Linux: priority too high?

Hi!

I think renoise isn’t the very most stable thing for sub 10ms latency. Or maybe 5-8ms with a hard rt kernel. And some xruns detected by jack don’t really seem to glitch the audio. IDK why, maybe the fixed prio 95 rr worker threads do have something to do with it, but maybe it’s allright and those threads handle getting the load done without interfering with other programs too much. And yes - on the one hand as a jack program you would expect renoise to do its processing in the jack threads, on the other hand this way it probably has its greater freedom for example for multicore scheduling. I’ve once tried (as the prio 95 has 4 prios above up to 99 possible) to put certain stuff (soundcard irq, jack, rtc, …) above the renoise rr threads, but it actually worsened performance and gave extremely more xruns iirc. Btw I think to recall that renoise realtime priorities are exclusive btw, there isn’t any “so and so much above and thus more priorised by a certain amount”, it is “above, even by just one, always gets served first until it passes control to all stuff below which will get served in order of priority”.

For another recent discussion on this topic see: https://forum.renoise.com/t/low-latency-and-xrun-optimizations-on-linux/45002