On Fri, Oct 20, 2023 at 11:34 AM Vishal Moola (Oracle)
<vishal.moola@xxxxxxxxx> wrote:
>
> Both callers of is_refcount_suitable() have been converted to use
> folios, so convert it to take in a folio. Both callers only operate on
> head pages of folios so mapcount/refcount conversions here are trivial.
>
> Removes 3 calls to compound head, and removes 315 bytes of kernel text.
>
> Signed-off-by: Vishal Moola (Oracle) <vishal.moola@xxxxxxxxx>
Reviewed-by: Yang Shi <shy828301@xxxxxxxxx>
> ---
> mm/khugepaged.c | 14 +++++++-------
> 1 file changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/mm/khugepaged.c b/mm/khugepaged.c
> index 6c4b5af43371..9efd8ff68f06 100644
> --- a/mm/khugepaged.c
> +++ b/mm/khugepaged.c
> @@ -524,15 +524,15 @@ static void release_pte_pages(pte_t *pte, pte_t *_pte,
> }
> }
>
> -static bool is_refcount_suitable(struct page *page)
> +static bool is_refcount_suitable(struct folio *folio)
> {
> int expected_refcount;
>
> - expected_refcount = total_mapcount(page);
> - if (PageSwapCache(page))
> - expected_refcount += compound_nr(page);
> + expected_refcount = folio_mapcount(folio);
> + if (folio_test_swapcache(folio))
> + expected_refcount += folio_nr_pages(folio);
>
> - return page_count(page) == expected_refcount;
> + return folio_ref_count(folio) == expected_refcount;
> }
>
> static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
> @@ -625,7 +625,7 @@ static int __collapse_huge_page_isolate(struct vm_area_struct *vma,
> * but not from this process. The other process cannot write to
> * the page, only trigger CoW.
> */
> - if (!is_refcount_suitable(&folio->page)) {
> + if (!is_refcount_suitable(folio)) {
> folio_unlock(folio);
> result = SCAN_PAGE_COUNT;
> goto out;
> @@ -1371,7 +1371,7 @@ static int hpage_collapse_scan_pmd(struct mm_struct *mm,
> * has excessive GUP pins (i.e. 512). Anyway the same check
> * will be done again later the risk seems low.
> */
> - if (!is_refcount_suitable(&folio->page)) {
> + if (!is_refcount_suitable(folio)) {
> result = SCAN_PAGE_COUNT;
> goto out_unmap;
> }
> --
> 2.40.1
>
>
