I'm running Ubuntu Jaunty 9.04 (on a different laptop, not the one
running AVLinux). Till recently, my linuxsampler setup on this
particular system was working without (major, noticable) glitches, i.e
very few xruns and not many dropped notes. Since the past few days,
however, I'm seeing a host of xruns and buzzes and drop notes. I tried
switching to the RT kernel (kernel 2.6.28-3-rt, via synaptic). The
result - a *huge*, unmanageable latency. I also noticed this warning
which I'd not seen before:
Thread: WARNING, can't assign realtime scheduling to thread!
I'm using jackdmp 1.9.4, compiled from source:
/usr/local/bin/jackd -S -R -dalsa -dhw:0 -r44100 -p256 -n2
I'm sure there are better realtime kernels out there, but before I
switch the kernel, I'd like to understand why exactly linuxsampler is
not being allocated realtime priority. I don't know much about this.
Incidentally, here's what 'top' reveals: (Note: these are with the
PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+
29516 guru 20 0 35872 13m 10m R 10.3 1.4 0:28.17
29503 guru 20 0 437m 436m 76m S 2.7 46.5 0:11.57
29493 guru 20 0 88632 74m 72m S 2.3 8.0 0:11.20
No user-owned entries have RT priority, but down the list some
root-owned processes do, for e.g:
3 root RT -5 0 0 0 S 0.0 0.0 0:00.00 migration/0
All user-oned processes have the same priority: 20
My /etc/security/limits.conf file ends with this:
@audio - rtprio 19
@audio - memlock unlimited
@audio - nice -19
And I'm a member of the group 'audio'.
Can someone help me out with this?
Thanks in advance!
Guru Prasad B.R.
Centre for Ecological Sciences
Indian Institute of Science
Bangalore - 560 012
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