A task-based GPU-compatible discontinuous Galerkin fluid solver

In order to address the ever increasing heterogeneity of high performance computing platforms, task-based programming models have emerged to facilitate the implementation and improve the scaling of computational physics solvers. Recently, we presented a discontinuous Galerkin solver for the compressible Navier-Stokes equations which leverages the Legion programming system for distributing and scheduling tasks. In this talk, we discuss the use of the Kokkos library to achieve performance portability by demonstrating efficient execution of the program on traditional CPUs and Nvidia GPUs from a single source code. Implementation and scaling challenges specific to the present application will be emphasized, in particular regarding the data layout choices, the splitting of the algorithm into tasks, and the communication pattern. Preliminary results for single and multi-GPU performance will be presented.