Re: [RFC PATCH net-next 07/15] ipv4: Only Replay routes of interest to new listeners

[Jiri Pirko <jiri@resnulli.us>]

Wed, Oct 02, 2019 at 10:40:55AM CEST, idosch@idosch.org wrote:
>From: Ido Schimmel <idosch@mellanox.com>
>
>When a new listener is registered to the FIB notification chain it
>receives a dump of all the available routes in the system. Instead, make
>sure to only replay the IPv4 routes that are actually used in the data
>path and are of any interest to the new listener.
>
>Signed-off-by: Ido Schimmel <idosch@mellanox.com>
>---
> net/ipv4/fib_trie.c | 10 ++++++++++
> 1 file changed, 10 insertions(+)
>
>diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
>index dc4c4e2cb0b3..4937a3503f4f 100644
>--- a/net/ipv4/fib_trie.c
>+++ b/net/ipv4/fib_trie.c
>@@ -2096,6 +2096,7 @@ static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
> 			   struct netlink_ext_ack *extack)
> {
> 	struct fib_alias *fa;
>+	int last_slen = -1;
> 	int err;
> 
> 	hlist_for_each_entry_rcu(fa, &l->leaf, fa_list) {
>@@ -2110,6 +2111,15 @@ static int fib_leaf_notify(struct key_vector *l, struct fib_table *tb,
> 		if (tb->tb_id != fa->tb_id)
> 			continue;
> 
>+		if (fa->fa_slen == last_slen)
>+			continue;

Hmm, I wonder, don't you want to continue only for FIB_EVENT_ENTRY_REPLACE_TMP
and keep the notifier call for FIB_EVENT_ENTRY_ADD?


>+
>+		last_slen = fa->fa_slen;
>+		err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_REPLACE_TMP,
>+					      l->key, KEYLENGTH - fa->fa_slen,
>+					      fa, extack);
>+		if (err)
>+			return err;
> 		err = call_fib_entry_notifier(nb, FIB_EVENT_ENTRY_ADD, l->key,
> 					      KEYLENGTH - fa->fa_slen,
> 					      fa, extack);
>-- 
>2.21.0
>