[PATCH -v5 11/14] futex,rt_mutex: Introduce rt_mutex_init_waiter()

[Peter Zijlstra]

Since there's already two copies of this code, introduce a helper now
before we get a third instance.

Signed-off-by: Peter Zijlstra (Intel) <pet...@infradead.org>
---
 kernel/futex.c                  |    5 +----
 kernel/locking/rtmutex.c        |   12 +++++++++---
 kernel/locking/rtmutex_common.h |    1 +
 3 files changed, 11 insertions(+), 7 deletions(-)

--- a/kernel/futex.c
+++ b/kernel/futex.c
@@ -2939,10 +2939,7 @@ static int futex_wait_requeue_pi(u32 __u
         * The waiter is allocated on our stack, manipulated by the requeue
         * code while we sleep on uaddr.
         */
-       debug_rt_mutex_init_waiter(&rt_waiter);
-       RB_CLEAR_NODE(&rt_waiter.pi_tree_entry);
-       RB_CLEAR_NODE(&rt_waiter.tree_entry);
-       rt_waiter.task = NULL;
+       rt_mutex_init_waiter(&rt_waiter);
 
        ret = get_futex_key(uaddr2, flags & FLAGS_SHARED, &key2, VERIFY_WRITE);
        if (unlikely(ret != 0))
--- a/kernel/locking/rtmutex.c
+++ b/kernel/locking/rtmutex.c
@@ -1151,6 +1151,14 @@ void rt_mutex_adjust_pi(struct task_stru
                                   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
@@ -1233,9 +1241,7 @@ rt_mutex_slowlock(struct rt_mutex *lock,
        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
--- a/kernel/locking/rtmutex_common.h
+++ b/kernel/locking/rtmutex_common.h
@@ -102,6 +102,7 @@ extern void rt_mutex_init_proxy_locked(s
                                       struct task_struct *proxy_owner);
 extern void rt_mutex_proxy_unlock(struct rt_mutex *lock,
                                  struct task_struct *proxy_owner);
+extern void rt_mutex_init_waiter(struct rt_mutex_waiter *waiter);
 extern int rt_mutex_start_proxy_lock(struct rt_mutex *lock,
                                     struct rt_mutex_waiter *waiter,
                                     struct task_struct *task);