[PATCH] uninline init_waitqueue_head()

allyesconfig vmlinux size delta:

  text            data    bss     dec          filename
  20736884        6073834 3075176 29885894     vmlinux.before
  20721009        6073966 3075176 29870151     vmlinux.after

~18 bytes per callsite, 15K of text size (~0.1%) saved.

(as an added bonus this also removes a lockdep annotation.)

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

include/linux/wait.h

@@ -77,17 +77,7 @@ struct task_struct;
 #define __WAIT_BIT_KEY_INITIALIZER(word, bit)				\
 	{ .flags = word, .bit_nr = bit, }
 
-/*
- * lockdep: we want one lock-class for all waitqueue locks.
- */
-extern struct lock_class_key waitqueue_lock_key;
-
-static inline void init_waitqueue_head(wait_queue_head_t *q)
-{
-	spin_lock_init(&q->lock);
-	lockdep_set_class(&q->lock, &waitqueue_lock_key);
-	INIT_LIST_HEAD(&q->task_list);
-}
+extern void init_waitqueue_head(wait_queue_head_t *q);
 
 static inline void init_waitqueue_entry(wait_queue_t *q, struct task_struct *p)
 {

kernel/wait.c

@@ -10,9 +10,13 @@
 #include <linux/wait.h>
 #include <linux/hash.h>
 
-struct lock_class_key waitqueue_lock_key;
+void init_waitqueue_head(wait_queue_head_t *q)
+{
+	spin_lock_init(&q->lock);
+	INIT_LIST_HEAD(&q->task_list);
+}
 
-EXPORT_SYMBOL(waitqueue_lock_key);
+EXPORT_SYMBOL(init_waitqueue_head);
 
 void fastcall add_wait_queue(wait_queue_head_t *q, wait_queue_t *wait)
 {