rhashtable: optimize rhashtable_lookup routine
Define an internal compare function and relevant compare argument,
and then make use of rhashtable_lookup_compare() to lookup key in
hash table, reducing duplicated code between rhashtable_lookup()
and rhashtable_lookup_compare().
Signed-off-by: Ying Xue <ying.xue@windriver.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: Thomas Graf <tgraf@suug.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/lib/rhashtable.c b/lib/rhashtable.c
index cbad192..f2fdd7a 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -612,6 +612,19 @@
}
EXPORT_SYMBOL_GPL(rhashtable_remove);
+struct rhashtable_compare_arg {
+ struct rhashtable *ht;
+ const void *key;
+};
+
+static bool rhashtable_compare(void *ptr, void *arg)
+{
+ struct rhashtable_compare_arg *x = arg;
+ struct rhashtable *ht = x->ht;
+
+ return !memcmp(ptr + ht->p.key_offset, x->key, ht->p.key_len);
+}
+
/**
* rhashtable_lookup - lookup key in hash table
* @ht: hash table
@@ -627,32 +640,14 @@
*/
void *rhashtable_lookup(struct rhashtable *ht, const void *key)
{
- const struct bucket_table *tbl, *old_tbl;
- struct rhash_head *he;
- u32 hash;
+ struct rhashtable_compare_arg arg = {
+ .ht = ht,
+ .key = key,
+ };
BUG_ON(!ht->p.key_len);
- rcu_read_lock();
- old_tbl = rht_dereference_rcu(ht->tbl, ht);
- tbl = rht_dereference_rcu(ht->future_tbl, ht);
- hash = key_hashfn(ht, key, ht->p.key_len);
-restart:
- rht_for_each_rcu(he, tbl, rht_bucket_index(tbl, hash)) {
- if (memcmp(rht_obj(ht, he) + ht->p.key_offset, key,
- ht->p.key_len))
- continue;
- rcu_read_unlock();
- return rht_obj(ht, he);
- }
-
- if (unlikely(tbl != old_tbl)) {
- tbl = old_tbl;
- goto restart;
- }
-
- rcu_read_unlock();
- return NULL;
+ return rhashtable_lookup_compare(ht, key, &rhashtable_compare, &arg);
}
EXPORT_SYMBOL_GPL(rhashtable_lookup);