On Thu, 31 Jul 2003 23:53:54 +0200, Ricardo Galli wrote:
> I have some doubts regarding cpufreq for SMP systems (for developing
> http://mnm.uib.es/~gallir/cpudyn/).
>
> If I remember well, I read a while ago that cpufreq didn't work in SMP
> systems, but reading the docs and kernel/cpufreq.c, it seems there should be
> any problem?
>
> Is it true?
>
> OTH, I trying it on a P4 HT, and it works, changes in the frequency of one of
> the "cpu's", changes both.
That makes sense, since the CPU only has one clock.
> What happens in the case of several real cpu's? Does it keep the same
> frequency for every cpu? According to a comment in cpufreq.c, it seems that
> each cpu might have different frequencies.
AFAIK no SMP systems have voltage/frequency scaling (SpeedStep/PowerNow).
I've heard that ACPI P-states works on SMP, but if it's not doing
voltage/frequency scaling then I don't know what it's doing.
Wes Felter - wesley@felter.org - http://felter.org/wesley/
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Thu Aug 07 2003 - 22:00:17 EST