Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit efb975a6 authored by Ying Xue's avatar Ying Xue Committed by David S. Miller
Browse files

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: default avatarYing Xue <ying.xue@windriver.com>
Cc: Thomas Graf <tgraf@suug.ch>
Acked-by: default avatarThomas Graf <tgraf@suug.ch>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7c1b7023

lib/rhashtable.c

+18 −23
Original line number Diff line number Diff line
@@ -612,6 +612,19 @@ bool rhashtable_remove(struct rhashtable *ht, struct rhash_head *obj) 
}

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);