[LAU] help request: RT audio checkup and xorg's xruns

[Nicola Pandini]

Hello list!
I have a setup that I use in my live sets made with an ASUS N551 laptops 
and a NI Komplete Audio 6, which allows me to play without XRUNS at 64 
frames / period with a modular approach (Qtractor, LinuxSampler, 
Yoshimi, SooperLooper, PureData).
The whole thing runs on Debian Stretch with AVLinux 4.9.47-rt37avl2 kernel.
I am quite happy with the performance of this setup, but I started 
having XRUNS when I added real-time video management as well. Those 
issues made me notice that the system runs without XRUNS only if XOrg is 
not stressed much, while it starts producing XRUNS when I play a video, 
or when I open the browser, or even when I quickly move or resize a window.

I would like to understand if the problem is due to an incorrect 
configuration of realtime priorities, or to something that I have not 
yet managed to trap.

I currently use these configurations:

[Xorg]
The video driver is i915.
I read on the internet that:
"If your graphic card was manufactured in 2007 and newer, try 
uninstalling the xserver-xorg-video-intel package and use the builtin 
modesetting driver (xserver-xorg-core) instead"
Questions:
- I uninstalled xserver-xorg-video-intel, but I still see the i915 
driver: is that correct, or should I see another driver?

[rtirq]
RTIRQ_NAME_LIST = "snd usb i8042"
RTIRQ_PRIO_HIGH = 90
RTIRQ_PRIO_DECR = 5
RTIRQ_PRIO_LOW = 51
RTIRQ_RESET_ALL = 0
RTIRQ_NON_THREADED = "rtc snd"
Questions:
- rtc must be in "NON_THREADED", or in "RTIRQ_NAME_LIST"?
- in "RTIRQ_NAME_LIST" can I remove "usb" and put only the item that 
manages my USB card? Should it be xhci?
- can i take i8042 off the list?
- is it recommended to use RTIRQ_RESET_ALL = 1 to override all other IRQs?

[jackd]
jackd -P83 -dalsa -dhw: K6 -r44100 -p64 -n2 -I1
Questions:
- the priority must be lower than those that are set to the IRQs by rtirq?

[limits.conf]
@audio - rtprio 99 # maximum realtime priority
@audio - memlock unlimited # maximum locked-in-memory address space (KB)
Questions:
- what is the recommended value of rtprio in 2020? On the internet I 
find 90, 95 and 99

Can you help me do a checkup of my configuration?

Thanks!

-- 
Nicola Pandini
http://nicolapandini.damai.it