[    2.426613] ip (276) used greatest stack depth: 12360 bytes left
[    2.472588] ip (280) used greatest stack depth: 12352 bytes left
[    5.699110] ip (453) used greatest stack depth: 12344 bytes left
[  831.688189] blackhole_netdev_xmit(): Dropping skb.
[  831.688254] blackhole_netdev_xmit(): Dropping skb.
[  831.688287] blackhole_netdev_xmit(): Dropping skb.
[  831.688320] blackhole_netdev_xmit(): Dropping skb.
[ 1148.314585] blackhole_netdev_xmit(): Dropping skb.
[ 1148.314665] blackhole_netdev_xmit(): Dropping skb.
[ 1148.314703] blackhole_netdev_xmit(): Dropping skb.
[ 1148.314740] blackhole_netdev_xmit(): Dropping skb.