Eat Memory. In C. For testing memory limits.

eatmem.c

// Compile with e.g. `gcc -o /tmp/eatmem /tmp/eatmem.c`

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

int main(int argc, char **argv)
{
    void *p, *end, *cur;
    size_t megs;
    const size_t default_megs = 16 * 1024;
    const size_t one_meg = 1024 * 1024;
    const size_t page_size = 4096;

    if (argc == 1) {
        printf("Using defaults. Specify some different with `%s <megs>`.\n",
                argv[0]);
        megs  = default_megs;
    }else {
        megs = atoi(argv[1]);
    }
    printf("Reserving %luM and touching in steps of %hu.\n",
            (unsigned long)megs,
            (unsigned short)page_size);

    p = calloc(megs, one_meg);
    if(!p) {
        perror("calloc()");
        exit(EXIT_FAILURE);
    }
    end = p + megs * one_meg;
    for (cur=p ;cur<end; cur += page_size) {
        *(char *)cur = 0xAA;
    }
    free(p);
    exit(EXIT_SUCCESS);
}