当我想通过MPI_Send发送非常大的消息时遇到了一个问题：有多个处理器，我们需要传输的int总数为2 ^ 25，我测试了1000的大小，我的代码可以正常工作，但是如果我将其设置为教授要求的尺寸，它将停留很长时间，并向我返回一些信息，如下所示：

 2 more processes have sent help message help-mpi-btl-base.txt / btl:no-nics

Set MCA parameter "orte_base_help_aggregate" to 0 to see all help / error messages

Primary job  terminated normally,but 1 process returned
a non-zero exit code. Per user-direction,the job has been aborted.

mpiexec noticed that process rank 0 with PID 0 on node srv-p22-13 exited on signal 24 (CPU time limit exceeded).

我在每行代码之后都使用了“ cout”，并且我确定它卡在MPI_Send行之前，Si的大小超过20,000,000。我不确定这是原因吗？但是我已经搜索到MPI_Send的最大限制是2 ^ 32-1 ...更大的是2 ^ 25 ...所以我感到困惑。

这是我代码的主要部分：

//This is send part
    for(int i=0; i<5; i++){
        if(i!=my_rank){//my_rank is from MPI_Comm_rank(MPI_COMM_WORLD,&my_rank)
            int n = A.size();//A is a vector of int
            int* Si= new int[n];//I want to convert vector to a int array
            std::copy(A.begin(),A.end(),Si);
            MPI_Send(&Si,n,Type,i,my_rank,MPI_COMM_WORLD);//**The code stuck here and says CPU time limit exceeded
            delete[] Si;
        }
    }
    MPI_Barrier(MPI_COMM_WORLD);//I want all the processor finish sending part,then start receive and save in vector

//This is receive part
    for(int i=0; i<5; i++){
        if(i!=my_rank){
            MPI_Status status;
            MPI_Probe(i,MPI_COMM_WORLD,&status);
            int rn = 0;
            MPI_Get_count(&status,&rn);
            int* Ri = new int[rn];
            MPI_Recv(Ri,rn,MPI_STATUS_IGNORE);
            /*Save received elements into vector A*/
            for(int i=0; i<sizeof(Ri);i++){
                inout.push_back(A);
            }

        }
    }