From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756979Ab0JAOCr (ORCPT ); Fri, 1 Oct 2010 10:02:47 -0400 Received: from bld-mail12.adl6.internode.on.net ([150.101.137.97]:37332 "EHLO mail.internode.on.net" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1756791Ab0JAOCq (ORCPT ); Fri, 1 Oct 2010 10:02:46 -0400 Date: Sat, 2 Oct 2010 00:02:37 +1000 From: Dave Chinner To: Johannes Weiner Cc: 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: <20101001140237.GC4681@dastard> References: <20101001074354.GF2618@cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20101001074354.GF2618@cmpxchg.org> 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 09:43:54AM +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 Looks OK to me, and has run through a few hours of testing without problems. Reviewed-by: Dave Chinner Cheers, Dave. -- Dave Chinner david@fromorbit.com