[    1.615247] ip (242) used greatest stack depth: 12416 bytes left
[    2.082052] ip (276) used greatest stack depth: 12320 bytes left
[    8.802946] ip (960) used greatest stack depth: 12272 bytes left
[ 1177.930860] blackhole_netdev_xmit(): Dropping skb.
[ 1177.930940] blackhole_netdev_xmit(): Dropping skb.
[ 1177.930984] blackhole_netdev_xmit(): Dropping skb.
[ 1177.931022] blackhole_netdev_xmit(): Dropping skb.