关键词: 多核, 集成众核, CFD应用程序, OpenMP, 性能分析

Abstract: Multicore and manycore are becoming mainstream architectures in high performance computing. OpenMP programming is one of the primary methods to exploit the parallel computing capabilities of them. By using a systematic approach which incorporates hardware performance counter based measurement and model based analysis, this paper evaluates the OpenMP performance of a real-world high order structured grids based CFD (computational fluids dynamics) application on Xeon E5 Sandy Bridge, an Intel multicore processor, and Knights Corner, an Intel many integrated core coprocessor. This paper analyzes the performance impacts of the OpenMP library cost, the load balance among different OpenMP threads, and the memory bandwidth to the application. The results show that the redundant computation introduced by OpenMP parallel programming is not significant. The serial portion and the load imbalance significantly affect the parallel efficiency. And memory access bandwidth significantly affects the achieved floating point performance. This paper also compares the performance differences between two architectures and discusses the directions of further performance tuning.

Key words: multicore, many integrated core, CFD application, OpenMP, performance analysis