[patch 08/50] rtmutex: Switch to try_cmpxchg()

From: Thomas Gleixner
Date: Tue Jul 13 2021 - 12:13:27 EST


From: Thomas Gleixner <tglx@xxxxxxxxxxxxx>

Allows the compiler to generate better code depending on the architecture.

Suggested-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
---
kernel/locking/rtmutex.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -145,14 +145,14 @@ static __always_inline bool rt_mutex_cmp
struct task_struct *old,
struct task_struct *new)
{
- return cmpxchg_acquire(&lock->owner, old, new) == old;
+ return try_cmpxchg_acquire(&lock->owner, &old, new);
}

static __always_inline bool rt_mutex_cmpxchg_release(struct rt_mutex *lock,
struct task_struct *old,
struct task_struct *new)
{
- return cmpxchg_release(&lock->owner, old, new) == old;
+ return try_cmpxchg_release(&lock->owner, &old, new);
}

/*