Check which preempts are set on your distribution:
cat /boot/config-4.15.0-50-generic | grep PREEMPT
- CONFIG_PREEMPT
- CONFIG_PREEMPTIRQ_EVENTS
- CONFIG_HZ
These options should be set (according to Real time ethernet)
- CONFIG_RCU_BOOST=y
- CONFIG_RCU_BOOST_PRIO=99
How To determine Linux Kernel Timer Interrupt Frequency
Interupt handling Red hat performance tuning
Compile linux kernel with preempt_rt for ubuntu 18.04
- Check your kernel version
uname -r
Ubuntu and linux kernel versions
Setting RT priority on non-rt kernel
Audio jack rt Linux configuration
References
Intel Optimizing Computer applications for latency
Video
Maintaining a Real Time Stable Kernel - Steven Rostedt, VMware
Kernel Recipes 2016 - Understanding a Real-Time System (more than just a kernel)
Linux Performance Optimization - Red Hat EX442 - Complete Video Course