fib_trie: only calc for the un-first node

This is a enhancement.

for the first node in fib_trie, newpos is 0, bit is 1.
Only for the leaf or node with unmatched key need calc pos.

Signed-off-by: baker.zhang <baker.kernel@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 5 deletions

diff --git a/net/ipv4/fib_trie.c b/net/ipv4/fib_trie.c
index 45c74ba03970..ec9a9ef4ce50 100644
--- a/net/ipv4/fib_trie.c
+++ b/net/ipv4/fib_trie.c
@@ -1117,12 +1117,8 @@ static struct list_head *fib_insert_node(struct trie *t, u32 key, int plen)
                  *  first tnode need some special handling
                  */
 
-                if (tp)
-                        pos = tp->pos+tp->bits;
-                else
-                        pos = 0;
-
                 if (n) {
+                        pos = tp ? tp->pos+tp->bits : 0;
                         newpos = tkey_mismatch(key, pos, n->key);
                         tn = tnode_new(n->key, newpos, 1);
                 } else {