Energy Aware Fault Tolerant Fixed Priority Task Scheduling in Multiprocessor System

Energy Management and Fault Tolerance are the two main design dimensions for Real Time Embedded Systems. In this paper, the combination of these two design parameters has been exploited. Various energy aware fault tolerant task scheduling techniques have been proposed for Standby-Sparing Systems. In these systems, one processor is used for executing primary tasks whereas other one executes only backup tasks. Energy is saved by applying DVS and DPM techniques or by shifting the backup task as late as possible to reduce the overlapped execution of Primary and Backup copy of a task. But using one processor for sole purpose of executing backups only, wastes the processor capacity as well as affects the energy consumption of the system. In this paper, it is conjectured that allocating mixture of primary and backup tasks on both processor will reduce the energy consumption of the system. The simulated results of the proposed Mix-Allocation policy for fixed-priority periodic real-time tasks in comparison to the recently proposed Standby/Sparing policy justifies our conjecture.