From efb975a67ea7846b966080f999589de570686aa0 Mon Sep 17 00:00:00 2001 From: Ying Xue Date: Wed, 7 Jan 2015 13:41:52 +0800 Subject: [PATCH] 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 Cc: Thomas Graf Acked-by: Thomas Graf Signed-off-by: David S. Miller --- lib/rhashtable.c | 41 ++++++++++++++++++----------------------- 1 file changed, 18 insertions(+), 23 deletions(-) diff --git a/lib/rhashtable.c b/lib/rhashtable.c index cbad192d3b3d..f2fdd7a7cb16 100644 --- a/lib/rhashtable.c +++ b/lib/rhashtable.c @@ -612,6 +612,19 @@ restart: } 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 @@ EXPORT_SYMBOL_GPL(rhashtable_remove); */ 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); -- 2.20.1