Commit-ID: c1661325597f68bc9e632c4fa9c86983d56fba4f Gitweb: https://git.kernel.org/tip/c1661325597f68bc9e632c4fa9c86983d56fba4f Author: Yuyang Du <[email protected]> AuthorDate: Mon, 6 May 2019 16:19:29 +0800 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 3 Jun 2019 11:55:46 +0200
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 <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Peter Zijlstra <[email protected]> Cc: Thomas Gleixner <[email protected]> Cc: [email protected] Cc: [email protected] Cc: [email protected] Cc: [email protected] Link: https://lkml.kernel.org/r/[email protected] Signed-off-by: Ingo Molnar <[email protected]> --- kernel/locking/lockdep.c | 21 +++++++++++++-------- 1 file changed, 13 insertions(+), 8 deletions(-) diff --git a/kernel/locking/lockdep.c b/kernel/locking/lockdep.c index d467ba825dca..d23dcb47389e 100644 --- a/kernel/locking/lockdep.c +++ b/kernel/locking/lockdep.c @@ -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) { + struct lock_list * lock; + if (__cq_empty(cq)) - return -1; + return NULL; - *elem = cq->element[cq->front]; + 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;
