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, 7 insertions, 7 deletions

diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index c112d00341b0..dc85ee23a26f 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -98,7 +98,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 
 	prev = decode_cpu(old);
 	node->prev = prev;
-	ACCESS_ONCE(prev->next) = node;
+	WRITE_ONCE(prev->next, node);
 
 	/*
 	 * Normally @prev is untouchable after the above store; because at that
@@ -109,7 +109,7 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 	 * cmpxchg in an attempt to undo our queueing.
 	 */
 
-	while (!ACCESS_ONCE(node->locked)) {
+	while (!READ_ONCE(node->locked)) {
 		/*
 		 * If we need to reschedule bail... so we can block.
 		 */
@@ -148,7 +148,7 @@ unqueue:
 		 * Or we race against a concurrent unqueue()'s step-B, in which
 		 * case its step-C will write us a new @node->prev pointer.
 		 */
-		prev = ACCESS_ONCE(node->prev);
+		prev = READ_ONCE(node->prev);
 	}
 
 	/*
@@ -170,8 +170,8 @@ unqueue:
 	 * it will wait in Step-A.
 	 */
 
-	ACCESS_ONCE(next->prev) = prev;
-	ACCESS_ONCE(prev->next) = next;
+	WRITE_ONCE(next->prev, prev);
+	WRITE_ONCE(prev->next, next);
 
 	return false;
 }
@@ -193,11 +193,11 @@ void osq_unlock(struct optimistic_spin_queue *lock)
 	node = this_cpu_ptr(&osq_node);
 	next = xchg(&node->next, NULL);
 	if (next) {
-		ACCESS_ONCE(next->locked) = 1;
+		WRITE_ONCE(next->locked, 1);
 		return;
 	}
 
 	next = osq_wait_next(lock, node, NULL);
 	if (next)
-		ACCESS_ONCE(next->locked) = 1;
+		WRITE_ONCE(next->locked, 1);
 }