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

Pull core locking updates from Ingo Molnar:
 "The main changes are:

   - mutex, completions and rtmutex micro-optimizations
   - lock debugging fix
   - various cleanups in the MCS and the futex code"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rtmutex: Optimize setting task running after being blocked
  locking/rwsem: Use task->state helpers
  sched/completion: Add lock-free checking of the blocking case
  sched/completion: Remove unnecessary ->wait.lock serialization when reading completion state
  locking/mutex: Explicitly mark task as running after wakeup
  futex: Fix argument handling in futex_lock_pi() calls
  doc: Fix misnamed FUTEX_CMP_REQUEUE_PI op constants
  locking/Documentation: Update code path
  softirq/preempt: Add missing current->preempt_disable_ip update
  locking/osq: No need for load/acquire when acquire-polling
  locking/mcs: Better differentiate between MCS variants
  locking/mutex: Introduce ww_mutex_set_context_slowpath()
  locking/mutex: Move MCS related comments to proper location
  locking/mutex: Checking the stamp is WW only

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index 90230d5811c5..3a6490e81b28 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -5,8 +5,11 @@
  * An MCS like lock especially tailored for optimistic spinning for sleeping
  * lock implementations (mutex, rwsem, etc).
  */
-
-#define OSQ_UNLOCKED_VAL (0)
+struct optimistic_spin_node {
+        struct optimistic_spin_node *next, *prev;
+        int locked; /* 1 if lock acquired */
+        int cpu; /* encoded CPU # + 1 value */
+};
 
 struct optimistic_spin_queue {
         /*
@@ -16,6 +19,8 @@ struct optimistic_spin_queue {
         atomic_t tail;
 };
 
+#define OSQ_UNLOCKED_VAL (0)
+
 /* Init macro and function. */
 #define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
 
@@ -24,4 +29,7 @@ static inline void osq_lock_init(struct optimistic_spin_queue *lock)
         atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
 }
 
+extern bool osq_lock(struct optimistic_spin_queue *lock);
+extern void osq_unlock(struct optimistic_spin_queue *lock);
+
 #endif