もしこの単純なMPIが送受信するコードがの2つのプロセッサで実行されない理由を誰かが教えてくれれば感謝します.n = 40(行20)の値がnの場合< = 30。言い換えれば、メッセージサイズが特定の数(これはそれほど大きくなく、約8100の1次元配列)を超えた場合、MPIはデッドロックします。単純なMPIプログラム
#include "mpi.h"
#include "stdio.h"
#include "stdlib.h"
#include "iostream"
#include "math.h"
using namespace std;
int main(int argc, char *argv[])
{
int processor_count, processor_rank;
double *buff_H, *buff_send_H;
int N_pa_prim1, l, n, N_p0;
MPI_Status status;
MPI_Init (&argc, &argv);
MPI_Comm_size (MPI_COMM_WORLD, &processor_count);
MPI_Comm_rank (MPI_COMM_WORLD, &processor_rank);
N_pa_prim1=14; l=7; n=40; N_p0=7;
buff_H = new double [n*n*N_p0+1]; //Receive buffer allocation
buff_send_H = new double [n*n*N_p0+1]; //Send buffer allocation
for (int j = 0; j < n*n*N_p0+1; j++)
buff_send_H[j] = 1e-8*rand();
if (processor_rank == 0)
MPI_Send(buff_send_H, n*n*N_p0+1, MPI_DOUBLE, 1, 163, MPI_COMM_WORLD);
else if(processor_rank == 1)
MPI_Send(buff_send_H, n*n*N_p0+1, MPI_DOUBLE, 0, 163, MPI_COMM_WORLD);
MPI_Recv(buff_H, n*n*N_p0+1, MPI_DOUBLE, MPI_ANY_SOURCE, 163, MPI_COMM_WORLD, &status);
cout << "Received successfully by " << processor_rank << endl;
MPI_Finalize();
return 0;
}