mmap_test.c

#include <stdio.h>
#include <string.h>
#include <sys/mman.h>
#include <unistd.h>

int main(void) {
  size_t pagesize = getpagesize();

  printf("System page size: %zu bytes\n", pagesize);

  for (size_t i = 0; i < 1000; i++) {
    char *region = mmap(
      NULL,
      pagesize * (i + 1),
      PROT_READ|PROT_WRITE,
      MAP_ANONYMOUS | MAP_PRIVATE,      // to a private block of hardware memory
      -1,
      0
    );
    if (region == MAP_FAILED) {
      perror("Could not mmap");
      return 1;
    }
    // Trigger page fault
    for (size_t j = 0; j < pagesize * (i + 1); j++) {
      region[j] = 'a';
    }

    int unmap_result = munmap(region, pagesize * (i + 1));
    if (unmap_result == -1) {
      perror("Could not munmap");
      return 1;
    }
    sleep(1);
  }

  return 0;
}

result.txt

pidstat -r 1 -e ./a.out
Linux 4.15.0-1044-aws (xxx) 	08/12/19 	_x86_64_	(16 CPU)
System page size: 4096 bytes

06:42:23      UID       PID  minflt/s  majflt/s     VSZ     RSS   %MEM  Command
06:42:24     1000      1192     33.00      0.00    4508    1472   0.00  a.out
06:42:25     1000      1192      2.00      0.00    4508    1536   0.00  a.out
06:42:26     1000      1192      3.00      0.00    4508    1536   0.00  a.out
06:42:27     1000      1192      4.00      0.00    4508    1536   0.00  a.out
06:42:28     1000      1192      5.00      0.00    4508    1536   0.00  a.out
06:42:29     1000      1192      6.00      0.00    4508    1536   0.00  a.out
06:42:30     1000      1192      7.00      0.00    4508    1536   0.00  a.out
06:42:31     1000      1192      8.00      0.00    4508    1536   0.00  a.out
06:42:32     1000      1192      9.00      0.00    4508    1536   0.00  a.out
06:42:33     1000      1192     10.00      0.00    4508    1536   0.00  a.out
06:42:34     1000      1192     11.00      0.00    4508    1536   0.00  a.out
06:42:35     1000      1192     12.00      0.00    4508    1536   0.00  a.out
06:42:36     1000      1192     13.00      0.00    4508    1536   0.00  a.out
06:42:37     1000      1192     14.00      0.00    4508    1536   0.00  a.out
06:42:38     1000      1192     15.00      0.00    4508    1536   0.00  a.out
06:42:39     1000      1192     16.00      0.00    4508    1536   0.00  a.out
06:42:40     1000      1192     17.00      0.00    4508    1536   0.00  a.out
06:42:41     1000      1192     18.00      0.00    4508    1536   0.00  a.out
06:42:42     1000      1192     19.00      0.00    4508    1536   0.00  a.out
06:42:43     1000      1192     20.00      0.00    4508    1536   0.00  a.out
06:42:44     1000      1192     21.00      0.00    4508    1536   0.00  a.out
06:42:45     1000      1192     22.00      0.00    4508    1536   0.00  a.out
06:42:46     1000      1192     23.00      0.00    4508    1536   0.00  a.out
06:42:47     1000      1192     24.00      0.00    4508    1536   0.00  a.out
06:42:48     1000      1192     25.00      0.00    4508    1536   0.00  a.out
06:42:49     1000      1192     26.00      0.00    4508    1536   0.00  a.out
06:42:50     1000      1192     27.00      0.00    4508    1536   0.00  a.out
06:42:51     1000      1192     28.00      0.00    4508    1536   0.00  a.out
06:42:52     1000      1192     29.00      0.00    4508    1536   0.00  a.out
06:42:53     1000      1192     30.00      0.00    4508    1536   0.00  a.out