Jaunty beta + RT + Jackd + Ardour, it works ;-D

laurent.bellegarde laurent.bellegarde at free.fr
Wed Apr 8 17:24:03 BST 2009

Cory K. a écrit :
> laurent.bellegarde wrote:
>> So packagers have to correct this problem of right to allow simple user 
>> (here it's laurent) to launch qjackctl with RT kernel as in hardy, and 
>> everythnig is ok.
> This should already be done by default with the -audio package /or/ it's
> done with Ubuntu Studio Controls.
> -Cory K.
Hi again,

i've done a new reboot, compared hardy's limits.conf to jaunty'one, and so

hardy'one working :

@audio          -       rtprio          99

@audio - memlock 999844

jaunty'one working but if i launch with sudo

@audio - memlock 770240
@audio - rtprio 99
@audio - nice -10

so I check ubuntustudio controls, everything is ok, the limits.conf is 
like the controls in GUI.

then i have a look to laurent un user, and see that in groups, there was 
no audio group. I add one, and tick laurent and root as members of this 
group, i've done a new reboot, and now i can launch qjackctl + ardour on 
RT without any xruns at 2,9ms latency !!!

what is surprising is that in hardy, i check audio group presence, 
there's none !!! but qjackctl is available as none root ???
But now, I understand why in hardy, changing the size of allowed memory 
change nothing face to the ardour message which was telling me there was 
a limit in my system...that's normal, because laurent is not in an audio 
group, so limits.conf can't work...

So I can't explain why in same condition hardy settings are working and 
why jaunty not, but after adding an audio group, and tick your account 
user in it, a reboot, it works perfectly...

RT kernel is ok for stable release the 23 of april...


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