locking/rwsem: Use OWNER_NONSPINNABLE directly instead of OWNER_SPINNABLE

After commit 7d43f1c ("locking/rwsem: Enable time-based spinning on
reader-owned rwsem"), OWNER_SPINNABLE contains all possible values except
OWNER_NONSPINNABLE, namely OWNER_NULL | OWNER_WRITER | OWNER_READER.

Therefore, it is better to use OWNER_NONSPINNABLE directly to determine
whether to exit optimistic spin.

And, remove useless OWNER_SPINNABLE to simplify the code.

Signed-off-by: Jinliang Zheng <[email protected]>
Acked-by: Waiman Long <[email protected]>
Signed-off-by: Boqun Feng <[email protected]>
Link: https://lore.kernel.org/r/[email protected]

Author: fatherMatrix

kernel/locking/rwsem.c

@@ -727,8 +727,6 @@ static inline bool rwsem_can_spin_on_owner(struct rw_semaphore *sem)
 	return ret;
 }
 
-#define OWNER_SPINNABLE		(OWNER_NULL | OWNER_WRITER | OWNER_READER)
-
 static inline enum owner_state
 rwsem_owner_state(struct task_struct *owner, unsigned long flags)
 {
@@ -835,7 +833,7 @@ static bool rwsem_optimistic_spin(struct rw_semaphore *sem)
 		enum owner_state owner_state;
 
 		owner_state = rwsem_spin_on_owner(sem);
-		if (!(owner_state & OWNER_SPINNABLE))
+		if (owner_state == OWNER_NONSPINNABLE)
 			break;
 
 		/*