From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752916Ab0JDHTP (ORCPT ); Mon, 4 Oct 2010 03:19:15 -0400 Received: from bld-mail15.adl6.internode.on.net ([150.101.137.100]:38900 "EHLO mail.internode.on.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751156Ab0JDHTO (ORCPT ); Mon, 4 Oct 2010 03:19:14 -0400 Date: Mon, 4 Oct 2010 18:19:04 +1100 From: Dave Chinner To: Alex Elder Cc: Johannes Weiner , xfs@oss.sgi.com, John Hawley , linux-kernel@vger.kernel.org, stable@kernel.org 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-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1285953443.2422.4.camel@doink> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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