[    2.101992] ip (250) used greatest stack depth: 12376 bytes left
[    2.720382] ip (281) used greatest stack depth: 12344 bytes left
[   18.558022] ip (1415) used greatest stack depth: 12304 bytes left
[   27.212834] ip (2372) used greatest stack depth: 12192 bytes left
[  652.968251] ip (21912) used greatest stack depth: 12064 bytes left
[ 1052.193031] blackhole_netdev_xmit(): Dropping skb.
[ 1052.193095] blackhole_netdev_xmit(): Dropping skb.
[ 1052.193124] blackhole_netdev_xmit(): Dropping skb.
[ 1052.193150] blackhole_netdev_xmit(): Dropping skb.