diff --git a/include/linux/llist.h b/include/linux/llist.h index ca91875286bf..27bbdf5ddf82 100644 --- a/include/linux/llist.h +++ b/include/linux/llist.h @@ -142,8 +142,10 @@ static inline bool llist_empty(const struct llist_head *head) * llist_add - add a new entry * @new: new entry to be added * @head: the head for your lock-less list + * + * Return whether list is empty before adding. */ -static inline void llist_add(struct llist_node *new, struct llist_head *head) +static inline bool llist_add(struct llist_node *new, struct llist_head *head) { struct llist_node *entry, *old_entry; @@ -156,6 +158,8 @@ static inline void llist_add(struct llist_node *new, struct llist_head *head) break; cpu_relax(); } + + return old_entry == NULL; } /** diff --git a/lib/llist.c b/lib/llist.c index 6c69f1d14c4b..878985c4d19d 100644 --- a/lib/llist.c +++ b/lib/llist.c @@ -34,8 +34,10 @@ * @new_first: first entry in batch to be added * @new_last: last entry in batch to be added * @head: the head for your lock-less list + * + * Return whether list is empty before adding. */ -void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, +bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, struct llist_head *head) { struct llist_node *entry, *old_entry; @@ -49,6 +51,8 @@ void llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, break; cpu_relax(); } + + return old_entry == NULL; } EXPORT_SYMBOL_GPL(llist_add_batch);