clear.c

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

int
main(void)
{
    for (;;) {
        void *x = malloc(4 * 1024);
        if (x == NULL) {
            break;
        }
        memset(x, 0, 4 * 1024);
    }
    return 0;
}