1 /******************************************************************************/
2 /* */
3 /* Copyright (c) 2009 FUJITSU LIMITED */
4 /* */
5 /* This program is free software; you can redistribute it and/or modify */
6 /* it under the terms of the GNU General Public License as published by */
7 /* the Free Software Foundation; either version 2 of the License, or */
8 /* (at your option) any later version. */
9 /* */
10 /* This program is distributed in the hope that it will be useful, */
11 /* but WITHOUT ANY WARRANTY; without even the implied warranty of */
12 /* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See */
13 /* the GNU General Public License for more details. */
14 /* */
15 /* You should have received a copy of the GNU General Public License */
16 /* along with this program; if not, write to the Free Software */
17 /* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */
18 /* */
19 /* Author: Li Zefan <lizf@cn.fujitsu.com> */
20 /* */
21 /******************************************************************************/
22
23 #include <stdio.h>
24 #include <stdlib.h>
25 #include <unistd.h>
26 #include <fcntl.h>
27 #include <sys/mman.h>
28 #include <sys/wait.h>
29
30 #define MAP_FLAGS (MAP_PRIVATE|MAP_ANONYMOUS|MAP_LOCKED)
31
32 #define LOOP 40
33
34 #define FORKED_PROC_COUNT 10
35
main(void)36 int main(void)
37 {
38 char buf[10];
39 int i;
40 int loop;
41 int pid;
42 int size = getpagesize();
43 int fd = open("memcg/0/tasks", O_WRONLY);
44
45 if (fd < 0)
46 return 1;
47
48 for (loop = 0; loop < LOOP; loop++) {
49 for (i = 0; i < FORKED_PROC_COUNT; i++) {
50 pid = fork();
51 if (pid == 0) {
52 char *p;
53
54 sprintf(buf, "%d", getpid());
55 write(fd, buf, 10);
56 fsync(fd);
57
58 p = mmap(NULL, size, PROT_READ | PROT_WRITE,
59 MAP_FLAGS, 0, 0);
60
61 if (p == MAP_FAILED) {
62 perror("mmap failed");
63 exit(1);
64 } else
65 exit(0);
66 }
67 }
68
69 for (i = 0; i < FORKED_PROC_COUNT; i++)
70 wait(NULL);
71 }
72
73 close(fd);
74
75 return 0;
76 }
77