Processor Sharing Queueing Models of Mixed Scheduling Disciplines for Time Shared System

Scheduling algorithms for time shared computing facilities are considered in terms of a queueing theory model. The extremely useful limit of "processor sharing" is adopted, wherein the quantum of service shrinks to zero; this approach greatly simplifies the problem. A class of algorithms is studied for which the scheduling discipline may change for a given job as a function of the amount of service received by that job. These multilevel disciplines form a natural extension to many of the disciplines previously considered.