1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
|
/*
* Copyright (C) by Argonne National Laboratory
* See COPYRIGHT in top-level directory
*/
#include "mpi.h"
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
/* A simple performance test. The file name is taken as a
command-line argument. */
#define SIZE (1048576*4) /* read/write size per node in bytes */
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); }
int main(int argc, char **argv)
{
int *buf, i, j, mynod, nprocs, ntimes = 5, len, err, flag;
double stim, read_tim, write_tim, new_read_tim, new_write_tim;
double min_read_tim = 10000000.0, min_write_tim = 10000000.0, read_bw, write_bw;
MPI_File fh;
MPI_Status status;
char *filename;
MPI_Init(&argc, &argv);
MPI_Comm_size(MPI_COMM_WORLD, &nprocs);
MPI_Comm_rank(MPI_COMM_WORLD, &mynod);
/* 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: 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);
fprintf(stderr, "Access size per process = %d bytes, ntimes = %d\n", SIZE, ntimes);
} 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);
}
buf = (int *) malloc(SIZE);
for (j = 0; j < ntimes; j++) {
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename,
MPI_MODE_CREATE | MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_seek(fh, mynod * SIZE, MPI_SEEK_SET));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_write(fh, buf, SIZE, MPI_BYTE, &status));
write_tim = MPI_Wtime() - stim;
MPI_CHECK(MPI_File_close(&fh));
MPI_Barrier(MPI_COMM_WORLD);
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE |
MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_seek(fh, mynod * SIZE, MPI_SEEK_SET));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_read(fh, buf, SIZE, MPI_BYTE, &status));
read_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);
MPI_Allreduce(&read_tim, &new_read_tim, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
min_read_tim = (new_read_tim < min_read_tim) ? new_read_tim : min_read_tim;
min_write_tim = (new_write_tim < min_write_tim) ? new_write_tim : min_write_tim;
}
if (mynod == 0) {
read_bw = (SIZE * nprocs) / (min_read_tim * 1024.0 * 1024.0);
write_bw = (SIZE * nprocs) / (min_write_tim * 1024.0 * 1024.0);
fprintf(stderr, "Write bandwidth without file sync = %f Mbytes/sec\n", write_bw);
fprintf(stderr, "Read bandwidth without prior file sync = %f Mbytes/sec\n", read_bw);
}
min_write_tim = 10000000.0;
min_read_tim = 10000000.0;
flag = 0;
for (j = 0; j < ntimes; j++) {
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE |
MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_seek(fh, mynod * SIZE, MPI_SEEK_SET));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_write(fh, buf, SIZE, MPI_BYTE, &status));
err = MPI_File_sync(fh);
write_tim = MPI_Wtime() - stim;
if (err == MPI_ERR_UNKNOWN) {
flag = 1;
break;
}
MPI_CHECK(MPI_File_close(&fh));
MPI_Barrier(MPI_COMM_WORLD);
MPI_CHECK(MPI_File_open(MPI_COMM_WORLD, filename, MPI_MODE_CREATE |
MPI_MODE_RDWR, MPI_INFO_NULL, &fh));
MPI_CHECK(MPI_File_seek(fh, mynod * SIZE, MPI_SEEK_SET));
MPI_Barrier(MPI_COMM_WORLD);
stim = MPI_Wtime();
MPI_CHECK(MPI_File_read(fh, buf, SIZE, MPI_BYTE, &status));
read_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);
MPI_Allreduce(&read_tim, &new_read_tim, 1, MPI_DOUBLE, MPI_MAX, MPI_COMM_WORLD);
min_read_tim = (new_read_tim < min_read_tim) ? new_read_tim : min_read_tim;
min_write_tim = (new_write_tim < min_write_tim) ? new_write_tim : min_write_tim;
}
if (mynod == 0) {
if (flag)
fprintf(stderr, "MPI_File_sync returns error.\n");
else {
read_bw = (SIZE * nprocs) / (min_read_tim * 1024.0 * 1024.0);
write_bw = (SIZE * nprocs) / (min_write_tim * 1024.0 * 1024.0);
fprintf(stderr, "Write bandwidth including file sync = %f Mbytes/sec\n", write_bw);
fprintf(stderr, "Read bandwidth after file sync = %f Mbytes/sec\n", read_bw);
}
}
free(buf);
free(filename);
MPI_Finalize();
return 0;
}
|
