// This program is a pointless memory hog to induce swapping.
// Build with -m64 for the 64-bit memory model. 
// 
#include <stdio.h>
#include <sys/mman.h>
#include <unistd.h>   

int main()
{
    // mlockall(MCL_FUTURE);
    int cnt = 0;
    void *addr;

    while(1){
	addr = mmap(NULL, 4096, PROT_READ|PROT_WRITE, MAP_PRIVATE|MAP_ANON, -1, 0);
	if(addr==MAP_FAILED){
	    perror("mmap failed: ");
	    return -1;
	}

	printf("allocated %p\n", addr);
    	*(unsigned long*)addr = 0xdeadbeef; // what happens without this write?
	
	if( cnt++ % 10000 == 0 ) 
	    sleep(1); 
    }
    return 0;
}