[mythtv-users] powernowd (et al) on SMP with Mythtv?

Jarod Wilson lists at wilsonet.com
Fri Feb 9 16:06:15 UTC 2007

Michael Thome wrote:
> I'm having trouble getting powernowd (and other cpu scalers) to react 
> appropriately to Myth's cpu loading patterns with my dual-core machine - 
> I suspect I need to play around with parameters some more, but I thought 
> I'd see if anyone else is happy with their settings.
> The problem: watch live tv on a software-encoded tuner leads to high cpu 
> utilization on one core (85-95%) but low on the other (10%).  powernowd 
> leaves the clock rate at lowest setting, resulting in jerky motion on 
> playback.  Similar situations can happing during DVD playing, HD 
> playback, etc - one cpu is all out, the other is idle, average is around 
> 50%.  Percept is great if I turn off powernowd, but then I'm always 
> running at high clockrate.  Kernel-only on_demand seems to behave similarly.
> My system is an Athlon 64 X2 4200+ (65W), Ubuntu Edgy

What kernel? There have been a number of multi-core specific fixes to 
the powernow-k8 code in recent kernels. The ondemand governor works 
perfectly for me w/a kernel in a dual-core opteron system.

Jarod Wilson
jarod at wilsonet.com

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