[ltp] Re: CPUFreq

[Daniel Pittman]

On 27 Aug 2004, T. Ivarsson wrote:
> ----- Original Message -----
> Didrik Pinte <pinted@tiscali.be>
>
>> You need to 
>> - load the cpufreq modules (not only the cpufreq module)
>> - or compile them in the kernel
>>
>> and install a cpufreq controller such as cpufreqd or powernowd (I'm
>> using powernowd).
>
> I've been trying to ger CPUFreq and powernowd to work...
>
> + powernowd requires the file:
> /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor
> (I have the sysfs establihed in /etc/fstab)
> + To have that file I need CPUFreq enabled in the kernel
> + Even though I have CPUFreq enabled (and the related settings), I do not have
> 	the ./cpufreq directory when I use APM. When I use ACPI I have the
> 	directory.

That will be the ACPI 'P-state' support in the CPUFreq system, then.

> The Debian page about the powernowd says that it "does not depend on
> APM or ACPI". My question is: can I not use CPUFreq (and some deamon
> e.g. powernowd) when I'm running APM, or must I use ACPI?

That depends a bit on your hardware.  I use the 'speedstep' CPUFreq
support, which does not depend on APM or ACPI to function.

Either you have not loaded the right speedstep module[1], or your
hardware does not (or is not) support the right magic.

I would try loading the various CPUFreq speedstep modules first, though,
and see if any of those add the right magic.

         Daniel

Footnotes: 
[1]  I believe there is standard speedstep, which my P4M has, and
     "Enhanced SpeedStep" which Centrino chipsets support.

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