Oops when completing request on the wrong queue

[Gabriel Krisman Bertazi]

Jens Axboe <axboe at kernel.dk> writes:
>> Can you try this patch? It's not perfect, but I'll be interested if it
>> makes a difference for you.
>

Hi Jens,

Sorry for the delay.  I just got back to this and have been running your
patch on top of 4.8 without a crash for over 1 hour.  I wanna give it
more time to make sure it's running properly, though.

Let me get back to you after a few more rounds of test.

> This one should handle the WARN_ON() for running the hw queue on the
> wrong CPU as well.

On the workaround you added to prevent WARN_ON, we surely need to
prevent blk_mq_hctx_next_cpu from scheduling dead cpus in the first
place, right..  How do you feel about the following RFC?  I know it's
not a complete fix, but it feels like a good improvement to me.

http://www.spinics.net/lists/linux-scsi/msg98608.html

-- 
Gabriel Krisman Bertazi