Lightweight Real-Time Synchronization under P-EDF on Symmetric and Asymmetric Multiprocessors

This paper revisits lightweight synchronization under partitioned earliest-deadline first (P-EDF) scheduling. Four different lightweight synchronization mechanisms - namely preemptive and non-preemptive lock-free synchronization, as well as preemptive and non-preemptive FIFO spin locks - are studied by developing a new inflation-free schedulability test, jointly with matching bounds on worst-case synchronization delays. The synchronization approaches are compared in terms of schedulability in a large-scale empirical study considering both symmetric and asymmetric multiprocessors. While non-preemptive FIFO spin locks were found to generally perform best, lock-free synchronization was observed to offer significant advantages on asymmetric platforms.