Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking changes from Ingo Molnar:
 "Main changes:

   - jump label asm preparatory work for PowerPC (Anton Blanchard)

   - rwsem optimizations and cleanups (Davidlohr Bueso)

   - mutex optimizations and cleanups (Jason Low)

   - futex fix (Oleg Nesterov)

   - remove broken atomicity checks from {READ,WRITE}_ONCE() (Peter
     Zijlstra)"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  powerpc, jump_label: Include linux/jump_label.h to get HAVE_JUMP_LABEL define
  jump_label: Allow jump labels to be used in assembly
  jump_label: Allow asm/jump_label.h to be included in assembly
  locking/mutex: Further simplify mutex_spin_on_owner()
  locking: Remove atomicy checks from {READ,WRITE}_ONCE
  locking/rtmutex: Rename argument in the rt_mutex_adjust_prio_chain() documentation as well
  locking/rwsem: Fix lock optimistic spinning when owner is not running
  locking: Remove ACCESS_ONCE() usage
  locking/rwsem: Check for active lock before bailing on spinning
  locking/rwsem: Avoid deceiving lock spinners
  locking/rwsem: Set lock ownership ASAP
  locking/rwsem: Document barrier need when waking tasks
  locking/futex: Check PF_KTHREAD rather than !p->mm to filter out kthreads
  locking/mutex: Refactor mutex_spin_on_owner()
  locking/mutex: In mutex_spin_on_owner(), return true when owner changes

1 files changed, 3 insertions, 3 deletions

diff --git a/kernel/locking/mcs_spinlock.h b/kernel/locking/mcs_spinlock.h
index d1fe2ba..75e114b 100644
--- a/kernel/locking/mcs_spinlock.h
+++ b/kernel/locking/mcs_spinlock.h
@@ -78,7 +78,7 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
 		 */
 		return;
 	}
-	ACCESS_ONCE(prev->next) = node;
+	WRITE_ONCE(prev->next, node);
 
 	/* Wait until the lock holder passes the lock down. */
 	arch_mcs_spin_lock_contended(&node->locked);
@@ -91,7 +91,7 @@ void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
 static inline
 void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
 {
-	struct mcs_spinlock *next = ACCESS_ONCE(node->next);
+	struct mcs_spinlock *next = READ_ONCE(node->next);
 
 	if (likely(!next)) {
 		/*
@@ -100,7 +100,7 @@ void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
 		if (likely(cmpxchg(lock, node, NULL) == node))
 			return;
 		/* Wait until the next pointer is set */
-		while (!(next = ACCESS_ONCE(node->next)))
+		while (!(next = READ_ONCE(node->next)))
 			cpu_relax_lowlatency();
 	}