A linux program that uses memory

Question

I need it execute a certain kind of linux program from the terminal. The only thing the linux program needs to do is use more and more memory. Are there any programs like that?

Answer 1

From my previous answer on StackOverflow:

#include <stdlib.h>

int main() {
int *p;
while(1) {
    int inc=1024*1024*sizeof(char);
    p=(int*) calloc(1,inc);
    if(!p) break;
    }
}

run

$ gcc memtest.c
$ ./a.out

upon running, this code fills up ones RAM until killed by the kernel. Using calloc instead of malloc to prevent "lazy evaluation". Ideas taken from this thread: http://stackoverflow.com/questions/4383059/malloc-memory-questions

This code quickly filled my RAM (4Gb) and then in about 2 minutes my 20Gb swap partition before it died. This works on 64bit Linux. If you use a 32bit OS, it will have a limit of 2 or 4GB before it dies.

Answer 2

how about a fork bomb ?

else something that creates a series of ever larger ram disks? You can create a ram disk with

mkdir /tmp/ramdisk; chmod 777 /tmp/ramdisk

mount -t tmpfs -o size=256M tmpfs /tmp/ramdisk/

to create a 256 mb ram disk. you could probably script a script that will make a series of ram disks, and fill them repeatedly up until whatever you need would happen

Answer 3

Save the following as mem.c, then run gcc -o mem mem.c, then run ./mem. It allocates 100MB of memory every second. It does nothing else. You can change the number of seconds its sleeps or how many MB it allocates by changing the numbers below.

#include <malloc.h>
#include <unistd.h>
#include <memory.h>
#define MB 1024 * 1024
int main() {
    while (1) {
        void *p = malloc( 100*MB );
        memset(p,0, 100*MB );
        sleep(1);
    }
}

EDIT
OK, tested and updated.

Answer 4

There's a utility called stress which does this, among other things. apt-get install stress from Debian.

Answer 5

You could use mprime, which is, IIRC, a linux port of Prime95 of overclocking fame. mprime (and Prime95) will allow you to stress test the memory and CPU of your computer system. In addition, you can specify exactly how much memory you want mprime to use (to overflow into swap space, if you like).

Find mprime and prime95 here. I apologize in advance for the state of the website's navigation.