[mythtv-users] Repeating audio on SMP machine

[Yan-Fa Li]

Take a look at Robert Love's web page.  Schedutils might have something 
you can try:

http://www.tech9.net/rml/schedutils/

Yan

Kane Tse wrote:
>>
>> Try forcing the capture card and audio capture IRQ processing onto one
>> CPU. It could be that the process is being migrated between CPUs and
>> the driver is not completely SMP safe.
>>
> 
> 
> I read up on the smp_affinity file and made the modifications, but 
> ultimately, it didn't help.  I made the following observations:
> 
> 1) When I did a 'cat /proc/irq/17/smp_affinity', I got 00000001 
> suggesting the IRQ was redirected to CPU0.  But when I did:
> 
> cd /proc/irq/17
> cat smp_affinity
> 
> I got 00000002.  Which is really strange, since they should be the same 
> file right?  Also, this also suggested that input is already handled by 
> one CPU, namely CPU0.
> 
> 2)  When I did an lspci -v | grep 17:, I noticed CPU0 was handling 
> almost all the processing for that card, so did an echo 2 > 
> /proc/irq/17/smp_affinity to redirect IRQ processing onto CPU1.  
> Performing a 'cat /proc/irq/17/smp_affinity' showed 00000002, which 
> suggested that IRQ processing was being handled by CPU1.   This was 
> confirmed by lspci -v | grep 17:.  But after a few minutes, 'cat 
> /proc/irq/17/smp_affinity' reverted back to 00000001... for no reason, 
> and the problems didn't go away (although i couldn't tell if this was 
> before or after the reversion back to 00000001.
> 
> What's up with that?  Why did it revert back?
> 
> 
> 
> 
> Anyway, it seems to me that CPU0 was already directed to process input 
> from IRQ17, so maybe that wasn't my problem.  But tonight when I get 
> home I am going to clean-install Fedora Core 3 on that machine and see 
> if things improve or not.
> 
> Thanks for your help though.  And let me know if you have any other ideas.
> 
> Is anyone else out there running a bt8x8 and btaudio on an SMP setup?  
> Which OS are you using?  Any problems?
> 
>