AMD P-State Preferred Core Support Coming With Linux 6.9

Since last August AMD Linux engineers have been working on P-State Preferred Core support for the "amd_pstate" driver so that this functionality can be leveraged under Linux for improved task placement.

Since Zen 2 there has been the notion of "preferred cores" that are expressed via ACPI CPPC for CPU cores that are capable of reaching a higher maximum frequency or should otherwise be treated as preferred cores for the placement of high priority (important) tasks. Especially now with some AMD CPUs having a mix of Zen 4 and Zen 4C cores, AMD P-State Preferred Core is all the more important for ensuring intended behavior and the most important processes wind up on the best performing CPU cores.

Since then AMD has continued working on the Preferred Core Linux patches and over the past few months has revised them 13+ times.

That work has paid off and AMD P-State Preferred Core support will now be introduced in the next kernel cycle. Linux power management subsystem maintainer Rafael Wysocki announced that he's queued AMD's v14 patches into his power management "-next" tree ahead of Linux 6.9.

So with the Linux 6.9 kernel in a few months AMD P-State Preferred Core support will be there and enabled by default for modern Ryzen systems that are defaulting to use the AMD P-State CPU frequency scaling driver. Fresh benchmarks soon on Phoronix.