parse_smaps.c

#include <stdint.h>
#include <stdio.h>
#include <string.h>
#include <sys/time.h>

void get_memusage_extra(uint64_t * uss, uint64_t * pss) {
  FILE *file = fopen("/proc/self/smaps", "r");

  char line [BUFSIZ];
  while (fgets(line, sizeof line, file))
    {
      char substr[32];
      int n;
      if (sscanf(line, "%31[^:]: %d", substr, &n) == 2)
        {
          if (strcmp(substr, "Private_Clean") == 0)  { *uss += n * 1024; }
          else if (strcmp(substr, "Private_Dirty") == 0)  { *uss += n * 1024; }
          else if (strcmp(substr, "Pss") == 0)            { *pss += n * 1024; }
        }
    }
  fclose(file);
}

int main() {
  struct timeval before, after;
  int iterations = 100000;
  int i;

  uint64_t uss;
  uint64_t pss;

  gettimeofday(&before, NULL);
  for (i = 0; i < iterations; ++i) {
    get_memusage_extra(&uss, &pss);
  }
  gettimeofday(&after, NULL);
  double duration = (after.tv_sec * 1000000 + after.tv_usec)
    - (before.tv_sec * 1000000 + before.tv_usec);
  printf("%f microseconds per iteration\n", (duration)/(iterations));

  return 0;
}