When __lock_release() is called, the most likely unlock scenario is
on the innermost lock in the chain. In this case, we can skip some of
the checks and provide a faster path to completion.
Signed-off-by: Waiman Long <long...@redhat.com>
---
kernel/locking/lockdep.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c
index bd59163b0550..b7774ff2516f 100644
--- a/kernel/locking/lockdep.c
+++ b/kernel/locking/lockdep.c
@@ -3625,6 +3625,13 @@ __lock_release(struct lockdep_map *lock, int nested,
unsigned long ip)
curr->lockdep_depth = i;
curr->curr_chain_key = hlock->prev_chain_key;
+ /*
+ * The most likely case is when the unlock is on the innermost
+ * lock. In this case, we are done!
+ */
+ if (i == depth - 1)
+ return 1;
+
if (reacquire_held_locks(curr, depth, i + 1))
return 0;
@@ -3632,10 +3639,14 @@ __lock_release(struct lockdep_map *lock, int nested,
unsigned long ip)
* We had N bottles of beer on the wall, we drank one, but now
* there's not N-1 bottles of beer left on the wall...
*/
- if (DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth - 1))
- return 0;
+ DEBUG_LOCKS_WARN_ON(curr->lockdep_depth != depth-1);
- return 1;
+ /*
+ * Since reacquire_held_locks() would have called check_chain_key()
+ * indirectly via __lock_acquire(), we don't need to do it again
+ * on return.
+ */
+ return 0;
}
static int __lock_is_held(const struct lockdep_map *lock, int read)
--
2.18.0
