A Group-Based Energy-Efficient Dual Priority Scheduling for Real-Time Embedded Systems

As the limitation of energy consumption of real-time embedded systems becomes more and more strict, it has been difficult to ignore the time overhead and energy consumption of context switches for fixed-priority tasks with preemption scheduling (FPP) in multitasking environments. In addition, the scheduling for different types of tasks may disrupt each other and affect system reliability. A group-based energy-efficient dual priority scheduling (GEDP) is proposed in this paper. The GEDP isolates different types of tasks to avoid the disruption. Furthermore, it also reduces context switches effectively, thus decreasing system energy consumption. As many studies ignored the context switches’ overhead in the worst-case response time (WCRT) model, and it will affect the accuracy of WCRT, thereby affecting the system schedulability. Consequently, the WCRT model is improved based on considering context switches’ overhead. The GEDP is designed and implemented in Linux, and the time overhead and energy consumption of context switches is compared in different situations with GEDP and FPP. The experimental results show that GEDP can reduce context switches by about 1% and decrease energy consumption by about 0.6% for given tasks.