Re: acpi_processor.c - kernel 2.6.1

["Yury V. Umanets" <umka-nJ1KrdHEGnBBDgjK7y7TUQ@public.gmane.org>]

On Sun, 2004-01-18 at 02:43, christian graf wrote:
> Hi,
Hello,
> 
> reading the /usr/src/linux-2.6.1/drivers/acpi/processor.c
> i thought the kernel should set the state dynamically, based on the
> load. Maybe it is possible to set the processor-state of my centrino
> manually. Can please anybody tell me how to get it right?
> 

There is an user-space daemon, which adjusts CPU speed basing on current
loading. And it is able to change CPU frequency if userspace cpufreq
governor is turned on. I would like to see this functionality in kernel
though.

> The reason I'm asking is, that once I do load the processor.ko module,
> my Centrino switches immediately into C2-state. It never switches back
> to C1 state, even under heavy load like compiling the kernel.
> 
I guess, that there is no code in kernel, which does watch current
loading and adjust CPU speed. Also this is job for a cpufreq governor,
not for CPU driver. 

For now, there are three governors:
(1) powersave -- setting CPU frequency statically to lowest available
frequency.
(2) performance -- setting to highest available frequency.
(3) userspace -- used for setting CPU frequency manually.

Probably there also should be number (4), which will set it basing on
current loading.
> I think the kernel should switch back from C2 to C1 state from alone????
> 
> Please ask me whatever you need to help me swtiching back into C1 state.
> 
> christian

-- 
umka



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