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#define __STDC_FORMAT_MACROS
#include <sys/time.h>
#include <time.h>
#include <stdlib.h>
#include <sys/syscall.h>
#include <unistd.h>
#include <stdio.h>
#include <string.h>
#include <inttypes.h>
#include <sys/mman.h>
#include <err.h>
#define NPAGES 512
#define PAGE_SIZE 4096
static uint64_t faults = 0;
static void iter(void)
{
clock_getres(CLOCK_REALTIME, (void *)8);
faults++;
}
int main(int argc, char **argv)
{
// Warm up
for (int i = 0; i < 1000000; i++)
iter();
faults = 0;
struct timespec start;
clock_gettime(CLOCK_MONOTONIC, &start);
for (int i = 0; i < 1000000; i++)
iter();
struct timespec end;
clock_gettime(CLOCK_MONOTONIC, &end);
unsigned long long duration = (end.tv_nsec - start.tv_nsec) + 1000000000ULL * (end.tv_sec - start.tv_sec);
printf("%ld faults in %.5fs = %.2f nsec / loop\n",
(long)faults, (float)duration * 1e-9f,
(float)duration / faults);
return 0;
}
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