Commit 939afb06 authored by Alexander Duyck's avatar Alexander Duyck Committed by David S. Miller

fib_trie: Optimize fib_find_node

This patch makes use of the same features I made use of for
fib_table_lookup to streamline fib_find_node.  The resultant code should be
smaller and run faster than the original.
Signed-off-by: default avatarAlexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 9f9e636d
...@@ -892,28 +892,34 @@ static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new) ...@@ -892,28 +892,34 @@ static void insert_leaf_info(struct hlist_head *head, struct leaf_info *new)
} }
/* rcu_read_lock needs to be hold by caller from readside */ /* rcu_read_lock needs to be hold by caller from readside */
static struct tnode *fib_find_node(struct trie *t, u32 key) static struct tnode *fib_find_node(struct trie *t, u32 key)
{ {
struct tnode *n = rcu_dereference_rtnl(t->trie); struct tnode *n = rcu_dereference_rtnl(t->trie);
int pos = 0;
while (n && IS_TNODE(n)) { while (n) {
if (tkey_sub_equals(n->key, pos, n->pos-pos, key)) { unsigned long index = get_index(key, n);
pos = n->pos + n->bits;
n = tnode_get_child_rcu(n, /* This bit of code is a bit tricky but it combines multiple
tkey_extract_bits(key, * checks into a single check. The prefix consists of the
n->pos, * prefix plus zeros for the bits in the cindex. The index
n->bits)); * is the difference between the key and this value. From
} else * this we can actually derive several pieces of data.
* if !(index >> bits)
* we know the value is cindex
* else
* we have a mismatch in skip bits and failed
*/
if (index >> n->bits)
return NULL;
/* we have found a leaf. Prefixes have already been compared */
if (IS_LEAF(n))
break; break;
}
/* Case we have found a leaf. Compare prefixes */
if (n != NULL && IS_LEAF(n) && tkey_equals(key, n->key)) n = rcu_dereference_rtnl(n->child[index]);
return n; }
return NULL; return n;
} }
static void trie_rebalance(struct trie *t, struct tnode *tn) static void trie_rebalance(struct trie *t, struct tnode *tn)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment