[ltp] Temperature increase after S2Ram

Paul Bolle linux-thinkpad@linux-thinkpad.org
Sun, 07 Jul 2013 01:03:59 +0200

On Sat, 2013-07-06 at 23:39 +0200, Paul Bolle wrote:
> 0) It seems I'm running into a similar issue but on a X61. On an
> uninteresting Gnome 3 session, running roughly 99% idle, the CPU
> temperature usually stays below 50 C. But after a few suspend and resume
> cycles, still on an equally undemanding, session the CPU temperature
> rises a bit above 60 C.
> 1) The rather course test
>     watch "cat /proc/cpuinfo | grep MHz"
> suggests that at this moment the second (of two) cores is stuck at 2 GHz
> (which I guess is full throttle). Could that be causing this?

Somehow, taking that second core offline and online again, through
the /sys/devices/system/cpu/cpu1/online interface, stops it running at
full throttle. After that a mostly idle system will have both cores
running at 800 MHz (the lower bound, apparently) most of the time. CPU
temperature then remains below 50 C again.

Paul Bolle