[    1.785726] ip (241) used greatest stack depth: 12352 bytes left
[    2.226580] ip (276) used greatest stack depth: 12320 bytes left
[  639.388341] ip (3177) used greatest stack depth: 12272 bytes left
[ 1078.195517] blackhole_netdev_xmit(): Dropping skb.
[ 1078.195570] blackhole_netdev_xmit(): Dropping skb.
[ 1078.195602] blackhole_netdev_xmit(): Dropping skb.
[ 1078.195649] blackhole_netdev_xmit(): Dropping skb.