Achieving Hard Real-Time Networking on PREEMPT_RT Linux with RTnet

There are many operating systems on the market, but, being free and having great user interface, connectivity and graphics features, Linux can be used in various scenarios like communication, trading and control systems. The PREEMPT_RT patch brings hard real-time behavior to Linux, but it lacks a real-time networking stack. RTnet is a mature hard real-time open source networking stack. This paper presents the main part port of the RTnet on PREEMPT_RT Linux kernel 5.9, along with stress tests that were run to prove the efficiency of the RTnet stack on PREEMPT_RT Linux.