From: Jeff Moyer Subject: Re: [patch/rft] jbd2: tag journal writes as metadata I/O Date: Mon, 05 Apr 2010 14:36:07 -0400 Message-ID: References: <20100405175205.GA4681@thunk.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, jens.axboe@oracle.com, esandeen@redhat.com To: tytso@mit.edu Return-path: Received: from mx1.redhat.com ([209.132.183.28]:7913 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755872Ab0DESgO (ORCPT ); Mon, 5 Apr 2010 14:36:14 -0400 In-Reply-To: <20100405175205.GA4681@thunk.org> (tytso@mit.edu's message of "Mon, 5 Apr 2010 13:52:05 -0400") Sender: linux-ext4-owner@vger.kernel.org List-ID: tytso@mit.edu writes: > On Thu, Apr 01, 2010 at 03:04:54PM -0400, Jeff Moyer wrote: >> >> So, I'm submitting this patch for comments and testing. I have a >> similar patch for jbd that I will submit if folks agree that this is a >> good idea. > > Added to the ext4 patch queue. > > What benchmark were you using to test small file writes? This looks > good to me as well, but we might want to do some extra benchmarking > just to be sure we're not accidentally introducing a performance > regression. iozone showed regressions for write and re-write in runs that include fsync timings for small files (<8MB). Here's the command line used for testing: iozone -az -n 4k -g 2048m -y 1k -q 1m -e I also ran fs_mark using the following command line: fs_mark -S 1 -D 100 -N 1000 -d /mnt/test/fs_mark -s 65536 -t 1 -w 4096 I'll let you know if there are any regressions caused by this patch in any of our other testing. Cheers, Jeff