ACPI - Dynamic CPU throttling

[MeMo_oMeM]

Hi! I am in deep trouble My Kubuntu 5.10 extremely slowed down , and I figured out that the problem is the wrong behaviour of dynamic CPU throttling. It always goes down to 13% of the CPU speed (in other words, it is reduced by 87%), no matter what I try.

I tried to set it up manually using:

echo 0 > /proc/acpi/processor/CPU0/throttling

and it worked... Well, just for a couple of seconds only!!!! It goes back to %13 soon.

Feeling desperate, I wrote a C code that updates the /proc/acpi/processor/CPU0/throttling every second in an infinite loop. But I have to run it as root everytime I boot linux, and I hate temporary solutions.

I am nervous because I spent days to setup the linux in my dreams. I don't want to trash it all just because this stupid problem. Besides, I make a lot of performance tests and I must be sure that I always use 100% of the CPU.

PLEASE HELP!!

Thanks in advance.

PS: I use Kubuntu (Breezy), kernel 2.6.12-9-686 on a Sony Vaio PCG-K25 laptop.

[incinerator]

Re: ACPI - Dynamic CPU throttling

You should not worry to much. In case an applications requires more performance, the os will automatically raise the cpu frequency as necessary.

On the other hand, coud could reconfigure KLaptop in order to activate other power-saving presets, e.g. when the box is connected to the AC adapter. See that little icon with a battery symbol (power connector symbol in case AC is plugged in) on the lower right corner of your desktop? Right-Click on it and then you can either directly choose a certain power profile or you can do "reconfigure KLaptop" and choose default profiles as you see fit.

In case of a laptop with AMD cpu, modifying that proc file won't help much, as frequency scaling is done by powernowd, a demon run from userspace. I don't know exactly how it works with Intel CPU laptops, though.

[MeMo_oMeM]

Re: ACPI - Dynamic CPU throttling

Thanks a lot for your reply incinerator!

Well, the problem is, klaptop, or the acpi module can not detect the battery. The indicator shows "Plugged-in, no battery". And Klaptop can not raise the CPU frequency, and it is always 87% (lowest possible). Choosing different default profiles doesn't change anything. Even typing becomes a problem and my P-IV works like a 486 until i run my little C program to keep the frequency up.

I'd like to turn Klaptop off completely, I don't care about battery saving anymore!! But I couldn't do that either...

Thanks in advance

MeMo

[MeMo_oMeM]

Re: ACPI - Dynamic CPU throttling

Problem Solved!

Hint for the people having the same problem: Try resetting your CMOS (Find a small reset hole /// find the option to reset BIOS back to to factory values /// unplug your laptop and take the battery out and leave it like that for a couple of hours /// ... )

When I switched to windows I realized that it is slow too. (I didn't use windows for maybe a week, so it took me long to figure this out) The Vaio Power Managment, which is provided by Sony, messed up everything. I don't have the time and energy to make a complaint to Sony people, I am just dissapointed about their driver & software support again and again.

BTW, Thanks again for the help incinerator!

MeMo

[incinerator]

Re: ACPI - Dynamic CPU throttling

You're welcome. Btw, maybe a BIOS update could help...