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From:   Byungchul Park <byungchul.park@lge.com>
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Subject: [PATCH RFC v5 13/21] dept: Apply SDT to swait
Date:   Wed, 16 Mar 2022 11:26:25 +0900
Message-Id: <1647397593-16747-14-git-send-email-byungchul.park@lge.com>
In-Reply-To: <1647397593-16747-1-git-send-email-byungchul.park@lge.com>
References: <1647397593-16747-1-git-send-email-byungchul.park@lge.com>
Precedence: bulk

Makes SDT able to track dependencies by swait.

Signed-off-by: Byungchul Park <byungchul.park@lge.com>
---
 include/linux/swait.h |  4 ++++
 kernel/sched/swait.c  | 10 ++++++++++
 2 files changed, 14 insertions(+)

diff --git a/include/linux/swait.h b/include/linux/swait.h
index 6a8c22b..dbdf2ce 100644
--- a/include/linux/swait.h
+++ b/include/linux/swait.h
@@ -6,6 +6,7 @@
 #include <linux/stddef.h>
 #include <linux/spinlock.h>
 #include <linux/wait.h>
+#include <linux/dept_sdt.h>
 #include <asm/current.h>
 
 /*
@@ -43,6 +44,7 @@
 struct swait_queue_head {
 	raw_spinlock_t		lock;
 	struct list_head	task_list;
+	struct dept_map		dmap;
 };
 
 struct swait_queue {
@@ -61,6 +63,7 @@ struct swait_queue {
 #define __SWAIT_QUEUE_HEAD_INITIALIZER(name) {				\
 	.lock		= __RAW_SPIN_LOCK_UNLOCKED(name.lock),		\
 	.task_list	= LIST_HEAD_INIT((name).task_list),		\
+	.dmap		= DEPT_SDT_MAP_INIT(name),			\
 }
 
 #define DECLARE_SWAIT_QUEUE_HEAD(name)					\
@@ -72,6 +75,7 @@ extern void __init_swait_queue_head(struct swait_queue_head *q, const char *name
 #define init_swait_queue_head(q)				\
 	do {							\
 		static struct lock_class_key __key;		\
+		sdt_map_init(&(q)->dmap);			\
 		__init_swait_queue_head((q), #q, &__key);	\
 	} while (0)
 
diff --git a/kernel/sched/swait.c b/kernel/sched/swait.c
index e1c655f..4ca7d6e 100644
--- a/kernel/sched/swait.c
+++ b/kernel/sched/swait.c
@@ -27,6 +27,7 @@ void swake_up_locked(struct swait_queue_head *q)
 		return;
 
 	curr = list_first_entry(&q->task_list, typeof(*curr), task_list);
+	sdt_event(&q->dmap);
 	wake_up_process(curr->task);
 	list_del_init(&curr->task_list);
 }
@@ -69,6 +70,7 @@ void swake_up_all(struct swait_queue_head *q)
 	while (!list_empty(&tmp)) {
 		curr = list_first_entry(&tmp, typeof(*curr), task_list);
 
+		sdt_event(&q->dmap);
 		wake_up_state(curr->task, TASK_NORMAL);
 		list_del_init(&curr->task_list);
 
@@ -97,6 +99,9 @@ void prepare_to_swait_exclusive(struct swait_queue_head *q, struct swait_queue *
 	__prepare_to_swait(q, wait);
 	set_current_state(state);
 	raw_spin_unlock_irqrestore(&q->lock, flags);
+
+	if (state & TASK_NORMAL)
+		sdt_wait_prepare(&q->dmap);
 }
 EXPORT_SYMBOL(prepare_to_swait_exclusive);
 
@@ -119,12 +124,16 @@ long prepare_to_swait_event(struct swait_queue_head *q, struct swait_queue *wait
 	}
 	raw_spin_unlock_irqrestore(&q->lock, flags);
 
+	if (!ret && state & TASK_NORMAL)
+		sdt_wait_prepare(&q->dmap);
+
 	return ret;
 }
 EXPORT_SYMBOL(prepare_to_swait_event);
 
 void __finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
 {
+	sdt_wait_finish();
 	__set_current_state(TASK_RUNNING);
 	if (!list_empty(&wait->task_list))
 		list_del_init(&wait->task_list);
@@ -134,6 +143,7 @@ void finish_swait(struct swait_queue_head *q, struct swait_queue *wait)
 {
 	unsigned long flags;
 
+	sdt_wait_finish();
 	__set_current_state(TASK_RUNNING);
 
 	if (!list_empty_careful(&wait->task_list)) {
-- 
1.9.1