[ltp] odd cpu spikes

Takis Diakoumis linux-thinkpad@linux-thinkpad.org
Thu, 12 Jul 2007 22:09:29 +1000


Hi

i have only just noticed that the cpu on my R52 jumps from less than
800MHz to 1800+MHz every 1-2 seconds. i have tried to trace back recent
package updates and selectively downgraded them (running debian testing)
to figure out what may be causing it. this hasn't worked. i also tried
to selectively remove services on startup and also kernel modules. i'm
no closer to figuring it out. 

i have also looked at running processes and tried using powertop for
some hints. i placed a script to record cpu freqs every couple of
seconds after it boots and before my window manager takes over. again,
no luck.

i'm running kernel v2.6.21.6 with the ondemand scaling governor. this
has only recently started to happen - previously (as far as i could
tell) it was fine and working as expected. 

is there any way i can trace those spikes to a specific process or
similar?? 

any suggestions would be most appreciated.

thanks
Takis