On-Line Dynamic Voltage Scaling for EDZL Scheduling on Symmetric Multiprocessor Real-Time Systems

Abstract

EDZL (Earliest Deadline Zero Laxity) scheduling is known to be at least as EDF (Earliest Deadline First) in task scheduling on symmetric multiprocessor real-time systems; however, there are few works on energy conversation on the EDZL. This paper proposes an on-line Dynamic Voltage Scaling (DVS) algorithm of the global EDZL to reduce energy consumption of real-time tasks. The proposed algorithm dynamically adjusts processor speed at each scheduling point with re-assigning deadlines of active jobs that reduces power consumption of processors while making all real-time tasks schedulable by EDZL. Extensive simulations show that the proposed algorithm reduces power consumption more than the previous algorithm for EDZL.