计算机工程与应用Issue(3)：22-29,116,9.DOI:10.3778/j.issn.1002-8331.1309-0307
基于OpenCL的累积汇流并行计算
Parallel computing with OpenCL for flow accumulation
摘要
Abstract
The growing demand for the applications of large scale and high resolution digital terrain data has brought new challenges to computationally intensive digital terrain analysis algorithms such as flow accumulation. According to the characteristics of heterogeneous computing platform with CPU/GPU(Graphics Processing Unit), a parallelization strategy for multiple flow direction flow accumulation algorithm is put forward based on the OpenCL(Open Computing Language). It has better platform independence and portability, which simplifies the programming for parallel computing under CPU/GPU heterogeneous platform. The parallel flow accumulation algorithm includes outflow allocation process independently with the space and time domain, and the inflow accumulation process depending on the space domain. The two processes are defined as OpenCL kernels and are executed parallelly on the OpenCL devices. The transfer matrix is used to transfer the recursive inflow accumulation process into iterative style for parallel computing. Compared with the parallel flow accumulation algorithm based on flow transfer matrix, the parallel flow accumulation algorithm based on indegree matrix with graph theory can reduce the computation redundancy in the iterative inflow accumulation process, but it requires atomic operations with large delay and more iterations. With limited GPU computing resources, the two parallel flow accumulation algorithms have no obvious differences in speedup performance. Experimental results show that the parallel flow accumulation algorithm obtains a good speedup on NVIDIA GeForce GT 650M GPU and the speedup is increased gradually with the increase of grid scale. The speedups are 50~70 for the outflow allocation process and 10~20 for the inflow accumulation process, which demonstrates the potential advantages of large scale digital terrain analysis on parallel com-puting devices such as GPU with OpenCL.关键词
并行计算/累积汇流/图形处理器/开放计算语言Key words
parallel computing/flow accumulation/Graphics Processing Unit(GPU)/Open Computing Language(OpenCL)分类
信息技术与安全科学引用本文复制引用
龙满生,罗文浪..基于OpenCL的累积汇流并行计算[J].计算机工程与应用,2014,(3):22-29,116,9.基金项目
江西省科技厅科技支撑计划项目资助（No.2010BGA00900）；江西省高等学校重点学科建设项目资助。 （）
