mem_process.c revision 354ebb48db8e66a853a58379a4808d5dcd1ceac3
1/*****************************************************************************/ 2/* */ 3/* Copyright (c) 2010 Mohamed Naufal Basheer */ 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/* File: mem_process.c */ 20/* */ 21/* Purpose: act as a memory hog for the memcg_control tests */ 22/* */ 23/* Author: Mohamed Naufal Basheer <naufal11@gmail.com > */ 24/* */ 25/*****************************************************************************/ 26 27#include <sys/types.h> 28#include <sys/mman.h> 29#include <sys/stat.h> 30#include <err.h> 31#include <errno.h> 32#include <fcntl.h> 33#include <stdio.h> 34#include <stdlib.h> 35#include <unistd.h> 36 37/* 38 * Named pipe to act as a communication channel between 39 * shell script & this process 40 */ 41#define STATUS_PIPE "status_pipe" 42 43int flag_exit; 44int flag_allocated; 45unsigned long memsize; 46 47/* 48 * process_options: process user specified options 49 */ 50void process_options(int argc, char **argv) 51{ 52 int c; 53 char *end; 54 55 opterr = 0; 56 while ((c = getopt(argc, argv, "pm:")) != -1) { 57 switch (c) { 58 case 'm': 59 memsize = strtoul(optarg, &end, 10); 60 if (*end != '\0') 61 errx(2, "invalid -m usage"); 62 break; 63 case 'p': 64 printf("%d\n", getpagesize()); 65 exit(0); 66 default: 67 errx(2, "invalid option specifed"); 68 } 69 } 70 71 if (memsize <= 0) 72 errx(3, "invalid usage"); 73} 74 75/* 76 * touch_memory: force physical memory allocation 77 */ 78void touch_memory(char *p) 79{ 80 int i; 81 int pagesize = getpagesize(); 82 83 for (i = 0; i < memsize; i += pagesize) 84 p[i] = 0xef; 85} 86 87void mem_map() 88{ 89 static char *p; 90 91 if (flag_allocated) { 92 if (munmap(p, memsize) == -1) 93 err(5, "munmap failed"); 94 } else { 95 p = mmap(NULL, memsize, PROT_READ | PROT_WRITE, 96 MAP_SHARED | MAP_ANONYMOUS, 0, 0); 97 if (p == MAP_FAILED) 98 err(4, "mmap failed"); 99 touch_memory(p); 100 } 101 flag_allocated = !flag_allocated; 102} 103 104/* 105 * done: retrieve instructions from the named pipe 106 */ 107char action() 108{ 109 char ch; 110 int fd; 111 112 if ((fd = open(STATUS_PIPE, O_RDONLY)) == -1) 113 err(6, "Error opening named pipe"); 114 115 if (read(fd, &ch, 1) == -1) 116 err(7, "Error reading named pipe"); 117 118 close(fd); 119 120 return ch; 121} 122 123int main(int argc, char **argv) 124{ 125 int ret; 126 char ch; 127 128 process_options(argc, argv); 129 130 ret = mkfifo(STATUS_PIPE, 0666); 131 132 if (ret == -1 && errno != EEXIST) 133 errx(1, "Error creating named pipe"); 134 135 do { 136 ch = action(); 137 138 if (ch == 'm') 139 mem_map(); 140 } while (ch != 'x'); 141 142 remove(STATUS_PIPE); 143 144 return 0; 145} 146