Re: [PATCH 10/15] ipv4: Cache input routes in fib_info nexthops.

[Joe Perches <joe@perches.com>]

On Wed, 2012-07-18 at 11:24 -0700, David Miller wrote:
> Caching input routes is slightly simpler than output routes, since we
> don't need to be concerned with nexthop exceptions.  (locally
> destined, and routed packets, never trigger PMTU events or redirects
> that will be processed by us).
[]
> diff --git a/net/ipv4/route.c b/net/ipv4/route.c
[]
> @@ -1355,11 +1357,11 @@ static int __mkroute_input(struct sk_buff *skb,
[]
> +	do_cache = false;
> +	if (res->fi) {
> +		if (!(flags & RTCF_DIRECTSRC) && !itag) {
> +			rth = FIB_RES_NH(*res).nh_rth_input;
> +			if (rth) {
> +				dst_use(&rth->dst, jiffies);
> +				goto out;
> +			}
> +			do_cache = true;
> +		}
> +	}
[]
> @@ -1568,8 +1580,20 @@ brd_input:
[]
> +	do_cache = false;
> +	if (res.fi) {
> +		if (!(flags & RTCF_DIRECTSRC) && !itag) {
> +			rth = FIB_RES_NH(res).nh_rth_input;
> +			if (rth) {
> +				dst_use(&rth->dst, jiffies);
> +				goto set_and_out;
> +			}
> +			do_cache = true;
> +		}
> +	}

Maybe a helper like:

	if (some_do_cache_name(rth, res, itag, flags, &do_cache))
		goto foo;