[    2.459609] ip (274) used greatest stack depth: 12344 bytes left
[   15.364369] ip (1391) used greatest stack depth: 12056 bytes left
[  822.940812] blackhole_netdev_xmit(): Dropping skb.
[  822.940898] blackhole_netdev_xmit(): Dropping skb.
[  822.940946] blackhole_netdev_xmit(): Dropping skb.
[  822.941003] blackhole_netdev_xmit(): Dropping skb.