Re: [RFC PATCH 03/21] list: Annotate lockless list primitives with data_race()

[Peter Zijlstra]

On Tue, Mar 24, 2020 at 03:36:25PM +0000, Will Deacon wrote:
> diff --git a/include/linux/list.h b/include/linux/list.h
> index 4fed5a0f9b77..4d9f5f9ed1a8 100644
> --- a/include/linux/list.h
> +++ b/include/linux/list.h
> @@ -279,7 +279,7 @@ static inline int list_is_last(const struct list_head *list,
>   */
>  static inline int list_empty(const struct list_head *head)
>  {
> -	return READ_ONCE(head->next) == head;
> +	return data_race(READ_ONCE(head->next) == head);
>  }

list_empty() isn't lockless safe, that's what we have
list_empty_careful() for.