mpi-bi-bandwidth.c

#define BENCHMARK "OSU MPI Bi-Directional Bandwidth Test"

/*
 * Copyright (C) 2002-2012 the Network-Based Computing Laboratory
 * (NBCL), The Ohio State University. 
 *
 * Contact: Dr. D. K. Panda (panda@cse.ohio-state.edu)
 *
 * For detailed copyright and licensing information, please refer to the
 * copyright file COPYRIGHT in the top level OMB directory.
 */

#include <mpi.h>
#include <unistd.h>
#include <stdlib.h>
#include <stdio.h>
#include <assert.h>

#define MAX_REQ_NUM 1000

#define MAX_ALIGNMENT 65536
#define MAX_MSG_SIZE (1<<22)
#define MYBUFSIZE (MAX_MSG_SIZE + MAX_ALIGNMENT)


#define LOOP_LARGE  20
#define WINDOW_SIZE_LARGE  64
#define SKIP_LARGE  2

int LARGE_MESSAGE_SIZE = 8192;

char s_buf_original[MYBUFSIZE];
char r_buf_original[MYBUFSIZE];

MPI_Request send_request[MAX_REQ_NUM];
MPI_Request recv_request[MAX_REQ_NUM];
MPI_Status  reqstat[MAX_REQ_NUM];

#ifdef PACKAGE_VERSION
#   define HEADER "# " BENCHMARK " v" PACKAGE_VERSION "\n"
#else
#   define HEADER "# " BENCHMARK "\n"
#endif

#ifndef FIELD_WIDTH
#   define FIELD_WIDTH 20
#endif

#ifndef FLOAT_PRECISION
#   define FLOAT_PRECISION 2
#endif

int main(int argc, char *argv[])
{
    int myid, numprocs, i, j;
    int size, align_size;
    char *s_buf, *r_buf;
    double t_start = 0.0, t_end = 0.0, t = 0.0;
    int loop = 100;
    int window_size = 64;
    int skip = 10;

    MPI_Init(&argc, &argv);
    MPI_Comm_size(MPI_COMM_WORLD, &numprocs);
    MPI_Comm_rank(MPI_COMM_WORLD, &myid);

    if(numprocs != 2) {
        if(myid == 0) {
            fprintf(stderr, "This test requires exactly two processes\n");
        }

        MPI_Finalize();

        return EXIT_FAILURE;
    }

    align_size = getpagesize();
    assert(align_size <= MAX_ALIGNMENT);

    /**************Allocating Memory*********************/

    s_buf =
        (char *) (((unsigned long) s_buf_original + (align_size - 1)) /
                align_size * align_size);

    r_buf =
        (char *) (((unsigned long) r_buf_original + (align_size - 1)) /
                align_size * align_size);

    /**************Memory Allocation Done*********************/

    if(myid == 0) {
        fprintf(stdout, HEADER);
        fprintf(stdout, "%-*s%*s\n", 10, "# Size", FIELD_WIDTH,
                "Bi-Bandwidth (MB/s)");
        fflush(stdout);
    }

    for(size = 1; size <= MAX_MSG_SIZE; size *= 2) {
        /* touch the data */
        for(i = 0; i < size; i++) {
            s_buf[i] = 'a';
            r_buf[i] = 'b';
        }

        if(size > LARGE_MESSAGE_SIZE) {
            loop = LOOP_LARGE;
            skip = SKIP_LARGE;
            window_size = WINDOW_SIZE_LARGE;
        }

        if(myid == 0) {
            for(i = 0; i < loop + skip; i++) {
                if(i == skip) {
                    t_start = MPI_Wtime();
                }

                for(j = 0; j < window_size; j++) {
                    MPI_Irecv(r_buf, size, MPI_CHAR, 1, 10, MPI_COMM_WORLD,
                            recv_request + j);
                }

                for(j = 0; j < window_size; j++) {
                    MPI_Isend(s_buf, size, MPI_CHAR, 1, 100, MPI_COMM_WORLD,
                            send_request + j);
                }

                MPI_Waitall(window_size, send_request, reqstat);
                MPI_Waitall(window_size, recv_request, reqstat);
            }

            t_end = MPI_Wtime();
            t = t_end - t_start;

        }

        else if(myid == 1) {
            for(i = 0; i < loop + skip; i++) {
                for(j = 0; j < window_size; j++) {
                    MPI_Irecv(r_buf, size, MPI_CHAR, 0, 100, MPI_COMM_WORLD,
                            recv_request + j);
                }

                for (j = 0; j < window_size; j++) {
                    MPI_Isend(s_buf, size, MPI_CHAR, 0, 10, MPI_COMM_WORLD,
                            send_request + j);
                }

                MPI_Waitall(window_size, send_request, reqstat);
                MPI_Waitall(window_size, recv_request, reqstat);
            }
        }

        if(myid == 0) {
            double tmp = size / 1e6 * loop * window_size * 2;

            fprintf(stdout, "%-*d%*.*f\n", 10, size, FIELD_WIDTH,
                    FLOAT_PRECISION, tmp / t);
            fflush(stdout);
        }
    }

    MPI_Finalize();

    return EXIT_SUCCESS;
}

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