Since linux v5.4 armbian_build enables the CONFIG_RT_GROUP_SCHED config option.   Some armbian users use the soft real-time features for either real-time audio (jackd), or control (eg. klipper_host_mcu), However, real-time group scheduling, enabled by this options complicates the user space configuration required to acquire real-time scheduling in applications and daemons.   Setting ulimit -r or LimitRTPRIO= is no longer enough, it is also required to allocate CPU time f