[    2.061622] ip (246) used greatest stack depth: 12376 bytes left
[    2.617012] ip (274) used greatest stack depth: 12344 bytes left
[  979.889368] blackhole_netdev_xmit(): Dropping skb.
[  979.889440] blackhole_netdev_xmit(): Dropping skb.
[  979.889477] blackhole_netdev_xmit(): Dropping skb.
[  979.889513] blackhole_netdev_xmit(): Dropping skb.