From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754095AbbE1QNl (ORCPT ); Thu, 28 May 2015 12:13:41 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:16711 "EHLO mx0b-00082601.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932237AbbE1QN0 (ORCPT ); Thu, 28 May 2015 12:13:26 -0400 Message-ID: <55673E9F.6040200@fb.com> Date: Thu, 28 May 2015 10:13:19 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.7.0 MIME-Version: 1.0 To: NeilBrown CC: Keith Busch , lkml Subject: Re: LOCKDEP warning due to ext_devt_lock References: <20150528123233.3df8ff55@notabene.brown> <55668C45.3060700@fb.com> <20150528134511.27f9bdbc@notabene.brown> In-Reply-To: <20150528134511.27f9bdbc@notabene.brown> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [192.168.54.13] X-Proofpoint-Spam-Reason: safe X-FB-Internal: Safe X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:5.14.151,1.0.33,0.0.0000 definitions=2015-05-28_04:2015-05-28,2015-05-28,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/27/2015 09:45 PM, NeilBrown wrote: > On Wed, 27 May 2015 21:32:21 -0600 Jens Axboe wrote: > >> On 05/27/2015 08:32 PM, NeilBrown wrote: >>> >>> Hi Keith, >>> I'm getting lockdep warning around use of ext_devt_lock. >>> >>> [11428.266019] inconsistent {SOFTIRQ-ON-W} -> {IN-SOFTIRQ-W} usage. >>> >>> As you say in >>> 2da78092dda1 ("block: Fix dev_t minor allocation lifetime") >>> ext_devt_lock can be taken from call_rcu's soft-irq. >>> I think that means it should always use the _irq verion of spinlock. >> >> Wouldn't spin_lock_bh() and friends suffice then? >> > > Quite possibly. I've never actually used those so I don't tend to think > about them. But only reflection I think they would be exactly right. > I'll modify my patch for future testing. > > BTW, did you get my: > > [PATCH v2] block: discard bdi_unregister() in favour of bdi_destroy() > > ?? I haven't seen it appear in your 'block' tree. I missed that, thanks for the reminder. I've queued it up for this series. -- Jens Axboe