Tip: How to "solve" laptop overheat

marcuzzi · n00b Joined: 17 Dec 2003 Posts: 5

I don't know if this solution has been ever posted here.

A solution is to use the Cap Processor Usage patch. This is a kernel patch made by Karol 'Broege' Golab which limits CPU usage for a given task.
http://www.tls-technologies.com/CPU/cpu-intro.html

You have to use the patch for the kernel 2.4.19-pre10-ac2 (with Ingo Molnar scheduler) sources. The patch has to be applied by hand and you have to do 2 things:
- insert the modified lines in the correct place
- change the syscall it uses to 253 (the first not used by gentoo-2.4.20-r7)
You can compile a new kernel with this capability, then. After that, you can limit the overheating proccess.

In my case, I have to limit my emerges to 40% CPU, otherwise my laptop hangs (I know it's crappy sh*!).

I dislike using a syscall for this. It should be somewhere in the limits module, or use the virtual filesystem to communicate with the kernel, but it works fine and I don't have time to migrate it. I also would like to integrate this in a kernel ebuild (what about a special version of emerge with absolute CPU limitations?), but I'm just a gentoo newbie.

Note that there might be other ways of solving this. I haven't search anything after finding this. If you have news about other solutions, please reply. Also, if you have problems with the patch insertion, etc.

I should post the kernel diff'ed with and without the patch applied, but I forgot to backup the original sources. If someone is interested, just let me know.

BobDylan · Posted: Wed Dec 17, 2003 1:05 pm Post subject: patch your kernel for acpi

Use acpi instead ....

marcuzzi · n00b Joined: 17 Dec 2003 Posts: 5

Easy to say, but hard to do.

My laptop is a Clevo 2700C and although acpi works ok for battery, it doesn't find any temperature sensors. Neither does lm-sensors. The chipset is Sis630 but there is no way to find and read the Sis950 chip (which should integrate the 3 temperature sensors).

Anyway, with the fan at full speed, it hangs. Also, note that as my laptop uses a Pentium III FPGA (not mobile) there is no way to slow down the CPU speed. So what can ACPI do when it overheats? I think I have to use a full soft approach like this patched scheduler. Any alternative?