AMD P-State Support Coming For The CPUPower Tool
With the forthcoming Linux 5.17 kernel there is the new AMD P-State driver aiming to provide better power efficiency than the ACPI CPUFreq driver that has long been used on AMD platforms. For complementing that AMD P-State driver, AMD has also been working on adding their CPU P-State support to Linux's cpupower tool.
The Linux cpupower tool is used for showing and setting various processor-related values. CPUPower can be used for examining the power-related behavior of the processor and also controlling various CPUFreq tunables. Currently the CPUPower tool doesn't have knowledge of the AMD performance states exposed via ACPI CPPC with Zen 2 and newer, but AMD has been working to change that.
Sent out today were the latest patches wiring up AMD P-State support within the CPUPower tool.
This support allows making use of the finer-grained AMD P-State features rather than legacy ACPI P-States, support for reading the AMD P-State kernel driver's sysfs data, displaying the P-State information, and more.
CPUPower lives within the Linux kernel source tree and hopefully this AMD P-State support will be buttoned up in time for the v5.18 cycle. This cpupower support is for convenience and not necessary for the AMD P-State kernel driver to properly behave, etc. I'll have up some fresh AMD P-State benchmarks from Linux 5.17 shortly on Phoronix.