[tip: locking/core] sched/wake_q: Provide WAKE_Q_HEAD_INITIALIZER()

[tip-bot2 for Thomas Gleixner]

The following commit has been merged into the locking/core branch of tip:

Commit-ID:     2c8bb85151d4bad825f8962792e9f53d22db81db
Gitweb:        https://git.kernel.org/tip/2c8bb85151d4bad825f8962792e9f53d22db81db
Author:        Thomas Gleixner <tglx@xxxxxxxxxxxxx>
AuthorDate:    Sun, 15 Aug 2021 23:27:49 +02:00
Committer:     Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Tue, 17 Aug 2021 16:57:55 +02:00

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@xxxxxxxxxxxxx>
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20210815211302.429918071@xxxxxxxxxxxxx
---
 include/linux/sched/wake_q.h | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/include/linux/sched/wake_q.h b/include/linux/sched/wake_q.h
index 26a2013..06cd8fb 100644
--- 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)
 {