[RFC] Patch to enable temperature ceiling in powerd

[Johannes Dieterich]

Hello everybody!

To get back to this discussion (sorry, normal job kicked me quite a bit
last week).

Peter Jeremy wrote:
> On Wed, Feb 20, 2008 at 05:06:41PM -0500, Daniel Eischen wrote:
>> I'm having similar problems with an Intel STL2 Tupelo motherboard
>> after upgrading to 7.0.
> 
> I had problems with one TZ on my laptop occasionally reporting
> nonsense values.  I suspect it was actually a dry joint somewhere near
> the sensor.  The MB eventually failed and the new MB is OK.  We had a
> similar issue on a server at work - the vendor noticed that the system
> was reporting an abnormally high temperature in one zone whilst
> investigating an unrelated problem.  We eventually decided it was a
> faulty sensor and a replacement board fixed it.
What I have now is the original hard drive (some 80 gig Fujitsu one)
with a freshly installed Fedora 8 on it. I have been letting two
instances of gnuchess playing against each other for a couple of hours
(yes, I know... best stress test ever... ;-) ) which kept cpu usage at a
nice 100 percent on both cores for all that time.
proc/acpi/thermal_zones/THM1/temperature (and THM0) reported
temperatures around 70 degrees, never over 72 for all that time. Lid was
closed, fan worked (not very noisy even) and blew a good load of hot air
out. I am tempted to say that my overheating problem is not hardware
related. Only parts different were ath0 not working with Fedora and hard
drive being not the 160 gig WD I am using for FreeBSD.

> 
>>  Only under load does the temperature
>> shoot up, but I know the chip isn't getting hot and the fan
>> is running - I've felt around in there and nothing was even
>> close to the 117+C it was sensing.
> 
> Apart from the actual CPU, most parts of a system have a fairly
> significant thermal mass so a rapid change in temperature either
> indicates a catastrophic failure or the temperature sensor isn't
> really reporting the temperature of the relevant zone.
> 
I totally agree with you, Peter. And either the hardware just fails
under FreeBSD  (or with ath0 and the other hard drive running) OR it is
a FreeBSD problem.

Everybody is invited to tell me how to stress test the system as brutal
as possible to show that the problem is hardware related.

Regards,

Johannes