Re: [RFC 4/6] workqueue: Convert for_each_wq to use built-in list check

[Daniel Jordan]

On Sat, Jun 01, 2019 at 06:27:36PM -0400, Joel Fernandes (Google) wrote:
> list_for_each_entry_rcu now has support to check for RCU reader sections
> as well as lock. Just use the support in it, instead of explictly
> checking in the caller.
> 
> Signed-off-by: Joel Fernandes (Google) <joel@xxxxxxxxxxxxxxxxx>
> ---
>  kernel/workqueue.c | 5 ++---
>  1 file changed, 2 insertions(+), 3 deletions(-)
> 
> diff --git a/kernel/workqueue.c b/kernel/workqueue.c
> index 9657315405de..91ed7aca16e5 100644
> --- a/kernel/workqueue.c
> +++ b/kernel/workqueue.c
> @@ -424,9 +424,8 @@ static void workqueue_sysfs_unregister(struct workqueue_struct *wq);
>   * ignored.
>   */
>  #define for_each_pwq(pwq, wq)						\
> -	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node)		\
> -		if (({ assert_rcu_or_wq_mutex(wq); false; })) { }	\
> -		else
> +	list_for_each_entry_rcu((pwq), &(wq)->pwqs, pwqs_node,		\
> +				 lock_is_held(&(wq->mutex).dep_map))
>  

I think the definition of assert_rcu_or_wq_mutex can also be deleted.