[LAU] Issues with kernel-rt, at least using Arch Linux

Ralf Mardorf ralf.mardorf at alice-dsl.net
Thu Sep 20 23:13:29 UTC 2012


Hi :)

this is very strange. A regular kernel doesn't cause xruns, but a
kernel-rt does always cause xruns, when running jack_midi_latency_test.
Because the proprietary nvidia driver doesn't work on my machine, when
using a kernel-rt, what ever trick I try, I tested the nouveau driver.
The nouveau driver does cause xruns for my RME card, but is ok with a
TerraTec card.
I switched to the nv driver and still get xruns for the RME card and the
TerraTec card completely fails the test using a kernel-rt.
When I repeat the test with a regular kernel, while using the
proprietary nvidia driver, the RME card passes the test without xruns
and the TerraTec card also is ok.

The only idea I've got is to compile a full preempt kernel, boot it with
threadirqs and to use the proprietary nvidia driver, but I would prefer
to use a kernel-rt.

Any hints are welcome.

Arch Linux x86_64
mouse and iPad connected to USB ports
when I started the test I thought the issues could be related to the
connected iPad, but they aren't

[spinymouse at archlinux ~]$ sudo cpupower frequency-set -g performance
[spinymouse at archlinux ~]$ uname -r 3.4.4-rt14-1-rt
[spinymouse at archlinux ~]$ hdspmixer
Card 0: RME AIO S/N 0x579bcc at 0xfdbf0000, irq 18
Card 1: TerraTec EWX24/96 at 0xbf00, irq 20
Card 2: TerraTec EWX24/96 at 0xbb00, irq 21
[spinymouse at archlinux ~]$ sudo chgrp audio /dev/hpet
[spinymouse at archlinux ~]$ sudo chmod g+rw /dev/hpet
[spinymouse at archlinux ~]$ sudo modprobe snd-hrtimer
[spinymouse at archlinux ~]$ /etc/rc.d/rtirq status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   59 FF      90   - 130  0.0 S    irq/8-rtc0	
  283 FF      85   - 125  0.0 S    irq/18-snd_hdsp	
  320 FF      80   - 120  0.0 S    irq/20-snd_ice1	
  322 FF      79   - 119  0.0 S    irq/21-snd_ice1	
  104 FF      70   - 110  0.0 S    irq/19-ehci_hcd	
  106 FF      70   - 110  0.3 S    irq/16-ohci_hcd	
  108 FF      69   - 109  0.0 S    irq/17-ohci_hcd	
  112 FF      68   - 108  0.0 S    irq/17-ohci_hcd	
   57 FF      65   - 105  0.0 S    irq/1-i8042	
   20 FF      50   -  90  0.0 S    irq/9-acpi	
   92 FF      50   -  90  0.1 S    irq/22-ahci	
  110 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  114 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  117 FF      50   -  90  0.0 S    irq/14-pata_ati	
  118 FF      50   -  90  0.0 S    irq/15-pata_ati	
  257 FF      50   -  90  0.0 S    irq/7-parport0	
  270 FF      50   -  90  0.0 S    irq/22-firewire	
  587 FF      50   -  90  0.0 S    irq/43-eth0	
    3 FF       1   -  41  0.0 S    ksoftirqd/0	
   11 FF       1   -  41  0.0 S    ksoftirqd/1
[spinymouse at archlinux ~]$ grep Driver /etc/X11/xorg.conf
        #Driver	    "nvidia"
	Driver	    "nv"
	#Driver     "nouveau"
        #Driver     "vesa"
[spinymouse at archlinux ~]$ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
jackdmp 1.9.8

[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:1-1 HDSPMx579bcc MIDI 1 1 out" "system:1-1 HDSPMx579bcc MIDI 1 1 in"
Waiting for connections ...
Waiting for test completion ...

Reported out-port latency: 5.33-5.33 ms (256-256 frames)
Reported in-port latency: 5.33-5.33 ms (256-256 frames)
Average latency: 11.67 ms (560.27 frames)
Lowest latency: 11.65 ms (559 frames)
Highest latency: 11.75 ms (564 frames)
Peak MIDI jitter: 0.10 ms (5 frames)
Average MIDI jitter: 0.01 ms (0.08 frames)

