[LAU] Regular Xruns?

[James Stone]

Arnold Krille wrote:
> Hi,
> 
> On Friday 07 August 2009 02:11:01 James Stone wrote:
>> It is often preceded by a slow
>> build-up of static on audio output, which stops when the xrun happens
>> (this isn't recorded to disk in ardour tho).
> 
> That is good (and new) information. This sounds more like some clock-skews 
> which run out of sync, then boom! a xrun and all is well again.
> 
>> Any ideas what might be
>> going on? Could it be hardware-related??
> 
> Follow Ken's advice: Use an RT-patched kernel.
> 

OK.. done that now.. also set IRQ sched prio for sound card to 99, jackd 
prio to 89, run the pci latency fix..

uname -a
Linux 2.6.29 #1 SMP PREEMPT RT Fri Aug 7 02:24:17 BST 2009 i686 GNU/Linux
  cat /proc/interrupts
            CPU0
   0:        119    XT-PIC-XT        timer
   1:        976    XT-PIC-XT        i8042
   2:          0    XT-PIC-XT        cascade
   4:          4    XT-PIC-XT        ehci_hcd:usb1
   5:     866799    XT-PIC-XT        EMU10K1
   6:          5    XT-PIC-XT        floppy
   7:       1711    XT-PIC-XT        NVidia nForce2
   8:          0    XT-PIC-XT        rtc0
   9:          0    XT-PIC-XT        acpi
  10:     339411    XT-PIC-XT        ohci_hcd:usb2, nvidia
  11:     546369    XT-PIC-XT        ohci_hcd:usb3, eth0
  12:          3    XT-PIC-XT        bttv0
  14:      11794    XT-PIC-XT        ide0
  15:      47804    XT-PIC-XT        ide1
NMI:          0   Non-maskable interrupts
LOC:    4999783   Local timer interrupts
SPU:          0   Spurious interrupts
CNT:          0   Performance counter interrupts
RES:          0   Rescheduling interrupts
CAL:          0   Function call interrupts
TLB:          0   TLB shootdowns
TRM:          0   Thermal event interrupts
ERR:          6
MIS:          0

~/jack_stuff$ ./irq_check 5
pid 2106's current scheduling policy: SCHED_FIFO
pid 2106's current scheduling priority: 99

#!/bin/sh

case $1 in
      start)
            # "open up" the PCI bus by allowing fairly long bursts for
all devices, increasing performance
            setpci -v -s "*:*.*" latency_timer=b0

            # maximise latency for SBLive!, thus allowing
            # more data per PCI transfer and minimizing xfuns
            setpci -v -s 01:0a.0 latency_timer=ff
esac

exit 0

But still get xruns every 14 mins!!!

08:34:43.555 JACK connection change.
08:34:43.563 JACK connection graph change.
08:49:02.342 XRUN callback (1).
**** alsa_pcm: xrun of at least 0.026 msecs
09:03:23.960 XRUN callback (2).
**** alsa_pcm: xrun of at least 0.026 msecs

James