From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o91HH7QV100479 for ; Fri, 1 Oct 2010 12:17:07 -0500 Subject: Re: [patch] xfs: properly account for reclaimed inodes From: Alex Elder In-Reply-To: <20101001074354.GF2618@cmpxchg.org> References: <20101001074354.GF2618@cmpxchg.org> Date: Fri, 01 Oct 2010 12:17:23 -0500 Message-ID: <1285953443.2422.4.camel@doink> Mime-Version: 1.0 Reply-To: aelder@sgi.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: Johannes Weiner Cc: stable@kernel.org, John Hawley , linux-kernel@vger.kernel.org, xfs@oss.sgi.com 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 _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs