From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755299Ab2CHSLe (ORCPT ); Thu, 8 Mar 2012 13:11:34 -0500 Received: from mail-gx0-f174.google.com ([209.85.161.174]:59997 "EHLO mail-gx0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753573Ab2CHSLc (ORCPT ); Thu, 8 Mar 2012 13:11:32 -0500 Date: Thu, 8 Mar 2012 10:11:25 -0800 From: Tejun Heo To: Vivek Goyal Cc: Andrew Morton , axboe@kernel.dk, hughd@google.com, avi@redhat.com, nate@cpanel.net, cl@linux-foundation.org, linux-kernel@vger.kernel.org, dpshah@google.com, ctalbott@google.com, rni@google.com Subject: Re: [PATCHSET] mempool, percpu, blkcg: fix percpu stat allocation and remove stats_lock Message-ID: <20120308181125.GB25508@google.com> References: <20120229173639.GB5930@redhat.com> <20120305221321.GF1263@google.com> <20120306210954.GF32148@redhat.com> <20120306132034.ecaf8b20.akpm@linux-foundation.org> <20120306213437.GG32148@redhat.com> <20120306135531.828ca78e.akpm@linux-foundation.org> <20120307145556.GA11262@redhat.com> <20120307150549.955d6f9c.akpm@linux-foundation.org> <20120308175708.GB22922@redhat.com> <20120308180833.GA25508@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20120308180833.GA25508@google.com> User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Mar 08, 2012 at 10:08:33AM -0800, Tejun Heo wrote: > It's probably from something forgetting to put cgroup and pre_destroy > waiting for it. Such bugs would have been masked before but now show > up as stalls during rmdir. I'm not too happy with how cgroup is > handling cgroup file additions and removals and hoping to implement > proper 'sever' semantics similar to that of sysfs. In the longer > term, such behavior should go away but for now we'll just have to hunt > down the actual bug to avoid stalls (which we have to do anyway but > it's more visible now). Hmm... I'll probably need it for dynamic file additions and removals for dynamic policy updates && the blkcg changes are scheduled for 3.5-rc1 window (not 3.4-rc1), so we should have enough time to resolve this. Thanks. -- tejun