RT_GROUP_SCHED kernel option makes JACK unusable in Ubuntu Natty

[Asmo Koskinen]

14.12.2010 21:06, Alessio Igor Bogani kirjoitti:
> Hi,
> The -lowlatency 2.6.37-8.21~ppa1 kernel have RT_GROUP_SCHED enabled.
> Instead the 2.6.37-9.22~ppa1 one's have RT_GROUP_SCHED disabled.
>
> Anyone could test those?

This kernel is very good for me. I can use NVIDIA (dual screen), M-Audio 
Delta 66 and Echo AudioFire 4 with no xruns when palying a session with 
Ardour. Here is screenshots for both devices with Ardour.

Merry Christmas Alessio!

Best Regards Asmo Koskinen.

1.

studio at ubuntu-studio:~$ uname -a
Linux ubuntu-studio 2.6.37-9-lowlatency #22~ppa1-Ubuntu SMP PREEMPT Tue 
Dec 14 14:50:39 UTC 2010 x86_64 GNU/Linux

2.

studio at ubuntu-studio:~$ lspci -k | grep nvidia
	Kernel driver in use: nvidia
	Kernel modules: nvidia-current, nouveau, nvidiafb

3.

studio at ubuntu-studio:~$ lspci -k | grep ice1712
	Kernel modules: snd-ice1712

4.

studio at ubuntu-studio:~$ ffado-test ListDevices
-----------------------------------------------
FFADO test and diagnostic utility
Part of the FFADO project -- www.ffado.org
Version: 2.999.0-
(C) 2008, Daniel Wagner, Pieter Palmers
This program comes with ABSOLUTELY NO WARRANTY.
-----------------------------------------------

=== 1394 PORT 0 ===
   Node id  GUID                  VendorId     ModelId   Vendor - Model
    0       0x0400000000000000  0x00040000  0x00000AF4   Echo Digital 
Audio - AudioFire4
01230689980: Error (configrom.cpp)[ 150] initialize: Could not parse 
config rom of node 1 on port 0
no message buffer overruns

5.

14:13:37.424 /usr/bin/jackd -m -dalsa -dhw:0 -r44100 -p128 -n3 -Xseq
14:13:37.426 JACK was started with PID=2757.
no message buffer overruns
no message buffer overruns
jackdmp 1.9.7
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2010 Grame.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK server starting in realtime mode with priority 10
control device hw:0
control device hw:0
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|128|3|44100|0|0|nomon|swmeter|-|32bit
control device hw:0
Using ALSA driver ICE1712 running on card 0 - M Audio Delta 66 at 
0x10c0, irq 22
configuring for 44100Hz, period = 128 frames (2.9 ms), buffer = 3 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 3 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 3 periods for playback
port created: Midi-Through:midi/playback_1
port created: Midi-Through:midi/capture_1
14:13:37.573 ALSA connection graph change.
14:13:39.625 JACK connection change.
14:13:39.626 Server configuration saved to "/home/studio/.jackdrc".
14:13:39.627 Statistics reset.
14:13:39.633 Client activated.
14:13:39.635 JACK connection graph change.

http://www.arkki.info/howto/Ubuntu_Studio_Testing/Natty/Natty_01.png

6.

14:10:32.977 /usr/bin/jackd -m -dfirewire -r44100 -p128 -n3
14:10:32.981 JACK was started with PID=2655.
no message buffer overruns
no message buffer overruns
jackdmp 1.9.7
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2010 Grame.
jackdmp comes with ABSOLUTELY NO WARRANTY
This is free software, and you are welcome to redistribute it
under certain conditions; see the file COPYING for details
JACK server starting in realtime mode with priority 10
libffado 2.999.0- built Nov  1 2010 21:44:06
14:10:38.115 JACK connection change.
14:10:38.116 Server configuration saved to "/home/studio/.jackdrc".
14:10:38.117 Statistics reset.
14:10:38.122 Client activated.
14:10:38.129 JACK connection graph change.

http://www.arkki.info/howto/Ubuntu_Studio_Testing/Natty/Natty_02.png