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

["Zi Yan" <ziy@nvidia.com>]

On Mon Sep 7, 2026 at 2:33 PM EDT, Kiryl Shutsemau wrote:
> From: "Kiryl Shutsemau (Meta)" <kas@kernel.org>
>
> __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@kernel.org>
> Assisted-by: Claude-Code:claude-fable-5-1
> Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
> ---
>  mm/huge_memory.c | 31 ++++++++++++++++++++-----------
>  1 file changed, 20 insertions(+), 11 deletions(-)
>
LGTM.

Reviewed-by: Zi Yan <ziy@nvidia.com>

-- 
Best Regards,
Yan, Zi