From: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Date: Tue, 19 Dec 2017 17:04:27 -0200

I understand that for all that matters, the hardware operations
involved on GRO_HW are really for only 1 packet, so it would make
sense to count it as 1. OTOH, this bump may cause additional pressure
in other places as in fact we are allowing more packets in in a given
cycle.

More data, but not more packets or (realistically) "work".

The stack is going to parse only one SKB, one set of networking
headers, do one route lookup, one socket demux, etc.

In that view, counting the HW GRO packet as only one frame is
appropriate.