From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S270338AbTHGTgt (ORCPT ); Thu, 7 Aug 2003 15:36:49 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S270444AbTHGTgs (ORCPT ); Thu, 7 Aug 2003 15:36:48 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:24528 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id S270338AbTHGTgr (ORCPT ); Thu, 7 Aug 2003 15:36:47 -0400 Date: Thu, 7 Aug 2003 20:36:43 +0100 From: Joel Becker To: Andrew Morton Cc: Badari Pulavarty , suparna@in.ibm.com, linux-kernel@vger.kernel.org, linux-aio@kvack.org Subject: Re: [PATCH][2.6-mm] Readahead issues and AIO read speedup Message-ID: <20030807193641.GM3164@parcelfarce.linux.theplanet.co.uk> Mail-Followup-To: Joel Becker , Andrew Morton , Badari Pulavarty , suparna@in.ibm.com, linux-kernel@vger.kernel.org, linux-aio@kvack.org References: <20030807100120.GA5170@in.ibm.com> <200308070901.01119.pbadari@us.ibm.com> <20030807092800.58335e84.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030807092800.58335e84.akpm@osdl.org> User-Agent: Mutt/1.4.1i X-Burt-Line: Trees are cool. X-Red-Smith: Ninety feet between bases is perhaps as close as man has ever come to perfection. Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 07, 2003 at 09:28:00AM -0700, Andrew Morton wrote: > If the database pagesize is 16k then the application should be submitting > 16k reads, yes? If so then these should not be creating 4k requests at the > device layer! So what we need to do is to ensure that at least those 16k Um, I thought bio enforced single CDB I/O for contiguous chunks of disk! If it doesn't, 2.6 is just as lame as 2.4. Joel -- "Three o'clock is always too late or too early for anything you want to do." - Jean-Paul Sartre http://www.jlbec.org/ jlbec@evilplan.org