Re: [PATCH] mm/huge_memory: add folio_reset_partially_mapped()

[Baolin Wang]

On 9/8/26 2:33 AM, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@xxxxxxxxxx>
>
> __folio_unqueue_deferred_split() and __folio_freeze_and_split_unmapped()
> both clear PG_partially_mapped and take the folio out of
> MTHP_STAT_NR_ANON_PARTIALLY_MAPPED with the same five lines.
>
> Move the block into folio_reset_partially_mapped() and call it from both
> places.
>
> The helper asserts what both callers rely on: the folio is frozen, so
> deferred_split_folio() cannot set the flag again under it, and the folio
> is already off the deferred split queue. The list check sits behind the
> flag test because order-1 folios have no _deferred_list.
>
> folio_order() is safe to use at this point in the split process: it
> still shows the pre-split order.
>
> Suggested-by: David Hildenbrand (Arm) <david@xxxxxxxxxx>
> Assisted-by: Claude-Code:claude-fable-5-1
> Signed-off-by: Kiryl Shutsemau (Meta) <kas@xxxxxxxxxx>
> ---

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>