From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262357AbVCBRA6 (ORCPT ); Wed, 2 Mar 2005 12:00:58 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262370AbVCBQ7b (ORCPT ); Wed, 2 Mar 2005 11:59:31 -0500 Received: from web53704.mail.yahoo.com ([206.190.37.25]:29304 "HELO web53704.mail.yahoo.com") by vger.kernel.org with SMTP id S262356AbVCBQ6P (ORCPT ); Wed, 2 Mar 2005 11:58:15 -0500 Comment: DomainKeys? See http://antispam.yahoo.com/domainkeys DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; b=rgMQJ6avE8aI8cKRWcRxdI0Jd0F/k+rRHeNHJKK9CKFEWlwf/h/zy1ikn5/4HAAB6CP5pZEeuN9vx3strh/O8FQqPxx3/bGhTV1kmTFYPybWcmis2rdboyEWvwxBiamBEYXgLvPdvJ+w+AC1ufMyKvuEKl7Pz+6a2CHjQSudM5g= ; Message-ID: <20050302165814.70651.qmail@web53704.mail.yahoo.com> Date: Wed, 2 Mar 2005 08:58:14 -0800 (PST) From: Muthian Sivathanu Subject: ext3 journal commit performance To: linux-kernel@vger.kernel.org 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 Hi, I have a question on ext3 journal commit code. When a transaction is committed in the ordered mode, ext3 first issues the data writes, waits for them to finish, then issues the journal writes, waits for them to finish, and then writes out the commit record. It appears that the first wait (for the data blocks) is unnecessary because all that is required is that before the commit, both the data and the metadata blocks should be on disk. This extra wait can potentially reduce performance in cases where the journal is on a separate disk, because you lose parallelism between data writes and the metadata writes. Does anyone have an idea as to why this extra wait was introduced? thanks very much, Muthian __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com