TY - GEN
T1 - Optimal Priority Assignment for Synchronous Harmonic Tasks with Dynamic Self-Suspension
AU - Günzel, Mario
AU - Sudvarg, Marion
AU - Deppert, Max
AU - Li, Ao
AU - Zhang, Ning
AU - Chen, Jian Jia
N1 - Publisher Copyright:
© 2025 IEEE.
PY - 2025
Y1 - 2025
N2 - Self-suspension behavior happens when a job has to wait for some activity to complete and results in substantial schedulability degradation in real-time systems. Despite extensive studies for self-suspending real-time task systems, the state of the art has barely addressed the optimality of the scheduling algorithms, especially for tasks with dynamic self-suspension. In this paper, we explore optimal priority assignment for periodic real-time tasks with dynamic self-suspension under Task-level Fixed-Priority (T-FP) scheduling. To that end, we provide exact schedulability tests for frame-based and synchronous harmonic tasks. We show that the Suspension-Aware Deadline-Monotonic (SADM) priority assignment is an optimal fixed-priority scheduler for many scenarios. Further, for cases where SADM is not optimal, we adopt Audsley's Optimal Priority Assignment (OPA) approach to derive an optimal fixedpriority assignment. Evaluation results show that the exact tests outperform state-of-the-art schedulability tests from the literature, and that optimal priority assignments significantly improve schedulability over classical priority assignments.
AB - Self-suspension behavior happens when a job has to wait for some activity to complete and results in substantial schedulability degradation in real-time systems. Despite extensive studies for self-suspending real-time task systems, the state of the art has barely addressed the optimality of the scheduling algorithms, especially for tasks with dynamic self-suspension. In this paper, we explore optimal priority assignment for periodic real-time tasks with dynamic self-suspension under Task-level Fixed-Priority (T-FP) scheduling. To that end, we provide exact schedulability tests for frame-based and synchronous harmonic tasks. We show that the Suspension-Aware Deadline-Monotonic (SADM) priority assignment is an optimal fixed-priority scheduler for many scenarios. Further, for cases where SADM is not optimal, we adopt Audsley's Optimal Priority Assignment (OPA) approach to derive an optimal fixedpriority assignment. Evaluation results show that the exact tests outperform state-of-the-art schedulability tests from the literature, and that optimal priority assignments significantly improve schedulability over classical priority assignments.
KW - audsleys optimal priority assignment (opa)
KW - dynamic self-suspension
KW - harmonic tasks
KW - priority assignment
KW - real-time scheduling
KW - schedulability analysis
KW - self-suspending tasks
UR - https://www.scopus.com/pages/publications/105008055605
U2 - 10.1109/RTAS65571.2025.00010
DO - 10.1109/RTAS65571.2025.00010
M3 - Conference contribution
AN - SCOPUS:105008055605
T3 - Proceedings of the IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS
SP - 40
EP - 53
BT - Proceedings - 31st IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2025
PB - Institute of Electrical and Electronics Engineers Inc.
T2 - 31st IEEE Real-Time and Embedded Technology and Applications Symposium, RTAS 2025
Y2 - 6 May 2025 through 9 May 2025
ER -