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The Exascale Computing Project (ECP) Capability Assessment Report for Software Technologies at Sandia National Laboratories is provided. The projects are now aggregated to include Kokkos, Kokkos Kernels, VTK-m Operating Systems, and On-Node Runtime efforts. Key challenges and solution strategies are presented for each.
Proxy applications are small, simplified codes that allow application developers to share important features of large applications without forcing collaborators to assimilate large and complex code bases. Proxies can also be though of as models for larger codes. Because proxies omit features and capabilities of their parent applications (otherwise they wouldn’t be small), the question naturally arises whether any given proxy is actually a faithful model for its parent application for some particular modeling purpose. This report sets out to answer that question for some of the proxies in the ECP proxy app collection, with particular attention to performance. It also completes the AD-CD-PA-504 Milestone: "We will assess the fidelity of 8 proxy applications with respect to their respective parent applications using the methodology previously developed."
The ForTrilinos subproject of the Exascale Computing Project (ECP) was initiated to bring the capabilities and scalability of the Trilinos numerical solver collection to Fortran scientific application codes. A novel Fortran extension to the Simplified Wrapper and Interface Generator (SWIG) tool, which automatically generates Fortran bindings from existing C/C++ library code, has been applied to key Trilinos solver libraries to generate the new ForTrilinos libraries. SWIG-Fortran has additionally been used to generate new Fortran compatibility layers for additional scientific libraries and applications. This report summarizes the products and impact of the ForTrilinos subproject.
The ECP STPR17-121 highlights slide is presented.
Testing conducted to determine the feasibility of converting the 16/35/70 hi-speed processor to process Kodak film types 7381/7271 (16mm) and 5381/5271 (35mm) color negative films using Kodak ECP chemistry is described.
The thesis of this session of the ECP Bone workshop is that computer modeling is required in order to evaluate factor of risk for fracture when considering the uniquely localized bone loss conditions experienced by Astronauts. This session provides an opportunity to introduce the Integrated Medical Model Bone Fracture Risk (IMM-BFxRM) simulation approach and how this and other models improve understanding of the effects of exercise countermeasures. This workshop session also provides an opportunity for the panel to provide recommendations on this and other "complex modeling" approaches, as well as, the importance of funding the IMM-BFxRM and companion efforts by external scientists (Lang and Keyak).
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The OpenMP language continues to evolve with every new specification release, as does the need to validate and verify the new features that have been implemented by the different vendors. With the release of OpenMP 5.0 and OpenMP 5.1, new target offload and host-based features have been introduced to the programming model. While OpenMP continues to grow in maturity, there is an observable growth in the number of compiler and hardware vendors that support OpenMP. In this manuscript, the main focus is on evaluating the conformity and OpenMP implementation progress of various compiler vendors such as Cray, IBM, GNU, Clang/LLVM, NVIDIA, and Intel. More specifically, the 4.5, 5.0, and 5.1 versions of the OpenMP specification are analyzed. For our experimental setup, the Crusher and Summit computing systems hosted by Oak Ridge National Lab’s Computing Facilities are utilized. The effort of vendor agnostic analysis of these implementations is especially valuable for application developers who are using new OpenMP features to accelerate their scientific codes. Insights are presented into the current implementation status of various vendors, the progression of specific compiler’s support for OpenMP overtime, the subset of OpenMP 4.5, 5.0, and 5.1 that is supported by all compilers, and examples of how our test suite has influenced discussion regarding the correct interpretation of the OpenMP specification. By evaluating OpenMP conformity of pre-Exascale computing systems, the aim is to detail progress and status of AMD + Cray ecosystem before the system and their OpenMP implementation is used for mission critical applications when the first Exascale Computer Frontier is made available to applications.
We investigate substituting a parallel, half-approximation for maximum weight matching instead of an exact computation. Our experiments show that the resulting difference in solution quality is negligible. We demonstrate almost a 20-fold speedup using 40 threads on an 8 processor Intel Xeon E7-8870 system and now solve real-world problems in 36 seconds instead of 10 minutes
A b-MATCHING is a subset of edges M such that at most b(v) edges in M are incident on each vertex v, where b(v) is specified. We present a distributed-memory parallel algorithm, b-SUITOR, that computes a b-MATCHING with more than half the maximum weight in a graph with weights on the edges
In HIHE01-1, "Evaluate a PathForward/Facilities memory-relevant performance study/analysis," we conducted a focused study on the performance differences between HBM2 and HBM3 as revealed through execution of representative benchmarks. We used measurements on an existing many-core system, Knight's Landing (KNL), to calibrate simulator settings, and then performed Structural Simulation Toolkit (SST) simulations of KNL-like CPUs that access future high bandwidth memories. This report documents our findings.
The third quarter FY18 status report is provided, showing Performance to Plan updates for SPARC and EMPIRE projects.
Accomplishments and progress on various milestones for the ATDM project are reported in a bulleted format.
The STDA05-15 milestone comprises the following 4 distinct deliverables: 1) External Surface, 2) Locate Point, 3) Locate Cell and 4) Point Movement.
In August the team was able to get CUDA-9.2 up and running on white. Ride is not update to be the same as White, to support Trilinos testing. CUDA-9.2 builds are up on both. The team also expanded ATDM testing for SPARC and finished up the KNL build. Worked on ATDM Trilinos configuration to include the packages necessary for SPARC.
The team worked on supporting compile and build on ATS2 initial deployment systems for SPARC. Conducted performance runs of EMPIRE on Trinity and an initial compile and run of SPARC on Intel Skylake processors.
DARMA (Distributed Asynchronous Resilient Models for Applications) is a runtime library developed as part of the the Sandia ATDM (Advanced Technology Development and Mitigation) program. DARMA supports applications within 2.2.5.03 ADNN03-ASC ATDM SNL Application, which includes a number of applications featuring dynamic physics which requires load balancing and asynchronous communication for high performance. We have implemented a modern C++ programming model that can enable dynamic, asynchronous communication on top of existing data structures from a serial or MPI code. DARMA development has occurred in parallel with a verification milestone for ATDM in FY18. For FY19, DARMA will impact ATDM by enabling the performance benefits of a dynamic runtime through only incremental changes to existing verified MPI codes. The results presented here demonstrate the DARMA development process for an MPI mini-app, showing a 3-4x improvement in performance for a challenging problem relative to the parent MPI code and coming within 25 percent of the theoretically optimal performance achievable from a perfect, fine-grained load balancer for most cases.
The DARMA many-task framework provides asynchronous communication and load balancing functionality. This functionality is embedded in standard, modern C++ through the use of the template wrapper classes similar to futures. DARMA codes previously could not interoperate with Kokkos or OpenMP since each runtime assumed sole ownership of thread resources. The most recent version now allows for the use of Kokkos/OpenMP within DARMA tasks, allowing for better performance through thread-level parallelism or use of accelerators.