On Mon, 2019-03-18 at 16:57 +0800, Yuyang Du wrote:
> __cq_empty() can be embeded in __cq_dequeue(), removing it. We get slightly
> simpler code. No functional change.
Does inlining __cq_empty() really improve readability of the lockdep code?
> -static inline int __cq_dequeue(struct circular_queue *cq, struct lock_list
> **elem)
> +/*
> + * Dequeue an element from the circular_queue, return the lock 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];
> + /*
> + * Is the circular_queue empty?
> + */
> + if (cq->front == cq->rear)
> + 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)
> @@ -1376,6 +1381,7 @@ 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;
> @@ -1397,10 +1403,7 @@ 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;
This is the most important change in this patch. Using the title "Remove
__cq_empty()"
for this patch is misleading because the above patch does something else,
namely changing
the return type of __cq_dequeue() from int into a pointer. Should this patch
perhaps be
split or should the __cq_empty() removal be left out from this patch?
Bart.
