memory_eater_ng.c

memory_eater_ng.c

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

// Author: pavel.odintsov@gmail.com at FastVPS Eesti OU
// License: GPLv2

// This script allocate huge block of memory and fill it with random crap
// It's useful for checking kdump or ISP's with memory oversell :)
// Compilation: gcc memory_eater_ng.c -omemory_eater_ng
// Run it for 4GB memory region: ./memory_eater_ng 4
// This code could work correctly only on 64 bit platforms, i.e. x86_64

int main(int argc, char *argv[]) {
    // Allocate 1GB memory by default
    unsigned long long int buffer_size_in_gb = 1L;

    if (argc > 1) {
        buffer_size_in_gb = atoi(argv[1]);
    } 

    // Calculate memory region in bytes
    unsigned long long int buffer_size = buffer_size_in_gb * 1024L * 1024L * 1024L;
    
    printf("I will allocate %d GB of RAM\n", buffer_size_in_gb);
    unsigned long long* buffer_as_array_of_64_bit_integers = (unsigned long long*)malloc(buffer_size);;
    printf("Well, I allocated memory\n");
    
    printf("I will fill this memory by random crap\n");
    unsigned int index = 0;
    for (index = 0; index < buffer_size / sizeof(unsigned long long); index++) {
        // Fill it with random crap
        buffer_as_array_of_64_bit_integers[index] = rand();
    }
    
    printf("Memory filled by crap corectly, go to infinite sleep\n");

    // Go to infinite loop, wait forever
    while (1) {
       sleep(10);
    }
}