RE: [RFT][PATCH v5 0/7] sched/cpuidle: Idle loop rework

From: Doug Smythies
Date: Sat Mar 17 2018 - 12:12:11 EST


On 2018.03.17 Thomas Ilsche wrote:

> Over the last week I tested v4+pollv2 and now v5+pollv3. With v5, I
> observe a particular idle behavior, that I have not seen before with
> v4. On a dual-socket Skylake system the idle power increases from
> 74.1 W (system total) to 85.5 W with a 300 HZ build and even to
> 138.3 W with a 1000 HZ build. A similar Haswell-EP system is also
> affected.

I confirm your idle findings. There is a regression between V4 and V5.
The differences on my test computer are much less than on yours,
probably because I have only 8 CPUs.

http://fast.smythies.com/rjw_idle.png

1000 Hz kernel only.

... Doug