Jitter Plot:
0.0 - 0.1 ms: 8191
     > 10 ms: 1

Latency Plot:
11.6 - 11.7 ms: 8091
11.7 - 11.8 ms: 100
     > 21.6 ms: 1

Messages sent: 8192
Messages received: 8192
Xruns: 1

computer issues, a reset was needed

only mouse connected to an USB port

[spinymouse at archlinux ~]$ sudo cpupower frequency-set -g performance
[spinymouse at archlinux ~]$ uname -r 3.4.4-rt14-1-rt
[spinymouse at archlinux ~]$ hdspmixer
Card 0: RME AIO S/N 0x579bcc at 0xfdef0000, irq 18
Card 1: TerraTec EWX24/96 at 0xbf00, irq 20
Card 2: TerraTec EWX24/96 at 0xbb00, irq 21
[spinymouse at archlinux ~]$ sudo chgrp audio /dev/hpet
[spinymouse at archlinux ~]$ sudo chmod g+rw /dev/hpet
[spinymouse at archlinux ~]$ sudo modprobe snd-hrtimer
[spinymouse at archlinux ~]$ /etc/rc.d/rtirq status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   59 FF      90   - 130  0.0 S    irq/8-rtc0	
  361 FF      85   - 125  0.0 S    irq/18-snd_hdsp	
  365 FF      80   - 120  0.0 S    irq/20-snd_ice1	
  368 FF      79   - 119  0.0 S    irq/21-snd_ice1	
  113 FF      70   - 110  0.0 S    irq/19-ehci_hcd	
  115 FF      70   - 110  0.3 S    irq/16-ohci_hcd	
  117 FF      69   - 109  0.0 S    irq/17-ohci_hcd	
  121 FF      68   - 108  0.0 S    irq/17-ohci_hcd	
   57 FF      65   - 105  0.0 S    irq/1-i8042	
   20 FF      50   -  90  0.0 S    irq/9-acpi	
  102 FF      50   -  90  0.2 S    irq/22-ahci	
  119 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  123 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  126 FF      50   -  90  0.0 S    irq/14-pata_ati	
  127 FF      50   -  90  0.0 S    irq/15-pata_ati	
  289 FF      50   -  90  0.0 S    irq/7-parport0	
  324 FF      50   -  90  0.0 S    irq/22-firewire	
  618 FF      50   -  90  0.0 S    irq/43-eth0	
    3 FF       1   -  41  0.1 S    ksoftirqd/0	
   11 FF       1   -  41  0.1 S    ksoftirqd/1	
[spinymouse at archlinux ~]$ grep Driver /etc/X11/xorg.conf
        #Driver	    "nvidia"
	Driver	    "nv"
	#Driver     "nouveau"
        #Driver     "vesa"
[spinymouse at archlinux ~]$ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
jackdmp 1.9.8

[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:1-1 HDSPMx579bcc MIDI 1 1 out" "system:1-1 HDSPMx579bcc MIDI 1 1 in"
Waiting for connections ...
Waiting for test completion ...

Reported out-port latency: 5.33-5.33 ms (256-256 frames)
Reported in-port latency: 5.33-5.33 ms (256-256 frames)
Average latency: 11.69 ms (560.56 frames)
Lowest latency: 11.64 ms (559 frames)
Highest latency: 11.77 ms (565 frames)
Peak MIDI jitter: 0.13 ms (6 frames)
Average MIDI jitter: 0.02 ms (0.04 frames)

Jitter Plot:
0.0 - 0.1 ms: 8187
     > 10 ms: 5

Latency Plot:
11.6 - 11.7 ms: 7919
11.7 - 11.8 ms: 268
     > 21.6 ms: 5

Messages sent: 8192
Messages received: 8192
Xruns: 5

[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:2-1 TerraTec EWX24/96 MIDI 1 out" "system:2-1 TerraTec EWX24/96 MIDI 1 in"
Waiting for connections ...
Waiting for test completion ...


Messages sent: 5619
Messages received: 5618
jack_midi_latency_test: handle_process: timed out while waiting for MIDI message

before I reset the computer I got this too, this time a shutdown was possible
I also disconnected the computer from the mains for 55 minutes, before I booted again
only mouse connected to an USB port
now without hpet enabled

[spinymouse at archlinux ~]$ sudo cpupower frequency-set -g performance
[spinymouse at archlinux ~]$ uname -r 3.4.4-rt14-1-rt
[spinymouse at archlinux ~]$ hdspmixer
Card 0: RME AIO S/N 0x579bcc at 0xfdef0000, irq 18
Card 1: TerraTec EWX24/96 at 0xbf00, irq 20
Card 2: TerraTec EWX24/96 at 0xbb00, irq 21
[spinymouse at archlinux ~]$ /etc/rc.d/rtirq status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
   59 FF      90   - 130  0.0 S    irq/8-rtc0	
  318 FF      85   - 125  0.0 S    irq/18-snd_hdsp	
  326 FF      80   - 120  0.0 S    irq/20-snd_ice1	
  328 FF      79   - 119  0.0 S    irq/21-snd_ice1	
  107 FF      70   - 110  0.0 S    irq/19-ehci_hcd	
  109 FF      70   - 110  0.2 S    irq/16-ohci_hcd	
  121 FF      69   - 109  0.0 S    irq/17-ohci_hcd	
  125 FF      68   - 108  0.0 S    irq/17-ohci_hcd	
   57 FF      65   - 105  0.0 S    irq/1-i8042	
   20 FF      50   -  90  0.0 S    irq/9-acpi	
  100 FF      50   -  90  0.0 S    irq/14-pata_ati	
  101 FF      50   -  90  0.0 S    irq/15-pata_ati	
  111 FF      50   -  90  0.2 S    irq/22-ahci	
  123 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  127 FF      50   -  90  0.0 S    irq/18-ohci_hcd	
  279 FF      50   -  90  0.0 S    irq/7-parport0	
  323 FF      50   -  90  0.0 S    irq/22-firewire	
  586 FF      50   -  90  0.0 S    irq/43-eth0	
    3 FF       1   -  41  0.1 S    ksoftirqd/0	
   11 FF       1   -  41  0.1 S    ksoftirqd/1	
[spinymouse at archlinux ~]$ grep Driver /etc/X11/xorg.conf
        #Driver	    "nvidia"
	Driver	    "nv"
	#Driver     "nouveau"
        #Driver     "vesa"
[spinymouse at archlinux ~]$ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
jackdmp 1.9.8

