Re: [PATCH] ipv4: Cache source address in nexthop entries.

[David Miller <davem@davemloft.net>]

From: Julian Anastasov <ja@ssi.bg>
Date: Thu, 10 Mar 2011 01:32:18 +0200 (EET)

> On Wed, 9 Mar 2011, David Miller wrote:
> 
>> So device address operations increment a generation ID and
>> FIB_RES_PREFSRC() checks that ID against one stored in the nexthop.
> 
> 	Yes, may be it is better this generation ID to be global
> value for netns, because the global addresses should cause
> refresh for all nexthops on all devices. The ID should be
> matched with corresponding value in NH. Another option is
> to use per-device gen_id instead of netns gen_id but in this
> case scope-global address event should increment gen_id for all
> devices while the device_UP event will increment only
> gen_id for the concerned DEV.
> 
> 	I.e. there are 2 variants:

I think the per-namespace ID makes the most sense.

If the whole idea of the genid is to reduce complication, trying to place
games on a per-device basis wrt. the scope cases seems to work against that
goal :-)

After I try to attack the ipv6 routing regression I added in net-2.6, I'll
take a stab at this.

Thanks!