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 q7KNLDgX012861 for ; Mon, 20 Aug 2012 18:21:13 -0500 Received: from ipmail05.adl6.internode.on.net (ipmail05.adl6.internode.on.net [150.101.137.143]) by cuda.sgi.com with ESMTP id PVuHbABWzdsEeJs1 for ; Mon, 20 Aug 2012 16:21:12 -0700 (PDT) Received: from dave by dastard with local (Exim 4.76) (envelope-from ) id 1T3bHS-0005VW-2s for xfs@oss.sgi.com; Tue, 21 Aug 2012 09:21:10 +1000 Date: Tue, 21 Aug 2012 09:21:10 +1000 From: Dave Chinner Subject: Re: [PATCH] xfs: fix race while discarding buffers [V4] Message-ID: <20120820232110.GM19235@dastard> References: <1344621711-8049-1-git-send-email-cmaiolino@redhat.com> <20120820205134.GB29979@sgi.com> <20120820224751.GA22096@orion.usersys.redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120820224751.GA22096@orion.usersys.redhat.com> 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 On Mon, Aug 20, 2012 at 07:47:51PM -0300, Carlos Maiolino wrote: > Hi Ben, > > > > > Thanks for the comments. > > > > What was the symptom that led to the discovery of this problem? > > > > Reviewed-by: Ben Myers > > > > It started with the messages like the example below being logged by syslog: > > shrink_slab: xfs_buftarg_shrink+0x0/0x160 [xfs] negative objects to delete nr=-61993820 > shrink_slab: xfs_buftarg_shrink+0x0/0x160 [xfs] negative objects to delete nr=-146 > shrink_slab: xfs_buftarg_shrink+0x0/0x160 [xfs] negative objects to delete nr=-240601220 > shrink_slab: xfs_buftarg_shrink+0x0/0x160 [xfs] negative objects to delete nr=-152 > shrink_slab: xfs_buftarg_shrink+0x0/0x160 [xfs] negative objects to delete nr=-2921236993 > > These messages came from shrink_slab(). Worth noting is that this warning came from a RHEL kernel, not a mainline kernel. The mainline kernels don't screw up the nr_to_scan calculations when a negative object count is returned to them. Hence mainline kernels are not impacted by the accounting bug at all... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs