On Mon, Dec 09, 2019 at 01:20:43PM +0530, madhuparnabhowmik04@gmail.com wrote:
> From: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>
>
> This patch adds the macro list_tail_rcu() and document it.
>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik04@gmail.com>

Queued with slight edits, thank you very much!

                                                        Thanx, Paul

> ---
>  include/linux/rculist.h | 10 ++++++++++
>  1 file changed, 10 insertions(+)
>
> diff --git a/include/linux/rculist.h b/include/linux/rculist.h
> index 4b7ae1bf50b3..9f21efa525ab 100644
> --- a/include/linux/rculist.h
> +++ b/include/linux/rculist.h
> @@ -40,6 +40,16 @@ static inline void INIT_LIST_HEAD_RCU(struct list_head *list)
>   */
>  #define list_next_rcu(list)  (*((struct list_head __rcu **)(&(list)->next)))
> 
> +/**
> + * list_tail_rcu - returns the prev pointer of the head of the list
> + * @head: the head of the list
> + *
> + * Note: This should only be used with the list header,
> + * but only if list_del() and similar primitives are not
> + * also used on the list header.
> + */
> +#define list_tail_rcu(head)  (*((struct list_head __rcu **)(&(head)->prev)))
> +
>  /*
>   * Check during list traversal that we are within an RCU reader
>   */
> --
> 2.17.1
>