Energy-aware Fixed-Priority Multi-core Scheduling for Real-time Systems

Multi-core processors are becoming more and more popular in embedded and real-time systems. While fixed-priority scheduling with task-splitting in real-time systems are widely applied, current approaches have not taken into consideration energy-aware aspects such as dynamic voltage/frequency scheduling (DVS). In this paper, we propose two strategies to apply dynamic voltage scaling (DVS) to fixed-priority scheduling algorithms with task-splitting for periodic real-time tasks on multi-core processors. The first strategy determines voltage scales for each processor after scheduling (Static DVS), which ensures all tasks meet the timing requirements on synchronization. The second strategy adaptively determines the frequency of each task before scheduling (Adaptive DVS) according to the total utilization of task-set and number of cores available. The combination of frequency pre-allocation and task-splitting makes it possible to maximize energy savings with DVS. Simulation results show that it is possible to achieve significant energy savings with DVS while preserving the schedulability requirements of real-time schedulers for multi-core processors.