From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751344AbdKUSJj (ORCPT ); Tue, 21 Nov 2017 13:09:39 -0500 Received: from mail-io0-f195.google.com ([209.85.223.195]:44872 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750794AbdKUSJh (ORCPT ); Tue, 21 Nov 2017 13:09:37 -0500 X-Google-Smtp-Source: AGs4zMYhjBO8Zx0JI01fL76f38d6IX2S9ndeTYKXcCSo7/GK0VQuoJ+XLJlSnNXNIJEGgdsRRew6NQ== Subject: Re: 4.14: WARNING: CPU: 4 PID: 2895 at block/blk-mq.c:1144 with virtio-blk (also 4.12 stable) From: Jens Axboe To: Christian Borntraeger , Bart Van Assche , "virtualization@lists.linux-foundation.org" , "linux-block@vger.kernel.org" , "mst@redhat.com" , "jasowang@redhat.com" , "linux-kernel@vger.kernel.org" , Christoph Hellwig References: <9c5eec5d-f542-4d76-6933-6fe31203ce09@de.ibm.com> <1511205644.2396.32.camel@wdc.com> <04526c98-ffc5-1eca-3aa8-50f9212c4323@de.ibm.com> <5c9f2228-0a8b-8225-7038-e6cb3f31ca0b@kernel.dk> <2e44dbd3-2f90-c267-560c-91d1d4b0e892@de.ibm.com> <823b9dd5-7781-5a72-03ff-bc931433fc19@kernel.dk> <15f232d2-2aaa-df7c-57e8-2f710e051e84@de.ibm.com> Message-ID: <055f040d-3f9a-a8fd-e8e2-326c6b9094a1@kernel.dk> Date: Tue, 21 Nov 2017 11:09:33 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.4.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/21/2017 10:27 AM, Jens Axboe wrote: > On 11/21/2017 03:14 AM, Christian Borntraeger wrote: >> Bisect points to >> >> 1b5a7455d345b223d3a4658a9e5fce985b7998c1 is the first bad commit >> commit 1b5a7455d345b223d3a4658a9e5fce985b7998c1 >> Author: Christoph Hellwig >> Date: Mon Jun 26 12:20:57 2017 +0200 >> >> blk-mq: Create hctx for each present CPU >> >> commit 4b855ad37194f7bdbb200ce7a1c7051fecb56a08 upstream. >> >> Currently we only create hctx for online CPUs, which can lead to a lot >> of churn due to frequent soft offline / online operations. Instead >> allocate one for each present CPU to avoid this and dramatically simplify >> the code. >> >> Signed-off-by: Christoph Hellwig >> Reviewed-by: Jens Axboe >> Cc: Keith Busch >> Cc: linux-block@vger.kernel.org >> Cc: linux-nvme@lists.infradead.org >> Link: http://lkml.kernel.org/r/20170626102058.10200-3-hch@lst.de >> Signed-off-by: Thomas Gleixner >> Cc: Oleksandr Natalenko >> Cc: Mike Galbraith >> Signed-off-by: Greg Kroah-Hartman > > I wonder if we're simply not getting the masks updated correctly. I'll > take a look. Can't make it trigger here. We do init for each present CPU, which means that if I offline a few CPUs here and register a queue, those still show up as present (just offline) and get mapped accordingly. >>From the looks of it, your setup is different. If the CPU doesn't show up as present and it gets hotplugged, then I can see how this condition would trigger. What environment are you running this in? We might have to re-introduce the cpu hotplug notifier, right now we just monitor for a dead cpu and handle that. -- Jens Axboe