Linux's x86_energy_perf_policy Utility Being Extended To AMD CPUs

For AMD Zen 2 and newer systems making use of the modern AMD P-State driver on Linux for CPU frequency scaling, ACPI Collaborative Processor Performance Control (CPPC) interface is being used. For managing the ACPI CPPC energy performance preference (EPP), Intel's x86_energy_perf_policy utility is now being extended to AMD processors.

Interacting with the AMD P-State driver via sysfs directly can be used for tuning the Energy Performance Preference and related tunables. But with a new patch series from AMD, the x86_energy_perf_policy utility started by Intel is being extended to AMD processors.

The patch series by AMD Linux engineer Perry Yuan sums it up as:

This patch series introduces support for the x86_energy_perf_policy utility on AMD processors that utilize the CPPC (Collaborative Processor Performance Control) interface for frequency scaling, using the amd_pstate driver module. AMD processors already support various Energy Performance Preference (EPP) profiles. With this utility, users can now seamlessly switch between these EPP profiles using the provided commands. And check the CPPC capabilities with this tool.

This enhancement aims to improve power efficiency and performance management for AMD processors, providing users with more control over their system's energy-performance behavior.

So with a command such as sudo x86_energy_perf_policy --hwp-epp performance the ACPI CPPC EPP preference can be set to the "performance" mode. The x86_energy_perf_policy utility can also be used for reading the per-core performance preference too.

This patch series extends the x86_energy_perf_policy support to AMD processors and is now under review.