AMD Zen/Zen2 RAPL Support Merged In Linux 5.8
Written by Michael Larabel in AMD on 3 June 2020 at 07:25 PM EDT. Add A Comment
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Complementing the new AMD Energy Driver in the hwmon subsystem for Linux 5.8 to provide per-socket/core reporting, the Linux perf subsystem in this new kernel version has run-time average power limiting (RAPL) framework integration for AMD Zen/Zen2 CPUs.

This Zen RAPL integration is what a Google engineer posted last month for integrating in the current-gen AMD processor power data into the RAPL framework, including exposing this information via the PowerCap sysfs interface and perf tool.

This RAPL code within the Linux kernel was led by Intel years ago when they added it for their processors. An example usage of the AMD RAPL usage with Linux 5.8 is perf stat -a --per-socket -I 1000 -e power/energy-pkg/ with energy-pkg being the only supported AMD event at this point.

This AMD Family 17h RAPL support was sent in via the perf updates for Linux 5.8 that have now been merged. This perf update also includes Zhaoxin CPU support for the perf subsystem and various perf tool updates.
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