On 07/26/2017 02:19 PM, Christoph Hellwig wrote: > This avoids having to deal with the nr_hw_queues = 1 case in the various > queue mapping helpers by special casing it in the blk-mq core. Why special case it at all? If ->map_queues() is properly written, the single queue case should just fall out naturally. I don't see why 1 should be any different than 2, 4, or N. -- Jens Axboe