[PlanetCCRMA] Configuring 2.6.11-0.3.rdt.rhfc2.ccrma for 0 xruns...

[Fernando Lopez-Lezcano]

On Thu, 2005-04-14 at 01:15, Rui Nuno Capela wrote:
> >
> >> As I say, I think it was Ingo who
> >> told me to try it back when I was having trouble with ACPI and USB
> >> mice in October, 04.
> >>
> >> Anyway, perfect results at 128/2.
> >
> > Good, maybe this should be something that rtirq should do by default.
> > Rui: are you reading this thread? Maybe rtirq should set the snd
> > interrupts to not threaded if it finds the proc controls for that.
>
> Damn. I'm running PREEMPT_RT (full realtime) for so long that I forgot
> that one could unthread the IRQ handlers with some other realtime-preempt
> kernel configurations. With PREEMPT_RT all IRQs are threaded, period.
> 
> And, believe me, PREEMPT_RT its the top performer configuration I ever saw
> for audio work. That's why I never thought of going to other lesser
> realtime-preempt configurations, once I got that stable on my laptop (UP)
> and desktop machine (SMP/HT).
> 
> Correct me if I'm wrong, the planet-edge kernels are configured as
> PREEMPT_DESKTOP ?

Yes, that is correct. I'm reluctant to go into PREEMPT_RT, I could not
make it work at all in my smp test machine, PREEMPT_DESKTOP is better
but not completely stable. Maybe the situation has changed...

-- Fernando

> OK. I'll check if I can remember how to unthread the snd related IRQs. For
> example, on my PREEMPT_RT machines I have nothing found as
> "/proc/irq/*/*/threaded" . May I assume that if "/proc/irq/*/*/threaded"
> is found we are under a PREEMPT_DESKTOP kernel, and then we can do the
> deeds:
>   for x in "/proc/irq/$IRQ/*/threaded"; do echo 0 > "$x"; done
> ?
>
> >> I'll be trying 64/2 in a few minutes.
> >>
> >> This can be set in rc.local, etc. and works every time I boot up on my
> >> laptop.
> >
> > The threaded stuff? Yes, I guess it could go there. It would be best to
> > incorporate it into rtirq, of course.
>
> I think I'll blind check this and introduce a new rtirq configuration
> switch as an option whether "snd" IRQs should be threaded or not. Default
> should be threaded, I guess.