Kokkos: Performance Portability for the Exascale Era

Speaker: Christian Trott, Sandia National Laboratories
April 4, 2024

Presentation

Abstract

The exascale computing era has started and brought with it new challenges for high performance computing (HPC) applications. One of the biggest challenges is the diversity of hardware and vendor programming models. While all of the available or announced exascale class systems use GPUs, they leverage technology from different vendors. In the US, the Department of Energy (DOE) purchased three machines – two using AMD GPUs and one using Intel GPUs, while Europe is installing systems with GPUs from NVIDIA. To be able to use the vendor toolchain on each machine, one has to support NVIDIA’s CUDA, AMD’s HIP and Intel’s OneAPI (SYCL) programming model.

Kokkos provides a unified programming model which can target all these architectures and others, using the primary vendor toolchains. It provides an interface that leads to more maintainable and productive code than the vendor programming models, and guides users to write performance portable algorithms. Having seen significant community growth during its time as part of the DOE Exascale Computing Project, Kokkos is now used at more than 160 organizations in the world by thousands of developers. Its usage spans everything from classical HPC such as computational fluid dynamics or molecular dynamics simulations, data analytics in the radio astronomy community, to embedded applications in robotics.

This talk will provide an overview of Kokkos and its community, explain why one might want to leverage it, and discuss its future directions.

Biography

Christian Trott is a high performance computing expert with extensive experience in designing and implementing software for modern HPC systems. He is a principal member of staff at Sandia National Laboratories, where he co-leads the Kokkos core team developing performance portability solutions for engineering and science applications. Christian is also the head of Sandia's delegation to the ISO C++ standards committee, and a principal author of C++ standard features such as mdspan and linear algebra support. He also serves as adviser to numerous application teams, helping them redesign their codes using Kokkos and achieve performance portability for the next generation of supercomputers. In the past, Christian contributed significantly to numerous scientific software projects such as Trilinos and LAMMPS. He earned a doctorate from the University of Technology Ilmenau in theoretical physics with a focus on computational material research.

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