Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965062AbVL2ItX (ORCPT ); Thu, 29 Dec 2005 03:49:23 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965063AbVL2ItW (ORCPT ); Thu, 29 Dec 2005 03:49:22 -0500 Received: from c158129.vh.plala.or.jp ([210.150.158.129]:32199 "EHLO mvs1.plala.or.jp") by vger.kernel.org with ESMTP id S965062AbVL2ItW (ORCPT ); Thu, 29 Dec 2005 03:49:22 -0500 Message-ID: <43B3A3D8.6050605@gmail.com> Date: Thu, 29 Dec 2005 17:52:40 +0900 From: cai User-Agent: Mozilla Thunderbird 1.0.6 (X11/20050716) X-Accept-Language: zh-cn,zh MIME-Version: 1.0 To: Pekka Enberg CC: OGAWA Hirofumi , linux-kernel Subject: Re: [RFC][fat] use mpage_readpage when cluster size is page-alignment References: <87u0ctwf93.fsf@devron.myhome.or.jp> <43B3844A.5050401@gmail.com> <84144f020512290006x71d2c245s5e148fae15720d59@mail.gmail.com> In-Reply-To: <84144f020512290006x71d2c245s5e148fae15720d59@mail.gmail.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 Content-Length: 841 Lines: 26 hi, >I am not sure I am following you. Shouldn't do_mpage_readpage work for >all adjacent blocks regardless of whether block size is page-aligned >or not? What's is the performance problem you're thinking of? > > Pekka > > > no, not block size but cluster size as you know, in FAT, file is organized in clusters and one cluster could have N blocks(sectors). so if cluster size is not page-aligned, a page may live in non-adjacent blocks, and do_mpage_readpage has to fall back to block_read_full_page in this case. thanks. junjie - 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/