Software CPU cooling - apm / acpi
I would like to cool my CPU in the same way CPUIdle does it under
windows : using the Hlt instruction when the CPU is idle. As far as I
know, it's possible to achieve this under linux with apm or acpi, but I
have never succeded.
I am running a Debian unstable, kernel 2.4.19-k7 (binary package) with
an Athlon XP 1700+ on a MSI K7T266 Pro2.
I first tried with apm, loading the module with the following options:
apm power_off=1 idle_threshold=90
This seems to work fine for the poweroff function, but that's all. I was
expecting to see a process "kapm_idle" running, but it never happened.
And looking at the sources of apm, I came across this:
* 1.16: Fix idle calling. (Andreas Steinmetz <email@example.com> et al.)
* Notify listeners of standby or suspend events before notifying
* drivers. Return EBUSY to ioctl() if suspend is rejected.
* Daemonize now gets rid of our controlling terminal (sfr).
* CONFIG_APM_CPU_IDLE now just affects the default value of
* idle_threshold (sfr).
* Change name of kernel apm daemon (as it no longer idles) (sfr).
So it seems that apm no longer idles: how can I do it then?
I also tried with acpi. Here, I have no clues of how to make idle calls
to the processor. The acpi modules can be found in
From what I have read, ospm_processor.o seems to be the one I need, but
if I simply load it, nothing happens... I didn't find any documentation
about these modules (and I don't know what parameters they can take).
Thank you very much if you can help with this problem!
My CPU is more than 20°C over the motherboard's temperature when I run
linux (that is 60°C, sometimes 65°), while it's only 3/4°C under windows
and a software cooler (dropping to 35/40°C)! And I can't afford to
change my CPU Cooler just now...