A Locality-Based Threading Algorithm for the Configuration-Interaction Method

Journal Article · Mon Jul 03 00:00:00 EDT 2017 · IEEE International Symposium on Parallel and Distributed Processing, Workshops and Phd Forum

DOI:https://doi.org/10.1109/IPDPSW.2017.15· OSTI ID:1393243

Shan, Hongzhang ^[1]; Williams, Samuel ^[1]; Johnson, Calvin ^[2]; McElvain, Kenneth ^[3]

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1. Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). Computational Research Division
2. San Diego State Univ., San Diego, CA (United States). Dept. of Physics
3. Univ. of California, Berkeley, CA (United States). Dept. of Physics

The Configuration Interaction (CI) method has been widely used to solve the non-relativistic many-body Schrodinger equation. One great challenge to implementing it efficiently on manycore architectures is its immense memory and data movement requirements. To address this issue, within each node, we exploit a hybrid MPI+OpenMP programming model in lieu of the traditional flat MPI programming model. Here in this paper, we develop optimizations that partition the workloads among OpenMP threads based on data locality,-which is essential in ensuring applications with complex data access patterns scale well on manycore architectures. The new algorithm scales to 256 threadson the 64-core Intel Knights Landing (KNL) manycore processor and 24 threads on dual-socket Ivy Bridge (Xeon) nodes. Compared with the original implementation, the performance has been improved by up to 7× on theKnights Landing processor and 3× on the dual-socket Ivy Bridge node.

• Research Organization: Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR)
• Grant/Contract Number: AC02-05CH11231
• OSTI ID: 1393243
• Journal Information: IEEE International Symposium on Parallel and Distributed Processing, Workshops and Phd Forum, Vol. 2017; Conference: 2017 IEEE International Parallel and Distributed Processing Symposium Workshops (IPDPSW), Lake Buena Vista, FL (United States), 29 May-2 Jun 2017; ISSN 2164-7062
• Publisher: IEEE
• Country of Publication: United States
• Language: English

Related Subjects

97 MATHEMATICS AND COMPUTING
Manycore
locality-based threading algorithm
bigstick
configuration-interaction method
knights landing
Ivy bridge
MPI
OpenMP
multithreading
hybrid programming model