[    2.731020] ip (275) used greatest stack depth: 12336 bytes left
[    7.541031] ip (621) used greatest stack depth: 12320 bytes left
[  754.110569] blackhole_netdev_xmit(): Dropping skb.
[  754.110636] blackhole_netdev_xmit(): Dropping skb.
[  754.110668] blackhole_netdev_xmit(): Dropping skb.
[  754.110694] blackhole_netdev_xmit(): Dropping skb.
[ 1096.569474] blackhole_netdev_xmit(): Dropping skb.
[ 1096.569540] blackhole_netdev_xmit(): Dropping skb.
[ 1096.569571] blackhole_netdev_xmit(): Dropping skb.
[ 1096.569605] blackhole_netdev_xmit(): Dropping skb.