Re: [PATCH 3/3] blk-mq: Use llist_head for blk_cpu_done

From: Jens Axboe
Date: Sat Oct 31 2020 - 11:00:55 EST


On 10/31/20 4:41 AM, Sebastian Andrzej Siewior wrote:
> On 2020-10-29 14:07:59 [-0700], Sagi Grimberg wrote:
>>> in which context?
>>
>> Not sure what is the question.
>
> The question is in which context do you complete your requests. My guess
> by now is "usually softirq/NAPI and context in rare error case".

There really aren't any rules for this, and it's perfectly legit to
complete from process context. Maybe you're a kthread driven driver and
that's how you handle completions. The block completion path has always
been hard IRQ safe, but possible to call from anywhere.

--
Jens Axboe