Publications

Trott, Christian R.; Liber, Nevin L.; Lebrun-Grandie, Damien L.; Poliakoff, David Z.; Hollman, David S.; Lewis, Cannada L.; Sunderland, Daniel S.

Abstract not provided.

Proceedings of P3HPC 2019: International Workshop on Performance, Portability and Productivity in HPC - Held in conjunction with SC 2019: The International Conference for High Performance Computing, Networking, Storage and Analysis

Hollman, David S.; Lelbach, Bryce; Edwards, H.C.; Hoemmen, Mark F.; Sunderland, Daniel S.; Trott, Christian R.

Multi-dimensional arrays are ubiquitous in high-performance computing (HPC), but their absence from the C++ language standard is a long-standing and well-known limitation of their use for HPC. This paper describes the design and implementation of mdspan, a proposed C++ standard multidimensional array view (planned for inclusion in C++23). The proposal is largely inspired by work done in the Kokkos project - a C++ performance-portable programming model de- ployed by numerous HPC institutions to prepare their code base for exascale-class supercomputing systems. This paper describes the final design of mdspan af- ter a five-year process to achieve consensus in the C++ community. In particular, we will lay out how the design addresses some of the core challenges of performance-portable programming, and how its cus- tomization points allow a seamless extension into areas not currently addressed by the C++ Standard but which are of critical importance in the heterogeneous computing world of today's systems. Finally, we have provided a production-quality implementation of the proposal in its current form. This work includes several benchmarks of this implementation aimed at demon- strating the zero-overhead nature of the modern design.

Hollman, David S.; Lelbach, Bryce L.; Edwards, H.C.; Hoemmen, Mark F.; Sunderland, Daniel S.; Trott, Christian R.

Abstract not provided.

Geoscientific Model Development

Bertagna, Luca B.; Deakin, Michael; Guba, Oksana G.; Sunderland, Daniel S.; Bradley, Andrew M.; Kalashnikova, Irina; Taylor, Mark A.; Salinger, Andrew G.

We present an architecture-portable and performant implementation of the atmospheric dynamical core (High-Order Methods Modeling Environment, HOMME) of the Energy Exascale Earth System Model (E3SM). The original Fortran implementation is highly performant and scalable on conventional architectures using the Message Passing Interface (MPI) and Open MultiProcessor (OpenMP) programming models. We rewrite the model in C++ and use the Kokkos library to express on-node parallelism in a largely architecture-independent implementation. Kokkos provides an abstraction of a compute node or device, layout-polymorphic multidimensional arrays, and parallel execution constructs. The new implementation achieves the same or better performance on conventional multicore computers and is portable to GPUs. We present performance data for the original and new implementations on multiple platforms, on up to 5400 compute nodes, and study several aspects of the single-and multi-node performance characteristics of the new implementation on conventional CPU (e.g., Intel Xeon), many core CPU (e.g., Intel Xeon Phi Knights Landing), and Nvidia V100 GPU.

Hollman, David S.; Hoemmen, Mark F.; Sunderland, Daniel S.; Trott, Christian R.

Abstract not provided.

Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics)

Scogland, Thomas R.W.; Sunderland, Daniel S.; Olivier, Stephen L.; Hollman, David S.; Evans, Noah; de Supinski, Bronis R.

For at least the last 20 years, many have tried to create a general resource management system to support interoperability across various concurrent libraries. The previous strategies all suffered from additional toolchain requirements, and/or a usage of a shared programing model that assumed it owned/controlled access to all resources available to the program. None of these techniques have achieved wide spread adoption. The ubiquity of OpenMP coupled with C++ developing a standard way to describe many different concurrent paradigms (C++23 executors) would allow OpenMP to assume the role of a general resource manager without requiring user code written directly in OpenMP. With a few added features such as the ability to use otherwise idle threads to execute tasks and to specify a task “width”, many interesting concurrent frameworks could be developed in native OpenMP and achieve high performance. Further, one could create concrete C++ OpenMP executors that enable support for general C++ executor based codes, which would allow Fortran, C, and C++ codes to use the same underlying concurrent framework when expressed as native OpenMP or using language specific features. Effectively, OpenMP would become the de facto solution for a problem that has long plagued the HPC community.

2018 IEEE High Performance Extreme Computing Conference, HPEC 2018

Kotteda, V.M.Krushnarao; Kumar, Vinod; Spotz, William S.; Sunderland, Daniel S.

