A large-scale study of MPI usage in open-source HPC applications

Abstract

Understanding the state-of-the-practice in MPI usage is paramount for many aspects of supercomputing, including optimizing the communication of HPC applications and informing standardization bodies and HPC systems procurements regarding the most important MPI features. Unfortunately, no previous study has characterized the use of MPI on applications at a significant scale; previous surveys focus either on small data samples or on MPI jobs of specific HPC centers. This paper presents the first comprehensive study of MPI usage in applications. We survey more than one hundred distinct MPI programs covering a significantly large space of the population of MPI applications. We focus on understanding the characteristics of MPI usage with respect to the most used features, code complexity, and programming models and languages. Our study corroborates certain findings previously reported on smaller data samples and presents a number of interesting, previously un-reported insights.