Route caching ?

[Claudio Jeker]

On Wed, Aug 22, 2007 at 05:37:50PM +0300, Ivo Vachkov wrote:
> Actually there is:
> 
> struct	route_in6 ip6_forward_rt;
> 
> that "caches" the last route used (thanks blue !!!) but i think this
> technique is pointless in a multiflow traffic.
> 
> Is it reasonable to believe that route caches can improve networking
> performance or we should leave it up to the routing table itself ?
> 

Just because you believe that route caches are great doesn't mean it is
true. Show some real code and include benchmarks with various workloads
(e.g. a core router that is hit by many many many sessions).

Until now all caching solutions resulted in very bad performance on busy
boxes. Remember ip_fastforward or how was it called? Another example are
all crapy L3 switches that burn down if the CAM (chache) is flodded.

IMO it is better to make the route lookup faster and forget about caching.
-- 
:wq Claudio