BCS-MPI: A New Approach in the System Software Design for Large-Scale Parallel Computers

Buffered CoScheduled MPI (BCS-MPI) introduces a new approach to design the communication layer for large-scale parallel machines. The emphasis of BCS-MPI is on the global coordination of a large number of communicating processes rather than on the traditional optimization of the point-to-point performance. BCS-MPI delays the inter-processor communication in order to schedule globally the communication pattern and it is designed on top of a minimal set of collective communication primitives. In this paper we describe a prototype implementation of BCS-MPI and its communication protocols. Several experimental results, executed on a set of scientific applications, show that BCS-MPI can compete with a production-level MPI implementation, but is much simpler to implement, debug and model.