Re: [PATCH net-next v4 0/4] ila: Optimization to preserve value of early demux

[David Miller <davem@davemloft.net>]

From: Tom Herbert <tom@herbertland.com>
Date: Thu, 10 Dec 2015 16:19:29 -0800

> In the current implementation of ILA, LWT is used to perform
> translation on both the input and output paths. This is functional,
> however there is a big performance hit in the receive path. Early
> demux occurs before the routing lookup (a hit actually obviates the
> route lookup). Therefore the stack currently performs early
> demux before translation so that a local connection with ILA
> addresses is never matched. Note that this issue is not just
> with ILA, but pretty much any translated or encapsulated packet
> handled by LWT would miss the opportunity for early demux. Solving
> the general problem seems non trivial since we would need to move
> the route lookup before early demx thereby mitigating the value.
> 
> This patch set addresses the issue for ILA by adding a fast locator
> lookup that occurs before early demux. This done by hooking in to
> NF_INET_PRE_ROUTING
> 
> For the backend we implement an rhashtable that contains identifier
> to locator to mappings. The table also allows more specific matches
> that include original locator and interface.
 ...

Please address Florian's feedback wrt. which nf hook registry interface
should be used, and otherwise I think this series is ready to go.