Re: [REGRESSION] sudden cpu hogging in kernel 3.2 rc-series

[Maciej Rutecki <maciej.rutecki@gmail.com>]

On piątek, 18 listopada 2011 o 21:33:15 Nicolas Kalkhof wrote:
> Hello,
> 
> since the merges for kernel 3.2 came in late october, my mobile i7 2620M
> sandybridge cpu/gpu seems to run hotter (approx 10 °C) when idling and
> after some minutes according to top the cpu load goes up on all cores but
> the cpu frequency stays low (800 MHz) as well as the gpu (650MHz) and the
> system is responding well. Yet still additional 5-8 watts are continously
> drained from the power supply. Something is throttling up :(. Oprofile
> shows that the kernel hogs the cpu (see dump below). This happens with
> every kernel since the 3.2 merge window closed up to latest linux-next. I
> wasn't able to track the bad commit down yet.
> 
> Could someone please confirm the issue?
> 

I observed similar behaviour, few minutes after boot, when KDE is working 
plasma-desktop process (sometimes another) uses 20-50% cpu. System and kernel 
works without any kernel, but cpu usage is greater than in 3.1 (and older).

Hardware: old hp/compaq nx6310

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Regards
-- 
Maciej Rutecki
http://www.mrutecki.pl