From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S966546AbbDWQ2N (ORCPT ); Thu, 23 Apr 2015 12:28:13 -0400 Received: from mx0b-00082601.pphosted.com ([67.231.153.30]:58543 "EHLO mx0a-00082601.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S966339AbbDWQ2I (ORCPT ); Thu, 23 Apr 2015 12:28:08 -0400 Message-ID: <55391D8C.1050505@fb.com> Date: Thu, 23 Apr 2015 10:27:56 -0600 From: Jens Axboe User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.6.0 MIME-Version: 1.0 To: Ming Lei , CC: Christoph Hellwig , Al Viro , Maxim Patlasov Subject: Re: [PATCH v1 0/2] blk-mq: fix oops caused by CPU hotplug References: <1429581620-27747-1-git-send-email-ming.lei@canonical.com> In-Reply-To: <1429581620-27747-1-git-send-email-ming.lei@canonical.com> 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=2.50.10432:5.13.68,1.0.33,0.0.0000 definitions=2015-04-23_06:2015-04-23,2015-04-23,1970-01-01 signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/20/2015 08:00 PM, Ming Lei wrote: > Hi Guys, > > Dongsu Park reported[1] that kernel oops can be triggered easily by > CPU plug when there is pending I/O on virtio-scsi. > > Turns out two problems exist in blk-mq core code and both can trigger > oops by CPU plug: > - timeout handling vs CPU hotplug, especially unmapped hw queue tags > is still touched by timeout handler > - in case of shared tags, there is one bug about setting and checking > hctx->tags during CPU hotplug > > The two patches fix the two problem, and Dongsu has verified that > the oops is fixed with the two patches too. > > [1], http://marc.info/?t=142926389200008&r=1&w=2 Applied, thanks Ming! -- Jens Axboe