并行计算方法

计算物理3/lesson/ComputationalPhysics并行计算方法并行计算方法简介并行编程√简介(1/2)什么是串行和并行串行：由一台机器，从前到后处理任务并行：由多台机器，同时处理类似的任务为什么要采用并行计算加快速度：在更短的时间内解决相同的问题节省投入：单台高效计算机的投入

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多台低效计算机避开约束：计算速度不能超越光速，器件不可能无限小环境要求Linux+MPICHWindows+MPICH√简介(2/2)算法的模型任务划分，通信，任务组合√并行编程(1/5)常用的语句MPICH库声明!DEC$OBJCOMMENTLIB:'mpichd.lib'!DEC$OBJCOMMENTLIB:'ws2_32.lib'INCLUDE'mpif.h'MPICH变量声明CHARACTER*(MPI_MAX_PROCESSOR_NAME)PROCESSOR_NAMEDIMENSIONISTATUS(MPI_STATUS_SIZE)DIMENSIONBUFFERS(KST)初始化CALLMPI_INIT(ierr)CALLMPI_COMM_RANK(comm,rank,ierr)CALLMPI_COMM_SIZE(comm,size,ierr)CALLMPI_GET_PROCESSOR_NAME(name,namelen,ierr)√并行编程(2/5)通信CALLMPI_SEND(buf(1),count,datatype,

destid,tag,comm,ierr)CALLMPI_RECV(buf,count,datatype,source,tag,comm,istatus,ierr)ISENDER=istatus(MPI_SOURCE)CALLMPI_BARRIER(comm,ierr)结束CALLMPI_FINALIZE(ierr)√并行编程(3/5)例：HelloWorld!编译(3)ifortPPT.8.07.for-oppt807-I/home5/software/mpich-ch_p4-cc-1.2.7-32b/include-L/home5/software/mpich-ch_p4-cc-1.2.7-32b/lib-L/var/lib/systemimager/images/oscarimage_ide/usr/lib-lmpich-O2节点分配：-machinefile

xxx运行：mpirun-np6-machinefile./PPT.8.07.mc./ppt807结果HelloWorld!Process0of6onHelloWorld!Process4of6onHelloWorld!Process2of6onHelloWorld!Process3of6onHelloWorld!Process5of6onHelloWorld!Process1of6on√并行编程(4/5)开始结束进程0进程1进程5MPI_INITMPI_COMM_RANKMYID=0MPI_COMM_SIZENUMPROCS=6MPI_GET_PROC…PROCESSOR_NAMEWRITEHelloWorld!0MPI_FINALIZE……MPI_INITMPI_COMM_RANKMYID=1MPI_COMM_SIZENUMPROCS=6MPI_GET_PROC…PROCESSOR_NAMEWRITEHelloWorld!1MPI_FINALIZEMPI_INITMPI_COMM_RANKMYID=5MPI_COMM_SIZENUMPROCS=6MPI_GET_PROC…PROCESSOR_NAMEWRITEHelloWorld!5MPI_FINALIZE√