Dynamic Partitioning of Non-Uniform Structured Workloads with Spacefilling Curves

We discuss Inverse Spaceelling Partitioning (ISP), a partitioning strategy for non-uniform scientiic computations running on distributed memory MIMD parallel computers. We consider the case of a dynamic workload distributed on a uniform mesh, and compare ISP against Orthogonal Recursive Bisection (ORB) and a Median of Medians variant of ORB, ORB-MM. We present two results. First, ISP and ORB-MM are superior to ORB in rendering balanced workloads|because they are more ne-grained|and incur communication overheads that are comparable to ORB. Second, ISP is more attractive than ORB-MM from a software engineering standpoint because it avoids elaborate bookkeeping. Whereas ISP partitionings can be described succinctly as logically contiguous segments of the line, ORB-MM's partitionings are inherently un-structured. We describe the general d-dimensional ISP algorithm and report empirical results with two-and three-dimensional, non-hierarchical particle methods.