From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id C94BC29DF9 for ; Sun, 30 Mar 2014 18:44:30 -0500 (CDT) Received: from cuda.sgi.com (cuda2.sgi.com [192.48.176.25]) by relay1.corp.sgi.com (Postfix) with ESMTP id ABA1E8F8033 for ; Sun, 30 Mar 2014 16:44:27 -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 yaCCDO6yyP7BfRJ3 for ; Sun, 30 Mar 2014 16:44:22 -0700 (PDT) Date: Mon, 31 Mar 2014 10:43:35 +1100 From: Dave Chinner Subject: Re: xfs i_lock vs mmap_sem lockdep trace. Message-ID: <20140330234335.GB16336@dastard> References: <20140329223109.GA24098@redhat.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20140329223109.GA24098@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 Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Jones , Linux Kernel , xfs@oss.sgi.com On Sat, Mar 29, 2014 at 06:31:09PM -0400, Dave Jones wrote: > Not sure if I've reported this already (it looks familiar, though I've not managed > to find it in my sent mail folder). This is rc8 + a diff to fix the stack usage reports > I was seeing (diff at http://paste.fedoraproject.org/89854/13210913/raw) > > ====================================================== > [ INFO: possible circular locking dependency detected ] > 3.14.0-rc8+ #153 Not tainted > ------------------------------------------------------- > git/32710 is trying to acquire lock: > (&(&ip->i_lock)->mr_lock){++++.+}, at: [] xfs_ilock+0x122/0x250 [xfs] > > but task is already holding lock: > (&mm->mmap_sem){++++++}, at: [] __do_page_fault+0x14a/0x610 > > which lock already depends on the new lock. filldir on a directory inode vs page fault on regular file. Known issue, definitely a false positive. We have to change locking algorithms to avoid such deficiencies of lockdep (a case of "lockdep considered harmful", perhaps?) so it's not something I'm about to rush... Cheers, Dave. -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs