Re: [Patch v2] mm/huge_memory: add pmd folio to ds_queue in do_huge_zero_wp_pmd()

[Zi Yan <ziy@nvidia.com>]

On 1 Oct 2025, at 21:38, Wei Yang wrote:

> We add pmd folio into ds_queue on the first page fault in
> __do_huge_pmd_anonymous_page(), so that we can split it in case of
> memory pressure. This should be the same for a pmd folio during wp
> page fault.
>
> Commit 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault") miss
> to add it to ds_queue, which means system may not reclaim enough memory
> in case of memory pressure even the pmd folio is under used.
>
> Move deferred_split_folio() into map_anon_folio_pmd() to make the pmd
> folio installation consistent.
>
> Fixes: 1ced09e0331f ("mm: allocate THP on hugezeropage wp-fault")
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
> Cc: David Hildenbrand <david@redhat.com>
> Cc: Lance Yang <lance.yang@linux.dev>
> Cc: Dev Jain <dev.jain@arm.com>
> Cc: <stable@vger.kernel.org>
>
> ---
> v2:
>   * add fix, cc stable and put description about the flow of current
>     code
>   * move deferred_split_folio() into map_anon_folio_pmd()
> ---
>  mm/huge_memory.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)

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

Best Regards,
Yan, Zi