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Summary: Maximizing Job Benets On-line
Baruch Awerbuch y Yossi Azar z Oded Regev x
November 19, 2000
Abstract
We consider a benet model for on-line preemptive scheduling. In this
model jobs arrive at the on-line scheduler at their release time. Each job
arrives with its own execution time and benet function. The
ow time
of a job is the time that passes from its release to its completion. The
benet function species the benet gained for any given
ow time. A
scheduler's goal is to maximize the total benet gained. We present a
constant competitive ratio algorithm for that model in the uniprocessor
case for benet functions that do not decrease too rapidly. We also extend
the algorithm to the multiprocessor case while maintaining constant com-
petitiveness. The multiprocessor algorithm does not use migration, i.e.,
preempted jobs continue their execution on the same processor on which
they were originally processed.
1 Introduction
1.1 The basic problem
We are given a sequence of n jobs to be assigned to one machine. Each job j
has a release time r j and a length or execution time w j . Each job is known
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