[linux-audio-user] Tuning Jack: Please help me prioritize IRQ 10

[Joe Hartley]

This has been a very timely discussion.  I just got my son a new mobo, CPU
and RAM, and he's been having a lot of trouble using jack, ardour and hydrogen
until I followed the advice here and tuned his machine up.  Thanks all!

On Sat, 20 Jan 2007 12:21:58 -0500
Rick Wright <riwright at vt.edu> wrote:
> Thus, your command should be something like :
> 
> /usr/bin/chrt -f -p 90 `pidof "IRQ 10"`

Here's a novel twist on all of this:  my sound and video cards don't seem
to exist on my FC5 system, so I can't run this command!

For example, my audio card is a Delta 1010.  lspci -v shows it:
02:0b.0 Multimedia audio controller: VIA Technologies Inc. ICE1712 [Envy24] PCI Multi-Channel I/O Controller (rev 02)
        Subsystem: VIA Technologies Inc. M-Audio Delta 1010
        Flags: bus master, medium devsel, latency 64, IRQ 11
        I/O ports at df80 [size=32]
        I/O ports at dfa0 [size=16]
        I/O ports at df60 [size=16]
        I/O ports at df00 [size=64]
        Capabilities: [80] Power Management version 1

However, it's not in /proc/interrupts, and trying to use chrt as shown
above fails:
[root at xtc ~]# cat /proc/interrupts 
           CPU0       CPU1       
  0:      67992    2883426  IO-APIC-edge   [........N/  0]  pit
  1:          8          0  IO-APIC-edge   [........./  0]  i8042
  8:          1          0  IO-APIC-edge   [........./  0]  rtc
  9:          0          1  IO-APIC-level  [........./  0]  acpi
 12:         96          0  IO-APIC-edge   [........./  0]  i8042
 14:       6779         89  IO-APIC-edge   [........./  2]  ide0
 15:      28172       6252  IO-APIC-edge   [........./  2]  ide1
 17:          2          0  IO-APIC-level  [........./  0]  ehci_hcd:usb1
 18:         31          0  IO-APIC-level  [........./  0]  uhci_hcd:usb2
 19:       1276          0  IO-APIC-level  [........./  0]  skge
NMI:          0          0 
LOC:    2951050    2954633 
ERR:          0
MIS:          0
[root at xtc ~]# chrt -f -p 82 `pidof "IRQ 11"`
sched_getscheduler: No such process
failed to get pid 82's policy

Hmmm, where's the process for IRQ 11??

[root at xtc ~]# ps -ef | grep IRQ
root        33    27  0 15:28 ?        00:00:00 [IRQ 9]
root       249    27  0 15:28 ?        00:00:00 [IRQ 8]
root       268    27  0 15:28 ?        00:00:00 [IRQ 12]
root       296    27  0 15:28 ?        00:00:00 [IRQ 14]
root       299    27  0 15:28 ?        00:00:00 [IRQ 15]
root       350    27  0 15:28 ?        00:00:00 [IRQ 1]
root       838    27  0 15:28 ?        00:00:00 [IRQ 17]
root       860    27  0 15:28 ?        00:00:00 [IRQ 18]
root       897    27  0 15:28 ?        00:00:00 [IRQ 19]
root      1133    27  0 15:28 ?        00:00:00 [IRQ 6]

I'm really baffled here!  Has anyone seen this?  My video card (listed
as having IRQ 18) is equally missing in action as well.  Thanks for any
clues sent this way.

-- 
======================================================================
       Joe Hartley - UNIX/network Consultant - jh at brainiac.com
Without deviation from the norm, "progress" is not possible. - FZappa