[arch-general] Laptop overheating causes decreased CPU performance until reboot (even after cooling)

[Anish Shankar]

Hi,
I have a dell 1564 laptop with an i5-M430 cpu, running arch linux. For a
long while now I've had issues with very degraded CPU performance if my cpu
temperature is very hot till around ~95 degree Celsius. The problem is that
the degraded cpu performance stays inspite of cooling down back to 60
degrees, and even multiple suspend-resume cycles. The only way to reset the
same is a reboot. I can't seem to track down the cause of this. The cpu
frequency etc. look normal, all 4 vitual-cpu's are active from cpuinfo.

top reports nearly 5x increased % cpu usage for process compared to what
they normally use. Some simple CPU benchmarks (N-Queens) also take
approximately 5 times longer.

I'm using kernel: 3.14.6-1-ARCH 64bit

Can you suggest some ways to track down this issue? or alternatively a way
to reset this so that I don't need to reboot to restore performance. The
issue is reproducable (I just need to use the CPU at max, for a while to
overheat  it), so I can provide any logs etc. if it will help to find the
cause. I also previously posted with some more details on
https://bbs.archlinux.org/viewtopic.php?id=183236 without any response.