[    2.099302] ip (274) used greatest stack depth: 12320 bytes left
[    5.948460] ip (609) used greatest stack depth: 12304 bytes left
[   21.278060] ip (2507) used greatest stack depth: 12272 bytes left
[  323.350433] ip (10436) used greatest stack depth: 12144 bytes left
[  689.558771] blackhole_netdev_xmit(): Dropping skb.
[  689.558831] blackhole_netdev_xmit(): Dropping skb.
[  689.558873] blackhole_netdev_xmit(): Dropping skb.
[  689.558911] blackhole_netdev_xmit(): Dropping skb.
[  799.469027] blackhole_netdev_xmit(): Dropping skb.
[  799.469084] blackhole_netdev_xmit(): Dropping skb.
[  799.469131] blackhole_netdev_xmit(): Dropping skb.
[  799.469183] blackhole_netdev_xmit(): Dropping skb.