Registration is now open for the one day ECP/NERSC UPC++ tutorial.
UPC++ is a C++11 library providing classes and functions that support Partitioned Global Address Space (PGAS) programming. UPC++ provides mechanisms for low-overhead one-sided communication, moving computation to data through remote-procedure calls, and expressing dependencies between asynchronous computations and data movement. It is particularly well-suited for implementing elaborate distributed data structures where communication is irregular or fine-grained. The UPC++ interfaces are designed to be composable and similar to those used in conventional C++. The UPC++ programmer can expect communication to run at close to hardware speeds.
In this tutorial we will introduce basic concepts and advanced optimization techniques of UPC++. We will discuss the UPC++ memory and execution models and walk through implementing basic algorithms in UPC++. We will also look at irregular applications and how to take advantage of UPC++ features to optimize their performance.
This event can be attended on-site at NERSC or remotely via Zoom. The remote connection information will be provided to the registrants closer to the event. Registration is required for this event and space is limited so please register as soon as possible. Registration closes for this event when the limit is reached or on October 18, 2019.
Abstract
This talk introduced SYCL as a programming model for Aurora, the upcoming Argonne exascale machine. SYCL is a single source heterogeneous programming model based on standard C++. It uses C++ templates and lambda functions for host and device code. SYCL builds on the underlying concepts of portability and efficiency of OpenCL that enables code for heterogeneous processors, however it is less verbose compare to OpenCL. The single-source programming enables the host and kernel code for an application to be contained in the same source file, in a type-safe way and with the simplicity of a cross-platform asynchronous task graph. We will provide an overview of the SYCL concepts, compilation and runtime. No prior knowledge of OpenCL was required. Once the core concepts of SYCL were reviewed, the presenters walked through several code examples to highlight the key features of SYCL. SYCL by design is hardware agnostic and offers the potential to be portable across many of DOE’s largest machines.
Organizers
- Haritha Siddabathuni Som (ALCF)
- Ray Loy (ALCF)
- Yasaman Ghadar (ALCF)
Presentation materials
The IDEAS Productivity project, in partnership with the DOE Computing Facilities of the ALCF, OLCF, and NERSC and the DOE Exascale Computing Project (ECP) has resumed the webinar series on Best Practices for HPC Software Developers, which we began in 2016.
As part of this series, we offer one-hour webinars on topics in scientific software development and high-performance computing, approximately once a month. The next webinar in the series was titled Building Community through xSDK Software Policies, and was presented by Ulrike Meier Yang (Lawrence Livermore National Laboratory) and Piotr Luszczek (The University of Tennessee, Knoxville). The webinar took place on Wednesday, December 11, 2019.
Abstract:
The development of increasingly complex computer architectures and software ecosystems continues. Applications that incorporate multiphysics modeling as well as the coupling of simulation and data analytics increasingly require the combined use of software packages developed by diverse, independent teams throughout the HPC community. The Extreme-scale Scientific Software Development Kit (xSDK) is being developed to provide coordinated infrastructure for independent mathematical libraries to support the productive and efficient development of high-quality applications. This webinar discussed the development and impact of xSDK community policies, which constitute an integral part of the project and have been defined to achieve improved code quality and compatibility across xSDK member packages and a sustainable software ecosystem.
This event was a repeat of the tutorial delivered on November 1, but with the restoration of the hands-on component which was omitted due to uncertainty surrounding the power outage at NERSC.
UPC++ is a C++11 library providing classes and functions that support Partitioned Global Address Space (PGAS) programming. UPC++ provides mechanisms for low-overhead one-sided communication, moving computation to data through remote-procedure calls, and expressing dependencies between asynchronous computations and data movement. It is particularly well-suited for implementing elaborate distributed data structures where communication is irregular or fine-grained. The UPC++ interfaces are designed to be composable and similar to those used in conventional C++. The UPC++ programmer can expect communication to run at close to hardware speeds.
In this tutorial we introduced basic concepts and advanced optimization techniques of UPC++. We discussed the UPC++ memory and execution models and walked through implementing basic algorithms in UPC++. We also discussed irregular applications and how to take advantage of UPC++ features to optimize their performance. The tutorial included hands-on exercises with basic UPC++ constructs. Registrants were given access to run their UPC++ exercises on NERSC’s Cori (currently the #14 fastest computer in the world).
We are pleased to announce that we are hosting the next Performance Portability with Kokkos Bootcamp January 14-17, 2020 at the Buffalo Thunder Resort in Santa Fe NM. This training is intended to teach new Kokkos users how to get started and to help existing Kokkos users to further improve their codes. The training will cover the minimum required topics to get your application started on using Kokkos, and Kokkos experts will be on hand to help the more advanced users.
A room block for this event has been reserved for January 13, 2020 – January 17, 2020 at the Hilton Santa Fe Buffalo Thunder. The deadline to book a room within the room block is January 1, 2020.
See tickets to register or to get more information.
The IDEAS Productivity project, in partnership with the DOE Computing Facilities of the ALCF, OLCF, and NERSC and the DOE Exascale Computing Project (ECP) has resumed the webinar series on Best Practices for HPC Software Developers, which we began in 2016.
As part of this series, we offer one-hour webinars on topics in scientific software development and high-performance computing, approximately once a month. The next webinar is titled Refactoring EXAALT MD for Emerging Architectures, and will be presented Aidan Thompson (Sandia National Laboratories), Stan Moore (Sandia National Laboratories), and Rahulkumar Gayatri (NERSC). The webinar will take place on Wednesday, January 15, 2020 at 1:00 pm ET.
