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 o947IFde050881 for ; Mon, 4 Oct 2010 02:18:15 -0500 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D38D4EB23C7 for ; Mon, 4 Oct 2010 00:32:48 -0700 (PDT) Received: from mail.internode.on.net (bld-mail15.adl6.internode.on.net [150.101.137.100]) by cuda.sgi.com with ESMTP id mnJnaX4lqPcmbdbX for ; Mon, 04 Oct 2010 00:32:48 -0700 (PDT) Date: Mon, 4 Oct 2010 18:19:04 +1100 From: Dave Chinner Subject: Re: [patch] xfs: properly account for reclaimed inodes Message-ID: <20101004071904.GH4681@dastard> References: <20101001074354.GF2618@cmpxchg.org> <1285953443.2422.4.camel@doink> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <1285953443.2422.4.camel@doink> 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: Alex Elder Cc: stable@kernel.org, xfs@oss.sgi.com, John Hawley , linux-kernel@vger.kernel.org, Johannes Weiner On Fri, Oct 01, 2010 at 12:17:23PM -0500, Alex Elder wrote: > On Fri, 2010-10-01 at 09:43 +0200, Johannes Weiner wrote: > > When marking an inode reclaimable, a per-AG counter is increased, the > > inode is tagged reclaimable in its per-AG tree, and, when this is the > > first reclaimable inode in the AG, the AG entry in the per-mount tree > > is also tagged. > > > > When an inode is finally reclaimed, however, it is only deleted from > > the per-AG tree. Neither the counter is decreased, nor is the parent > > tree's AG entry untagged properly. > > > > Since the tags in the per-mount tree are not cleared, the inode > > shrinker iterates over all AGs that have had reclaimable inodes at one > > point in time. > > > > The counters on the other hand signal an increasing amount of slab > > objects to reclaim. Since "70e60ce xfs: convert inode shrinker to > > per-filesystem context" this is not a real issue anymore because the > > shrinker bails out after one iteration. > > > > But the problem was observable on a machine running v2.6.34, where the > > reclaimable work increased and each process going into direct reclaim > > eventually got stuck on the xfs inode shrinking path, trying to scan > > several million objects. > > > > Fix this by properly unwinding the reclaimable-state tracking of an > > inode when it is reclaimed. > > > > Signed-off-by: Johannes Weiner > > Cc: stable@kernel.org > > Yes, this looks right to me. The state was correctly > adjusted in xfs_iget_cache_hit() when a RECLAIMABLE > inode is found in the cache, but it was not done when > reclaim completes. > > Reviewed-by: Alex Elder Alex, can you push this to Linus ASAP? This needs to go back to stable kernels as well.. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs