Ulrik Kjems
August 18th, 2009, 08:09 AM
Hi
I want to start a multimedia real-time audioprocessing application using jackd at boot time running as a non-root user. I am using Ubuntu studio 8.04
The core of the problem is as follows:
If I login normally (as str_uk) I can start jackd with real-time priority just fine, e.g. with
jackd -R -d alsa
so I'm pretty sure my /etc/security/limits.conf is ok (I append it at the end of this message)
However, I run into problems when trying to run jackd as user str_uk from an init script. What I do boils down to
su str_uk -c "jackd -R -d alsa"
and I get the following error:
...
JACK compiled with System V SHM support.
cannot use real-time scheduling (FIFO at priority 10) [for thread -1210001744, from thread -1210001744] (1: Operation not permitted)
cannot create engine
The strange thing is that if I open a terminal in a gnome session and run the above "su" command as root, I get no error. But if I login as root from the console window (text mode) and issue the su-command I get the error. If I log in on the console as user "str_uk" I dont get the error.
I am guessing that the settings in /etc/security/limits.conf are not being applied in the cases where I get the error.
The output of "id" is given here, and it is the same when I get the error or not.
id:
uid=2206(str_uk) gid=1000(mha) groups=4(adm),20(dialout),24(cdrom),25(floppy),29( audio),30(dip),44(video),46(plugdev),104(scanner), 109(lpadmin),110(admin),115(netdev),117(powerdev), 1000(mha)
uname -a:
Linux kbnux-mha-3 2.6.24-24-rt #1 SMP PREEMPT RT Sat Jul 25 01:01:25 UTC 2009 i686 GNU/Linux
/etc/security/limits.conf:
@audio - rtprio 99
@audio - memlock unlimited
I want to start a multimedia real-time audioprocessing application using jackd at boot time running as a non-root user. I am using Ubuntu studio 8.04
The core of the problem is as follows:
If I login normally (as str_uk) I can start jackd with real-time priority just fine, e.g. with
jackd -R -d alsa
so I'm pretty sure my /etc/security/limits.conf is ok (I append it at the end of this message)
However, I run into problems when trying to run jackd as user str_uk from an init script. What I do boils down to
su str_uk -c "jackd -R -d alsa"
and I get the following error:
...
JACK compiled with System V SHM support.
cannot use real-time scheduling (FIFO at priority 10) [for thread -1210001744, from thread -1210001744] (1: Operation not permitted)
cannot create engine
The strange thing is that if I open a terminal in a gnome session and run the above "su" command as root, I get no error. But if I login as root from the console window (text mode) and issue the su-command I get the error. If I log in on the console as user "str_uk" I dont get the error.
I am guessing that the settings in /etc/security/limits.conf are not being applied in the cases where I get the error.
The output of "id" is given here, and it is the same when I get the error or not.
id:
uid=2206(str_uk) gid=1000(mha) groups=4(adm),20(dialout),24(cdrom),25(floppy),29( audio),30(dip),44(video),46(plugdev),104(scanner), 109(lpadmin),110(admin),115(netdev),117(powerdev), 1000(mha)
uname -a:
Linux kbnux-mha-3 2.6.24-24-rt #1 SMP PREEMPT RT Sat Jul 25 01:01:25 UTC 2009 i686 GNU/Linux
/etc/security/limits.conf:
@audio - rtprio 99
@audio - memlock unlimited