On 1/19/2023 7:22 AM, Vishal Moola (Oracle) wrote:
> Replace migrate_page_add() with migrate_folio_add().
> migrate_folio_add() does the same a migrate_page_add() but takes in a
> folio instead of a page. This removes a couple of calls to
> compound_head().
>
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
> ---
> mm/mempolicy.c | 34 +++++++++++++++-------------------
> 1 file changed, 15 insertions(+), 19 deletions(-)
>
> diff --git a/mm/mempolicy.c b/mm/mempolicy.c
> index 0a3690ecab7d..253ce368cf16 100644
> --- a/mm/mempolicy.c
> +++ b/mm/mempolicy.c
> @@ -414,7 +414,7 @@ static const struct mempolicy_operations mpol_ops[MPOL_MAX] = {
> },
> };
>
> -static int migrate_page_add(struct page *page, struct list_head *pagelist,
> +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist,
> unsigned long flags);
>
> struct queue_pages {
> @@ -476,7 +476,7 @@ static int queue_folios_pmd(pmd_t *pmd, spinlock_t *ptl, unsigned long addr,
> /* go to folio migration */
> if (flags & (MPOL_MF_MOVE | MPOL_MF_MOVE_ALL)) {
> if (!vma_migratable(walk->vma) ||
> - migrate_page_add(&folio->page, qp->pagelist, flags)) {
> + migrate_folio_add(folio, qp->pagelist, flags)) {
> ret = 1;
> goto unlock;
> }
> @@ -544,7 +544,7 @@ static int queue_folios_pte_range(pmd_t *pmd, unsigned long addr,
> * temporary off LRU pages in the range. Still
> * need migrate other LRU pages.
> */
> - if (migrate_page_add(&folio->page, qp->pagelist, flags))
> + if (migrate_folio_add(folio, qp->pagelist, flags))
> has_unmovable = true;
> } else
> break;
> @@ -1022,27 +1022,23 @@ static long do_get_mempolicy(int *policy, nodemask_t *nmask,
> }
>
> #ifdef CONFIG_MIGRATION
> -/*
> - * page migration, thp tail pages can be passed.
> - */
> -static int migrate_page_add(struct page *page, struct list_head *pagelist,
> +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist,
> unsigned long flags)
> {
> - struct page *head = compound_head(page);
> /*
> - * Avoid migrating a page that is shared with others.
> + * Avoid migrating a folio that is shared with others.
> */
> - if ((flags & MPOL_MF_MOVE_ALL) || page_mapcount(head) == 1) {
> - if (!isolate_lru_page(head)) {
> - list_add_tail(&head->lru, pagelist);
> - mod_node_page_state(page_pgdat(head),
> - NR_ISOLATED_ANON + page_is_file_lru(head),
> - thp_nr_pages(head));
> + if ((flags & MPOL_MF_MOVE_ALL) || folio_mapcount(folio) == 1) {
One question to the page_mapcount -> folio_mapcount here.
For a large folio with 0 entire mapcount, if the first sub-page and any
other sub-page are mapped, page_mapcount(head) == 1 is true while
folio_mapcount(folio) == 1 is not.
Regards
Yin, Fengwei
> + if (!folio_isolate_lru(folio)) {
> + list_add_tail(&folio->lru, foliolist);
> + node_stat_mod_folio(folio,
> + NR_ISOLATED_ANON + folio_is_file_lru(folio),
> + folio_nr_pages(folio));
> } else if (flags & MPOL_MF_STRICT) {
> /*
> - * Non-movable page may reach here. And, there may be
> - * temporary off LRU pages or non-LRU movable pages.
> - * Treat them as unmovable pages since they can't be
> + * Non-movable folio may reach here. And, there may be
> + * temporary off LRU folios or non-LRU movable folios.
> + * Treat them as unmovable folios since they can't be
> * isolated, so they can't be moved at the moment. It
> * should return -EIO for this case too.
> */
> @@ -1234,7 +1230,7 @@ static struct page *new_page(struct page *page, unsigned long start)
> }
> #else
>
> -static int migrate_page_add(struct page *page, struct list_head *pagelist,
> +static int migrate_folio_add(struct folio *folio, struct list_head *foliolist,
> unsigned long flags)
> {
> return -EIO;
