From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751990Ab3HTCiz (ORCPT ); Mon, 19 Aug 2013 22:38:55 -0400 Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:5989 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751350Ab3HTCiy (ORCPT ); Mon, 19 Aug 2013 22:38:54 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AmMHAOfVElJ5LJ62/2dsb2JhbABagwWDN7dHhTuBJBd0giQBAQU6HCMQCAMOCgklDwUlAyETiA+rMhaQRgeDG3cDl2ORVoMuKg Date: Tue, 20 Aug 2013 12:38:49 +1000 From: Dave Chinner To: Andy Lutomirski Cc: linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, "Theodore Ts'o" , Dave Hansen , xfs@oss.sgi.com, Jan Kara , Tim Chen , Christoph Hellwig Subject: Re: [PATCH v3 5/5] ext4: Defer mmap cmtime update until writeback Message-ID: <20130820023849.GF6023@dastard> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 16, 2013 at 04:22:12PM -0700, Andy Lutomirski wrote: > A fancier implementation could probably avoid an extra journal > transaction by adding a mapping_test_clear_cmtime call in > ext4_writepages, but this should already be a considerable > improvement -- we'll start one transaction per writepages call > instead of one per page. I'd like to see more than just an ext4 implementation - btrfs and XFS are the other main filesystems that should behave identically. Also, it's worthwhile to write a generic xfstest to ensure that they all update the timestamp appropriately - if its' in xfstests, then we can basically guarantee that it won't get randomly regressed in future, and other filesystems can be easily verified as well sa their implement this. Cheers, Dave. -- Dave Chinner david@fromorbit.com