From: "Eric W. Biederman" <redacted>
Date: Tue, 17 Sep 2013 16:41:37 -0700

List/count I don't much care but currently we don't have a list of
all of the devices that are unregistering.

The problem with this is that netdev_run_todo moves all of the
devices to a local list, so they are only visible from a list_head
on the stack.  Which makes sense as we run this all in the context
of rtnl_unlock.

And when that local list is processed (the while loop completes and
has iterated over the entire list), either the global todo list is
empty, or it is not empty.

And the waked up code will check for this.

I really don't see what the problem is.