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/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
#include "mpi.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
static void handle_error(int errcode, const char *str)
{
char msg[MPI_MAX_ERROR_STRING];
int resultlen;
MPI_Error_string(errcode, msg, &resultlen);
fprintf(stderr, "%s: %s\n", str, msg);
MPI_Abort(MPI_COMM_WORLD, 1);
}
#define MPI_CHECK(fn) { int errcode; errcode = (fn); if (errcode != MPI_SUCCESS) handle_error(errcode, #fn); }
/* The file name is taken as a command-line argument. */
/* Measures the I/O bandwidth for writing/reading a 3D
block-distributed array to a file corresponding to the global array
in row-major (C) order.
Note that the file access pattern is noncontiguous.
Array size 128^3. For other array sizes, change array_of_gsizes below.*/
int main(int argc, char **argv)
{
MPI_Datatype newtype;
int i, ndims, array_of_gsizes[3], array_of_distribs[3];
int order, nprocs, len, *buf, mynod;
MPI_Count bufcount;
int array_of_dargs[3], array_of_psizes[3];
MPI_File fh;
MPI_Status status;
double stim, write_tim, new_write_tim, write_bw;
double read_tim, new_read_tim, read_bw;
char *filename;
MPI_Init(&argc, &argv);
MPI_Comm_rank(MPI_COMM_WORLD, &mynod);
MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
/* process 0 takes the file name as a command-line argument and
broadcasts it to other processes */
if (!mynod) {
i = 1;
while ((i < argc) && strcmp("-fname", *argv)) {
i++;
argv++;
}
if (i >= argc) {
fprintf(stderr, "\n*# Usage: coll_perf -fname filename\n\n");
MPI_Abort(MPI_COMM_WORLD, 1);
}
argv++;
len = strlen(*argv);
filename = (char *) malloc(len + 1);
strcpy(filename, *argv);
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
MPI_Bcast(filename, len + 1, MPI_CHAR, 0, MPI_COMM_WORLD);
} else {
MPI_Bcast(&len, 1, MPI_INT, 0, MPI_COMM_WORLD);
filename = (char *) malloc(len + 1);
MPI_Bcast(filename, len + 1, MPI_CHAR, 0, MPI_COMM_WORLD);
}
ndims = 3;
order = MPI_ORDER_C;
array_of_gsizes[0] = 128 * 17;
array_of_gsizes[1] = 128 * 9;
array_of_gsizes[2] = 128 * 11;
array_of_distribs[0] = MPI_DISTRIBUTE_BLOCK;
array_of_distribs[1] = MPI_DISTRIBUTE_BLOCK;
array_of_distribs[2] = MPI_DISTRIBUTE_BLOCK;
array_of_dargs[0] = MPI_DISTRIBUTE_DFLT_DARG;
array_of_dargs[1] = MPI_DISTRIBUTE_DFLT_DARG;
array_of_dargs[2] = MPI_DISTRIBUTE_DFLT_DARG;
for (i = 0; i < ndims; i++)
array_of_psizes[i] = 0;
MPI_Dims_create(nprocs, ndims, array_of_psizes);
MPI_Type_create_darray(nprocs, mynod, ndims, array_of_gsizes,
array_of_distribs, array_of_dargs,
array_of_psizes, order, MPI_INT, &newtype);
MPI_Type_commit(&newtype);
MPI_Type_size_x(newtype, &bufcount);
bufcount = bufcount / sizeof(int);
buf = (int *) malloc(bufcount * sizeof(int));
/* to eliminate paging effects, do the operations once but don't time
them */
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", MPI_INFO_NULL));
MPI_CHECK(MPI_File_write_all(fh, buf, bufcount, MPI_INT, &status));
MPI_CHECK(MPI_File_seek(fh, 0, MPI_SEEK_SET));
MPI_CHECK(MPI_File_read_all(fh, buf, bufcount, MPI_INT, &status));
MPI_CHECK(MPI_File_close(&fh));
MPI_Barrier(MPI_COMM_WORLD);
/* now time write_all */
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", MPI_INFO_NULL));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_write_all(fh, buf, bufcount, MPI_INT, &status));
write_tim = MPI_Wtime() - stim;
MPI_CHECK(MPI_File_close(&fh));
MPI_Allreduce(&write_tim, &new_write_tim, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
if (mynod == 0) {
write_bw =
(array_of_gsizes[0] * array_of_gsizes[1] * array_of_gsizes[2] * sizeof(int)) /
(new_write_tim * 1024.0 * 1024.0);
fprintf(stderr, "Global array size %d x %d x %d integers\n", array_of_gsizes[0],
array_of_gsizes[1], array_of_gsizes[2]);
fprintf(stderr,
"Collective write time = %f sec, Collective write bandwidth = %f Mbytes/sec\n",
new_write_tim, write_bw);
}
MPI_Barrier(MPI_COMM_WORLD);
/* now time read_all */
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_set_view(fh, 0, MPI_INT, newtype, "native", MPI_INFO_NULL));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_read_all(fh, buf, bufcount, MPI_INT, &status));
read_tim = MPI_Wtime() - stim;
MPI_CHECK(MPI_File_close(&fh));
MPI_Allreduce(&read_tim, &new_read_tim, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
if (mynod == 0) {
read_bw =
(array_of_gsizes[0] * array_of_gsizes[1] * array_of_gsizes[2] * sizeof(int)) /
(new_read_tim * 1024.0 * 1024.0);
fprintf(stderr,
"Collective read time = %f sec, Collective read bandwidth = %f Mbytes/sec\n",
new_read_tim, read_bw);
}
MPI_Type_free(&newtype);
free(buf);
free(filename);
MPI_Finalize();
return 0;
}
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