Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965123AbVL2JTP (ORCPT ); Thu, 29 Dec 2005 04:19:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965126AbVL2JTP (ORCPT ); Thu, 29 Dec 2005 04:19:15 -0500 Received: from mail.parknet.co.jp ([210.171.160.6]:27917 "EHLO mail.parknet.co.jp") by vger.kernel.org with ESMTP id S965123AbVL2JTO (ORCPT ); Thu, 29 Dec 2005 04:19:14 -0500 To: cai Cc: 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> From: OGAWA Hirofumi Date: Thu, 29 Dec 2005 18:19:02 +0900 In-Reply-To: <43B3844A.5050401@gmail.com> (cai's message of "Thu, 29 Dec 2005 15:38:02 +0900") Message-ID: <87y824p8ft.fsf@devron.myhome.or.jp> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.0.50 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 970 Lines: 26 cai writes: >>Can't we use mpage_readpage() always? IIRC, that should work fine >>without disadvantage. >> > it should work, but maybe some performance loses if the > cluster size is not page-alignment, for example, 4 sector/cluster > in a 4KB/page system. > because it will fall back to the block_read_full_page when > non-adjacent block found in do_mpage_readpage, i think. > the same applies to mpage_readpages too. Ah, yes. But if cluster is not fragmented it shouldn't fall back, and rather it will get advantage. And I guess, even if it fall back to block_read_full_page(), it would be very trivial. What do you think? We may need benchmark... -- OGAWA Hirofumi - 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/