tree 9cb766b5b66f700528722b2e92745a2a6dcc3288
parent 87bf9c97b4b3af8dec7b2b79cdfe7bfc0a0a03b2
author Robert Olsson <robert.olsson@its.uu.se> 1128456118 -0700
committer David S. Miller <davem@davemloft.net> 1128456118 -0700

[IPV4]: fib_trie root-node expansion

The patch below introduces special thresholds to keep root node in the trie 
large. This gives a flatter tree at the cost of a modest memory increase.
Overall it seems to be gain and this was also proposed by one the authors 
of the paper in recent a seminar.

Main table after loading 123 k routes.

	Aver depth:     3.30
	Max depth:      9
        Root-node size  12 bits
        Total size: 4044  kB

With the patch:
	Aver depth:     2.78
	Max depth:      8
        Root-node size  15 bits
        Total size: 4150  kB

An increase of 8-10% was seen in forwading performance for an rDoS attack. 

Signed-off-by: Robert Olsson <robert.olsson@its.uu.se>
Signed-off-by: David S. Miller <davem@davemloft.net>