News: 0001509576

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AMD Per-Core Energy Counter Support Slated For Linux 6.14

([AMD] 2 Hours Ago Per-Core Energy Monitoring)


While the [1]Linux 6.13 merge window just closed yesterday in landing all of the new features and functionality for that first kernel version of 2025, already for the Linux 6.14 kernel cycle to follow a feature was queued up early this morning in a TIP branch: AMD per-core energy counter support.

The past few months AMD Linux engineers have been working on per-core energy counter support under the Linux Runtime Average Power Limiting (RAPL) infrastructure. After going through [2]the v7 patches , they are now ready for the mainline Linux kernel once Linux 6.14 rolls around with its merge window in late January / early February.

The AMD per-core energy counter patch series explains:

"Currently the energy-cores event in the power PMU aggregates energy consumption data at a package level. On the other hand the core energy RAPL counter in AMD CPUs has a core scope (which means the energy consumption is recorded separately for each core). Earlier efforts to add the core event in the power PMU had failed [1], due to the difference in the scope of these two events. Hence, there is a need for a new core scope PMU.

This patchset adds a new "power_core" PMU alongside the existing "power" PMU, which will be responsible for collecting the new "energy-core" event.

Tested the package level and core level PMU counters with workloads pinned to different CPUs."

As of this morning, the patches were picked up by the [3]tip/tip.git's perf/core branch .

With the patches now queued as part of the TIP branch and with two months to go until the Linux 6.14 cycle, it looks like the per-core energy counter support is ready to roll with that next kernel cycle. Linux 6.14 is also going to be exciting for AMD customers with [4]the AMDXDNA driver ready for inclusion in supporting the Ryzen AI NPU on the mainline Linux kernel.



[1] https://www.phoronix.com/news/Linux-6.13-rc1-Released

[2] https://lore.kernel.org/all/20241115060805.447565-1-Dhananjay.Ugwekar@amd.com/

[3] https://git.kernel.org/pub/scm/linux/kernel/git/tip/tip.git/log/?h=perf/core

[4] https://www.phoronix.com/news/AMDXDNA-DRM-Misc-Next



Mitch

Briefly stated, the findings are that when presented with an array of
data or a sequence of events in which they are instructed to discover
an underlying order, subjects show strong tendencies to perceive order
and causality in random arrays, to perceive a pattern or correlation
which seems a priori intuitively correct even when the actual correlation
in the data is counterintuitive, to jump to conclusions about the correct
hypothesis, to seek and to use only positive or confirmatory evidence, to
construe evidence liberally as confirmatory, to fail to generate or to
assess alternative hypotheses, and having thus managed to expose themselves
only to confirmatory instances, to be fallaciously confident of the validity
of their judgments (Jahoda, 1969; Einhorn and Hogarth, 1978). In the
analyzing of past events, these tendencies are exacerbated by failure to
appreciate the pitfalls of post hoc analyses.
-- A. Benjamin