1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * Copyright 2016, Anton Blanchard, Michael Ellerman, IBM Corp.
4 */
5
6#include <stdio.h>
7#include <stdlib.h>
8#include <sys/mman.h>
9#include <time.h>
10#include <getopt.h>
11
12#include "utils.h"
13
14#define ITERATIONS 5000000
15
16#define MEMSIZE (1UL << 27)
17#define PAGE_SIZE (1UL << 16)
18#define CHUNK_COUNT (MEMSIZE/PAGE_SIZE)
19
20static int pg_fault;
21static int iterations = ITERATIONS;
22
23static struct option options[] = {
24 { "pgfault", no_argument, &pg_fault, 1 },
25 { "iterations", required_argument, 0, 'i' },
26 { 0, },
27};
28
29static void usage(void)
30{
31 printf("mmap_bench <--pgfault> <--iterations count>\n");
32}
33
34int test_mmap(void)
35{
36 struct timespec ts_start, ts_end;
37 unsigned long i = iterations;
38
39 clock_gettime(CLOCK_MONOTONIC, &ts_start);
40
41 while (i--) {
42 char *c = mmap(NULL, MEMSIZE, PROT_READ|PROT_WRITE,
43 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
44 FAIL_IF(c == MAP_FAILED);
45 if (pg_fault) {
46 int count;
47 for (count = 0; count < CHUNK_COUNT; count++)
48 c[count << 16] = 'c';
49 }
50 munmap(c, MEMSIZE);
51 }
52
53 clock_gettime(CLOCK_MONOTONIC, &ts_end);
54
55 printf("time = %.6f\n", ts_end.tv_sec - ts_start.tv_sec + (ts_end.tv_nsec - ts_start.tv_nsec) / 1e9);
56
57 return 0;
58}
59
60int main(int argc, char *argv[])
61{
62 signed char c;
63 while (1) {
64 int option_index = 0;
65
66 c = getopt_long(argc, argv, "", options, &option_index);
67
68 if (c == -1)
69 break;
70
71 switch (c) {
72 case 0:
73 if (options[option_index].flag != 0)
74 break;
75
76 usage();
77 exit(1);
78 break;
79 case 'i':
80 iterations = atoi(optarg);
81 break;
82 default:
83 usage();
84 exit(1);
85 }
86 }
87
88 test_harness_set_timeout(300);
89 return test_harness(test_mmap, "mmap_bench");
90}
91

source code of linux/tools/testing/selftests/powerpc/benchmarks/mmap_bench.c