CPU Overheating Problem When Running 4 CPU Intensive Threads with Latest Untained Kernel

[Oleg Goldshmidt]

Shlomi Fish <shlomif at gmail.com> writes:

> I'm getting many high temperatures in the log:
>
> coretemp-isa-0000
> Adapter: ISA adapter
> Physical id 0:  +98.0°C  (high = +82.0°C, crit = +102.0°C)
> Core 0:         +98.0°C  (high = +82.0°C, crit = +102.0°C)
> Core 1:         +97.0°C  (high = +82.0°C, crit = +102.0°C)
>
> They eventually are dropped but it's still alarming.
>
> My questions are:
>
> 1. Is this a problem with the kernel? (Muli? Anyone? Can you comment?)

You can either wait for Muli's authoritative response about the kernel
or run a test with a signficantly different kernel version yourself. It
is reasonable to assume that if the kernel were to blame for CPU
overheating for *any* reason at all it would have been noticed by people
in any version that is more than a month old. So if your cutting edge
3.15.0-rc5 runs hot and some reasonably stable kernel (preferably
distro-compiled and not self-compiled to avoid Kconfig weirdness on your
end) doesn't you may start to suspect something.
 
If you do get suspicious run your test (with both kernels) on a
different computer - convince someone to boot off your USB or
something. Then you may decide to report that 3.15.0-rc5 with a given
configuration seems to act weirdly on more than one system. If it does,
of course.
 
In general, I wouldn't blame the kernel too soon. You do not provide any
information on your computer's cooling facilities, form factor,
enclosure type or brand, or, indeed, provenance (brand name?
self-specced and self-assembled? overclocked by an unscrupulous
neighbourhood computer shop without your knowledge?  etc.). Could it be
that its cooling is insufficient at high load? Have you verified that
all your fans work fine?  Is air flow good enough (you won't know, but
[some] big brands are more likely to design for that)? Does anything
(from dust to a wall that is too close) clog or block ventilation holes?
Are the sensors correcty located, well calibrated, and working properly?

As an additional wild hand-waving, does anything change if you switch
hyperthreading off in the BIOS?

-- 
Oleg Goldshmidt | pub at goldshmidt.org