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 o959PvRW186603 for ; Tue, 5 Oct 2010 04:25:58 -0500 Received: from moutng.kundenserver.de (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id D35834C8417 for ; Tue, 5 Oct 2010 02:26:59 -0700 (PDT) Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.186]) by cuda.sgi.com with ESMTP id Q2pWuoZTEehkUc7l for ; Tue, 05 Oct 2010 02:26:59 -0700 (PDT) From: "Hans-Peter Jansen" Subject: Re: [patch] xfs: properly account for reclaimed inodes Date: Tue, 5 Oct 2010 11:26:46 +0200 References: <20101001074354.GF2618@cmpxchg.org> <20101004071904.GH4681@dastard> <20101004102213.GJ2618@cmpxchg.org> In-Reply-To: <20101004102213.GJ2618@cmpxchg.org> MIME-Version: 1.0 Content-Disposition: inline Message-Id: <201010051126.47537.hpj@urpla.net> 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: xfs@oss.sgi.com Cc: John Hawley , linux-kernel@vger.kernel.org, Johannes Weiner , Alex Elder , stable@kernel.org On Monday 04 October 2010, 12:22:13 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); > > Ping? Masters of xfs, please raise your voices! Pete _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs