memory_test/test_swap.c

70 lines
1.3 KiB
C

#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <sys/time.h>
#define SIZE 500*1024*1024
#define PAGE_SIZE 4096 // 4KB
#define CHUNK_SIZE 8 * 1024 // 8KB
unsigned long long tv_to_ms(struct timeval tv)
{
return tv.tv_sec * 1000 + tv.tv_usec / 1000;
}
int main()
{
int i;
char *c;
pid_t pid;
unsigned long *p;
struct timeval tv_b, tv_e;;
p = mmap(NULL, SIZE, PROT_READ | PROT_WRITE, MAP_PRIVATE | MAP_ANONYMOUS, -1, 0);
if (!p) {
perror("fail to get memory");
exit(-1);
}
c = (unsigned char *)p;
/* fill data */
for (i = 0; i < SIZE / 8; i += 8)
*(p + i) = 0xffff + i;
/* trigger pageout and get time of pageout */
gettimeofday(&tv_b, NULL);
madvise(p, SIZE, MADV_PAGEOUT);
gettimeofday(&tv_e, NULL);
printf("swp out bandwidth: %ld bytes/ms\n", SIZE/(tv_to_ms(tv_e) - tv_to_ms(tv_b)));
/* read to trigger swapin and */
gettimeofday(&tv_b, NULL);
for (i = 0; i < SIZE; i += PAGE_SIZE)
*(c + i) = i;
gettimeofday(&tv_e, NULL);
printf("swp in bandwidth: %ld bytes/ms\n", SIZE/(tv_to_ms(tv_e) - tv_to_ms(tv_b)));
pid = fork();
if (pid) {
munmap(p, SIZE);
return 0;
}
madvise(p, SIZE, MADV_PAGEOUT);
while (1) {
sleep(10);
}
return 0;
}