[    1.942768] ip (242) used greatest stack depth: 12320 bytes left
[   11.485177] ip (960) used greatest stack depth: 12192 bytes left
[  632.913449] ip (8288) used greatest stack depth: 12144 bytes left
[  915.972976] blackhole_netdev_xmit(): Dropping skb.
[  915.973048] blackhole_netdev_xmit(): Dropping skb.
[  915.973089] blackhole_netdev_xmit(): Dropping skb.
[  915.973127] blackhole_netdev_xmit(): Dropping skb.