> I'm not sure what a cache of size 1 really buys you anyway, so I
> just rewrote ip_forward() and ip_rtaddr() to always allocate.  If
> caching really makes such a big difference, the cache size should
> probably be configurable.

If lookups in the central forwarding table are so slow that caching makes
a big difference then the very best thing to work on might be to replace
the central forwarding table data structure with one which is cheaper to
do lookups in, as that would benefit every use of the forwarding table
rather than the few special-cases and benchmarks that a cache usually
helps out with.

Dennis Ferguson