Re: [PATCH 15/20] balloon: Convert to migrate_folio

From: David Hildenbrand
Date: Tue Jun 07 2022 - 03:37:12 EST


On 06.06.22 22:40, Matthew Wilcox (Oracle) wrote:
> This is little more than changing the types over; there's no real work
> being done in this function.
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
> mm/balloon_compaction.c | 15 +++++++--------
> 1 file changed, 7 insertions(+), 8 deletions(-)
>
> diff --git a/mm/balloon_compaction.c b/mm/balloon_compaction.c
> index 4b8eab4b3f45..3f75b876ad76 100644
> --- a/mm/balloon_compaction.c
> +++ b/mm/balloon_compaction.c
> @@ -230,11 +230,10 @@ static void balloon_page_putback(struct page *page)
>
>
> /* move_to_new_page() counterpart for a ballooned page */
> -static int balloon_page_migrate(struct address_space *mapping,
> - struct page *newpage, struct page *page,
> - enum migrate_mode mode)
> +static int balloon_migrate_folio(struct address_space *mapping,
> + struct folio *dst, struct folio *src, enum migrate_mode mode)
> {
> - struct balloon_dev_info *balloon = balloon_page_device(page);
> + struct balloon_dev_info *balloon = balloon_page_device(&src->page);
>
> /*
> * We can not easily support the no copy case here so ignore it as it
> @@ -244,14 +243,14 @@ static int balloon_page_migrate(struct address_space *mapping,
> if (mode == MIGRATE_SYNC_NO_COPY)
> return -EINVAL;
>
> - VM_BUG_ON_PAGE(!PageLocked(page), page);
> - VM_BUG_ON_PAGE(!PageLocked(newpage), newpage);
> + VM_BUG_ON_FOLIO(!folio_test_locked(src), src);
> + VM_BUG_ON_FOLIO(!folio_test_locked(dst), dst);
>
> - return balloon->migratepage(balloon, newpage, page, mode);
> + return balloon->migratepage(balloon, &dst->page, &src->page, mode);
> }
>
> const struct address_space_operations balloon_aops = {
> - .migratepage = balloon_page_migrate,
> + .migrate_folio = balloon_migrate_folio,
> .isolate_page = balloon_page_isolate,
> .putback_page = balloon_page_putback,
> };

I assume you're working on conversion of the other callbacks as well,
because otherwise, this ends up looking a bit inconsistent and confusing :)

Change LGTM.

--
Thanks,

David / dhildenb