From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031241AbXDZO4y (ORCPT ); Thu, 26 Apr 2007 10:56:54 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031239AbXDZO4y (ORCPT ); Thu, 26 Apr 2007 10:56:54 -0400 Received: from il.qumranet.com ([82.166.9.18]:38965 "EHLO il.qumranet.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031241AbXDZO4x (ORCPT ); Thu, 26 Apr 2007 10:56:53 -0400 Message-ID: <4630BDB1.8090606@argo.co.il> Date: Thu, 26 Apr 2007 17:56:49 +0300 From: Avi Kivity User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: David Chinner CC: Nick Piggin , Christoph Lameter , "Eric W. Biederman" , linux-kernel@vger.kernel.org, Mel Gorman , William Lee Irwin III , Jens Axboe , Badari Pulavarty , Maxim Levitsky Subject: Re: [00/17] Large Blocksize Support V3 References: <463048FE.5000600@yahoo.com.au> <46304D50.1040706@yahoo.com.au> <46305327.2000206@yahoo.com.au> <4630593C.8070905@yahoo.com.au> <20070426092014.GT65285596@melbourne.sgi.com> <4630AEBC.4000002@argo.co.il> <20070426143303.GW65285596@melbourne.sgi.com> In-Reply-To: <20070426143303.GW65285596@melbourne.sgi.com> 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 David Chinner wrote: >> Why is it necessary to assume that one filesystem block == one buffer? >> Is it for atomicity, efficiency, or something else? >> > > By definition, really - each filesystem block has it's own state and > it's own disk mapping and so we need something to carry that > information around.... > Well, for block sizes > PAGE_SIZE, you can just duplicate the mapping information (with an offset-in-block bit field) in each page's struct page. But I see from your other posts that there are atomicity and performance reasons as well. -- error compiling committee.c: too many arguments to function