[    1.930482] ip (240) used greatest stack depth: 12616 bytes left
[    2.518790] ip (274) used greatest stack depth: 12344 bytes left
[   11.253058] ip (1072) used greatest stack depth: 12168 bytes left
[ 1049.605727] blackhole_netdev_xmit(): Dropping skb.
[ 1049.605795] blackhole_netdev_xmit(): Dropping skb.
[ 1049.605834] blackhole_netdev_xmit(): Dropping skb.
[ 1049.605878] blackhole_netdev_xmit(): Dropping skb.