Introduction
Preempt_RT is a patch set of patches for the Linux kernel maintained by Ingo Molnar. It modifies the kernel so that it becomes (almost) completely preemptive. The classic kernel spinlocks are replaced by mutexes which support priority inheritance. In addition, the handling of all interrupts is outsourced to separate kernel threads. The presentation Linux und Echtzeit (German) by Jan Altenberg offers a very good and short summary about Preemt-RT and Xenomai
From 2024 on Preemp-RT was fully merged and enabled in mainline Linux for popular architectures.
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