Finding the optimal quantum size: Sensitivity analysis of the M/G/1 round-robin queue

We consider the round robin (RR) scheduling policy where the server processes each job in its buffer for at most a fixed quantum, q, in a round-robin fashion. The processor sharing (PS) policy is an idealization of the quantum-based round-robin scheduling in the limit where the quantum size becomes infinitesimal, and has been the subject of many papers. It is well known that the mean response time in an M/G/1/PS queue depends on the job size distribution via only its mean. However, almost no explicit results are available for the round-robin policy. For example, how does the variability of job sizes affect the mean response time in an M/G/1/RR queue? How does one choose the optimal quantum size in the presence of switching overheads? In this paper we present some preliminary answers to these fundamental questions.

• Type: Journal
• Year: 2008
• Where: SIGMETRICS
• Authors: Varun Gupta
• Keywords: Hardware, Mean Response Time, Quantum Size, Quantum-based Round-robin Scheduling, SIGMETRICS 2008