaskirq = 1 (on) ~ using_dma = 1 (on) ~ keepsettings = 0 (off) ~ readonly = 0 (off) ~ readahead = 256 (on) ~ geometry = 65535/16/63, sectors = 80418240, start = 0 # hdparm -t /dev/hdb ~ Timing buffered disk reads: 34 MB in 3.09 seconds = 11.02 MB/sec # hdparm -a 4096 /dev/hdb /dev/hdb: readahead = 4096 (on) # hdparm -t /dev/hdb ~ Timing buffered disk reads: 34 MB in 3.08 seconds = 11.04 MB/sec # hdparm -a 4096 /dev/hdc /dev/hdc: readahead = 4096 (on) # hdparm -t /dev/hdb ~ Timing buffered disk reads: 46 MB in 3.12 seconds = 14.76 MB/sec - -- Jean-Luc Fontaine mailto:jfontain@free.fr http://jfontain.free.fr/ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.3 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQE/7ZqDkG/MMvcT1qQRAvLKAKC0t3Lsq+B4DBCAwQVadoXVkPxahACfZbfU UBE4kGDSf6WpuMRtsuxSJCU= =0u8i -----END PGP SIGNATURE-----