Dynamic Voltage Scaling for Priority-Driven Distributed Real-Time Systems

Energy consumption is increasingly affecting battery life and cooling for computer systems. Dynamic Voltage and frequency Scaling (DVS) has been shown to substantially reduce the amount of power required for uniprocessor and multiprocessor real-time systems that have independent tasks or a statically computed schedule. However, no DVS algorithm has been demonstrated for tasks with precedence constraints and using a priority-driven scheduler. Static scheduling relies an offline scheduling algorithms to determine voltage assignments. More flexible scheduling is needed for applications like target tracking, in which tasks arrive and depart the system frequently at run time. This paper describes how to schedule end-to-end tasks with DVS on priority-driven partitioned real-time multiprocessor systems. DVS scheduling can reduce energy consumption to as little as 11% of energy consumption without DVS.