On Fri, 2012-09-07 at 17:13 +0200, Nicolas Dichtel wrote:
> Le 07/09/2012 17:09, Eric Dumazet a écrit :
> > On Fri, 2012-09-07 at 16:47 +0200, Nicolas Dichtel wrote:
> >> Le 07/09/2012 16:35, Eric Dumazet a écrit :
> >>>
> >>> Hmm... cant we reuse rt_genid ?
> >>>
> >>> (When changing flow_cache_genid, change &net->ipv4.rt_genid)
> >>
> >> And so adding a new field in net->ipv6?
> >
> > or move net->ipv4.rt_genid to net->rt_genid
> >
> > Having separate field for IPv4/IPv6 is of little interest IMHO
> >
> Ok, I will wait feedback from other people and repost a patch after.
By the way, the get_random_bytes() calls in rt_cache_invalidate() and in
rt_genid_init() are no longer needed, since we dont use jhash anymore
(no more route cache)
diff --git a/net/ipv4/route.c b/net/ipv4/route.c
index dc9549b..d6b2b1c 100644
--- a/net/ipv4/route.c
+++ b/net/ipv4/route.c
@@ -448,26 +448,12 @@ static inline bool rt_is_expired(const struct rtable *rth)
}
/*
- * Perturbation of rt_genid by a small quantity [1..256]
- * Using 8 bits of shuffling ensure we can call rt_cache_invalidate()
- * many times (2^24) without giving recent rt_genid.
- * Jenkins hash is strong enough that litle changes of rt_genid are OK.
- */
-static void rt_cache_invalidate(struct net *net)
-{
- unsigned char shuffle;
-
- get_random_bytes(&shuffle, sizeof(shuffle));
- atomic_add(shuffle + 1U, &net->ipv4.rt_genid);
-}
-
-/*
* delay < 0 : invalidate cache (fast : entries will be deleted later)
* delay >= 0 : invalidate & flush cache (can be long)
*/
void rt_cache_flush(struct net *net, int delay)
{
- rt_cache_invalidate(net);
+ atomic_inc(&net->ipv4.rt_genid);
}
static struct neighbour *ipv4_neigh_lookup(const struct dst_entry *dst,
@@ -2533,8 +2519,7 @@ static __net_initdata struct pernet_operations sysctl_route_ops = {
static __net_init int rt_genid_init(struct net *net)
{
- get_random_bytes(&net->ipv4.rt_genid,
- sizeof(net->ipv4.rt_genid));
+ atomic_set(&net->ipv4.rt_genid, 0);
get_random_bytes(&net->ipv4.dev_addr_genid,
sizeof(net->ipv4.dev_addr_genid));
return 0;
--
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