On 7/9/18 7:03 PM, Ming Lei wrote: > In case of 'none' io scheduler, when hw queue isn't busy, it isn't > necessary to enqueue request to sw queue and dequeue it from > sw queue because request may be submitted to hw queue asap without > extra cost, meantime there shouldn't be much request in sw queue, > and we don't need to worry about effect on IO merge. > > There are still some single hw queue SCSI HBAs(HPSA, megaraid_sas, ...) > which may connect high performance devices, so 'none' is often required > for obtaining good performance. > > This patch improves IOPS and decreases CPU unilization on megaraid_sas, > per Kashyap's test. Looks reasonable to me, applied for 4.19. -- Jens Axboe
