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Date: Tue, 13 Oct 2015 22:59:37 +0530
From: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
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To: Jeff Moyer <jmoyer@redhat.com>
CC: axboe@kernel.dk, linuxppc-dev@lists.ozlabs.org, ming.lei@canonical.com,
 keith.busch@intel.com, snitzer@redhat.com, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] block-mq:Fix the null memory access while setting tags
 cpumask
References: <1444713927-16261-1-git-send-email-raghavendra.kt@linux.vnet.ibm.com>
 <x491tcy7m2j.fsf@segfault.boston.devel.redhat.com>
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On 10/13/2015 10:17 PM, Jeff Moyer wrote:
> Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> writes:
>
>> In nr_hw_queues >1 cases when certain number of cpus are onlined/or
>> offlined, that results change in request_queue map in block-mq layer,
>> we see the kernel dumping like:
>
> What version is that patch against?  This problem should be fixed by the
> patch set from Akinobu Mita.  I tested cpu hot-plugging on my system
> with an nvme device, and it is fixed there on mainline.
>

Hi Jeff,

My patch was against (4.3.0-rc2) bcee19f424a.

I do see now that  commit 1356aae08338 (blk-mq: avoid setting
hctx->tags->cpumask before allocation) has equivalent fix.

Thanks for the information.