[    1.915042] ip (244) used greatest stack depth: 12576 bytes left
[    2.462974] ip (275) used greatest stack depth: 12336 bytes left
[  643.738829] ip (14371) used greatest stack depth: 12320 bytes left
[  834.181246] blackhole_netdev_xmit(): Dropping skb.
[  834.181303] blackhole_netdev_xmit(): Dropping skb.
[  834.181340] blackhole_netdev_xmit(): Dropping skb.
[  834.181376] blackhole_netdev_xmit(): Dropping skb.
[ 1130.111269] blackhole_netdev_xmit(): Dropping skb.
[ 1130.111360] blackhole_netdev_xmit(): Dropping skb.
[ 1130.111427] blackhole_netdev_xmit(): Dropping skb.
[ 1130.111492] blackhole_netdev_xmit(): Dropping skb.