New Resource Augmentation Analysis of the Total Stretch of SRPT and SJF in Multiprocessor Scheduling

Abstract

This paper studies online job scheduling on multiprocessors and, in particular, investigates the algorithms SRPT and SJF for minimizing total stretch, where the stretch of a job is its flow time (response time) divided by its processing time. SRPT is perhaps the most well-studied algorithm for minimizing total flow time or stretch. This paper gives the first resource augmentation analysis of the total stretch of SRPT, showing that it is indeed O(1)-speed 1-competitive. This paper also gives a simple lower bound result that SRPT is not s-speed 1-competitive for any s 1). We conjecture that SRPT also admits a similar result.