From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o94ALH1I057661 for ; Mon, 4 Oct 2010 05:21:17 -0500 Date: Mon, 4 Oct 2010 12:22:13 +0200 From: Johannes Weiner Subject: Re: [patch] xfs: properly account for reclaimed inodes Message-ID: <20101004102213.GJ2618@cmpxchg.org> References: <20101001074354.GF2618@cmpxchg.org> <1285953443.2422.4.camel@doink> <20101004071904.GH4681@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20101004071904.GH4681@dastard> 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: Dave Chinner Cc: stable@kernel.org, xfs@oss.sgi.com, John Hawley , linux-kernel@vger.kernel.org, Alex Elder Hi, On Mon, Oct 04, 2010 at 06:19:04PM +1100, Dave Chinner wrote: > 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.. Here is my suggestion of a backport to .34. Dave, Alex, do you approve? Hannes diff --git a/fs/xfs/xfs_iget.c b/fs/xfs/xfs_iget.c index 6845db9..3314f2a 100644 --- a/fs/xfs/xfs_iget.c +++ b/fs/xfs/xfs_iget.c @@ -499,6 +499,7 @@ xfs_ireclaim( write_lock(&pag->pag_ici_lock); if (!radix_tree_delete(&pag->pag_ici_root, agino)) ASSERT(0); + pag->pag_ici_reclaimable--; write_unlock(&pag->pag_ici_lock); xfs_perag_put(pag); _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs