From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay3.corp.sgi.com [198.149.34.15]) by oss.sgi.com (Postfix) with ESMTP id 55BBF7F37 for ; Tue, 7 Jul 2015 18:37:50 -0500 (CDT) Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by relay3.corp.sgi.com (Postfix) with ESMTP id E8340AC005 for ; Tue, 7 Jul 2015 16:37:46 -0700 (PDT) Received: from ipmail04.adl6.internode.on.net (ipmail04.adl6.internode.on.net [150.101.137.141]) by cuda.sgi.com with ESMTP id xL4wFAT5JnBMp7lV for ; Tue, 07 Jul 2015 16:37:44 -0700 (PDT) Date: Wed, 8 Jul 2015 09:37:43 +1000 From: Dave Chinner Subject: Re: Possible memory allocation deadlock in kmem_alloc and hung task in xfs_log_commit_cil and xlog_cil_push Message-ID: <20150707233743.GZ7943@dastard> References: MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: 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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Gavin Guo Cc: linux-kernel , xfs@oss.sgi.com On Tue, Jul 07, 2015 at 05:29:43PM +0800, Gavin Guo wrote: > Hi all, > > Recently, we observed that there is the error message in > Ubuntu-3.13.0-48.80: > > "XFS: possible memory allocation deadlock in kmem_alloc (mode:0x8250)" > > repeatedly shows in the dmesg. Temporarily, our workaround is to tune the > parameters, such as, vfs_cache_pressure, min_free_kbytes, and dirty_ratio. > > And we also found that there are different error messages regarding the > hung tasks which happened in xfs_log_commit_cil and xlog_cil_push. > > The log is available at: http://paste.ubuntu.com/11835007/ > > The following link seems the same problem we suffered: > > XFS hangs with XFS: possible memory allocation deadlock in kmem_alloc > http://oss.sgi.com/archives/xfs/2015-03/msg00172.html > > I read the mail and found that there might be some modification regarding > to move the memory allocation outside the ctx lock. And I also read the > latest patch from February of 2015 to see if there is any new change > about that. Unfortunately, I didn't find anything regarding the change (may > be I'm not familiar with the XFS, so didn't find the commit). If it's > possible for someone who is familiar with the code to point out the commits > related to the bug if already exist or any status about the plan. No commits - the approach I thought we might be able to take to avoid the problem didn't work out. I have another idea of how we might solve the problem, but I haven't ad a chance to prototype it yet. Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs