It is hard not to talk about real-time when it comes to embedded systems. And when it comes to embedded system it would be unfair if we don’t talk about Linux. For those of you who are new to real-time systems and would like to learn fundamentals of it, following is a white paper which explains basics of real-time systems:
Besides discussing the fundamental concepts of real-time systems, the paper also distinguishes between soft real-time systems and hard real-time systems. It then discusses different metrics of real-time systems in depth like Interrupt latency, Scheduling latency and Worst-case latency by an example. It also highlights some major difference between GPOS (General Purpose OS) and RTOS (Real-Time OS).
The last two sections talks about current state of PREEMPT_RT patch – real time patch for Linux kernel. Also it discusses the relationship between Linux devices drivers and PREEMPT_RT patch and how can we get better (reduced) latency using PREEMPT_RT patch in Linux kernel.