[Bug 219213] powerd causing problems with ryzen

bugzilla-noreply at freebsd.org bugzilla-noreply at freebsd.org
Sat Aug 19 09:32:06 UTC 2017


mailsed at yahoo.co.jp changed:

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--- Comment #6 from mailsed at yahoo.co.jp ---
Created attachment 185570
  --> https://bugs.freebsd.org/bugzilla/attachment.cgi?id=185570&action=edit
x86/cpufreq/hwpstate.c patch for powerd++ (not tested)


I think Ryzen has so many cores that the frequency to change must be various.
But, x86/cpufreq/hwpstate.c is written as a module that changes only one
frequency for ALL cores such like "sysctl dev.cpu.0.freq=XXXX".
So the sysctl nodes from dev.cpu.1.freq to dev.cpu.15.freq, when it has 16 CPU
threads, are not be generated and estimated as the same as dev.cpu.0.freq.
So, I made this patch (removed some of the lines of hwpstate.c). This patch
will generate the nodes from dev.cpu.1.freq to dev.cpu.15.freq, if it has 16
CPU's for example, and you can set each CPU's frequency as different from
I think powerd++(sysutils/powerdxx) is requiring such situation that setting
each CPU's frequency as possibly different frequencies from others.
Though I didn't tested, I don't have Ryzen, but It will be compiled.
I think this patch is not enough. Because 8 core 16 thread is a problem, If the
same core but different thread and frequency, what will be occurred?
so, the cpufreq of different thread but same core, will be treated in
kern_cpu.c. But I'm not sure what to do, sorry for that. Disabling the SMT in
BIOS is one workaround. I hope so.

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