On Mon, 2018-01-29 at 14:00 -0700, Jens Axboe wrote: > On 1/29/18 1:56 PM, James Bottomley wrote: > > > > On Mon, 2018-01-29 at 23:46 +0800, Ming Lei wrote: > > [...] > > > > > > 2. When to enable SCSI_MQ at default again? > > > > I'm not sure there's much to discuss ... I think the basic answer > > is as soon as Christoph wants to try it again. > > FWIW, internally I've been running various IO intensive workloads on > what is essentially 4.12 upstream with scsi-mq the default (with > mq-deadline as the scheduler) and comparing IO workloads with a > previous 4.6 kernel (without scsi-mq), and things are looking > great. > > We're never going to iron out the last kinks with it being off > by default, I think we should attempt to flip the switch again > for 4.16. Absolutely, I agree we turn it on ASAP. I just don't want to be on the receiving end of Linus' flamethrower because a bug we already had reported against scsi-mq caused problems. Get confirmation from the original reporters (or as close to it as you can) that their problems are fixed and we're good to go; he won't kick us nearly as hard for new bugs that turn up. James
