Scalable Equation of State Capability

Epperly, T W ; Fritsch, F N ; Norquist, P D ; Sanford, L A

Lawrence Livermore National Laboratory

关键词: Communications;    Processing;    Testing;    Algorithms;    99 General And Miscellaneous//Mathematics, Computing, And Information Science;   

DOI  :  10.2172/923991
RP-ID  :  UCRL-TR-236997
RP-ID  :  W-7405-ENG-48
RP-ID  :  923991

美国|英语

来源: UNT Digital Library

【 摘 要 】

The purpose of this techbase project was to investigate the use of parallel array data types to reduce the memory footprint of the Livermore Equation Of State (LEOS) library. Addressing the memory scalability of LEOS is necessary to run large scientific simulations on IBM BG/L and future architectures with low memory per processing core. We considered using normal MPI, one-sided MPI, and Global Arrays to manage the distributed array and ended up choosing Global Arrays because it was the only communication library that provided the level of asynchronous access required. To reduce the runtime overhead using a parallel array data structure, a least recently used (LRU) caching algorithm was used to provide a local cache of commonly used parts of the parallel array. The approach was initially implemented in a isolated copy of LEOS and was later integrated into the main trunk of the LEOS Subversion repository. The approach was tested using a simple test. Testing indicated that the approach was feasible, and the simple LRU caching had a 86% hit rate.