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1.1 root 1: /*
2: * Random I/O benchmark.
3: *
4: * Process reads blocks from a
5: * file in a random order.
6: */
7: #include <sys/types.h>
8: #include <sys/file.h>
9: #include <sys/stat.h>
10:
11: char *malloc();
12:
13: main(argc, argv)
14: char *argv[];
15: {
16: char *buf;
17: int size, fd, bn, maxblocks;
18: struct stat sb;
19: register int i, niter;
20:
21: if (argc < 3) {
22: printf("usage: %s file read-size #reads\n", argv[0]);
23: exit(1);
24: }
25: fd = open(argv[1], 0);
26: if (fd < 0) {
27: perror(argv[1]);
28: exit(2);
29: }
30: fstat(fd, &sb);
31: buf = malloc(1024);
32: if (buf == (char *)0) {
33: printf("Couldn't allocate i/o buffer.\n");
34: exit(3);
35: }
36: size = atoi(argv[2]);
37: if (size > 1024) {
38: printf("Reads must be no larger than block size (%d)\n",
39: 1024);
40: exit(4);
41: }
42: niter = atoi(argv[3]);
43: printf("%d random %d byte reads, file size %d kb (bsize %d)\n",
44: niter, size, sb.st_size / 1024, 1024);
45: for (i = 0; i < niter; i++) {
46: lseek(fd, random() % sb.st_size, 0);
47: read(fd, buf, size);
48: }
49: }
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