Provably Optimal Parallel Transport Sweeps on Semi-Structured Grids
Autor: | Nancy M. Amato, Robert D. Falgout, Michael P. Adams, T S Bailey, Marvin L. Adams, Adam Kunen, Timmie Smith, W. Daryl Hawkins, Lawrence Rauchwerger, Peter Brown |
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Jazyk: | angličtina |
Rok vydání: | 2019 |
Předmět: |
Imagination
Numerical Analysis Physics and Astronomy (miscellaneous) Parallel transport Applied Mathematics media_common.quotation_subject Parallel algorithm FOS: Physical sciences Octant (solid geometry) 010103 numerical & computational mathematics Thread (computing) Parallel computing Computational Physics (physics.comp-ph) 01 natural sciences Computer Science Applications 010101 applied mathematics Computational Mathematics Search engine Analytic geometry Modeling and Simulation Polygon mesh 0101 mathematics Physics - Computational Physics media_common Mathematics |
Popis: | We have found provably optimal algorithms for full-domain discrete-ordinate transport sweeps on a class of grids in 2D and 3D Cartesian geometry that are regular at a coarse level but arbitrary within the coarse blocks. We describe these algorithms and show that they always execute the full eight-octant (or four-quadrant if 2D) sweep in the minimum possible number of stages for a given Px x Py x Pz partitioning. Computational results confirm that our optimal scheduling algorithms execute sweeps in the minimum possible stage count. Observed parallel efficiencies agree well with our performance model. Our PDT transport code has achieved approximately 68% parallel efficiency with > 1.5M parallel threads, relative to 8 threads, on a simple weak-scaling problem with only three energy groups, 10 direction per octant, and 4096 cells/core. We demonstrate similar efficiencies on a much more realistic set of nuclear-reactor test problems, with unstructured meshes that resolve fine geometric details. These results demonstrate that discrete-ordinates transport sweeps can be executed with high efficiency using more than 106 parallel processes. intended for journal submission soon |
Databáze: | OpenAIRE |
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