[dm-devel] [PATCH 3/4] swait: export the symbols __prepare_to_swait and __finish_swait

[Mikulas Patocka]

In order to reduce locking overhead, I use the spinlock in
swait_queue_head to protect not only the wait queue, but also the list of
events. Consequently, I need to use unlocked functions __prepare_to_swait
and __finish_swait. These functions are declared in the file
include/linux/swait.h, but they are not exported, and so they are not
useable from kernel modules.

Signed-off-by: Mikulas Patocka <mpatocka at redhat.com>

---
 kernel/sched/swait.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6/kernel/sched/swait.c
===================================================================
--- linux-2.6.orig/kernel/sched/swait.c
+++ linux-2.6/kernel/sched/swait.c
@@ -73,6 +73,7 @@ void __prepare_to_swait(struct swait_que
 	if (list_empty(&wait->task_list))
 		list_add(&wait->task_list, &q->task_list);
 }
+EXPORT_SYMBOL(__prepare_to_swait);
 
 void prepare_to_swait(struct swait_queue_head *q, struct swait_queue *wait, int state)
 {
@@ -102,6 +103,7 @@ void __finish_swait(struct swait_queue_h
 	if (!list_empty(&wait->task_list))
 		list_del_init(&wait->task_list);
 }
+EXPORT_SYMBOL(__finish_swait);
 
 void finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
 {