gko::ext::kokkos

Helpers for round-tripping Ginkgo containers and executors through Kokkos. The integration lets a Kokkos-based application reuse its existing execution / memory spaces with Ginkgo, and pass Ginkgo arrays into Kokkos kernels (and vice versa) without copying.

For the user-facing walk-through, see the Kokkos extension page.

Executor interop

Ginkgo executors map onto Kokkos execution spaces. The free helpers in <ginkgo/extensions/kokkos/spaces.hpp> create a Ginkgo Executor whose memory and stream are backed by a Kokkos space:

• create_default_host_executor() — returns a ReferenceExecutor or OmpExecutor matching the active Kokkos default-host space.

• create_executor(ExecSpace, MemorySpace = {}) — explicit pairing of a Kokkos execution space with a memory space.

• create_default_executor() — returns an executor matching Kokkos’s current default execution space.

check_compatibility(exec) returns true iff a Ginkgo executor’s memory space matches the templated Kokkos memory space; assert_compatibility(obj) throws when it doesn’t. Use these as defensive checks at the boundary of a kernel parameterised over a Kokkos space.

Container interop

map_data converts a Ginkgo array, matrix::Dense, or raw pointer into a Kokkos View aliasing the same storage. The memory space is inferred from the type, so the resulting view is safe to pass to a Kokkos kernel without an extra copy:

auto arr = gko::array<double>{exec, 10};
auto view = gko::ext::kokkos::map_data(arr);  // Kokkos::View<double*>

The underlying mapper<Container, MemorySpace> template (gko::ext::kokkos::detail::mapper) is the extension point — specialise it to map a non-Ginkgo container into a Kokkos view.