Jason, I thought I'd try hwp on a SapphireRapids system, and of course - short of easy other ways of seeing whether it actually has any apparent effect - I've looked at "xenpm get-cpufreq-states" output. Just to find that according to this, the system never enters any of the designated Pn states (all CPUs are always claimed to be in P0), while at the same time the P0 residencies remain in the hundreds of milliseconds. The latter suggests CPUs do leave P0, yet it's then unclear what state they are in during such time periods.
I was also a little puzzled when comparing "xenpm get-cpufreq-para" output with hwp against that with acpi-cpufreq: The latter lists a range of 800MHz ... 2501MHz, while with hwp base is 2500MHz and max is 4800MHz. Do you have any explanation for these apparent anomalies? Thanks, Jan
