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

[Shlomi Fish]

Hi all,

happy Lag Baomer everybody, and you may have enjoyed the game tonight.

I'm running Mageia Linux x86-64 Cauldron (= the development distribution -
what will become v5) on an Intel Core i3 machine with two cores and two
hyperthreads per core, whose SPECs are:

   - An Intel Core i3 CPU (x86-64).
   - 8 GB of RAM.
   - Intel Corporation Sandy Bridge Integrated Graphics Controller (rev 09)
   - A 2 TB hard-disk.
   - A 21" Wide LCD Screen by LG.
   - Intel Corporation Cougar Point High Definition Audio Controller.
   - Intel Corporation 82579V Gigabit Network Connection.

Now, I noticed that if I run CPU intensive tasks on it with two or more
threads, then the "sensors" program (of lm-sensors) often reports an
overheating and I get traces on virtual console 1, even if I'm using nice
-19 and ionice. Here is a demo:

with kernel:

1. 3.15.0-rc5 - built from source and untainted.

2. This program:

shlomif at telaviv1:~$ cat overheat1.bash
#!/bin/bash
cd ~/progs/freecell/git/fc-solve/fc-solve/B
sudo ionice -c3 -p$$
nice -n19 freecell-solver-multi-thread-solve 1 100000000 \
     1000 --num-workers 4 --worker-step 16 -l as -mi 1000000

shlomif at telaviv1:~$

(The executable is part of the Freecell Solver package that is available
for Debian, Mageia and other distributions. You may need to increase
--num-workers).

3. After running it inside tmux and running this:

shlomif at telaviv1:~$ cat sensors_loop.bash
#!/bin/bash
(while true ; do date +"Time=%s" ; sensors | head -5 ; sleep 5 ; done) >>
sensors.log.txt

---
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?)

2. Should I report it to bugzilla.kernel.org?

3. Is it a known problem?

Thanks for any help.

Regards,

-- Shlomi Fish
-- 
------------------------------------------
Shlomi Fish http://www.shlomifish.org/

Chuck Norris helps the gods that help themselves.

Please reply to list if it's a mailing list post - http://shlom.in/reply .
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mailman.cs.huji.ac.il/pipermail/linux-il/attachments/20140518/721400b4/attachment-0001.html>