From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id q835RoW8146960 for ; Mon, 3 Sep 2012 00:27:50 -0500 Received: from ipmail07.adl2.internode.on.net (ipmail07.adl2.internode.on.net [150.101.137.131]) by cuda.sgi.com with ESMTP id KPHZ8CRO3UWrFEpg for ; Sun, 02 Sep 2012 22:28:46 -0700 (PDT) Date: Mon, 3 Sep 2012 15:28:42 +1000 From: Dave Chinner Subject: Re: [RFC PATCH 4/4] xfs: add background scanning to clear EOFBLOCKS inodes Message-ID: <20120903052842.GT15292@dastard> References: <1346097111-4476-1-git-send-email-bfoster@redhat.com> <1346097111-4476-5-git-send-email-bfoster@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1346097111-4476-5-git-send-email-bfoster@redhat.com> 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: Brian Foster Cc: xfs@oss.sgi.com On Mon, Aug 27, 2012 at 03:51:51PM -0400, Brian Foster wrote: > Create a delayed_work to enable background scanning and freeing > of EOFBLOCKS inodes. The scanner kicks in once speculative > preallocation occurs and stops requeueing itself when no EOFBLOCKS > inodes exist. > > Scans are queued on the existing syncd workqueue and the interval > is tied to the syncd interval, which is a default of 30s. The > minimum file size for a background scan is hardcoded to 100MB. I'd set it to be much longer than the xfs_syncd_centisecs period. The data may not be written back for a long while, and a file that is open, written and closed repeatedly (NFS write patterns for large and/or slowly written files) should not have it's preallocation truncated every 30s. I'd suggest that a 5 minute sweep is probably sufficiently frequent to avoid most fragmentation issues and long term buildup of speculative preallocation whilst not perturbing large/slow writers too much.... Apart from that, there isn't anything wrong with the code, except I'll note again that it conflicts with my syncd removal patchset.... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs