Re: [PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-14 Thread Ming Lei
On Fri, Oct 13, 2017 at 02:23:07PM -0600, Jens Axboe wrote: > On 10/13/2017 01:21 PM, Jens Axboe wrote: > > On 10/13/2017 01:08 PM, Jens Axboe wrote: > >> On 10/13/2017 12:05 PM, Ming Lei wrote: > >>> Hi Jens, > >>> > >>> In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O >

Re: [PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-13 Thread Ming Lei
On Fri, Oct 13, 2017 at 02:23:07PM -0600, Jens Axboe wrote: > On 10/13/2017 01:21 PM, Jens Axboe wrote: > > On 10/13/2017 01:08 PM, Jens Axboe wrote: > >> On 10/13/2017 12:05 PM, Ming Lei wrote: > >>> Hi Jens, > >>> > >>> In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O >

Re: [PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-13 Thread Jens Axboe
On 10/13/2017 01:21 PM, Jens Axboe wrote: > On 10/13/2017 01:08 PM, Jens Axboe wrote: >> On 10/13/2017 12:05 PM, Ming Lei wrote: >>> Hi Jens, >>> >>> In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O >>> performance is much bad with mq-deadline, especially about sequential

Re: [PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-13 Thread Jens Axboe
On 10/13/2017 01:08 PM, Jens Axboe wrote: > On 10/13/2017 12:05 PM, Ming Lei wrote: >> Hi Jens, >> >> In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O >> performance is much bad with mq-deadline, especially about sequential I/O >> on some multi-queue SCSI devcies(lpfc,

Re: [PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-13 Thread Jens Axboe
On 10/13/2017 12:05 PM, Ming Lei wrote: > Hi Jens, > > In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O > performance is much bad with mq-deadline, especially about sequential I/O > on some multi-queue SCSI devcies(lpfc, qla2xxx, SRP...) > > Turns out one big issue

[PATCH V9 0/7] blk-mq-sched: improve sequential I/O performance

2017-10-13 Thread Ming Lei
Hi Jens, In Red Hat internal storage test wrt. blk-mq scheduler, we found that I/O performance is much bad with mq-deadline, especially about sequential I/O on some multi-queue SCSI devcies(lpfc, qla2xxx, SRP...) Turns out one big issue causes the performance regression: requests are still