From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754401AbcAOQk1 (ORCPT ); Fri, 15 Jan 2016 11:40:27 -0500 Received: from mail-yk0-f182.google.com ([209.85.160.182]:34518 "EHLO mail-yk0-f182.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753016AbcAOQkZ (ORCPT ); Fri, 15 Jan 2016 11:40:25 -0500 Date: Fri, 15 Jan 2016 11:40:23 -0500 From: Tejun Heo To: Christian Borntraeger Cc: "linux-kernel@vger.kernel.org >> Linux Kernel Mailing List" , linux-s390 , KVM list , Oleg Nesterov , Peter Zijlstra , "Paul E. McKenney" Subject: Re: regression 4.4: deadlock in with cgroup percpu_rwsem Message-ID: <20160115164023.GH3520@mtj.duckdns.org> References: <56978452.6010606@de.ibm.com> <20160114195630.GA3520@mtj.duckdns.org> <5698A023.9070703@de.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5698A023.9070703@de.ibm.com> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 15, 2016 at 08:30:43AM +0100, Christian Borntraeger wrote: > On 01/14/2016 08:56 PM, Tejun Heo wrote: > > Hello, > > > > Thanks a lot for the report and detailed analysis. Can you please > > test whether the following patch fixes the issue? > > > > Thanks. > > > > > Yes, the deadlock is gone and the system is still running. > After some time I had the following WARN in the logs, though. > Not sure yet if that is related. Hmmm... doesn't seem to be related. I'll spruce up the patch and route it through cgroup tree w/ stable cc'd. Please keep me posted on the lockdep issue. Thanks! -- tejun