Exact schedulability test for sporadic mixed-criticality real-time systems using antichains and oracles
Simon Picard, Antonio Paolillo, Gilles Geeraerts, Joël Goossens · 2024
This work addresses the problem of exact schedulability assessment in uniprocessor mixed-criticality real-time systems with sporadic task sets.We model the problem by means of a finite automaton that has to be explored in order to check for schedulability.To mitigate the state explosion problem, we provide a generic algorithm which is parameterised by several techniques called oracles and simulation relations.These techniques leverage results from the scheduling literature as "plug-ins" that make the algorithm more efficient in practice.Our approach achieves up to a 99.998% reduction in the search space required for exact schedulability testing, making it practical for a range of task sets, up to 8 tasks or maximum periods of 350.This method enables to challenge the pessimism of an existing schedulability test and to derive a new dynamic-priority scheduler, demonstrating its good performance.