如何制作/配置MPI项目以在多个进程上运行？ [英] How to make/configure an MPI project to run on multiple processes?

问题描述

我有一小段代码应该在多个进程上运行，即：

I have a small piece of code that should run on multilple processes, which is :

#include <stdio.h>
 #include <mpi.h>

   main(int argc, char **argv)
   {
      int ierr, num_procs, my_id;

      ierr = MPI_Init(&argc, &argv);

      /* find out MY process ID, and how many processes were started. */

      ierr = MPI_Comm_rank(MPI_COMM_WORLD, &my_id);
      ierr = MPI_Comm_size(MPI_COMM_WORLD, &num_procs);

      printf("Hello world! I'm process %i out of %i processes\n",
         my_id, num_procs);

      ierr = MPI_Finalize();
   }

the output is :Hello world! I'm process 0 out of 1 processes.

虽然它应该在多个进程上运行





我们编辑了运行配置参数到-np 2所以它会在2个进程上运行，但它总是给我们一个进程，无论值是什么。



使用的环境是：

Ubuntu 12.04上的Eclipse Juno





代码来源： http://condor.cc .ku.edu /~grobe / docs / intro-MPI-C.shtml [ ^ ]

although it should run on more than one process


We edited the run configurations arguments to "-np 2" so it would run on 2 processes but it always gives us 1 process no matter what the value is.

The used environment is:
Eclipse Juno on Ubuntu 12.04


Source of code: http://condor.cc.ku.edu/~grobe/docs/intro-MPI-C.shtml[^]

推荐答案

据我所知，你永远不会创建任何线程。 MPI_Init <的文档/ a> [ ^ ]没有提到创建线程。

As far as I can see you do not ever create any threads. The documentation for MPI_Init[^] does not mention creating threads.

你似乎认为MPI_Init函数会为你启动多个进程。不是这种情况。您必须通过mpirun命令运行程序，例如：

You seem to be under the impression that the MPI_Init function will launch multiple processes for you. This is not the case. You have to run your program via the mpirun command, for example:

mpirun -np 4 a.out

mpirun -np 4 a.out

和mpirun将为您解释-np 4并启动四个进程。当您手动（从IDE）启动流程时，您将只运行单个流程。

and mpirun will interpret the "-np 4" for you and launch the four processes. As you started your process manually (from the IDE) you will only have that single processes running.

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