Extreme-scale particle-based simulations on advanced HPC platformsLessons from PEZY-SC2, Sunway Taihulight and NVIDIA Volta

We overview the current status and future development directions of our framework for developing particle simulator (FDPS). Many of particle-based simulation codes share the same characteristic that the most time-consuming part of the simulation is the calculation of the interactions between particles, and a large fraction of programming effort is spent for procedures to make the force calculation efficient, such as the decomposition of computational domain, exchange of particles between domains, exchange of information necessary to calculate the interaction to particles in different domains, and efficient neighbor search. The basic idea of FDPS is to provide generic and high-performance library for these procedures. Using these procedures, researchers or application programmers in various fields can write their programs without taking care of parallelization and performance tuning. In order to make FDPS useful on advanced HPC platforms at present and in (near) future, we investigated its performance on several modern platforms and learned what can be the bottleneck. In this paper we summarize what we learned.