fib_trie: only calc for the un-first node

baker.zhang · davem330 · commit 4c60f1d67fae · 2013-10-10T00:08:07.000-04:00
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 &lt;baker.kernel@gmail.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
diff --git 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 {
