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Samba: A Detailed Memory Management Unit (MMU) for the SST Simulation Framework

Awad, Amro A.; Voskuilen, Gwendolyn R.; Hammond, Simon D.; Hoekstra, Robert J.

The Memory Management Unit (MMU) is one of the most important parts of any modern computing system. It can be thought of as the hardware support for virtual memory, which enforces access permissions, and manages the translation of processes' virtual addresses into real memory physical addresses. The operating system (OS) allocates the physical memory in a small granularity frames that can be accessed by processes with appropriate permissions. Each process has the illusion of having an entire memory space, however, the actual addresses issued by the process, (`virtual addresses'), are translated into the physical frame address allocated by the OS through virtual memory.

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ASC Trilab L2 Codesign Milestone 2015

Trott, Christian R.; Hammond, Simon D.; Dinge, Dennis D.; Lin, Paul L.; Vaughan, Courtenay T.; Cook, Jeanine C.; Rajan, Mahesh R.; Edwards, Harold C.; Hoekstra, Robert J.

For the FY15 ASC L2 Trilab Codesign milestone Sandia National Laboratories performed two main studies. The first study investigated three topics (performance, cross-platform portability and programmer productivity) when using OpenMP directives and the RAJA and Kokkos programming models available from LLNL and SNL respectively. The focus of this first study was the LULESH mini-application developed and maintained by LLNL. In the coming sections of the report the reader will find performance comparisons (and a demonstration of portability) for a variety of mini-application implementations produced during this study with varying levels of optimization. Of note is that the implementations utilized including optimizations across a number of programming models to help ensure claims that Kokkos can provide native-class application performance are valid. The second study performed during FY15 is a performance assessment of the MiniAero mini-application developed by Sandia. This mini-application was developed by the SIERRA Thermal-Fluid team at Sandia for the purposes of learning the Kokkos programming model and so is available in only a single implementation. For this report we studied its performance and scaling on a number of machines with the intent of providing insight into potential performance issues that may be experienced when similar algorithms are deployed on the forthcoming Trinity ASC ATS platform.

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FY14 Codesign Milestone Summary

Hoekstra, Robert J.; Barrett, Richard F.; Howell, Louis; Daniel, David

This milestone was the 2nd in a series of Tri-Lab Co-Design L2 milestones supporting ‘Co-Design’ efforts in the ASC program. It is a crucial step towards evaluating the effectiveness of proxy applications in exploring code performance on next generation architectures. All three labs evaluated the performance of 2 proxy applications on modern architectures and/or testbeds for pre-production hardware. The results are captured in this document as well as annotated presentations from all 3 laboratories.

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Results 51–75 of 107
Results 51–75 of 107