linux-kernel - [tip: locking/core] locking/rwsem: Use OWNER_NONSPINNABLE directly instead of OWNER

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Message-ID: <175294681307.1420.8503001269438279756.tip-bot2@tip-bot2>
Date: Sat, 19 Jul 2025 17:40:13 -0000
From: "tip-bot2 for Jinliang Zheng" <tip-bot2@...utronix.de>
To: linux-tip-commits@...r.kernel.org
Cc: Jinliang Zheng <alexjlzheng@...cent.com>, Waiman Long <longman@...hat.com>,
 Boqun Feng <boqun.feng@...il.com>, x86@...nel.org,
 linux-kernel@...r.kernel.org
Subject: [tip: locking/core] locking/rwsem: Use OWNER_NONSPINNABLE directly
 instead of OWNER_SPINNABLE

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     f84a15b90d96f3da99f67fea2e116850d99fb7c4
Gitweb:        https://git.kernel.org/tip/f84a15b90d96f3da99f67fea2e116850d99fb7c4
Author:        Jinliang Zheng <alexjlzheng@...cent.com>
AuthorDate:    Tue, 10 Jun 2025 21:01:58 +08:00
Committer:     Boqun Feng <boqun.feng@...il.com>
CommitterDate: Fri, 11 Jul 2025 15:11:54 -07:00

locking/rwsem: Use OWNER_NONSPINNABLE directly instead of OWNER_SPINNABLE

After commit 7d43f1ce9dd0 ("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 <alexjlzheng@...cent.com>
Acked-by: Waiman Long <longman@...hat.com>
Signed-off-by: Boqun Feng <boqun.feng@...il.com>
Link: https://lore.kernel.org/r/20250610130158.4876-1-alexjlzheng@tencent.com
---
 kernel/locking/rwsem.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/kernel/locking/rwsem.c b/kernel/locking/rwsem.c
index 2ddb827..8572dba 100644
--- a/kernel/locking/rwsem.c
+++ b/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;
 
 		/*