Overhead-Aware Schedulability Evaluation of Semi-Partitioned Real-Time Schedulers

Schedulability analyses, while valuable in theoretical research, cannot be used in practice to reason about the timing behaviour of a real-time system without including the overheads induced by the implementation of the scheduling algorithm. In this paper, we provide an overhead-aware schedulability analysis based on demand bound functions for two hard real-time semi-partitioned scheduling algorithms, EDF-WM and C=D. This analysis is based on a novel implementation that uses a global clock to reduce the overheads incurred due to the release jitter of migrating subtasks. The analysis is used to guide the respective off-line task assignment and splitting procedures. Finally, results of an evaluation are provided highlighting how the different algorithms perform with and without a consideration of overheads.