A comparison of heuristics for scheduling DAGs on multiprocessors

Many algorithms to schedule directed acyclic graphs (DAGs) on multiprocessors have been proposed, but there has been little work done to determine their effectiveness. Since multiprocessor scheduling is an NP-hard problem, no exact tractable algorithm exists, and no baseline is available from which to compare the resulting schedules. This paper is an attempt to quantify the differences in a few of the heuristics. The empirical performance of five heuristics is compared when they are applied to ten specific DAGs which represent program dependence graphs of important applications. The comparison is made between a graph based method a list scheduling technique and three critical path methods