From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Chinner Subject: Re: [PATCH v3 5/5] ext4: Defer mmap cmtime update until writeback Date: Tue, 20 Aug 2013 12:38:49 +1000 Message-ID: <20130820023849.GF6023@dastard> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii 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 To: Andy Lutomirski Return-path: 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 Content-Disposition: inline In-Reply-To: Sender: linux-ext4-owner@vger.kernel.org List-ID: 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