Hi,
I'm having a problem with Isend, Recv and Test in Linux Mint 16 Petra. The
source is attached.
Open MPI 1.10.2 is configured with
./configure --enable-debug --prefix=/home/<me>/Tool/openmpi-1.10.2-debug
The source is built with
~/Tool/openmpi-1.10.2-debug/bin/mpiCC a5.cpp
and run in one node with
~/Tool/openmpi-1.10.2-debug/bin/mpirun -n 2 ./a.out
The output is in the end. What puzzles me is why MPI_Test is called so many
times, and it takes so long to send a message. Am I doing something wrong?
I'm simulating a more complicated program: MPI 0 Isends data to MPI 1,
computes (usleep here), and calls Test to check if data are sent. MPI 1
Recvs data, and computes.
Thanks in advance.
Best regards,
Zhen
MPI 0: Isend of 0 started at 20:32:35.
MPI 1: Recv of 0 started at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:35.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:36.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:37.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:38.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 1: Recv of 0 finished at 20:32:39.
MPI 0: MPI_Test of 0 at 20:32:39.
MPI 0: Isend of 0 finished at 20:32:39.
#include "mpi.h"
#include <unistd.h>
#include <stdio.h>
#include <vector>
#include <time.h>
int main(int argc, char* argv[])
{
MPI_Init(&argc, &argv);
int rank;
MPI_Comm_rank(MPI_COMM_WORLD, &rank);
int n = 999999;
const int m = 1;
std::vector<std::vector<int> > vec(m);
for (int i = 0; i < m; i++)
{
vec[i].resize(n);
}
MPI_Request mpiRequest[m];
MPI_Status mpiStatus[m];
char tt[99] = {0};
MPI_Barrier(MPI_COMM_WORLD);
if (rank == 0)
{
for (int i = 0; i < m; i++)
{
MPI_Isend(&vec[i][0], n, MPI_INT, 1, i, MPI_COMM_WORLD, &mpiRequest[i]);
time_t t = time(0);
strftime(tt, 9, "%H:%M:%S", localtime(&t));
printf("MPI %d: Isend of %d started at %s.\n", rank, i, tt);
}
for (int i = 0; i < m; i++)
{
int done = 0;
while (done == 0)
{
usleep(100000);
time_t t = time(0);
strftime(tt, 9, "%H:%M:%S", localtime(&t));
printf("MPI %d: MPI_Test of %d at %s.\n", rank, i, tt);
MPI_Test(&mpiRequest[i], &done, &mpiStatus[i]);
// printf("MPI %d: MPI_Wait of %d at %s.\n", rank, i, tt);
// MPI_Wait(&mpiRequest[i], &mpiStatus[i]);
}
time_t t = time(0);
strftime(tt, 9, "%H:%M:%S", localtime(&t));
printf("MPI %d: Isend of %d finished at %s.\n", rank, i, tt);
}
}
else
{
for (int i = 0; i < m; i++)
{
time_t t = time(0);
strftime(tt, 9, "%H:%M:%S", localtime(&t));
printf("MPI %d: Recv of %d started at %s.\n", rank, i, tt);
MPI_Recv(&vec[i][0], n, MPI_INT, 0, i, MPI_COMM_WORLD, &mpiStatus[i]);
t = time(0);
strftime(tt, 9, "%H:%M:%S", localtime(&t));
printf("MPI %d: Recv of %d finished at %s.\n", rank, i, tt);
}
}
MPI_Finalize();
return 0;
}
