Computer Science Department
School of Computer Science, Carnegie Mellon University
Classifying Scheduling Policies
with Respect to Unfairness in an M/GI/1
Adam Wierman, Mor Harchol-Balter
Keywords: Scheduling; unfairness; M/G/1; FB; LAS; SET; feedback; least attained service; shortest elapsed time; PS; processor sharing; SRPT; shortest remaining processing time; slowdown.
It is common to classify scheduling policies based on their mean response
times. Another important, but sometimes opposing, performance metric is a
scheduling policy's fairness. For example, a policy that biases towards
short jobs so as to minimize mean response time, may end up being unfair to
long jobs. In this paper we define three types of unfairness and
demonstrate large classes of scheduling policies that fall into each type.
We end with a discussion on which jobs are the ones
being treated unfairly.