Intel Sends Out Linux Patches For Speed Select Core-Power Controls

Coming to Linux last year with the 5.3 kernel was Intel Speed Select Technology support as a Cascade Lake feature for optimizing the per-core performance configurations to favor certain cores at the cost of reducing the performance capacity for other CPU cores. That Intel Speed Select (SST) support for Linux is now being enhanced with core-power controls.

Speed Select Core-Power (SST-CP) has been one of the features of Intel SST to begin with for allowing users to define per-core priorities when encountering power constraints. Intel SST to date has supported the performance profile and base/turbo frequency knobs while this SST-CP support is on the way and currently available in patch form.

There are 5 patches adding the Intel SST-CP support with new mailbox commands necessary kernel-side while the other work is to the intel-speed-select user-space tool. Intel-speed-select is the user-space tool for manipulating the SST behavior and is developed in-tree with the Linux kernel, similar to turbostat and other select utilities.