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 (at) 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 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
