c++ - 使用 MPI 时并行 Eclipse 无法识别处理器的真实数量

Question

我有以下代码，当使用 eclipse 2020.12 执行时，输出是这样的：“Hello from rank 0 out of 1”

#include <iostream>
#include <mpi.h>
using namespace std;

int main(int argc, char* argv[])
{

    MPI_Init(&argc, &argv);

    int rank;
    MPI_Comm_rank(MPI_COMM_WORLD, &rank);

    int size;
    MPI_Comm_size(MPI_COMM_WORLD, &size);
    int data;

    if (rank > 0) {

        MPI_Recv(&data, 1, MPI_INT, rank-1, 0, MPI_COMM_WORLD,MPI_STATUS_IGNORE);
                cout << "Rank "<< rank<< " has received message with data " << data
                        << " from rank " << rank-1
                        << endl;
    }

    cout << "Hello from rank " << rank<< " out of " << size<< endl;

    if (rank < size-1) {
        data = rank*rank;

        MPI_Send(&data, 1, MPI_INT, rank+1, 0, MPI_COMM_WORLD);
    }

    MPI_Finalize();
    return 0;
}

但是，当我通过命令行使用以下命令执行此操作时，它按预期工作

mpic++ -o name name.cpp
mpiexec -np 4 ./name

它显示 4 hello ，这是我的核心数。我想知道为什么 eclipse 无法识别，但是具有另一种执行方式的 sampe cpp 文件可以正常工作！输出将是：

Hello from rank 0 out of 4
Rank 1 has received message with data 0 from rank 0
Hello from rank 1 out of 4
Rank 2 has received message with data 1 from rank 1
Hello from rank 2 out of 4
Rank 3 has received message with data 4 from rank 2
Hello from rank 3 out of 4

score 1 · Accepted Answer

从并行应用程序模板创建一个新的运行配置。在Resources选项卡上，根据您的 MPI 实现是从 Open MPI 还是 MPICH 派生，将Target System Configuration 设置为Generic OpenMPI Interactive或Generic MPICH2 Interactive 。将连接类型设置为本地。然后在基本选项选项卡中设置进程数。