Re: Strange entries in /proc/acpi/thermal_zone for Thinkpad X60

Robert Hancock
2006-10-13T03:59:35Z

Jeremy Fitzhardinge wrote:
> I have a Thinkpad X60 with an Intel Core Duo T2400. In
> /proc/acpi/thermal_zone, I'm getting two subdirectories, each with their
> own set of files:
>

So your machine has two thermal zones..

> The interesting thing is that the two sets of files are not consistent -
> sometimes they don't even show the same temperature.

I would expect they wouldn't, otherwise there would be no reason for the
BIOS people to set up two thermal zones..

>
> The reason I'm interested in this is that I think it's behind some of my
> cpufreq problems. Sometimes the kernel decides that I just can't raise
> the max frequency above 1GHz, because its been thermally limited (I've
> put printks in to confirm that its the ACPI thermal limit on the policy
> notifier chain which is limiting the max speed). It seems to me that
> having a thermal zone for each core is a BIOS bug, since they're really
> the same chip, but the THM1 entries should be ignored. I don't believe

How do you know they are one for each core? ACPI thermal zones can be
anywhere in the machine that needs OS-controlled cooling. Could be the
CPU heatsink, voltage regulator, or someplace else.

> the CPU has ever approached either 97 C, let alone 127; while I put it
> under a fair amount of load, it is sitting on a desktop with no airflow
> obstructions, so if it really is overheating it suggests a serious
> design problem with the hardware.
>
> But I'm just speculating; I'm not really sure what all this means. Any
> clues?

I think we need more information to decide what is going on here.. what
temperatures are registering in the thermal zones when the CPU clock is
being limited?

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Robert Hancock Saskatoon, SK, Canada
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