Performance portability is a challenge for application developers as the source code needs to be executed and performant on various hybrid computing architectures. The linear iterative solvers implemented in most applications consume more than 70% of the runtime. This paper presents the results of a linear solver in Trilinos for fluidized bed applications. The linear solver implemented in our code is based on the Kokkos programming model in Trilinos, which uses a library approach to provide performance portability across diverse devices with different memory models. For large scale problems, the numerical experiments on Xeon Phi and Kepler GPU architectures show good performance over the results on Xeon (Haswell) computing architectures.

Bertagna, Luca B.; Deakin, Michael D.; Guba, Oksana G.; Sunderland, Daniel S.; Bradley, Andrew M.; Kalashnikova, Irina; Taylor, Mark A.; Salinger, Andrew G.

Abstract not provided.

Sunderland, Daniel S.; Hoemmen, Mark F.; Trott, Christian R.

This report documents the completion of milestone STPRO4-4 Kokkos back-ends research, collaborations, development, optimization, and documentation. The Kokkos team updated its existing backend to support the software stack and hardware of DOE's Sierra, Summit and Astra machines. They also collaborated with ECP PathForward vendors on developing backends for possible exa-scale architectures. Furthermore, the team ramped up its engagement with the ISO/C++ committee to accelerate the adoption of features important for the HPC community into the C++ standard.

Trott, Christian R.; Sunderland, Daniel S.; Hoemmen, Mark F.

This report documents the completion of milestone STPRO4-4 Kokkos back-ends research, collaborations, development, optimization, and documentation. The Kokkos team updated its existing backend to support the software stack and hardware of DOE's Sierra, Summit and Astra machines. They also collaborated with ECP PathForward vendors on developing backends for possible exa-scale architectures. Furthermore, the team ramped up its engagement with the ISO/C++ committee to accelerate the adoption of features important for the HPC community into the C++ standard.

Spotz, William S.; Kotteda, V M.; Kumar, V.K.; Sunderland, Daniel S.

Abstract not provided.

Hammond, Simon D.; Trott, Christian R.; Ibanez-Granados, Daniel A.; Sunderland, Daniel S.

Abstract not provided.

Bertagna, Luca B.; Deakin, Michael D.; Guba, Oksana G.; Sunderland, Daniel S.; Bradley, Andrew M.; Kalashnikova, Irina; Taylor, Mark A.; Salinger, Andrew G.

Abstract not provided.

Hammond, Simon D.; Trott, Christian R.; Ibanez-Granados, Daniel A.; Sunderland, Daniel S.

Abstract not provided.

Salinger, Andrew G.; Bertagna, Luca B.; Bradley, Andrew M.; Deakin, Michael D.; Guba, Oksana G.; Sunderland, Daniel S.; Kalashnikova, Irina

Abstract not provided.

Hammond, Simon D.; Trott, Christian R.; Ibanez-Granados, Daniel A.; Edwards, Harold C.; Sunderland, Daniel S.; Ellingwood, Nathan D.; Brandt, James M.; Gentile, Ann C.; Cook, Jeanine C.; Hoekstra, Robert J.

Abstract not provided.

Trott, Christian R.; Edwards, Harold C.; Ibanez-Granados, Daniel A.; Sunderland, Daniel S.; Bova, S.W.; Labreche, Duane A.; Ellingwood, Nathan D.

Abstract not provided.

Trott, Christian R.; Edwards, Harold C.; Hammond, Simon D.; Sunderland, Daniel S.

Abstract not provided.

Sunderland, Daniel S.; Peterson, Brad P.; schmidt, john s.; Humphrey, Alan H.; Thornock, Jeremy T.; Berzins, Martin B.; Sunderland, Daniel S.

Abstract not provided.

Sunderland, Daniel S.; Edwards, Harold C.; Trott, Christian R.

Abstract not provided.

Edwards, Harold C.; Trott, Christian R.; Sunderland, Daniel S.

Abstract not provided.

Sunderland, Daniel S.

Abstract not provided.

Edwards, Harold C.; Sunderland, Daniel S.; Hoemmen, Mark F.; Ellingwood, Nathan D.; Trott, Christian R.; Mackey, Greg

Abstract not provided.

Sunderland, Daniel S.; Peterson, Brad P.; schmidt, john s.; Humphrey, Alan H.; Thornock, Jeremy T.; Berzins, Martin B.

Abstract not provided.

Rajamanickam, Sivasankaran R.; Edwards, Harold C.; Trott, Christian R.; Sunderland, Daniel S.

Abstract not provided.