[PlanetCCRMA] Help with APIC/IRQ setup...

[Brian Jarrett]

OK, here's some more data:

The BIOS allows me to select IRQs for each PCI slot, but making
adjustments in there has no effect on /proc/interrupts.  I was finally
able to get the Delta66 on its own IRQ by moving it to another PCI slot.
Now it's at IRQ 19.  I'm now booting into the rdt kernel and looking for
xruns using Ardour.  I've got jack set to 128/2 so that the latency is <
6ms at 48000.

When playing back 3 tracks and recording a 4th I do get an xrun and
there _is_ a glitch in the recorded sound.  I only did a 10 second
recording.

Is this a valid test?  Is it reasonable that it should be able to do
this without xruns?  I use Ableton Live under Windows on this PC, so I
know what to expect performance-wise under Windows, but don't know what
realistic expectations for Ardour would be.  Also, this is an AMD64
processor, but I'm using it in 32bit mode, would switching to 64bit
improve the situation?


> -----Original Message-----
> From: Fernando Lopez-Lezcano [mailto:nando@ccrma.Stanford.EDU]
> Sent: Wednesday, June 22, 2005 1:35 PM
> To: Brian Jarrett
> Cc: Mark Knecht; planetccrma@ccrma.Stanford.EDU
> Subject: RE: [PlanetCCRMA] Help with APIC/IRQ setup...
> 
> On Wed, 2005-06-22 at 11:58, Brian Jarrett wrote:
> > The only thing I've noticed is some pops when I was recording a
single
> > track in Ardour, but I've not really done anything to configure it
and
> > haven't done much else with my new system.
> >
> > I was just following the instructions and attempting to tune the
system.
> > *grin*
> 
> If you are using the "rdt" edge kernels then the tuning is mostly done
> automatically through the rtirq startup script (which sets the
realtime
> priorities of the lower half of the interrupts processes). I see that
> the sound card appears to share an interrupt with the video card, you
> may want to move the soundcard to a different slot to see which irq it
> picks up. It is unlikely that the bios will let you assign interrupts
to
> individual pci slots (although it is possible).
> 
> -- Fernando
> 
> > > -----Original Message-----
> > > From: Mark Knecht [mailto:markknecht@gmail.com]
> > > Sent: Wednesday, June 22, 2005 12:48 PM
> > > To: Brian Jarrett
> > > Cc: planetccrma@ccrma.stanford.edu
> > > Subject: Re: [PlanetCCRMA] Help with APIC/IRQ setup...
> > >
> > > Do you need to do anything? You don't speak of any xrun problems
here.
> > > Are you having any troubles with the default setup that would
really
> > > require a change?
> > >
> > > - Mark
> > >
> > > On 6/22/05, Brian Jarrett <bjarrett@garcoschools.org> wrote:
> > > > Hello all,
> > > >
> > > > I've got a Gigabyte K8NS Ultra939 MB w/AMD64 CPU and 2 SATA HDD.
> > > >
> > > > I've installed 32bit FC3 and loaded "the Planet" audio apps.
> > > >
> > > > I haven't been able to "tune" the system by adjusting IRQs, or
> > causing
> > > > the system to do it, and I'm not even sure if I need to.  Here's
my
> > > > /proc/interrupts:
> > > >
> > > >            CPU0
> > > >   0:     267756    IO-APIC-edge  timer
> > > >   1:        268    IO-APIC-edge  i8042
> > > >   8:          1    IO-APIC-edge  rtc
> > > >   9:          0   IO-APIC-level  acpi
> > > >  12:       1766    IO-APIC-edge  i8042
> > > >  15:        864    IO-APIC-edge  ide1
> > > >  16:      21284   IO-APIC-level  ICE1712, nvidia
> > > >  17:      12942   IO-APIC-level  libata
> > > >  18:          3   IO-APIC-level  ohci1394
> > > >  20:          2   IO-APIC-level  ehci_hcd
> > > >  21:          0   IO-APIC-level  NVidia CK8S, ohci_hcd
> > > >  22:      23934   IO-APIC-level  ohci_hcd, eth0
> > > > NMI:          0
> > > > LOC:     267680
> > > > ERR:          0
> > > > MIS:          0
> > > >
> > > > I don't see any way to turn off APIC in the BIOS and I've tried
> > > > kernel-level options "noapic" and "apic=off" but it seems to
have no
> > > > effect.
> > > >
> > > > Of course, I'd like my Delta66 (ICE1712) to have as high a
priority
> > as
> > > > possible.  The things I have tried are a result of reading a lot
of
> > > > information that doesn't even really apply directly to dealing
with
> > > > APIC.
> > > >
> > > > Any suggestions?  I'm out of ideas, if there's anything I can
even
> > do
> > > > about it.
> > > >
> > > > Brian
> > > >
> > > > _______________________________________________
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> > > > PlanetCCRMA@ccrma.stanford.edu
> > > > http://ccrma-mail.stanford.edu/mailman/listinfo/planetccrma
> > > >
> >
> >
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