[    1.872411] ip (247) used greatest stack depth: 12376 bytes left
[    2.452147] ip (281) used greatest stack depth: 12360 bytes left
[    2.496755] ip (285) used greatest stack depth: 12344 bytes left
[   26.106308] ip (2499) used greatest stack depth: 12288 bytes left
[  671.365862] blackhole_netdev_xmit(): Dropping skb.
[  671.365926] blackhole_netdev_xmit(): Dropping skb.
[  671.365959] blackhole_netdev_xmit(): Dropping skb.
[  671.365997] blackhole_netdev_xmit(): Dropping skb.
[  916.557237] blackhole_netdev_xmit(): Dropping skb.
[  916.557336] blackhole_netdev_xmit(): Dropping skb.
[  916.557394] blackhole_netdev_xmit(): Dropping skb.
[  916.557429] blackhole_netdev_xmit(): Dropping skb.