[openib-general] Unicast ARP

[Roland Dreier]

    Ido> I think that we should hold a link list which contains the
    Ido> current address handles with the corresponding GID. When a
    Ido> unicast ARP is sent (hard_xmit), instead of going to the SA,
    Ido> look up the right GID in our list, then send a unicast ARP
    Ido> with this address handle. If path has changed, then the ARP
    Ido> reply won't arrive and it will cause the ARP cache to be
    Ido> refreshed.

This makes sense, although I would use an rb_tree indexed by GID
rather than a linked list.

Another possibility would be to perform the SA lookup for unicast ARPs
and then update any neighbour path information if the reply is
different from what we have stored.

 - Roland