16 Mar
2013
16 Mar
'13
1:49 p.m.
I just noticed this on my Fedora 17 system. I run jackd like this:
[paul@watt ~]$ /usr/bin/jackd --realtime -dalsa -dhw:0 -r48000 -p512 -n2
jackdmp 1.9.9.5
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2012 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
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 20
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|512|2|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 512 frames (10.7 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback
Using port names patch v0.1 (07.04.2010)
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ss.ports.in
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ports.in
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ss.ports.in
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ports.in
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ss.ports.out
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ports.out
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ss.ports.out
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ports.out
Everything looks fine, and jackd claims it has realtime mode. I've
been away from Linux audio for a while, but doesn't realtime mode mean
RT scheduling? If I check the process's scheduler policy and
priority, it is NOT RT:
[paul@watt ~]$ ps -p 20370 -o cmd,class,pri,rtprio
CMD CLS PRI RTPRIO
/usr/bin/jackd --realtime - TS 19 -
I've added myself to the jackuser group:
[paul@watt ~]$ groups
paul wheel dialout wireshark jackuser
That group is already set up properly:
[paul@watt ~]$ cat /etc/security/limits.d/95-jack.conf
# Default limits for users of jack-audio-connection-kit
@jackuser - rtprio 70
@jackuser - memlock 4194304
@pulse-rt - rtprio 20
@pulse-rt - nice -20
Anyone have any idea what's going on here?
16 Mar
16 Mar
1:55 p.m.
A vanilla kernel nowadays already enables soft real-time. For jack you
even don't need to use the --realtime switch, since it's the default.
usage: jackdmp [ --no-realtime OR -r ]
[ --realtime OR -R [ --realtime-priority OR -P priority ] ]
(the two previous arguments are mutually exclusive. The default is --realtime)
2:03 p.m.
On Sat, Mar 16, 2013 at 8:49 AM, Paul Coccoli <pcoccoli(a)gmail.com> wrote:
I just noticed this on my Fedora 17 system. I run
jackd like this:
you've fallen for a classic mistake when using ps(1) on multithreaded
applications.
[paul@watt ~]$ ps -p 20370 -o cmd,class,pri,rtprio
CMD CLS PRI RTPRIO
/usr/bin/jackd --realtime - TS 19 -
jackd runs more than one thread. your use of ps(1) shows only the initial
thread, which is not RT.
--p
2:08 p.m.
On Sat, Mar 16, 2013 at 9:03 AM, Paul Davis <paul(a)linuxaudiosystems.com> wrote:
you've fallen for a classic mistake when using
ps(1) on multithreaded
applications.
D'oh! I knew I was doing something wrong.
[paul@watt ~]$ ps -Tp 20597 -o cmd,class,pri,rtprio
CMD CLS PRI RTPRIO
/usr/bin/jackd --realtime - TS 19 -
/usr/bin/jackd --realtime - TS 19 -
/usr/bin/jackd --realtime - FF 60 20
/usr/bin/jackd --realtime - TS 19 -
Pretty embarrassing since I work on a realtime multithreaded app every
day. Sorry for the noise. I'll go get more coffee.
[paul@watt ~]$ ps -p 20370 -o
cmd,class,pri,rtprio
CMD CLS PRI RTPRIO
/usr/bin/jackd --realtime - TS 19 -
jackd runs more than one thread. your use of ps(1) shows only the initial
thread, which is not RT.
--p
2:20 p.m.
On 03/16/2013 12:49 PM, Paul Coccoli wrote:
I just noticed this on my Fedora 17 system. I run
jackd like this:
[paul@watt ~]$ /usr/bin/jackd --realtime -dalsa -dhw:0 -r48000 -p512 -n2
jackdmp 1.9.9.5
Copyright 2001-2005 Paul Davis and others.
Copyright 2004-2012 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
no message buffer overruns
no message buffer overruns
no message buffer overruns
JACK server starting in realtime mode with priority 20
audio_reservation_init
Acquire audio card Audio0
creating alsa driver ... hw:0|hw:0|512|2|48000|0|0|nomon|swmeter|-|32bit
configuring for 48000Hz, period = 512 frames (10.7 ms), buffer = 2 periods
ALSA: final selected sample format for capture: 32bit integer little-endian
ALSA: use 2 periods for capture
ALSA: final selected sample format for playback: 32bit integer little-endian
ALSA: use 2 periods for playback
Using port names patch v0.1 (07.04.2010)
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ss.ports.in
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ports.in
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ss.ports.in
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ports.in
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ss.ports.out
Trying to load portnames from /home/paul/.config/jack/cards/M Audio
Delta 66.ports.out
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ss.ports.out
Trying to load portnames from /etc/jack/cards/M Audio Delta 66.ports.out
Everything looks fine, and jackd claims it has realtime mode. I've
been away from Linux audio for a while, but doesn't realtime mode mean
RT scheduling? If I check the process's scheduler policy and
priority, it is NOT RT:
it is not the main jackd process which is set to realtime class (FF) but
one of its threads
[paul@watt ~]$ ps -p 20370 -o cmd,class,pri,rtprio
CMD CLS PRI RTPRIO
/usr/bin/jackd --realtime - TS 19 -
you should rephrase the ps command line with the -L switch (list
light-weight threads), like so
ps -p <PID> -L -o tid,class,pri,rtprio,cmd
or, generically
ps -Leo pid,tid,class,pri,rtprio,comm | egrep "(PID|jackd)"
cheers
--
rncbc aka Rui Nuno Capela
rncbc(a)rncbc.org
4206
days inactive
4206
days old
linux-audio-user@lists.linuxaudio.org
4 comments
4 participants
participants (4)
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Paul Coccoli -
Paul Davis -
Ralf Mardorf -
Rui Nuno Capela