PUMA publications for /tag/Task-basedThu Mar 24 16:12:08 CET 20222021 {IEEE} International Parallel and Distributed Processing Symposium Workshops ({IPDPSW})377--386Beyond Fork-Join: Integration of Performance Portable Kokkos Kernels with HPX2021Kokkos Performance Portability Task-based hpc myown {CUDA} {GPU} {HPX} Between a widening range of {GPU} vendors and the trend of having more {GPUs} per compute node in supercomputers such as Summit, Perlmutter, Frontier and Aurora, developing performant yet portable distributed {HPC} applications becomes ever more challenging. Leveraging existing solutions like Kokkos for platform-independent code and {HPX} for distributing the application in a task-based fashion can alleviate these challenges. However, using such frameworks in the same application requires them to work together seamlessly. In this work we present an {HPX} Kokkos integration that works both ways: we can integrate {CPU} and {GPU} Kokkos kernels as {HPX} tasks and inversely use {HPX} worker threads to work on Kokkos kernels. Using {HPX} futures makes launching and synchronizing Kokkos kernels from multiple threads easy, allowing us to move away from the more traditional fork-join model. To evaluate our integrations we ported existing Vc and {CUDA} kernels within an existing {HPX} application, Octo-Tiger, to use Kokkos instead. We achieve comparable, or better, performance than with previous Vc and {CUDA} kernels, showing both the viability of our {HPX} Kokkos integration, as well as future-proofing Octo-Tiger for a wider range of potential machines. Furthermore, we introduce event polling for synchronizing {CUDA} kernels (or Kokkos kernels on the respective backend) achieving speedups over the previous solution using callbacks.Task-basedCommunity for tag(s) Task-based