From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261391AbVFOTPv (ORCPT ); Wed, 15 Jun 2005 15:15:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261438AbVFOTPv (ORCPT ); Wed, 15 Jun 2005 15:15:51 -0400 Received: from mailhub3.nextra.sk ([195.168.1.146]:30214 "EHLO mailhub3.nextra.sk") by vger.kernel.org with ESMTP id S261391AbVFOTPp (ORCPT ); Wed, 15 Jun 2005 15:15:45 -0400 Message-ID: <42B07E5D.9070004@rainbow-software.org> Date: Wed, 15 Jun 2005 21:15:41 +0200 From: Ondrej Zary User-Agent: Mozilla Thunderbird 1.0.2 (X11/20050317) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Alan Cox CC: Nick Piggin , Grant Coady , Linux Kernel Mailing List Subject: Re: Odd IDE performance drop 2.4 vs 2.6? References: <42AD6362.1000109@rainbow-software.org> <1118669975.13260.23.camel@localhost.localdomain> <42AD92F2.7080108@yahoo.com.au> <1118675343.13773.1.camel@localhost.localdomain> In-Reply-To: <1118675343.13773.1.camel@localhost.localdomain> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Alan Cox wrote: > On Llu, 2005-06-13 at 15:06, Nick Piggin wrote: > >>>Make sure you have pre-empt disabled and the antcipatory I/O scheduler >>>disabled. >>> >> >>I don't think that those could explain it. > > > Try it and see. The anticipatory I/O scheduler does horrible things to > my IDE streaming performance numbers and to swap performance. It tries > to merge I/O by delaying it which is deeply ungood when it comes to IDE > streaming even if its good for general I/O. Now I've tested it with preempt disabled and nothing has changed. When fiddling around with hdparm, I got about 16MB/s max. with 2.6.12-rc5. With 2.4.31, I got about 21MB/s when just the DMA was enabled (read-ahead and multcount set to 0 - changing them does not make almost any difference). -- Ondrej Zary