[PATCH 13/16] dept: Apply SDT to swait

Byungchul Park
2022-02-17T10:58:51Z

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