From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261399AbVFNCUe (ORCPT ); Mon, 13 Jun 2005 22:20:34 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261407AbVFNCUe (ORCPT ); Mon, 13 Jun 2005 22:20:34 -0400 Received: from smtp208.mail.sc5.yahoo.com ([216.136.130.116]:12464 "HELO smtp208.mail.sc5.yahoo.com") by vger.kernel.org with SMTP id S261399AbVFNCU1 (ORCPT ); Mon, 13 Jun 2005 22:20:27 -0400 Message-ID: <42AE3EE2.9020002@yahoo.com.au> Date: Tue, 14 Jun 2005 12:20:18 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.6) Gecko/20050324 Debian/1.7.6-1 X-Accept-Language: en MIME-Version: 1.0 To: Alan Cox CC: Ondrej Zary , 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=us-ascii; 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. > > Sure it has regression cases here and there, as you would expect. But I'm fairly sure this won't be one of them. If there is just a single process submitting the IO the anticipatory scheduler should completely turn of any delays, and degenerate basically to the deadline scheduler. Send instant messages to your online friends http://au.messenger.yahoo.com