[plug] APM and kapm-idled

[Jason Nicholls]

Hello People,

Since switching to kernel 2.4.x i've been able to see the kapm-idled (kernel
idle thread) take up CPU time when the box is not very active or not active at
all. BTW, this is how it was supposed to work.

To get this going you need to compile in APM support and "Make CPU Idle calls
when idle". It's supposed to help in 2 ways, reduced power usage (maybe) and
reduce heat generated. ie: overall cooler CPU.

When I upgraded to 2.4.14 from 2.4.12 I noticed no kapm-idled was always at 
0% of CPU time. Is this the experience of others on the list? As a
result my CPU was running a couple degrees hotter - as if it was fully loaded
all the time.


Yes I read the kernel mailing list since the introduction of 2.4.13 (APM
changes occured in that release) but no one has mentioned anything. There was
one interesting thread that talked about something called LVCool:

	http://www.naggelgames.de/vcool/VCool.html
	NOTE: ONLY for Athlon/Duron and mainly KT133 chipset

I certainly recommend you have a read before using it, but for me my CPU is
now OVER 10 degrees C cooler. There are side effects though but since you can
run it as a user-space program it's easy to turn off. BTW, I haven't had any
corruption of data or lockups, by side effects I'm talking about reduced
system bus performance. eg: my IDE performance drops in half if the system
isn't loaded. With a loaded system the idle thread (or user space program)
doesn't run and you get full performance...

If you don't believe me, have a look at my sensors data:

	SYS Temp:  +27.5°C  (limit =  +45°C, hysteresis =  +40°C) 
	CPU Temp:  +29.7°C  (limit =  +70°C, hysteresis =  +60°C) 

Previously my CPU Temp: would have been around 40-42. Later on in the
afternoon with the sun on my window it'd get up to 45/46.



Later!

Jason Nicholls
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Jason Nicholls    icq: 11745841    email: <jason at mindsocket.com.au>
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