From: Jiri Pirko <jiri@resnulli.us>
Date: Wed, 2 Nov 2016 08:35:02 +0100

How do you imagine this mode should looks like? Could you draw me some
example?

Well, first of all, there is no reason we can't provide a mechanism by
which the driver can request and obtain a FIB dump.

And it can be designed in a way to be preemptible or at least not
require RTNL to be held during the entire operation.  Sequence
counters or similar can be used to make sure that if the table changes
mid-dump due to RTNL being dropped, the dump can be rewound and
restarted.