Subject: Re: [PATCH] ipv6: shouldn't dump the expired routes

From: Stephen Hemminger <[email-masked]>
Date: Thu, 26 Dec 2013 09:48:19 -0800

On Thu, 26 Dec 2013 14:00:25 +0800
Duan Jiong <[email-masked]> wrote:

> 
> If we execute the command "ip -6 route show table all", those routes
> that have been expired will be dumped.  But as everyone knows, those
> expired routes will not be used, and they will be deleted by the kernel.
> So why we still need to dump they, and just don't dump them.
> 
> Signed-off-by: Duan Jiong <[email-masked]>

I can see three issues with this patch.

1. You are changing output of iproute2, and there is a slim chance somebody is
   expecting those routes in some test script.

2. Developers maybe using this to check that the expiration of routes is really
   working.

3. By making rt6_check_expired a global symbol, it can't be optimized as well in
   a potentially hot path for routing.

I am not saying the patch shouldn't go in, just raising the possibility that such
a seemingly trivial change could cause other impacts.