Combined model Open MP&MPI for parallel computations in gas dynamics program

Abstract

This chapter discusses the combined computation model for parallel gas dynamics program. The efficiency of combined model has been analyzed theoretically. The estimates obtained allow getting the upper bound of the combined model OpenMP & message passing interface (MPI) efficiency using the efficiency of MPI model. Models of parallel calculations reflect architectural features of multiprocessor systems. The parallel algorithm can use one of the standards OpenMP or MPI, and both standards simultaneously. Creation of the parallel algorithm realizing mixed model of calculations represents consecutive development of two versions of algorithm on the basis of each model. Some stages involved in development of parallel algorithms are: defining of an opportunity of parallel calculations in initial algorithm, a choice of model of parallel calculations, development of algorithm, and program realization. Parallel algorithms are characterized by the following properties portability, scalability, and development expenses.