Re: [Patch v2] mm/page_reporting: drop stale list head check in page_reporting_cycle

[Alexander Duyck <alexander.duyck@gmail.com>]

On Tue, Aug 18, 2020 at 1:45 AM Wei Yang
<richard.weiyang@linux.alibaba.com> wrote:
>
> list_for_each_entry_safe() guarantees that we will never stumble over
> the list head; "&page->lru != list" will always evaluate to true. Let's
> simplify.
>
> Signed-off-by: Wei Yang <richard.weiyang@linux.alibaba.com>
> Reviewed-by: David Hildenbrand <david@redhat.com>
> ---
>  mm/page_reporting.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/mm/page_reporting.c b/mm/page_reporting.c
> index 3bbd471cfc81..aaaa3605123d 100644
> --- a/mm/page_reporting.c
> +++ b/mm/page_reporting.c
> @@ -178,7 +178,7 @@ page_reporting_cycle(struct page_reporting_dev_info *prdev, struct zone *zone,
>                  * the new head of the free list before we release the
>                  * zone lock.
>                  */
> -               if (&page->lru != list && !list_is_first(&page->lru, list))
> +               if (!list_is_first(&page->lru, list))
>                         list_rotate_to_front(&page->lru, list);
>
>                 /* release lock before waiting on report processing */

Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>