From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id D06157F51 for ; Wed, 13 Nov 2013 15:01:37 -0600 (CST) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id B76E18F8033 for ; Wed, 13 Nov 2013 13:01:34 -0800 (PST) Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id MLA657cWAhGttjIi for ; Wed, 13 Nov 2013 13:01:31 -0800 (PST) Date: Thu, 14 Nov 2013 08:01:28 +1100 From: Dave Chinner Subject: Re: [PATCH 35/36] repair: Increase default repair parallelism on large filesystems Message-ID: <20131113210128.GH6188@dastard> References: <1384324860-25677-1-git-send-email-david@fromorbit.com> <1384324860-25677-36-git-send-email-david@fromorbit.com> <20131113161029.GD32627@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20131113161029.GD32627@infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Wed, Nov 13, 2013 at 08:10:29AM -0800, Christoph Hellwig wrote: > On Wed, Nov 13, 2013 at 05:40:59PM +1100, Dave Chinner wrote: > > From: Dave Chinner > > > > Large filesystems or high AG count filesystems generally have more > > inherent parallelism in the backing storage. We shoul dmake use of > > this by default to speed up repair times. Make xfs_repair use an > > "auto-stride" configuration on filesystems with enough AGs to be > > considered "multidisk" configurations. > > > > This difference in elaspsed time to repair a 100TB filesystem with > > 50 million inodes in it with all metadata in flash is: > > > > Time IOPS BW CPU RAM > > vanilla: 2719s 2900 55MB/s 25% 0.95GB > > patched: 908s varied varied varied 2.33GB > > > > With the patched kernel, there were IO peaks of over 1.3GB/s during > > AG scanning. Some phases now run at noticably different speeds > > - phase 3 ran at ~180% CPU, 18,000 IOPS and 130MB/s, > > - phase 4 ran at ~280% CPU, 12,000 IOPS and 100MB/s > > - the other phases were similar to the vanilla repair. > > > > Memory usage is increased because of the increased buffer cache > > size as a result of concurrent AG scanning using it. > > Looks good as long as you stick your promise to clean up the magic > numbers later. Already got a prototype patch for it. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs