Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> writes:
> Saves a couple of calls to compound_head() and remove last two callers
> of putback_lru_page().
>
> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
> ---
> mm/migrate_device.c | 41 ++++++++++++++++++++++-------------------
> 1 file changed, 22 insertions(+), 19 deletions(-)
>
> diff --git a/mm/migrate_device.c b/mm/migrate_device.c
> index b49f4956617a..6ea3d055f520 100644
> --- a/mm/migrate_device.c
> +++ b/mm/migrate_device.c
> @@ -815,42 +815,45 @@ void migrate_device_finalize(unsigned long *src_pfns,
> unsigned long i;
>
> for (i = 0; i < npages; i++) {
> - struct folio *dst, *src;
> + struct folio *dst = NULL, *src = NULL;
> struct page *newpage = migrate_pfn_to_page(dst_pfns[i]);
> struct page *page = migrate_pfn_to_page(src_pfns[i]);
We could probably simplify this even further with a
migrate_pfn_to_folio() function. I'm still working on extending
ZONE_DEVICE to support higher order folios though (held up fixing
refcounts) so this can wait until then.
Reviewed-by: Alistair Popple <apopple@xxxxxxxxxx>
>
> + if (newpage)
> + dst = page_folio(newpage);
> +
> if (!page) {
> - if (newpage) {
> - unlock_page(newpage);
> - put_page(newpage);
> + if (dst) {
> + folio_unlock(dst);
> + folio_put(dst);
> }
> continue;
> }
>
> - if (!(src_pfns[i] & MIGRATE_PFN_MIGRATE) || !newpage) {
> - if (newpage) {
> - unlock_page(newpage);
> - put_page(newpage);
> + src = page_folio(page);
> +
> + if (!(src_pfns[i] & MIGRATE_PFN_MIGRATE) || !dst) {
> + if (dst) {
> + folio_unlock(dst);
> + folio_put(dst);
> }
> - newpage = page;
> + dst = src;
> }
>
> - src = page_folio(page);
> - dst = page_folio(newpage);
> remove_migration_ptes(src, dst, false);
> folio_unlock(src);
>
> - if (is_zone_device_page(page))
> - put_page(page);
> + if (folio_is_zone_device(src))
> + folio_put(src);
> else
> - putback_lru_page(page);
> + folio_putback_lru(src);
>
> - if (newpage != page) {
> - unlock_page(newpage);
> - if (is_zone_device_page(newpage))
> - put_page(newpage);
> + if (dst != src) {
> + folio_unlock(dst);
> + if (folio_is_zone_device(dst))
> + folio_put(dst);
> else
> - putback_lru_page(newpage);
> + folio_putback_lru(dst);
> }
> }
> }
