Re: [PATCH v5 3/9] mm: use enum migrate_reason instead of int for migration reason parameters

["David Hildenbrand (Arm)" <david@kernel.org>]

On 7/1/26 08:10, Ye Liu wrote:
> Replace all 'int reason' function parameters that carry migrate_reason
> values with the proper 'enum migrate_reason' type.  This makes the
> intent explicit and leverages compiler type checking.  The affected
> subsystems are:
> 
>   - page_owner: __folio_set_owner_migrate_reason(),
>                 folio_set_owner_migrate_reason()
>   - migrate: migrate_pages(), migrate_pages_sync(),
>              migrate_pages_batch(), migrate_folios_move(),
>              migrate_hugetlbs(), unmap_and_move_huge_page()
>   - hugetlb: move_hugetlb_state(), htlb_allow_alloc_fallback()
>   - trace: mm_migrate_pages and mm_migrate_pages_start events
> 
> The 'short last_migrate_reason' struct field and internal helper
> parameter in page_owner are intentionally left as 'short' since they
> store per-page metadata where size matters.
> 
> No functional change.
> 
> Signed-off-by: Ye Liu <ye.liu@linux.dev>
> Reviewed-by: Zi Yan <ziy@nvidia.com>
> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
> ---
>  include/linux/hugetlb.h        |  9 +++++----
>  include/linux/migrate.h        |  6 ++++--
>  include/linux/page_owner.h     |  7 ++++---
>  include/trace/events/migrate.h |  8 ++++----
>  mm/hugetlb.c                   |  3 ++-
>  mm/migrate.c                   | 12 ++++++------
>  mm/page_owner.c                |  2 +-
>  7 files changed, 26 insertions(+), 21 deletions(-)
> 
> diff --git a/include/linux/hugetlb.h b/include/linux/hugetlb.h
> index 2abaf99321e9..fa828232dfcc 100644
> --- a/include/linux/hugetlb.h
> +++ b/include/linux/hugetlb.h
> @@ -154,7 +154,8 @@ long hugetlb_unreserve_pages(struct inode *inode, long start, long end,
>  bool folio_isolate_hugetlb(struct folio *folio, struct list_head *list);
>  int get_hwpoison_hugetlb_folio(struct folio *folio, bool *hugetlb, bool unpoison);
>  void folio_putback_hugetlb(struct folio *folio);
> -void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio, int reason);
> +void move_hugetlb_state(struct folio *old_folio, struct folio *new_folio,
> +			enum migrate_reason reason);

Two tabs indent, applies to all other cases in here as well.

Besides the "extern" Lorenzo mentioned, LGTM.

-- 
Cheers,

David