Exhausts all memory (physical and virtual)

memory_murder.c

#include <stdlib.h>
#include <stdio.h>
#include <sys/types.h>
#include <sys/mman.h>
#include <unistd.h>

int main(void) {
    char * page;
    size_t memory_allocated = 0;
    while ((page = mmap(NULL, sysconf(_SC_PAGE_SIZE)
            , PROT_READ | PROT_WRITE
            , MAP_ANON | MAP_PRIVATE, -1, 0))
            != MAP_FAILED) {
        memory_allocated += sysconf(_SC_PAGE_SIZE);
        // optionally touch the page
        // otherwise the mapping won't use physical RAM/swap
        *page = 1; 
    }

    fprintf(stderr, "Allocated %zu MiB\n", memory_allocated >> 20);
    perror("mmap");
    return 0;
}