cpu throttling powernow-k8 and acpi in kernel

cpu throttling powernow-k8 and acpi in kernel

[Georg Schild]

Hi guys!

I have an acer aspire 1501 lmi with amd64 @3000+. i am running a gentoo 
64bit dist with vanilla 2.6.10 kernel on it.

i encounter some problems with the speed throttling of the cpu. this 
kind of cpu has 3 steps which a gouvernor can reach, 1800, 1600 and 
800Mhz. i am using the ondemand gouvernor. so far this works quite good, 
ondemand puts it at 800 until i do something. as it should be. i have 
also CONFIG_ACPI_PROCESSOR=y and CONFIG_ACPI_THERMAL=y enabled. when 
acpi thinks the temperature is too high (95° for cpu) it throttles the 
cpu down to 800Mhz, no care what ondemand tells it. okay, why not, is a 
good protection for overheating. but i don't think the cpu has 95°, i 
have run the laptop much hotter once, and there was no downthrottling. 
it cannot be that i am not able to compile a simple package without 
getting a critical temperature. i am watching the temps in gkrellm and 
this leads me to the thing that there is something wrong with it cause 
it jumps a bit when the temps are getting higher and one thing more, 
when the laptop is doing nothing, e.g. over night, screen is off, cpu is 
at 800 the temp is still at about 55° and more, how can that be? but i 
cannot disable the two acpi-options mentionend above. at first the cpu 
runs at 800, no problem, fan is almost off. but when i start e.g. a 
compilation first the fan starts spinning up a bit, the cpu goes to 
1800mhz but after a while the fan gives all the speed it is able to, 
much noise, and after one or 2 minutes the laptop switches off immediate.

Has anyone any idea on this? a tipp or something? i hope i did not 
forget any information.

Regards and keep on the good work

Georg Schild

Re: cpu throttling powernow-k8 and acpi in kernel

[Guennadi Liakhovetski]

On Sun, 2 Jan 2005, Georg Schild wrote:

> I have an acer aspire 1501 lmi with amd64 @3000+. i am running a gentoo 64bit
> dist with vanilla 2.6.10 kernel on it.
> 
> i encounter some problems with the speed throttling of the cpu. this kind of

skipped...

Try writing to sensors@stimpy.netroedge.com. I had a CPU-throttling 
problem, when the CPU got throttled down without really getting hot - I 
just had wrongly configured /etc/sensors.conf. Might be your problem too?

HTH
Guennadi
---
Guennadi Liakhovetski

Re: cpu throttling powernow-k8 and acpi in kernel

[Georg Schild]

> skipped...
> 
> Try writing to sensors@stimpy.netroedge.com. I had a CPU-throttling 
> problem, when the CPU got throttled down without really getting hot - I 
> just had wrongly configured /etc/sensors.conf. Might be your problem too?

Would be happy if it were the sensors but i am not using them, a least 
not the ones lm-sensors can use. My temperature is shown via ACPI 
Thermal zone of the processor driver. Afaik ACPI does also regulate the 
fan-speed so it doesn't work proper without acpi-processor driver as 
mentionend in the first post. so i don't think that the different 
sensors in i2c have to do something with it. But thanks for response, 
good to know that others have similar problems, even if they are not the 
same ;) Anyone else an idea how to tell acpi that it has perhaps wrong 
values?. I remember that when i first used this laptop with linux the 
fan went off after some time but now the fan doesn't go off, at least i 
don't recognize it. this is just because acpi has too high temps and 
lets the fan cool down the cpu because of that (at least acpi thinks so 
;)). Thanks for every help


Georg Schild

Re: cpu throttling powernow-k8 and acpi in kernel

[Pavel Machek]

Hi!

> I have an acer aspire 1501 lmi with amd64 @3000+. i am running a 
> gentoo 64bit dist with vanilla 2.6.10 kernel on it.
> 
> i encounter some problems with the speed throttling of the cpu. this 
> kind of cpu has 3 steps which a gouvernor can reach, 1800, 1600 and 
> 800Mhz. i am using the ondemand gouvernor. so far this works quite 
> good, ondemand puts it at 800 until i do something. as it should be. 
> i have also CONFIG_ACPI_PROCESSOR=y and CONFIG_ACPI_THERMAL=y 
> enabled. when acpi thinks the temperature is too high (95 for cpu) 
> it throttles the cpu down to 800Mhz, no care what ondemand tells it. 
> okay, why not, is a good protection for overheating. but i don't 
> think the cpu has 95, i have run the laptop much hotter once, and 
> there was no downthrottling. it cannot be that i am not able to 
> compile a simple package without getting a critical temperature. i am 
> watching the temps in gkrellm and this leads me to the thing that 
> there is something wrong with it cause it jumps a bit when the temps 
> are getting higher and one thing more, when the laptop is doing 
> nothing, e.g. over night, screen is off, cpu is at 800 the temp is 
> still at about 55 and more, how can that be? but i cannot disable 
> the two acpi-options mentionend above. at first the cpu runs at 800, 
> no problem, fan is almost off. but when i start e.g. a compilation 
> first the fan starts spinning up a bit, the cpu goes to 1800mhz but 
> after a while the fan gives all the speed it is able to, much noise, 
> and after one or 2 minutes the laptop switches off immediate.
> 

It seems your machine indeed is overheating. Modern cpus produce a lot
of heat.

55C idle temperature seems okay. Open machine and attach your
own temperature sensor to cpu to verify...
				Pavel
-- 
64 bytes from 195.113.31.123: icmp_seq=28 ttl=51 time=448769.1 ms         

Re: cpu throttling powernow-k8 and acpi in kernel

[Georg Schild]

> It seems your machine indeed is overheating. Modern cpus produce a lot
> of heat.
> 
> 55C idle temperature seems okay. Open machine and attach your
> own temperature sensor to cpu to verify...
> 				Pavel

I have found this out on my own now, indeed the cpu was overheating, 
there was dust or something in the fans way outside, when i blew into 
the laptop the fan got much more silent and the temp went down. works 
now quite good ;)

Re: cpu throttling powernow-k8 and acpi in kernel

[Georg Schild]

Georg Schild wrote:
> Hi guys!
> 
> I have an acer aspire 1501 lmi with amd64 @3000+. i am running a gentoo 
> 64bit dist with vanilla 2.6.10 kernel on it.
> 
> i encounter some problems with the speed throttling of the cpu. this 

Just for telling you what has caused my cpu to spin down all the time. 
it looks like the acpi was right to tell me that the laptop got very 
hot, i just didn't notice cause the air out of the laptop wasn't hot, 
this was because some dust was somewhere in the fan/heatpipe which 
caused the machine to overheat. now i know a bit more, acpi was right in 
throttling the cpu, thank god for acpi ;)

cya and keep on the good work

Georg Schild