Re: [dm-devel] [PATCH V6 1/5] blk-mq-sched: fix scheduler bad performance

2017-10-11 Thread Omar Sandoval
On Mon, Oct 09, 2017 at 07:24:20PM +0800, Ming Lei wrote: > When hw queue is busy, we shouldn't take requests from > scheduler queue any more, otherwise it is difficult to do > IO merge. > > This patch fixes the awful IO performance on some > SCSI devices(lpfc, qla2xxx, ...) when

[dm-devel] [PATCH V6 1/5] blk-mq-sched: fix scheduler bad performance

2017-10-09 Thread Ming Lei
When hw queue is busy, we shouldn't take requests from scheduler queue any more, otherwise it is difficult to do IO merge. This patch fixes the awful IO performance on some SCSI devices(lpfc, qla2xxx, ...) when mq-deadline/kyber is used by not taking requests if hw queue is busy. Reviewed-by: