基于MIC平台的三维瑞雷面波有限差分并行模拟

3D finite difference parallel simulation of Rayleigh wave based on MIC platform

三维地震波动方程有限差分数值模拟,受到计算量大且内存消耗大地制约而计算效率较低,严重影响其发展和应用。目前,一种全新的异构众核协处理器,为三维并行计算提供了一条解决计算效率和数据存储问题的重要途径。基于三维有限差分计算的特点,介绍了面向MIC(Many Integrated Core)平台的三维瑞雷波有限差分并行算法移植和性能优化,采用ofload模式将计算核函数加载到MIC上,在MIC协处理上使用openMP多线程并行方式,并通过循环合并、nocopy数据传输、SIMD向量化和CPU+MIC协同计算方式进行优化。通过模型计算可知:三维数值计算程序在MIC上具有近线性加速比,MIC+CPU协同并行计算的性能可以达到纯CPU节点的4.5倍,大大提高了计算效率。通过对模拟结果与解析解的比较,以及对频散曲线特征的分析,验证了数值模拟的正确性。

The development and application of Numerical simulation of three-dimensional seismic wave equation is hindered for its huge computation and large computer memory.In recent years,MIC(Many Integrated Core),as a new kind of heterogeneous core coprocessor,provides a better choice for three-dimensional parallel modeling.Based on the characteristic of 3D finite difference computation,we introduce the code migration and performance optimization on MIC platform.We offload the kernel function to MIC with openMP parallel method,and optimize the performance by loop confusion,data transfer optimization,SIMD vectorization and CPU+MIC cooperative computation.Through the model computation,the speed-up ratio on MIC is nearly linear.The performance of the MIC+CPU cooperative computation was 4.5 times faster than pure CPU compute node.The method is verified by the comparison of numerical simulation result and analytical solution,as well as by the analysis of dispersion curves from wave record.