rts - as in *r*eal-*t*ime *s*settings is a script used by a systemd service, allowing to set pre-defined real-time related scheduling settings. Its service files are dependant upon the real-time kernel, which means, they will only start if /sys/kernel/realtime is present and not empty. This software and all of its components are licensed under the GPLv3.
When starting the systemd service rts.service, the general settings file /etc/rts/rts will be sourced.
Using rts@.service a configuration file (by the name of the word following the @) below /etc/rts/ will be used.
Some examples can be found in /etc/rts/examples. For further settings and a general overview, please have a look at the tuna documentation