Messages in this thread Patch in this message | | | From | Huang Ying <> | Subject | [PATCH -mm -v2 4/5] llist, Return whether list is empty before adding in llist_add | Date | Thu, 8 Sep 2011 14:00:45 +0800 |
| |
This is needed by irq_work. And because list_add_xxx functions are inline, this can be optimized out if not needed by callers.
Signed-off-by: Huang Ying <ying.huang@intel.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Peter Zijlstra <peterz@infradead.org> --- include/linux/llist.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-)
--- a/include/linux/llist.h +++ b/include/linux/llist.h @@ -148,8 +148,10 @@ static inline bool llist_empty(const str * 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; @@ -164,6 +166,8 @@ static inline void llist_add(struct llis break; cpu_relax(); } + + return old_entry == NULL; } /** @@ -171,8 +175,10 @@ static inline void llist_add(struct llis * @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. */ -static inline void llist_add_batch(struct llist_node *new_first, +static inline bool llist_add_batch(struct llist_node *new_first, struct llist_node *new_last, struct llist_head *head) { @@ -189,6 +195,8 @@ static inline void llist_add_batch(struc break; cpu_relax(); } + + return old_entry == NULL; } /**
| |