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#define _GNU_SOURCE
#include <assert.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
typedef unsigned long long u64;
static size_t length = 1 << 24;
static u64 read_rss(void)
{
char buf[4096], *s = buf;
int i, fd;
u64 rss;
fd = open("/proc/self/statm", O_RDONLY);
assert(fd > 2);
memset(buf, 0, sizeof(buf));
read(fd, buf, sizeof(buf) - 1);
for (i = 0; i < 1; i++)
s = strchr(s, ' ') + 1;
rss = strtoull(s, NULL, 10);
return rss << 12; /* assumes 4k pagesize */
}
static void do_mmap(int fd, int extra_flags, int unmap)
{
int *p;
int flags = MAP_PRIVATE | MAP_POPULATE | extra_flags;
u64 before, after;
before = read_rss();
p = mmap(NULL, length, PROT_READ | PROT_WRITE, flags, fd, 0);
assert(p != MAP_FAILED ||
!"mmap returned an unexpected error");
after = read_rss();
assert(llabs(after - before - length) < 0x40000 ||
!"rss didn't grow as expected");
if (!unmap)
return;
munmap(p, length);
after = read_rss();
assert(llabs(after - before) < 0x40000 ||
!"rss didn't shrink as expected");
}
static int open_file(const char *path)
{
int fd, err;
unlink(path);
fd = open(path, O_CREAT | O_RDWR | O_TRUNC | O_EXCL
| O_LARGEFILE | O_CLOEXEC, 0600);
assert(fd > 2);
unlink(path);
err = ftruncate(fd, length);
assert(!err);
return fd;
}
int main(void)
{
int hugefd, fd;
fd = open_file("/dev/shm/hugetlbhog");
hugefd = open_file("/hugepages/hugetlbhog");
system("echo 100 > /proc/sys/vm/nr_hugepages");
do_mmap(-1, MAP_ANONYMOUS, 1);
do_mmap(fd, 0, 1);
do_mmap(-1, MAP_ANONYMOUS | MAP_HUGETLB, 1);
do_mmap(hugefd, 0, 1);
do_mmap(hugefd, MAP_HUGETLB, 1);
/* Leak the last one to test do_exit() */
do_mmap(-1, MAP_ANONYMOUS | MAP_HUGETLB, 0);
printf("oll korrekt.\n");
return 0;
}
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