Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933030AbZDHTyX (ORCPT ); Wed, 8 Apr 2009 15:54:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759352AbZDHTyK (ORCPT ); Wed, 8 Apr 2009 15:54:10 -0400 Received: from moutng.kundenserver.de ([212.227.126.188]:61481 "EHLO moutng.kundenserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758160AbZDHTyI (ORCPT ); Wed, 8 Apr 2009 15:54:08 -0400 Date: Wed, 8 Apr 2009 21:56:10 +0200 From: Heinz Diehl To: linux-kernel@vger.kernel.org Cc: Corrado Zoccolo , =?iso-8859-1?Q?J=2EA=2E_Magall=F3n?= , Jan Knutar Subject: Re: SSD and IO schedulers Message-ID: <20090408195610.GA5447@fancy-poultry.org> Reply-To: linux-kernel@vger.kernel.org Mail-Followup-To: linux-kernel@vger.kernel.org, Corrado Zoccolo , =?iso-8859-1?Q?J=2EA=2E_Magall=F3n?= , Jan Knutar References: <4dcf7d360901301355l7ed26a5aob7ef6d79d9607b6b@mail.gmail.com> <20090204004003.26068f72@werewolf.home> <200902071858.40146.jk-lkml@sci.fi> <4e5e476b0904081218i29871702qc8bacb680c51ec2c@mail.gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4e5e476b0904081218i29871702qc8bacb680c51ec2c@mail.gmail.com> Organization: private site User-Agent: Mutt/1.5.19+20090405 (GNU/Linux) X-Provags-ID: V01U2FsdGVkX19Y/l5ANLhTUk4/0ZtyCqRJ81g3JyZXGtp3x6W HM5ToSJynGA68JTCDPDQhZUYLM+KdXZts0H1KYn6cZfOYY5TDG TWc7KCIv5E2rlUSET+1BQuWyhC1bgePqM81ZURUhfk= Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1683 Lines: 73 On 08.04.2009, Corrado Zoccolo wrote: > I found that elevator=deadline performs much better than noop for > writes, and almost as well for reads [....] The DL elevator has slightly more throughput than cfq and anticipatory, but is almost unusuable under load. Running Theodore Ts'os "fsync-tester" while doing Linus' torture test "while : ; do time sh -c "dd if=/dev/zero of=bigfile bs=8M count=256 ; sync; rm bigfile"; done" shows it clearly: mount: /dev/sda4 on /home type xfs (rw,noatime,logbsize=256k,logbufs=2,nobarrier) Kernel 2.6.29.1 (vanilla) with cfq: htd@liesel:~/!> ./fsync-tester fsync time: 0.7640 fsync time: 0.6166 fsync time: 1.2830 fsync time: 0.4273 fsync time: 1.1693 fsync time: 1.7466 fsync time: 1.2477 fsync time: 1.9411 fsync time: 1.9636 fsync time: 1.9065 fsync time: 1.1561 fsync time: 1.8267 fsync time: 0.2431 fsync time: 0.2898 fsync time: 0.2394 fsync time: 0.4309 fsync time: 1.5699 fsync time: 0.3742 fsync time: 1.3194 fsync time: 1.9442 fsync time: 1.0899 fsync time: 1.9443 fsync time: 1.0062 with dl: fsync time: 10.5853 fsync time: 10.3339 fsync time: 5.3374 fsync time: 6.5707 fsync time: 10.6095 fsync time: 4.1154 fsync time: 4.9604 fsync time: 10.5325 fsync time: 10.4543 fsync time: 10.4970 fsync time: 10.5570 fsync time: 5.2717 fsync time: 10.5619 fsync time: 5.3058 fsync time: 3.1019 fsync time: 5.1504 fsync time: 5.7564 fsync time: 10.5998 fsync time: 4.0895 Regards, Heinz. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/