Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932296AbWEDMjD (ORCPT ); Thu, 4 May 2006 08:39:03 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932299AbWEDMjC (ORCPT ); Thu, 4 May 2006 08:39:02 -0400 Received: from smtp.ustc.edu.cn ([202.38.64.16]:56529 "HELO ustc.edu.cn") by vger.kernel.org with SMTP id S932296AbWEDMjA (ORCPT ); Thu, 4 May 2006 08:39:00 -0400 Message-ID: <346744890.14268@ustc.edu.cn> X-EYOUMAIL-SMTPAUTH: wfg@mail.ustc.edu.cn Date: Thu, 4 May 2006 20:14:54 +0800 From: Wu Fengguang To: Arjan van de Ven Cc: "Ph. Marek" , Linus Torvalds , Linda Walsh , linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty Subject: Re: [RFC] kernel facilities for cache prefetching Message-ID: <20060504121454.GB6008@mail.ustc.edu.cn> Mail-Followup-To: Wu Fengguang , Arjan van de Ven , "Ph. Marek" , Linus Torvalds , Linda Walsh , linux-kernel@vger.kernel.org, Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty References: <346556235.24875@ustc.edu.cn> <44594AA9.8020906@tlinx.org> <200605040908.10727.philipp.marek@bmlv.gv.at> <1146728004.3101.17.camel@laptopd505.fenrus.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1146728004.3101.17.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.5.11+cvs20060126 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 983 Lines: 22 On Thu, May 04, 2006 at 09:33:24AM +0200, Arjan van de Ven wrote: > > > > Ascending block numbers on disk can be read very fast, as the disk needs no or > > less seeking. That's even true for stripes and mirrors. (I grant you that > > there are complicated setups out there, but these could be handled similar.) > > > > > btw this all really spells out that you may want to do this as a device > mapper thing; eg have a device mapper module that can do "lookaside" to > a different order/mirror block whatever. The filesystem just doesn't > want to know; do it at the DM level ;) That also solves the entire > caching layering problem etc ;) I guess some big corps might want to install such a layer into their storage products ;) - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/