Abstract:
As part of the DOE Exascale Computing Project, members of the EXAALT project are working to increase the accuracy, time, and length scales of molecular dynamics simulations of materials for fusion energy. Simulations rely on the SNAP machine-learning interatomic potential to accurately capture material properties. The SNAP kernel recursively evaluates a set of complex polynomial functions, requiring many deeply nested loops with irregular loop bounds. Last year, a worrisome trend in the SNAP force kernel was identified. With each new generation of emerging architectures, performance relative to theoretical peak was decreasing, particularly on GPUs. This webinar will discuss the approach used to rewrite the SNAP kernel from the ground up, using more compact memory representation, refactoring the main loop, using sub-kernels to reduce pressure on GPU threads, and improving coalesced memory accesses on the GPU. This work has enabled a spectacular increase of roughly 10x in performance over the baseline implementation of the SNAP benchmark running on NVIDIA V100 GPUs. Extrapolated to the full machine, this predicts an increase of over 100x in the Figure of Merit over the baseline on the ALCF/Mira system, putting EXAALT on track to meeting, and even exceeding performance targets on exascale systems. The webinar will emphasize key strategies and lessons learned in code transitions for emerging architectures.
The IDEAS Productivity project, in partnership with the DOE Computing Facilities of the ALCF, OLCF, and NERSC and the DOE Exascale Computing Project (ECP) has resumed the webinar series on Best Practices for HPC Software Developers, which we began in 2016.
As part of this series, we offer one-hour webinars on topics in scientific software development and high-performance computing, approximately once a month. The next webinar is titled Introduction to Kokkos, and will be presented by Christian Trott (Sandia National Laboratories). The webinar will take place on Wednesday, February 19, 2020 at 1:00 pm ET.
Abstract:
The Kokkos C++ Performance Portability Ecosystem is a production-level solution for writing modern C++ applications in an hardware-agnostic way. It is part of the US Department of Energy’s Exascale Computing Project—the leading effort in the US to prepare the HPC community for the next generation of supercomputing platforms. Kokkos is now used by more than a hundred HPC projects, and Kokkos-based codes are running regularly at-scale on at least five of the top ten supercomputers in the world. In this webinar, we will give a short overview of what the Kokkos Ecosystem provides, including its programming model, math kernels library, tools, and training resources, before providing an overview of the Kokkos team’s efforts surrounding the ISO-C++ standard, and how Kokkos both influences future standards and aligns with developments occurring in them. The webinar will include a status update on the progress in supporting the upcoming exascale class HPC systems announced by DOE.
The IDEAS Productivity project, in partnership with the DOE Computing Facilities of the ALCF, OLCF, and NERSC and the DOE Exascale Computing Project (ECP) has resumed the webinar series on Best Practices for HPC Software Developers, which we began in 2016.
As part of this series, we offer one-hour webinars on topics in scientific software development and high-performance computing, approximately once a month. The next webinar was titled Testing: Strategies When Learning Programming Models and Using High-Performance Libraries, and was presented by Balint Joo (Jefferson Lab). The webinar took place on Wednesday, March 18, 2020 at 1:00 pm ET.
Abstract:
Software testing is an invaluable practice, albeit the level of testing in scientific applications can vary widely, from no testing at all to full continuous integration (as discussed in earlier webinars of the HPC-BP series). In this webinar I will consider a specific case: the use of unit-testing when developing a mini-app as an approach to learn about new programming models such as Kokkos and SYCL, or when using (or contributing to) high-performance libraries. I will illustrate with an example from Lattice QCD, focusing on the integration of the QUDA optimized library with the Chroma application. The webinar will focus on lessons learned and generally applicable strategies.
Abstract
The Distributed Asynchronous Object Storage (DAOS) is an open-source, scale-out object store designed from the ground up for massively distributed Non-Volatile Memory (NVM). DAOS takes advantage of next-generation NVM technology, like Storage Class Memory (SCM) and NVM express (NVMe), and is extremely lightweight since it operates end-to-end in user space with full OS bypass. DAOS offers a shift away from an I/O model designed for block-based and high-latency storage to one that inherently supports fine-grained data access and unlocks the performance of the next-generation storage technologies. This presentation introduced the key concepts behind DAOS and the software ecosystem enabling this technology. The presentation provided details on the DAOS deployment on Aurora and how applications can benefit from this new storage tier.
Organizers
- Ray Loy (ALCF)
- Yasaman Ghadar (ALCF)
Presentation materials
Registration for this event is now closed.
Abstract: Working remotely has suddenly become a near-universal experience for staff members of research organizations, but for some it has been a way of life for years. In this panel discussion, we brought together five staff members of U.S. Department of Energy (DOE) laboratories, all members of the DOE Exascale Computing Project (ECP), with years of varied experience working remotely. Topics included advice to people just getting started with working remotely, challenges, unforeseen benefits, and opportunities to look for from this experience, with emphasis on issues faced by collaborating teams in computational research. Panelists made brief introductory comments followed by open discussion. We invite you to check out the slides, video, and Q&A document from the webinar below.
Moderator: Mike Heroux, Sandia National Laboratories
Panelists:
- Mike Bernhardt, Oak Ridge National Laboratory
- Lois Curfman McInnes, Argonne National Laboratory
- Mark Miller, Lawrence Livermore National Laboratory
- Kathryn Mohror, Lawrence Livermore National Laboratory
- Elaine Raybourn, Sandia National Laboratories
