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Re: How does one control fans?



Frank said...
> > I noticed that a lot of folk use
> > # modprobe cpufreq_userspace
> > so I loaded that, which at least stops the fan from time to time,
> > although I have no idea what it does! (Despite goggling for a while...)
> > That said, it seemed to have created the /proc/acpi/processor/ chain.
> >
> > Which modules and packages are the "best" too use, or to start with?
> 
> I would rather use the direct kernel functions to control the frequency (as 
> opposed to using the cpufreq_userspace and a userspace program). That means 
> you should for example 
> # modprobe cpufreq_ondemand 

Yes, now I understand the mechanism, that's my plan.
 
> and tell the kernel to use the ondemand governor for frequency scaling:
> # echo "ondemand" > /sys/devices/system/cpu/cpu0/cpufreq/scaling_governor

My problem is that /cpufreq/scaling_governor doesn't appear until after 
I do:
# modprobe acpi_cpufreq
Is that correct?

> (you will have to do that every time you boot, so add a script to your 
> runlevel)

What? And miss out on all that typing?
 
> The only disadvantage of the direct kernel method is, that you won't be able 
> to scale the frequency according to battery/AC-adapter status, which some of 
> the userspace programs will.

That's okay. The recommendation in the kernel config notes is to use 
'conservative' as the battery-alternative to 'ondemand', so I'll use a 
script to make the change, as necessary.

> Hope that helps a bit, feel free to ask further questions.

It helps a lot. Thanks to all for all the assistance and suggestions.

-- 
Best,
Marc



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