futex,rt_mutex: Introduce rt_mutex_init_waiter()

Since there's already two copies of this code, introduce a helper now
before adding a third one.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: juri.lelli@arm.com
Cc: bigeasy@linutronix.de
Cc: xlpang@redhat.com
Cc: rostedt@goodmis.org
Cc: mathieu.desnoyers@efficios.com
Cc: jdesfossez@efficios.com
Cc: dvhart@infradead.org
Cc: bristot@redhat.com
Link: http://lkml.kernel.org/r/20170322104151.950039479@infradead.org
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 9 insertions, 3 deletions

diff --git a/kernel/locking/rtmutex.c b/kernel/locking/rtmutex.c
index 7d63bc5dd9b2..d2fe4b472b13 100644
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1153,6 +1153,14 @@ void rt_mutex_adjust_pi(struct task_struct *task)
                                    next_lock, NULL, task);
 }
 
+void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter)
+{
+        debug_rt_mutex_init_waiter(waiter);
+        RB_CLEAR_NODE(&waiter->pi_tree_entry);
+        RB_CLEAR_NODE(&waiter->tree_entry);
+        waiter->task = NULL;
+}
+
 /**
  * __rt_mutex_slowlock() - Perform the wait-wake-try-to-take loop
  * @lock:                the rt_mutex to take
@@ -1235,9 +1243,7 @@ rt_mutex_slowlock(struct rt_mutex *lock, int state,
         unsigned long flags;
         int ret = 0;
 
-        debug_rt_mutex_init_waiter(&waiter);
-        RB_CLEAR_NODE(&waiter.pi_tree_entry);
-        RB_CLEAR_NODE(&waiter.tree_entry);
+        rt_mutex_init_waiter(&waiter);
 
         /*
          * Technically we could use raw_spin_[un]lock_irq() here, but this can