[LAU] realtime priority - FIFO vs Round Robin and scheduling

hi Linux audio community!

i've been strugling with XRUNS and glitches on a machine using Renoise,
SuperCollider and Processing. i wrote a question also on Renoise forum,
but everything boils down to this:

Renoise seems to be running some threads with FIFO scheduler with a
priority that is _below_ that of JACK and firewire driver (correct
right?), but ALSO some threads using Round Robin scheduler with VERY
HIGH RT priority of 95. my question is if this is a possible cause for
glitches and XRUNS? the priority of 95 is above realtime clock (RTC)
and firewire irq! i wonder if Round Robin scheduler isn't somewhat less
stressful for the system and FIFO threads would still have priority?

PRI RTPRIO CLS PID NI CMD
135 95 RR 2255 - renoise
135 95 RR 2255 - renoise
130 90 FF 114 - [irq/8-rtc0]
125 85 FF 200 - [irq/20-firewire]
106 66 FF 2583 - jackd -R -P 60 -d firewire -r 44100 -p 128 -n 3

so i'm asking Renoise guys if they know anything about it.

to test, is there a way to start a process and force to use different
scheduler AND/OR change priority?

chrt reports Renoise is using SCHED_OTHER.

any ideas greatly appreciated.

the full forum post (with more data) is here:
http://forum.renoise.com/index.php/topic/47767-linux-priority-too-high/

best,
Luka

--
Luka Prinčič / Nova deViator // + 386-40-66-77-98 / http://deviator.si /
- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
27·may Interface Fractures III:SILICON | In/Visible Cities, Gorizia, IT
31·may Turns Me On EP & VIDEO release | http://patreon.com/novadeviator 
01·jun Koordinate Zvoka | Pritličje | Ljubljana·SI
· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
OUT NOW!
*Wanda & Nova deViator: Recursion EP (free DL & video)*
http://wndv.bandcamp.com/album/recursion-ep 
https://youtu.be/4D2cTyAmj0k 
· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
MORE MUSIC: http://novadeviator.bandcamp.com 
SUBSCRIBE: http://nova.deviator.si/follow 
PATREON: http://patreon.com/novadeviator 
MORE: http://wndv.si | http://kamizdat.si | http://emanat.si 
· · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · · ·
gpg key: http://pgp.mit.edu/pks/lookup?op=get&search=0x1397C721FFA52FD7
·                                                                     ·
The great moral question of the twenty-first century is this:
if all knowledge, all culture, all art, all useful information can be
costlessly given to everyone at the same price that it is given to
anyone; if everyone can have everything, anywhere, all the time,
why is it ever moral to exclude anyone? 
                                                         -- Eben Moglen
-                                                                     -

_______________________________________________
Linux-audio-user mailing list
Linux-audio-user@email-addr-hidden
http://lists.linuxaudio.org/listinfo/linux-audio-user