Subject: Re: [PATCH] block-mq:Fix the null memory access while setting tags cpumask

From: Raghavendra K T <[email-masked]>
Date: Tue, 13 Oct 2015 22:59:37 +0530

On 10/13/2015 10:17 PM, Jeff Moyer wrote:
> Raghavendra K T <[email-masked]> 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.