linux-kernel - [RFC PATCH 1/1] remove redundant compare, cmpxchg already does it

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Date:	Wed, 04 Jun 2014 16:38:55 -0400
From:	Pranith Kumar <pranith@...ech.edu>
To:	peterz@...radead.org
CC:	linux-kernel@...r.kernel.org
Subject: [RFC PATCH 1/1] remove redundant compare, cmpxchg already does it

remove a redundant comparision

Signed-off-by: Pranith Kumar <bobby.prani@...il.com>
---
 kernel/locking/rwsem-xadd.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/kernel/locking/rwsem-xadd.c b/kernel/locking/rwsem-xadd.c
index 1f99664b..6f8bd3c 100644
--- a/kernel/locking/rwsem-xadd.c
+++ b/kernel/locking/rwsem-xadd.c
@@ -249,8 +249,7 @@ static inline bool rwsem_try_write_lock(long count, struct rw_semaphore *sem)
 {
     if (!(count & RWSEM_ACTIVE_MASK)) {
         /* try acquiring the write lock */
-        if (sem->count == RWSEM_WAITING_BIAS &&
-            cmpxchg(&sem->count, RWSEM_WAITING_BIAS,
+        if (cmpxchg(&sem->count, RWSEM_WAITING_BIAS,
                 RWSEM_ACTIVE_WRITE_BIAS) == RWSEM_WAITING_BIAS) {
             if (!list_is_singular(&sem->wait_list))
                 rwsem_atomic_update(RWSEM_WAITING_BIAS, sem);
-- 
1.9.1
--
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