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