On 08/15/2014 10:36 AM, Jens Axboe wrote:
> On 08/15/2014 10:31 AM, Christoph Hellwig wrote:
>>> +static void loop_queue_work(struct work_struct *work)
>>
>> Offloading work straight to a workqueue dosn't make much sense
>> in the blk-mq model as we'll usually be called from one.  If you
>> need to avoid the cases where we are called directly a flag for
>> the blk-mq code to always schedule a workqueue sounds like a much
>> better plan.
> 
> That's a good point - would clean up this bit, and be pretty close to a
> one-liner to support in blk-mq for the drivers that always need blocking
> context.

Something like this should do the trick - totally untested. But with
that, loop would just need to add BLK_MQ_F_WQ_CONTEXT to it's tag set
flags and it could always do the work inline from ->queue_rq().

-- 
Jens Axboe