sched/wake_q: Provide WAKE_Q_HEAD_INITIALIZER()

The RT specific spin/rwlock implementation requires special handling of the
to be woken waiters. Provide a WAKE_Q_HEAD_INITIALIZER(), which can be used by
the rtmutex code to implement an RT aware wake_q derivative.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Link: https://lore.kernel.org/r/20210815211302.429918071@linutronix.de

diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h
index 26a2013..06cd8fb 100644 (file)
--- a/include/linux/sched/wake_q.h
+++ b/include/linux/sched/wake_q.h
@@ -42,8 +42,11 @@ struct wake_q_head {
 
 #define WAKE_Q_TAIL ((struct wake_q_node *) 0x01)
 
-#define DEFINE_WAKE_Q(name)                            \
-       struct wake_q_head name = { WAKE_Q_TAIL, &name.first }
+#define WAKE_Q_HEAD_INITIALIZER(name)                          \
+       { WAKE_Q_TAIL, &name.first }
+
+#define DEFINE_WAKE_Q(name)                                    \
+       struct wake_q_head name = WAKE_Q_HEAD_INITIALIZER(name)
 
 static inline void wake_q_init(struct wake_q_head *head)
 {