[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:1-1 HDSPMx579bcc MIDI 1 1 out" "system:1-1 HDSPMx579bcc MIDI 1 1 in"
Waiting for connections ...
Waiting for test completion ...

Reported out-port latency: 5.33-5.33 ms (256-256 frames)
Reported in-port latency: 5.33-5.33 ms (256-256 frames)
Average latency: 11.67 ms (560.32 frames)
Lowest latency: 11.64 ms (559 frames)
Highest latency: 11.75 ms (564 frames)
Peak MIDI jitter: 0.11 ms (5 frames)
Average MIDI jitter: 0.01 ms (0.09 frames)

Jitter Plot:
0.0 - 0.1 ms: 8192

Latency Plot:
11.6 - 11.7 ms: 8024
11.7 - 11.8 ms: 168

Messages sent: 8192
Messages received: 8192

after the test for the TerraTec failed again, I had to reset the
computer
I booted a kernel-rt for AV Linux unfortunately Jack2 is version 1.9.6,
so I booted Arch Linux again, but this time I didn't boot the kernel-rt

[spinymouse at archlinux ~]$ sudo cpupower frequency-set -g performance
[spinymouse at archlinux ~]$ uname -r 3.5.4-1-ARCH
[spinymouse at archlinux ~]$ hdspmixer 
Card 0: RME AIO S/N 0x579bcc at 0xfdbf0000, irq 18
Card 1: TerraTec EWX24/96 at 0xbf00, irq 20
Card 2: TerraTec EWX24/96 at 0xbb00, irq 21
[spinymouse at archlinux ~]$ /etc/rc.d/rtirq status
  PID CLS RTPRIO  NI PRI %CPU STAT COMMAND	
    3 TS       -   0  19  0.0 S    ksoftirqd/0	
   10 TS       -   0  19  0.0 S    ksoftirqd/1
[spinymouse at archlinux ~]$ grep Driver /etc/X11/xorg.conf        ### 
        Driver	    "nvidia"
	#Driver	    "nv"
	#Driver     "nouveau"
        #Driver     "vesa"
spinymouse at archlinux ~]$ jackd --sync -Xalsarawmidi -dalsa -r48000 -p256
jackdmp 1.9.8

[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:2-1 TerraTec EWX24/96 MIDI 1 out" "system:2-1 TerraTec EWX24/96 MIDI 1 in"
Waiting for connections ...
Waiting for test completion ...

Reported out-port latency: 5.33-5.33 ms (256-256 frames)
Reported in-port latency: 5.33-5.33 ms (256-256 frames)
Average latency: 11.67 ms (560.05 frames)
Lowest latency: 11.67 ms (560 frames)
Highest latency: 11.77 ms (565 frames)
Peak MIDI jitter: 0.11 ms (5 frames)
Average MIDI jitter: 0.00 ms (0.01 frames)

Jitter Plot:
0.0 - 0.1 ms: 8191
0.1 - 0.2 ms: 1

Latency Plot:
11.6 - 11.7 ms: 8146
11.7 - 11.8 ms: 46

Messages sent: 8192
Messages received: 8192
[spinymouse at archlinux ~]$ jack_midi_latency_test -m 3 -s 8192 -t 5 "system:1-1 HDSPMx579bcc MIDI 1 1 out" "system:1-1 HDSPMx579bcc MIDI 1 1 in"
Waiting for connections ...
Waiting for test completion ...

Reported out-port latency: 5.33-5.33 ms (256-256 frames)
Reported in-port latency: 5.33-5.33 ms (256-256 frames)
Average latency: 11.68 ms (560.43 frames)
Lowest latency: 11.65 ms (559 frames)
Highest latency: 11.73 ms (563 frames)
Peak MIDI jitter: 0.08 ms (4 frames)
Average MIDI jitter: 0.01 ms (0.01 frames)

Jitter Plot:
0.0 - 0.1 ms: 8192

Latency Plot:
11.6 - 11.7 ms: 8156
11.7 - 11.8 ms: 36

Messages sent: 8192
Messages received: 8192

Regards,
Ralf



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