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

Jarod Wilson lists at wilsonet.com
Sat Feb 24 01:59:42 UTC 2007

On Feb 23, 2007, at 09:39, Michael Thome wrote:

> Whups - missed your reply...  I'm running 2.6.17 (ubuntu build)...   
> I'm
> holding off on later kernels because of the mess that is ivtv/dvb/v4l
> being in transition - had a *terrible* time finding a kernel+drivers
> combination where both pvr-150 and hd5500 would work at the same time.

Ah, okay. I'm pretty sure the bulk of said dual-core fixes were  
2.6.18 and later.

> Jarod Wilson wrote:
>> 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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