Skip to contentSkip to conversation

swait: export the symbols __prepare_to_swait and __finish_swait

PATCH In review Mikulas Patocka 1 participant 1 message May 30, 2018

Subsystems (2)
Scheduler Device mapper
lore
Share & tools
lore

Mikulas Patocka

author maintainer
#0 lore raw

PATCH 2/4 swait: export the symbols __prepare_to_swait and __finish_swait

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 <[email protected]>
---
 kernel/sched/swait.c |    2 ++
 1 file changed, 2 insertions(+)
kernel/sched/swait.c +2 -0
Index: linux-2.6/kernel/sched/swait.c
===================================================================
@@ -75,6 +75,7 @@ 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)
 {

@@ -104,6 +105,7 @@ 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)
 {