linux-kernel - [PATCH] locking: Remove rt_rwlock_is

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Message-ID: <20210907103458.l2iyvjps5bjwnzng@linutronix.de>
Date:   Tue, 7 Sep 2021 12:34:58 +0200
From:   Sebastian Andrzej Siewior <bigeasy@...utronix.de>
To:     linux-kernel@...r.kernel.org
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>, Will Deacon <will@...nel.org>,
        Waiman Long <longman@...hat.com>,
        Boqun Feng <boqun.feng@...il.com>,
        Thomas Gleixner <tglx@...utronix.de>
Subject: [PATCH] locking: Remove rt_rwlock_is_contended()

rt_rwlock_is_contended() has not users. It makes no sense to use it as
rwlock_is_contended() because it is a sleeping lock on RT and preemption
is possible. It reports always != 0 if used by a writer and even if
there is a waiter then the lock might not be handed over if the
current owner has the highest priority.

Remove rt_rwlock_is_contended().

Reported-by: kernel test robot <lkp@...el.com>
Fixes: 8282947f67345 ("locking/rwlock: Provide RT variant")
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@...utronix.de>
---
 kernel/locking/spinlock_rt.c |    6 ------
 1 file changed, 6 deletions(-)

--- a/kernel/locking/spinlock_rt.c
+++ b/kernel/locking/spinlock_rt.c
@@ -246,12 +246,6 @@ void __sched rt_write_unlock(rwlock_t *r
 }
 EXPORT_SYMBOL(rt_write_unlock);
 
-int __sched rt_rwlock_is_contended(rwlock_t *rwlock)
-{
-	return rw_base_is_contended(&rwlock->rwbase);
-}
-EXPORT_SYMBOL(rt_rwlock_is_contended);
-
 #ifdef CONFIG_DEBUG_LOCK_ALLOC
 void __rt_rwlock_init(rwlock_t *rwlock, const char *name,
 		      struct lock_class_key *key)