[LAU] Too many xruns

[Kevin Cosgrove]

On 5 September 2012 at 22:28, "Len Ovens" <len at ovenwerks.net> wrote:

> 
> On Wed, September 5, 2012 12:24 pm, Kevin Cosgrove wrote:
> 
> >> cat /proc/interrupts
> >
> > Xrunning system says:
> >
> >        CPU0   CPU1   CPU2   CPU3   CPU4   CPU5   CPU6   CPU7
> > 16:    56322  0      0      0      0      0      0      0   
> > IO-APIC-fasteoi   ahci, ehci_hcd:usb1, firewire_ohci, snd_ice1712, nvidia
> 
> That would give me xruns too.

OK.  I see it now.  I've never had to fight the interrupt problem
before.

> I was able to change slots. Also try to keep some distance
> between the video card and the audio card.

There are two PCI (legacy) slots in this ASUS P8Z68 DELUXE GEN3
1155 Motherboard.  I intend to use both of them as I have a pair
of M-Audio Delta 1010 audio adapters.

> (if you can) See if you can set IRQ in the bios for that slot
> to something else if there is only one.

I'll look at the manual for my MB and see what I can do.

> I find the same thing with USB audio. I have to find a USB plug
> on my laptop that does not share irq with anything else and
> only plug the audio IF in that one plug.
> 
> > Fine system says:
> >
> >  17:      0      0      0      0   IO-APIC-fasteoi ICE1712
> 
> Nice.

A happy accident.

> >> cat /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor
> >
> > Xrunning system says:
> >
> >   ondemand
> >   ondemand
> >   ondemand
> >   ondemand
> >   ondemand
> >   ondemand
> >   ondemand
> >   ondemand
> 
> What may help if you don't want to use performance is to set it
> to user and then set a lower than top speed. I seem to get less
> problems setting my system to 50% speed than with the (faster)
> ondemand setting.
>
> cpufreq-set and cpufreq-info are great to play with this stuff.
> the -info one will tell you what frequencies you can choose
> from. I found choosing the exact frequency didn't always work,
> slightly higher or lower would though. Play with it. Read the
> man page. My laptop runs at 1.6Ghz, but also has 1.33, 1.06
> and .8. I can do a lot more than I would think at 800Mhz as it
> turns out.

Very interesting.

It's also interesting that my system with no xruns has RT priority 
for jackd turned OFF.   ???   I just discovered that last night.

> rtirq can help. If used wrong it can make things worse... for
> example the stock setting is bad for FW or USB audio IFs.

Wow.

> It comes with the snd first or second. as someone else says in another
> message put snd_ice1712 and then snd after. This will put your internal IF
> in it's proper place, second.

That makes sense.  The internal IF is only used for playing my music 
collection's files and the audio for on-line things.

> I do the same with USB cards. I find out which USB plug has no
> other irqs with it (USB3 on mine) and put : usb3 snd usb as the
> order. This puts my external audio first, then the internal
> crap audio and then whatever other usb stuff there is (in a
> laptop that includes webcam in the lid and SD reader and maybe
> other things too...

I'm only using USB for mass storage.  Eventually I hope that my 
Behringer BCF2000 will be usable again with ardour.  I'm hoping 
ardour 3 will restore that functionality.

> take a look through dmesg for all the stuff that is USB)

In order to look for conflicting IRQs with my audio interface?

> Be aware that putting: snd-ice1712 snd will put all that other
> stuff on irq 16 between your ice and your internal card and you
> may wish to explicitly make them lower. Check your priorities
> after you have it going:
> 
> ps -eLo pid,cls,rtprio,pri,nice,cmd | grep -i irq
> 
> Look at the third column over.

This is looking as complicated as slackware was in 1996, back
when I had to build a special kernel with each OS release.

Thanks for the detailed info!


--
Kevin