linux/tools/testing/selftests/powerpc/benchmarks/mmap_bench.c
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   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