From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with SMTP id p370CZHq063090 for ; Wed, 6 Apr 2011 19:12:35 -0500 Received: from ipmail04.adl6.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 0DCB03AF5AF for ; Wed, 6 Apr 2011 17:15:51 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id Nt8B9bkEPNnIZ9h1 for ; Wed, 06 Apr 2011 17:15:51 -0700 (PDT) Date: Thu, 7 Apr 2011 10:15:48 +1000 From: Dave Chinner Subject: Re: [PATCH 7/9] xfs: push the AIL from memory reclaim and periodic sync Message-ID: <20110407001548.GQ31057@dastard> References: <1302070758-17312-1-git-send-email-david@fromorbit.com> <1302070758-17312-8-git-send-email-david@fromorbit.com> <20110406183356.GA23275@infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20110406183356.GA23275@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 Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Wed, Apr 06, 2011 at 02:33:56PM -0400, Christoph Hellwig wrote: > The patch looks correct, but I wonder what the performance implications > of flushing the AIL every 30 seconds are. Did you benchmark the > patchset to see what it does to performance numbers for metadata > intensive workloads? In my measurements it's made no difference. If the workload is being sustained for more than a few seconds, then memory reclaim typically becomes active and the push from there becomes the dominating factor. This effectively makes the syncd work trigger a no-op. If the push from the syncd work does trigger work to be done, it's generally because the filesystem has gone to idle or only has a low level of modifications being done. In either case, it doesn't affect performance, especially with delaylog pinning the working set of metadata in memory... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs