Re: [PATCH 0/5] Long term PMTU/redirect storage in ipv4.

David Miller
2012-07-17T20:46:57Z

From: Julian Anastasov <ja@ssi.bg>
Date: Tue, 17 Jul 2012 23:41:16 +0300 (EEST)

> IIRC, struct fib_info was shared by different
> prefixes. It saves a lot of memory when thousands of
> routes are created to same GW. Now if we end up with 1 or
> 2 fib_info structures for default routes, the nh_exceptions list
> can become very long. May be fib_info is not a good place
> to hide such data.

Your analysis of what fib_info is and how it's intended to
work is accurate.

But we don't use a linked list for the exceptions in the final
version, we use a reclaiming RCU'd hash table like we use for TCP
metrics.

See the updated version of patch #5 and what I actually committed to
net-next.