On 03/08/20 at 04:10pm, qiwuchen55@xxxxxxxxx wrote:
> From: chenqiwu <chenqiwu@xxxxxxxxxx>
>
> Simplify page_is_buddy() to reduce the redundant code for better
> code readability.
>
> Signed-off-by: chenqiwu <chenqiwu@xxxxxxxxxx>
> ---
> mm/page_alloc.c | 13 +++----------
> 1 file changed, 3 insertions(+), 10 deletions(-)
>
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 79e950d..c6eef38 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -797,16 +797,8 @@ static inline void set_page_order(struct page *page, unsigned int order)
> static inline int page_is_buddy(struct page *page, struct page *buddy,
> unsigned int order)
> {
> - if (page_is_guard(buddy) && page_order(buddy) == order) {
> - if (page_zone_id(page) != page_zone_id(buddy))
> - return 0;
> -
> - VM_BUG_ON_PAGE(page_count(buddy) != 0, buddy);
> -
> - return 1;
> - }
This duplicated removing Looks good, not sure if there's any performance
impact or other considering.
FWIW,
Reviewed-by: Baoquan He <bhe@xxxxxxxxxx>
> -
> - if (PageBuddy(buddy) && page_order(buddy) == order) {
> + if ((page_is_guard(buddy) || PageBuddy(buddy))
> + && page_order(buddy) == order) {
> /*
> * zone check is done late to avoid uselessly
> * calculating zone/node ids for pages that could
> @@ -819,6 +811,7 @@ static inline int page_is_buddy(struct page *page, struct page *buddy,
>
> return 1;
> }
> +
> return 0;
> }
>
> --
> 1.9.1
>
>
