TWO PRECEDENCE-RELATED TASK-SCHEDULING ALGORITHMS

Abstract

We propose two scheduling algorithms for precedence-related tasks in a parallel computing system with finite number of available processors. The first algorithm, called Scheduling with Successors' Level Tracking (SSLT), is designed for TOS (Task-Only-Scheduling) on multiprocessor systems. The second algorithm, named Scheduling with Communication Successors' Priority Tracking (SCST), is designed for TCS (Task-with-Communication Scheduling) on distributed systems. The performance analysis and simulation studies of SSLT and SCST are given. The results have shown that the performance of the SSLT is better than classical LEVEL and LABEL algorithms in terms of application program execution time. The schedule returned by SSLT or SCST is very near to the optimal schedule determined using exhaustive search. Both SSLT and SCST require much less computational effort compared with exhaustive search in obtaining task schedule.