hwpstate_intel cpufreq and est.

[Jesper Schmitz Mouridsen]

Hi list.

I am working on sysutils/libsysstat [1], I have maintained it over the
years.

I even have a little testprogram [2]

Recently I  got a new CPU which uses freq_driver: hwpstate_intel.

It seems to me from values from dev.cpu.X.freq that this drivers
supports different freq levels per core?

And that the BUG section in man cpufreq stating that

"When multiple CPUs offer frequency control, they cannot be set to
different levels and must all offer the same frequency settings."

Does not apply to hwpstate_intel? Is this correct. My current code relies on

this same freq on all cores bug.

[1] https://www.freshports.org/sysutils/libsysstat

[2] https://people.freebsd.org/~jsm/libsysstat-test.tar.gz

Thanks

Jesper Schmtiz Mouridsen.

[Jesper Schmitz Mouridsen]

Post by Jesper Schmitz Mouridsen
Hi list.
I am working on sysutils/libsysstat [1], I have maintained it over the
years.
I even have a little testprogram [2]
Recently I  got a new CPU which uses freq_driver: hwpstate_intel.
It seems to me from values from dev.cpu.X.freq that this drivers
supports different freq levels per core?
And that the BUG section in man cpufreq stating that
"When multiple CPUs offer frequency control, they cannot be set to
different levels and must all offer the same frequency settings."
Does not apply to hwpstate_intel? Is this correct. My current code relies on
this same freq on all cores bug.
[1] https://www.freshports.org/sysutils/libsysstat
[2] https://people.freebsd.org/~jsm/libsysstat-test.tar.gz
Thanks
Jesper Schmtiz Mouridsen.

I think I found the answer in https://reviews.freebsd.org/D30004:

Users running newer Intel(R) CPUs may find some differences in dynamic
frequency control when upgrading to FreeBSD 13.0.
A new driver for the Intel(R) Speed Shift(TM) feature set, available on
certain SKUs, exposes the ability for the hardware to dynamically vary
the core frequencies, including on a per core basis.

Post by Jesper Schmitz Mouridsen
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