Re: [PATCH V3 0/4] cpufreq: cppc: Add support for frequency invariance

On 6/24/2021 6:48 AM, Ionela Voinescu wrote: 

Not if the counters are implemented properly. The kernel considers that
both reference and delivered performance counters should stop or reset
during idle. The kernel would not account for idle itself.

If the reference performance counter does not stop during idle, while
the core performance counter (delivered) does stop, the behavior above
should be seen very often.

Qian, do you see these small delivered performance values often or
seldom?

FYI, the latest data point it that on the new kernel, the delivered performance does match the cpufreq_cur_freq. IOW, feedback_ctrs works fine. Also, "powersave" governor could bring down the scaling_cur_freq to scaling_min_freq. Right now, looks like the puzzles on this particular system as mentioned in the previous post are,

1) lowest_freq/lowest_perf != scaling_min_freq
2) CPPC + schedutil is not able to scale down CPUs.