rhashtable: Avoid calculating hash again to unlock
Caching the lock pointer avoids having to hash on the object
again to unlock the bucket locks.
Signed-off-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 eae26a6..09a7ada 100644
--- a/lib/rhashtable.c
+++ b/lib/rhashtable.c
@@ -384,14 +384,16 @@
struct rhash_head *head;
bool no_resize_running;
unsigned hash;
+ spinlock_t *old_lock;
bool success = true;
rcu_read_lock();
old_tbl = rht_dereference_rcu(ht->tbl, ht);
hash = head_hashfn(ht, old_tbl, obj);
+ old_lock = bucket_lock(old_tbl, hash);
- spin_lock_bh(bucket_lock(old_tbl, hash));
+ spin_lock_bh(old_lock);
/* Because we have already taken the bucket lock in old_tbl,
* if we find that future_tbl is not yet visible then that
@@ -428,13 +430,10 @@
schedule_work(&ht->run_work);
exit:
- if (tbl != old_tbl) {
- hash = head_hashfn(ht, tbl, obj);
+ if (tbl != old_tbl)
spin_unlock(bucket_lock(tbl, hash));
- }
- hash = head_hashfn(ht, old_tbl, obj);
- spin_unlock_bh(bucket_lock(old_tbl, hash));
+ spin_unlock_bh(old_lock);
rcu_read_unlock();