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 36int 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