Re: [PATCH 2/5] mm: migrate: Introduce a local variable to get the number of pages

[Yang Shi <shy828301@gmail.com>]

On Thu, Aug 5, 2021 at 8:06 AM Baolin Wang
<baolin.wang@linux.alibaba.com> wrote:
>
> Use thp_nr_pages() instead of compound_nr() to get the number of pages
> for THP page, meanwhile introducing a local variable 'nr_pages' to
> avoid getting the number of pages repeatedly.
>
> Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>

Reviewed-by: Yang Shi <shy828301@gmail.com>

> ---
>  mm/migrate.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/mm/migrate.c b/mm/migrate.c
> index 5559571..eeba4c6 100644
> --- a/mm/migrate.c
> +++ b/mm/migrate.c
> @@ -2106,6 +2106,7 @@ static struct page *alloc_misplaced_dst_page_thp(struct page *page,
>  static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
>  {
>         int page_lru;
> +       int nr_pages = thp_nr_pages(page);
>
>         VM_BUG_ON_PAGE(compound_order(page) && !PageTransHuge(page), page);
>
> @@ -2114,7 +2115,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
>                 return 0;
>
>         /* Avoid migrating to a node that is nearly full */
> -       if (!migrate_balanced_pgdat(pgdat, compound_nr(page)))
> +       if (!migrate_balanced_pgdat(pgdat, nr_pages))
>                 return 0;
>
>         if (isolate_lru_page(page))
> @@ -2122,7 +2123,7 @@ static int numamigrate_isolate_page(pg_data_t *pgdat, struct page *page)
>
>         page_lru = page_is_file_lru(page);
>         mod_node_page_state(page_pgdat(page), NR_ISOLATED_ANON + page_lru,
> -                               thp_nr_pages(page));
> +                           nr_pages);
>
>         /*
>          * Isolating the page has taken another reference, so the
> --
> 1.8.3.1
>
>