基于动态松弛时间回收的开销敏感节能实时调度算法

An overhead-aware energy-efficient real-time scheduling algorithm based on dynamic slack reclamation

为适应实际系统中任务集的不断变化以及不可忽视状态切换开销的要求,针对多核多处理器系统中常见的周期任务模型,提出一种基于动态松弛时间回收的开销敏感节能实时调度算法DSROM,在每个TL面的初始时刻、任务提前完成时刻实现节能调度及动态松弛时间回收,在不违反周期任务集可调度性的基础上,达到实时约束与能耗节余之间的合理折衷。模拟实验结果表明,DSROM算法不仅保证了周期任务集的最优可调度性,而且当任务集总负载超过某一个值后,其节能效果整体优于现有方法,最多可节能近20%。

To meet the changeable reality of task sets for the runtime system and needs of non-ignorable switching overhead for processor state, we propose an overhead-aware energy-efficient real-time scheduling algorithm called a dynamic slack reclamation based overhead-aware energy-efficient real-time scheduling in multiprocessor systems （DSROM） for periodic tasks deployed on multi-core and multiprocessor systems. The main idea of the algorithm is to implement energy-efficient scheduling for real-time tasks at the initial time of each TL plane, and to reclaim dynamic slack time at the earlier completion time of a periodic task in each TL plane. Consequently, the algorithm can obtain a reasonable tradeoff between real-time constraint and energy-saving while guaranteeing the optimal feasibility of periodic tasks. Extensive simulation results demonstrate that the DSROM can guarantee the optimal feasibility of periodic tasks and save more energy on average than the existing algorithms when the total workload of the system exceeds a threshold, saving energy by about 20% at most.