SUNDIALS Multiphysics+MPIManyVector Performance Testing

Technical Report · Thu Sep 26 04:00:00 EDT 2019

DOI:https://doi.org/10.2172/1567994· OSTI ID:1567994

Reynolds, Daniel R. ^[1]; Gardner, David J. ^[2]; Balos, Cody J. ^[2]; Woodward, Carol S. ^[2]

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1. Southern Methodist Univ., Dallas, TX (United States)
2. Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)

In this report we document performance test results on a SUNDIALS-based multiphysics demonstration application. We aim to assess the large-scale parallel performance of new capabilities that have been added to the SUNDIALS suite of time integrators and nonlinear solvers in recent years under funding from both the Exascale Computing Project (ECP) and the Scientific Discovery through Advanced Scientific (SciDAC) program, specifically: 1. SUNDIALS’ new MPIManyVector module, that allows extreme flexibility in how a solution "vector" is staged on computational resources. 2. ARKode’s new multirate integration module, MRIStep, allowing high-order accurate calculations that subcycle "fast" processes within "slow" ones. 3. SUNDIALS’ new flexible linear solver interfaces, that allow streamlined specification of problem-specific linear solvers. 4. SUNDIALS’ new N_Vector additions of "fused" vector operations (to increase arithmetic intensity) and separation of reduction operations into "local" and "global" versions (to reduce latency by combining multiple reductions into a single MPI_Allreduce call). We anticipate that subsequent reports will extend this work to investigate a variety of other new features, including SUNDIALS’ generic SUNNonlinearSolver interface and accelerator-enabled N Vector modules, and upcoming MRIStep extensions to support custom "fast" integrators (that leverage problem structure) and IMEX integration of the "slow" time scale (to add diffusion).

• Research Organization: Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Oak Ridge National Laboratory (ORNL), Oak Ridge, TN (United States). Oak Ridge Leadership Computing Facility (OLCF)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Contributing Organization: Exascale Computing Project (ECP)
• DOE Contract Number: AC52-07NA27344; AC05-00OR22725
• OSTI ID: 1567994
• Report Number(s): LLNL--TR-791538; 990780
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICS AND COMPUTING