From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756430Ab3KOITm (ORCPT ); Fri, 15 Nov 2013 03:19:42 -0500 Received: from mail-pb0-f53.google.com ([209.85.160.53]:51163 "EHLO mail-pb0-f53.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752005Ab3KOITe (ORCPT ); Fri, 15 Nov 2013 03:19:34 -0500 Date: Fri, 15 Nov 2013 17:19:29 +0900 From: Tejun Heo To: Shawn Bohrer Cc: cgroups@vger.kernel.org, linux-kernel@vger.kernel.org, Li Zefan Subject: Re: 3.10.16 cgroup css_set_lock deadlock Message-ID: <20131115081929.GA11530@mtj.dyndns.org> References: <20131114232529.GB16725@sbohrermbp13-local.rgmadvisors.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20131114232529.GB16725@sbohrermbp13-local.rgmadvisors.com> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Nov 14, 2013 at 05:25:29PM -0600, Shawn Bohrer wrote: > In trying to reproduce the cgroup_mutex deadlock I reported earlier > in https://lkml.org/lkml/2013/11/11/574 I believe I encountered a > different issue that I'm also unable to understand. This machine > started out reporting some soft lockups that look to me like they are > on a read_lock(css_set_lock): > ... > RIP: 0010:[] [] cgroup_attach_task+0xdc/0x7a0 ... > [] attach_task_by_pid+0x167/0x1a0 > [] cgroup_tasks_write+0x13/0x20 Most likely the bug fixed by ea84753c98a7 ("cgroup: fix to break the while loop in cgroup_attach_task() correctly"). 3.10.19 contains the backported fix. Thanks. -- tejun