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arXiv · 1410.4713

Weighted decomposition in high-performance lattice-Boltzmann simulations: are some lattice sites more equal than others?

Derek Groen·David Abou Chacra·Rupert W. Nash·Jiri Jaros·Miguel O. Bernabeu·Peter V. Coveney
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Abstract

Obtaining a good load balance is a significant challenge in scaling up lattice-Boltzmann simulations of realistic sparse problems to the exascale. Here we analyze the effect of weighted decomposition on the performance of the HemeLB lattice-Boltzmann simulation environment, when applied to sparse domains. Prior to domain decomposition, we assign wall and in/outlet sites with increased weights which reflect their increased computational cost. We combine our weighted decomposition with a second optimization, which is to sort the lattice sites according to a space filling curve. We tested these strategies on a sparse bifurcation and very sparse aneurysm geometry, and find that using weights reduces calculation load imbalance by up to 85%, although the overall communication overhead is higher than some of our runs.

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Derek Groen, David Abou Chacra, Rupert W. Nash, Jiri Jaros, Miguel O. Bernabeu, Peter V. Coveney. 2014-10-17. Weighted decomposition in high-performance lattice-Boltzmann simulations: are some lattice sites more equal than others?. https://arxiv.org/abs/1410.4713

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