Transform Analysis of Preemption Overhead in the M/G/1

Abstract

Preemptive scheduling policies, which allow pausing jobs mid-service, are ubiquitous because they allow important jobs to receive service ahead of unimportant jobs that would otherwise delay their completion. The canonical example is Shortest Remaining Processing Time (SRPT), which preemptively serves the job with least remaining work at every moment in time [9]. There is a robust literature analyzing response time (elapsed time between a job's arrival and completion) in the M/G/1 queue under many preemptive policies [6, 10, 11], shedding light on questions such as how preemption affects the mean and tail of response time, and whether preemption is unfair towards low-priority jobs.