Re: [PATCH v4 1/6] x86,sched: Add support for frequency invariance

Giovanni Gherdovich
2019-11-25T16:00:23Z

On Sat, 2019-11-23 at 23:49 -0800, Doug Smythies wrote:
> ...
> Kernel 5.4-rc8 + revert, intel_cpufreq/schedutil: 3899 seconds
> Kernel 5.4-rc8 + gg 6 + revert, intel_cpufreq/schedutil: 2740.7 seconds
> Ratio: 0.70 (as expected)
> Kernel 5.4-rc8, intel_cpufreq/schedutil: 2334.7 seconds (faster than expected)
> Kernel 5.4-rc8 + gg 6 patch set, intel_cpufreq/schedutil: 2275.0 seconds (faster than expected)
> Ratio: 0.97 (not as expected)
> Kernel 5.4-rc8, intel_cpufreq/performance: 2215.3 seconds
> Kernel 5.4-rc8, intel_cpufreq/ondemand: 3286.3 seconds
> Re-stated from previous e-mail:
> Kernel 5.3-rc8, intel_cpufreq/schedutil: ratio: 0.69 (I don't have the original times)

Hello Doug,

schedutil in 5.4 going a lot faster than in 5.3 would be a surprise. I'm
running that same test too to check if I can see it as well.

Besides, as it's already been said this patchset adds frequency
scale-invariance to scheduler metrics such as load and utilization and that's
useful also in areas other than frequency scaling (most notably the scheduler
load balancer).

Thanks,
Giovanni