On 07/03/2017 06:37 AM, Ming Lei wrote: > When mq-deadline is taken, IOPS of sequential read and > seqential write is observed more than 20% drop on sata(scsi-mq) > devices, compared with using 'none' scheduler. > > The reason is that the default nr_requests for scheduler is > too big for small queuedepth devices, and latency is increased > much. > > Since the principle of taking 256 requests for mq scheduler > is based on 128 queue depth, this patch changes into > double size of min(hw queue_depth, 128).
That's somewhat odd, but it's a better default than some random value. I'll apply it, thanks Ming. -- Jens Axboe
