Linux 6.8 Perf Tools Add Support For AMD Zen 4 Memory Controller Events

The tooling changes around the perf subsystem have been submitted for the Linux 6.8 kernel merge window and provide some new hardware features and other new perf profiling capabilities.

The perf tool changes with Linux 6.8 allow associating samples that identify loads and stores with particular data structures, initialization speed-ups for the perf tools, various bug fixes, and updated Intel platform support. The Intel support includes adding support for UPI bandwidth metrics on Skylake-X / Cascade Lake / Ice Lake / Sapphire Rapids processors as well as updating the perf events for Sapphire Rapids and Emerald Rapids. Plus some Alder Lake and Rocket Lake metric fixes too.

On the AMD side the perf tool changes include now supporting AMD Zen 4 memory controller events. The AMD Zen 4 unified memory controller (UMC) events are now supported for these Ryzen 7000 and EPYC 8004/9004 series processors. There are AMD Zen 4 UMC events for the number of memory clock cycles, number of CAS commands sent / read, number of clocks used by the data bus, memory controller data bus utilization, and other common memory events.

The full list of perf tool feature changes on their way to the Linux 6.8 kernel can be found via this pull request.