On Wed, Jan 03, 2018 at 01:21:05PM -0700, Keith Busch wrote: > > I've removed the submission side poll in a local build, and amazingly I > am observing a not insignificant increase in latency without it on some > workloads with certain hardware. I will have to delay recommending/posting > removal of this pending further investigation. This took longer to narrow than I hoped. I had been getting very wild results, and there were two things to blame: a kernel irq issue[*], and a platform bios causing a lot of CPU thermal frequency throttling. Now that's sorted out, I am back to tuning this and the opprotunistic nvme submission side polling once again does not produce a measurable difference. My world is sane again. Will try to send an update for consideration this week after some more testing. * https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit?id=a0c9259dc4
