From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261872AbUBLCXS (ORCPT ); Wed, 11 Feb 2004 21:23:18 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263462AbUBLCXS (ORCPT ); Wed, 11 Feb 2004 21:23:18 -0500 Received: from ppp-217-133-42-200.cust-adsl.tiscali.it ([217.133.42.200]:63677 "EHLO dualathlon.random") by vger.kernel.org with ESMTP id S261872AbUBLCXP (ORCPT ); Wed, 11 Feb 2004 21:23:15 -0500 Date: Thu, 12 Feb 2004 03:23:14 +0100 From: Andrea Arcangeli To: Dave Olien Cc: Diego Calleja , Michael Frank , linux-kernel@vger.kernel.org Subject: Re: ext2/3 performance regression in 2.6 vs 2.4 for small interleaved writes Message-ID: <20040212022314.GS4478@dualathlon.random> References: <200402120502.39300.mhf@linuxmail.org> <20040211221806.106eed62.grundig@teleline.es> <20040212020019.GA22344@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20040212020019.GA22344@osdl.org> User-Agent: Mutt/1.4.1i X-GPG-Key: 1024D/68B9CB43 13D9 8355 295F 4823 7C49 C012 DFA1 686E 68B9 CB43 X-PGP-Key: 1024R/CB4660B9 CC A0 71 81 F4 A0 63 AC C0 4B 81 1D 8C 15 C8 E5 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 11, 2004 at 06:00:19PM -0800, Dave Olien wrote: > > 2.4 does not have deadline scheduler. But the 2.6 deadline scheduler > is more similar to 2.4's scheduler than is the anticipatory scheduler. the main difference is that 2.4 isn't in function of time, it's in function of requests, no matter how long it takes to write a request, so it's potentially optimizing slow devices when you don't care about latency (deadline can be tuned for each dev via /sys/block/*/queue/iosched/).