Automatic Placement of Communications in Mesh-Partitioning Parallelization

Abstract

We present a tool for mesh-partitioning parallelization of numerical programs working iteratively on an unstructured mesh. This conventional method splits a mesh into sub-meshes, adding some overlap on the boundaries of the sub-meshes. The program is then run in SPMD mode on a parallel architecture with distributed memory. It is necessary to add calls to communication routines at a few carefully selected locations in the code. The tool presented here uses the data-dependence information to mechanize the placement of these synchronizations. Additionally, we see that there is not a unique solution for placing these synchronizations, and performance depends on this choice.