Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1750859AbWAPTr1 (ORCPT ); Mon, 16 Jan 2006 14:47:27 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751169AbWAPTr1 (ORCPT ); Mon, 16 Jan 2006 14:47:27 -0500 Received: from ns.virtualhost.dk ([195.184.98.160]:52539 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S1750859AbWAPTr1 (ORCPT ); Mon, 16 Jan 2006 14:47:27 -0500 Date: Mon, 16 Jan 2006 20:49:07 +0100 From: Jens Axboe To: Mingming Cao Cc: Andrew Morton , seelam@cs.utep.edu, linux-kernel@vger.kernel.org, ext2-devel@lists.sourceforge.net Subject: Re: [PATCH] Fall back io scheduler ( Re: [Ext2-devel] Re: Fall back io scheduler for 2.6.15?) Message-ID: <20060116194907.GO3945@suse.de> References: <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> <20060116084309.GN3945@suse.de> <1137440735.3724.17.camel@dyn9047017067.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1137440735.3724.17.camel@dyn9047017067.beaverton.ibm.com> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1702 Lines: 48 On Mon, Jan 16 2006, Mingming Cao wrote: > On Mon, 2006-01-16 at 09:43 +0100, Jens Axboe wrote: > > 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. > > > > How about this one? > > > In the case the chosen io scheduler (elevator = "xxx") is not on the > registered list, fall back to default scheduler makes more sense. > > Signed-off-by: Mingming Cao I think you just recreated an identical patch to the one I added this morning: http://brick.kernel.dk/git/?p=linux-2.6-block.git;a=commitdiff;h=b7bfcf7cbd58d2a64aa46f3b4bec921e346e604f :-) -- Jens Axboe - 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/