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

#define S (1<<27)

int main(int argc, char* argv[])
{
    void *a, *b;

    a = malloc(S);
    b = malloc(S);

    if (a == 0 || b == 0) {
        puts("malloc failed\n");
        return EXIT_FAILURE;
    }
    puts("malloced\n");

    while (1) {
        memcpy(b,a, S);
        puts("a->b\n");
        memcpy(a,b, S);
        puts("b->a\n");
    }

}