Scalable MiniMD Design with Hybrid MPI and OpenSHMEM

Abstract

The MPI programming model has been widely used for scientific applications. The emergence of Partitioned Global Address Space (PGAS) programming models presents an alternative approach to improve programmability. With the global data view and lightweight communication operations, PGAS has the potential to increase the performance of scientific applications at scale. However, since the PGAS models are emerging, it is unlikely that entire applications will be re-written with them. Instead, unified communication runtimes have paved the way for a new class of hybrid applications that can leverage the benefits of both MPI and PGAS models. In this paper, we re-design an existing MPI based scientific mini-application (MiniMD) with MPI and OpenSHMEM programming models. We propose two alternative designs using MPI and OpenSHMEM programming models and compare performance and scalability of those designs with the original MPI-based implementation. Our performance evaluations using MVAPICH2-X (Unified MPI+PGAS Communication Runtime over InfiniBand) show a 17% reduction in total execution time, compared to existing MPI-based design with 1,024 cores.