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 ESMTP id o964r1iP044792 for ; Tue, 5 Oct 2010 23:53:01 -0500 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id 60F58C648E for ; Tue, 5 Oct 2010 21:54:03 -0700 (PDT) Received: from mail.internode.on.net (bld-mail14.adl6.internode.on.net [150.101.137.99]) by cuda.sgi.com with ESMTP id zfC72YCGnFSu5Bmv for ; Tue, 05 Oct 2010 21:54:03 -0700 (PDT) Date: Wed, 6 Oct 2010 15:53:49 +1100 From: Dave Chinner Subject: Re: [patch] xfs: properly account for reclaimed inodes Message-ID: <20101006045349.GA13191@dastard> References: <20101001074354.GF2618@cmpxchg.org> <1285953443.2422.4.camel@doink> <20101004071904.GH4681@dastard> <20101004102213.GJ2618@cmpxchg.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20101004102213.GJ2618@cmpxchg.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: Johannes Weiner Cc: stable@kernel.org, xfs@oss.sgi.com, John Hawley , linux-kernel@vger.kernel.org, Alex Elder On Mon, Oct 04, 2010 at 12:22:13PM +0200, Johannes Weiner wrote: > 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); Looks good to me. Reviewed-by: Dave Chinner Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs