locking/lockdep: Change the return type of __cq_dequeue()

With the change, we can slightly adjust the code to iterate the queue in BFS
search, which simplifies the code. No functional change.

Signed-off-by: Yuyang Du <duyuyang@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: bvanassche@acm.org
Cc: frederic@kernel.org
Cc: ming.lei@redhat.com
Cc: will.deacon@arm.com
Link: https://lkml.kernel.org/r/20190506081939.74287-14-duyuyang@gmail.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Yuyang Du 2019-05-06 16:19:29 +08:00 committed by Ingo Molnar
parent aa4807719e
commit c166132559

View File

@ -1308,14 +1308,21 @@ static inline int __cq_enqueue(struct circular_queue *cq, struct lock_list *elem
return 0;
}
static inline int __cq_dequeue(struct circular_queue *cq, struct lock_list **elem)
/*
* Dequeue an element from the circular_queue, return a lock_list if
* the queue is not empty, or NULL if otherwise.
*/
static inline struct lock_list * __cq_dequeue(struct circular_queue *cq)
{
if (__cq_empty(cq))
return -1;
struct lock_list * lock;
*elem = cq->element[cq->front];
if (__cq_empty(cq))
return NULL;
lock = cq->element[cq->front];
cq->front = (cq->front + 1) & CQ_MASK;
return 0;
return lock;
}
static inline unsigned int __cq_get_elem_count(struct circular_queue *cq)
@ -1367,6 +1374,7 @@ static int __bfs(struct lock_list *source_entry,
int forward)
{
struct lock_list *entry;
struct lock_list *lock;
struct list_head *head;
struct circular_queue *cq = &lock_cq;
int ret = 1;
@ -1388,10 +1396,7 @@ static int __bfs(struct lock_list *source_entry,
__cq_init(cq);
__cq_enqueue(cq, source_entry);
while (!__cq_empty(cq)) {
struct lock_list *lock;
__cq_dequeue(cq, &lock);
while ((lock = __cq_dequeue(cq))) {
if (!lock->class) {
ret = -2;