On 10/10/2017 02:46, Ming Lei wrote:
> > I tested this series for the SAS controller on HiSilicon hip07 platform as I
> > am interested in enabling MQ for this driver. Driver is
> > ./drivers/scsi/hisi_sas/.
> >
> > So I found that that performance is improved when enabling default SCSI_MQ
> > with this series vs baseline. However, it is still not as a good as when
> > default SCSI_MQ is disabled.
> >
> > Here are some figures I got with fio:
> > 4.14-rc2 without default SCSI_MQ
> > read, rw, write IOPS
> > 952K, 133K/133K, 800K
> >
> > 4.14-rc2 with default SCSI_MQ
> > read, rw, write IOPS
> > 311K, 117K/117K, 320K
> >
> > This series* without default SCSI_MQ
> > read, rw, write IOPS
> > 975K, 132K/132K, 790K
> >
> > This series* with default SCSI_MQ
> > read, rw, write IOPS
> > 770K, 164K/164K, 594K
>
> Thanks for testing this patchset!
>
> Looks there is big improvement, but the gap compared with
> block legacy is not small too.
>
> >
> > Please note that hisi_sas driver does not enable mq by exposing multiple
> > queues to upper layer (even though it has multiple queues). I have been
> > playing with enabling it, but my performance is always worse...
> >
> > * I'm using
> > https://github.com/ming1/linux/commits/blk_mq_improve_scsi_mpath_perf_V5.1,
> > as advised by Ming Lei.
>
> Could you test on the following branch and see if it makes a
> difference?
>
> https://github.com/ming1/linux/commits/blk_mq_improve_scsi_mpath_perf_V6.1_test
Hi John,
Please test the following branch directly:
https://github.com/ming1/linux/tree/blk_mq_improve_scsi_mpath_perf_V6.2_test
And code is simplified and cleaned up much in V6.2, then only two extra
patches(top 2) are needed against V6 which was posted yesterday.
Please test SCSI_MQ with mq-deadline, which should be the default
mq scheduler on your HiSilicon SAS.
Hi Ming Lei,
It's using cfq (for non-mq) and mq-deadline (obviously for mq).
root@(none)$ pwd
/sys/devices/platform/HISI0162:01/host0/port-0:0/expander-0:0/port-0:0:7/end_device-0:0:7
root@(none)$ more ./target0:0:3/0:0:3:0/block/sdd/queue/scheduler
noop [cfq]
and
root@(none)$ more ./target0:0:3/0:0:3:0/block/sdd/queue/scheduler
[mq-deadline] kyber none
Unfortunately my setup has changed since yeterday, and the absolute
figures are not the exact same (I retested 4.14-rc2). However, we still
see that drop when mq is enabled.
Here's the results:
4.14-rc4 without default SCSI_MQ
read, rw, write IOPS
860K, 112K/112K, 800K
4.14-rc2 without default SCSI_MQ
read, rw, write IOPS
880K, 113K/113K, 808K
V6.2 series without default SCSI_MQ
read, rw, write IOPS
820K, 114/114K, 790K
V6.2 series with default SCSI_MQ
read, rw, write IOPS
700K, 130K/128K, 640K
Cheers,
John
-- Ming .
