A new heuristic for scheduling parallel programs on multiprocessor

In this paper we present an efficient algorithm, called CASS-II, for task clustering without task duplication. Unlike the DSC algorithm, which is empirically the best known algorithm to date in terms of both speed and solution quality, CASS-II uses only limited “global” information and does not recompute the critical path in each refinement step. Therefore, the algorithm runs in O(|E|+|V|lg|V|) which is faster than O((|V|+|E|)lg|V|) of the DSC algorithm. Indeed, our experimental results show that CASS-II is between 3 to 5 times faster than DSC. (It is worth pointing out that we used the C code for DSC developed by the authors of the DSC algorithm. The C code for CASS-II was developed by the authors of this paper). With respect to solution quality, experimental results show that CASS-II is virtually as good as DSC and, in fact, even outperforms DSC for very fine grain DAGs (granularity less than 0.6)