[    1.823953] ip (243) used greatest stack depth: 12352 bytes left
[    2.282165] ip (277) used greatest stack depth: 12320 bytes left
[    9.085432] ip (920) used greatest stack depth: 12304 bytes left
[  810.307407] blackhole_netdev_xmit(): Dropping skb.
[  810.307588] blackhole_netdev_xmit(): Dropping skb.
[  810.307639] blackhole_netdev_xmit(): Dropping skb.
[  810.307685] blackhole_netdev_xmit(): Dropping skb.
[  846.617347] blackhole_netdev_xmit(): Dropping skb.
[  846.617420] blackhole_netdev_xmit(): Dropping skb.
[  846.617459] blackhole_netdev_xmit(): Dropping skb.
[  846.617510] blackhole_netdev_xmit(): Dropping skb.