Suspension-Aware Analysis for Hard Real-Time Multiprocessor Scheduling

In many real-time systems, tasks may experience suspension delays when accessing external devices. The problem of analyzing task systems with such suspensions on multiprocessors has been relatively unexplored. The commonly used suspension-oblivious approach of treating all suspensions as computation can be quite pessimistic. As an alternative, this paper presents the first suspension-aware hard real-time multiprocessor schedulability analysis for task systems with suspensions, under both global fixed-priority and global EDF scheduling. In experiments presented herein, the proposed schedulability tests proved to be superior to suspension-oblivious tests. Moreover, when applied to ordinary arbitrary-deadline sporadic task systems with no suspensions, the proposed analysis for fixed-priority scheduling improves upon prior analysis.