From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271233AbTHHFmx (ORCPT ); Fri, 8 Aug 2003 01:42:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271235AbTHHFmw (ORCPT ); Fri, 8 Aug 2003 01:42:52 -0400 Received: from ns.virtualhost.dk ([195.184.98.160]:34238 "EHLO virtualhost.dk") by vger.kernel.org with ESMTP id S271233AbTHHFmv (ORCPT ); Fri, 8 Aug 2003 01:42:51 -0400 Date: Fri, 8 Aug 2003 07:42:39 +0200 From: Jens Axboe To: Joel Becker , Andrew Morton , 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: <20030808054239.GB2886@suse.de> References: <20030807100120.GA5170@in.ibm.com> <200308070901.01119.pbadari@us.ibm.com> <20030807092800.58335e84.akpm@osdl.org> <20030807193641.GM3164@parcelfarce.linux.theplanet.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20030807193641.GM3164@parcelfarce.linux.theplanet.co.uk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 07 2003, Joel Becker wrote: > 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. It does of course, that was one of the main points of the bio structure. ->readpages() can submit those 16k minimum chunks in one bio. -- Jens Axboe