From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932245AbWAPIlc (ORCPT ); Mon, 16 Jan 2006 03:41:32 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932246AbWAPIlc (ORCPT ); Mon, 16 Jan 2006 03:41:32 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:57163 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S932245AbWAPIlb (ORCPT ); Mon, 16 Jan 2006 03:41:31 -0500 Date: Mon, 16 Jan 2006 09:43:09 +0100 From: Jens Axboe To: Andrew Morton Cc: cmm@us.ibm.com, seelam@cs.utep.edu, linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net Subject: Re: Fall back io scheduler for 2.6.15? Message-ID: <20060116084309.GN3945@suse.de> References: <1113388142.3019.12.camel@sisko.sctweedie.blueyonder.co.uk> <1114207837.7339.50.camel@localhost.localdomain> <1114659912.16933.5.camel@mindpipe> <1114715665.18996.29.camel@localhost.localdomain> <1136935562.4901.41.camel@dyn9047017067.beaverton.ibm.com> <20060110212551.411a766d.akpm@osdl.org> <1137007032.4395.24.camel@localhost.localdomain> <20060111114303.45540193.akpm@osdl.org> <1137201135.4353.81.camel@localhost.localdomain> <20060113174914.7907bf2c.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20060113174914.7907bf2c.akpm@osdl.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 13 2006, Andrew Morton wrote: > Mingming Cao wrote: > > > > On 2.6.14, the > > fall back io scheduler (if the chosen io scheduler is not found) is set > > to the default io scheduler (anticipatory, in this case), but since > > 2.6.15-rc1, this semanistic is changed to fall back to noop. > > OK. And I assume that AS wasn't compiled, so that's why it fell back? > > I actually thought that elevator= got removed, now we have > /sys/block/sda/queue/scheduler. But I guess that's not very useful with > CONFIG_SYSFS=n. > > > Is there any reason to fall back to noop instead of as? It seems > > anticipatory is much better than noop for ext3 with large sequential > > write tests (i.e, 1G dd test) ... > > I suspect that was an accident. Jens? It is, it makes more sense to fallback to the default of course. -- Jens Axboe