On Thu, Nov 15, 2018 at 12:51:27PM -0700, Jens Axboe wrote: > Put the short code in the fast path, where we don't have any > functions attached to the queue. This minimizes the impact on > the hot path in the core code. This looks mechanically fine: Reviewed-by: Christoph Hellwig <hch@xxxxxx> But since I seem to have missed the introduction of it - why do we need multiple struct rq_qos per request to start with? This sort of stacking seems rather odd and counter-productive, and the commit introducing this code doesn't explain the rationale at all.
