2019-12-09 07:54:39

by Madhuparna Bhowmik

Subject: [PATCH] rculist.h: Add list_tail_rcu()

From: Madhuparna Bhowmik <[email protected]>

This patch adds the macro list_tail_rcu() and document it.

Signed-off-by: Madhuparna Bhowmik <[email protected]>
---
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

2019-12-09 18:34:03

by Paul E. McKenney

Subject: Re: [PATCH] rculist.h: Add list_tail_rcu()

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

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
>