From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758231AbXKYX3f (ORCPT ); Sun, 25 Nov 2007 18:29:35 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757214AbXKYX3S (ORCPT ); Sun, 25 Nov 2007 18:29:18 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:33367 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757094AbXKYX3R (ORCPT ); Sun, 25 Nov 2007 18:29:17 -0500 Date: Sun, 25 Nov 2007 15:27:45 -0800 From: Arjan van de Ven To: Adrian Bunk Cc: Jens Axboe , linux-kernel@vger.kernel.org Subject: Re: [2.6 patch] make I/O schedulers non-modular Message-ID: <20071125152745.6d23f435@laptopd505.fenrus.org> In-Reply-To: <20071125165654.GE21947@stusta.de> References: <20071125161801.GB21947@stusta.de> <20071125162105.GA6658@kernel.dk> <20071125163153.GD21947@stusta.de> <20071125164532.GB6658@kernel.dk> <20071125165654.GE21947@stusta.de> Organization: Intel X-Mailer: Claws Mail 3.0.2 (GTK+ 2.12.1; i386-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, 25 Nov 2007 17:56:54 +0100 Adrian Bunk wrote: > Is there any technical reason why we need 4 different schedulers at > all? > there is at least one technical reason to need more than one: certain types of storage (both big EMC boxes as well as solid state disks) don't behave like disks and have no seek penalty; any cpu time spent on avoiding seeks is wasted on those, so for these devices one really wants to use a different IO scheduler, one which is much lighter weight