[    1.902571] ip (240) used greatest stack depth: 12376 bytes left
[    2.512844] ip (274) used greatest stack depth: 12344 bytes left
[   21.179175] ip (2213) used greatest stack depth: 12072 bytes left
[ 1071.968571] blackhole_netdev_xmit(): Dropping skb.
[ 1071.968664] blackhole_netdev_xmit(): Dropping skb.
[ 1071.968712] blackhole_netdev_xmit(): Dropping skb.
[ 1071.968771] blackhole_netdev_xmit(): Dropping skb.
[ 1189.206296] blackhole_netdev_xmit(): Dropping skb.
[ 1189.206366] blackhole_netdev_xmit(): Dropping skb.
[ 1189.206411] blackhole_netdev_xmit(): Dropping skb.
[ 1189.206456] blackhole_netdev_xmit(): Dropping skb.