entropy sike

$ cat /proc/sys/kernel/random/entropy_avail
2181
$ dd if=/dev/urandom of=/dev/null bs=512 count=100
100+0 records in
100+0 records out
51200 bytes (51 kB) copied, 0.012414 seconds, 4.1 MB/s
$ cat /proc/sys/kernel/random/entropy_avail
170
$ sudo ./rand_ioctl 4096
Adding 4096 bits of fake entropy to the pool.
4096 bits added.
$ cat /proc/sys/kernel/random/entropy_avail
4096
$