On Wed, Mar 04, 2015 at 09:58:28AM -0600, Eric W. Biederman wrote:

Andy Gospodarek [off-list ref] writes:

quoted

On Tue, Mar 03, 2015 at 05:10:44PM -0600, Eric W. Biederman wrote:

quoted

While looking at the mpls code I found myself writing yet another
version of neigh_lookup_noref.  We currently have __ipv4_lookup_noref
and __ipv6_lookup_noref.

So to make my work a little easier and to make it a smidge easier to
verify/maintain the mpls code in the future I stopped and wrote
___neigh_lookup_noref.  Then I rewote __ipv4_lookup_noref and
__ipv6_lookup_noref in terms of this new function.  I tested my new
version by verifying that the same code is generated in
ip_finish_output2 and ip6_finish_output2 where these functions are
inlined.

To get to ___neigh_lookup_noref I added a new neighbour cache table
function key_eq.  So that the static size of the key would be
available.

I also added __neigh_lookup_noref for people who want to to lookup
a neighbour table entry quickly but don't know which neibhgour table
they are going to look up.

While I understand your intent here, you do really need to know which
neighbour table being used in order to do the look-up with your new
function, so this changelog isn't quite accurate.  I know Dave has
already accepted this patch, but it did not appear in the tree I just
updated, so hopefully there is time to fix this if you agree with me.

Currently __ipv4_lookup_noref and __ipv6_lookup_noref hard code the
table.  __neigh_lookup_noref works without needing to hard code the
neighbour table.  The neighbour table being a variable in the code and
not a hard coded value is what I was referring to above when I said you
don't need to know your neighbour table.  That is you still need a
neighbour table it just doesn't need to be hard coded.

Thanks for the clarification.