A Practical Scheduling Scheme for Non-Uniform Parallel Loops on Distributed Memory Parallel Machines

Loops without dependence8 among iterations are a rich source of paTalle&sm in many applications. Among these type8 of loops, non-uniform loops with vatiable execution times need eficient scheduling schemes to take advantages of the capabilities of parallel machines. In this paper, we present a global distributed control scheme (GDC) to schedule nonuniform loops on distributed memory parallel machines. GDC decentralizes scheduling controls among all processors with an attempt to keep heavily loaded processors being in charge of scheduling tasks. For comparative evaluation, GDC and other well-known scheduling schemes are implemented on a 512 proceasor Intel Delta parallel machine. Our experimental results show that GDC performs well on many applications with a’iflerent characteri&ics.