[LAU] Issue with the priority of the sound cards using rtirq

Ralf Mardorf ralf.mardorf at alice-dsl.net
Sun Apr 29 19:59:58 UTC 2012


The config of the Ubuntu Studio Precise kernel 3.2.0-23-lowlatency,
seems to be ready to use it with threadirqs as boot option.
Anyway, I still get
$ /etc/init.d/rtirq status

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND 
   92 FF      90   - 130  0.0 S    irq/8-rtc0 
   85 FF      85   - 125  0.0 S    irq/18-ohci_hcd 
   89 FF      84   - 124  0.0 S    irq/18-ohci_hcd 
  611 FF      83   - 123  0.0 S    irq/18-snd_hdsp 
1285 FF      82   - 122  0.8 S    irq/18-nvidia 
  652 FF      80   - 120  0.0 S    irq/20-snd_ice1 
  656 FF      80   - 120  0.0 S    irq/21-snd_ice1

instead the of the wanted

$ /etc/init.d/rtirq status

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND 
  384 FF      90   - 130  0.0 S    irq/8-rtc0 
1102 FF      85   - 125  0.0 S    irq/18-hdspm 
1123 FF      80   - 120  0.0 S    irq/20-ICE1712 
1135 FF      80   - 120  0.0 S    irq/21-ICE1712

So for the moment I guess it's better instead of using
$ grep RTIRQ_NAME_LIST /etc/default/rtirq
RTIRQ_NAME_LIST="rtc hdspm snd usb i8042"
which does the trick for other installs, to use
$ grep RTIRQ_NAME_LIST /etc/default/rtirq
RTIRQ_NAME_LIST="rtc snd usb i8042"
since this results in
$ /etc/init.d/rtirq status

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   92 FF      90   - 130  0.0 S    irq/8-rtc0	
  702 FF      85   - 125  0.0 S    irq/20-snd_ice1	
  724 FF      85   - 125  0.0 S    irq/21-snd_ice1	
  717 FF      83   - 123  0.0 S    irq/18-snd_hdsp	
 1348 FF      82   - 122  0.8 S    irq/18-nvidia	
   78 FF      80   - 120  0.0 S    irq/19-ehci_hcd	
   80 FF      80   - 120  0.3 S    irq/16-ohci_hcd	
   82 FF      79   - 119  0.0 S    irq/17-ohci_hcd	
   84 FF      78   - 118  0.0 S    irq/18-ohci_hcd	
   87 FF      78   - 118  0.0 S    irq/17-ohci_hcd	
   89 FF      77   - 117  0.0 S    irq/18-ohci_hcd	
   91 FF      75   - 115  0.0 S    irq/1-i8042	
   20 FF      50   -  90  0.0 S    irq/9-acpi	
   67 FF      50   -  90  0.2 S    irq/22-ahci	
  279 FF      50   -  90  0.0 S    irq/14-pata_ati	
  280 FF      50   -  90  0.0 S    irq/15-pata_ati	
  292 FF      50   -  90  0.0 S    irq/22-firewire	
  561 FF      50   -  90  0.0 S    irq/7-parport0	
 1020 FF      50   -  90  0.0 S    irq/43-eth0	
    3 TS       -   0  19  0.2 S    ksoftirqd/0	
    9 TS       -   0  19  0.2 S    ksoftirqd/1
so my MIDI interfaces snd_ice1... get a higher priority than the audio
card snd_hdsp..., but at least all the other stuff get a lower priority.

On other installs I also got/get the wanted priority for a non-rt, with
threadirqs, e.g.:
spinymouse at avlinux:~$ uname -a
Linux avlinux 3.0.23-avl-7-pae #28 SMP PREEMPT Thu Mar 1 19:14:14 EST
2012 i686 GNU/Linux
spinymouse at avlinux:~$ /etc/init.d/rtirq status

  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
  452 FF      90   - 130  0.0 S    irq/8-rtc0	
 1028 FF      85   - 125  0.0 S    irq/18-hdspm	
 1040 FF      80   - 120  0.0 S    irq/20-ICE1712	
 1042 FF      80   - 120  0.0 S    irq/21-ICE1712	
  615 FF      75   - 115  0.0 S    irq/19-ehci_hcd	
  620 FF      75   - 115  0.2 S    irq/16-ohci_hcd	
  622 FF      74   - 114  0.0 S    irq/17-ohci_hcd	
  626 FF      73   - 113  0.0 S    irq/17-ohci_hcd	
  445 FF      70   - 110  0.0 S    irq/1-i8042	
   96 FF      50   -  90  0.0 S    irq/9-acpi	
  621 FF      50   -  90  0.1 S    irq/22-firewire	
  625 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  627 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  628 FF      50   -  90  0.0 S    irq/14-pata_ati	
  629 FF      50   -  90  0.0 S    irq/15-pata_ati	
  634 FF      50   -  90  0.3 S    irq/22-ahci	
  909 FF      50   -  90  0.0 S    irq/7-parport0	
 1414 FF      50   -  90  0.0 S    irq/43-eth0	
    3 TS       -   0  19  0.0 S    ksoftirqd/0	
    9 TS       -   0  19  0.0 S    ksoftirqd/1

Could it be the kernel version or video driver?

Any hints are welcome,
Ralf

PS: I did not test if it really does matter if the audio card has a
higher or lower priority than the MIDI cards.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.linuxaudio.org/pipermail/linux-audio-user/attachments/20120429/8f0cf99b/attachment.htm>


More information about the Linux-audio-user mailing list