Re: [PATCH mm-new v2 1/2] mm: make is_guard_pte_marker() available for hugepage collapse

[Zi Yan <ziy@nvidia.com>]

On 18 Sep 2025, at 1:04, Lance Yang wrote:

> From: Lance Yang <lance.yang@linux.dev>
>
> The hugepage collapsing code needs is_guard_pte_marker() to correctly
> handle PTE guard markers. Move the helper to a shared header and expose
> it.
>
> While at it, simplify the implementation. The current code is redundant
> as it effectively expands to:
>
>   is_swap_pte(pte) &&
>   is_pte_marker_entry(...) && // from is_pte_marker()
>   is_pte_marker_entry(...)    // from is_guard_swp_entry()
>
> While a modern compiler could likely optimize this away, let's have clean
> code and not rely on it.
>
> Cc: Kairui Song <kasong@tencent.com>
> Acked-by: David Hildenbrand <david@redhat.com>
> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
> Signed-off-by: Lance Yang <lance.yang@linux.dev>
> ---
>  include/linux/swapops.h | 6 ++++++
>  mm/madvise.c            | 6 ------
>  2 files changed, 6 insertions(+), 6 deletions(-)
>
LGTM. Reviewed-by: Zi Yan <ziy@nvidia.com>

Best Regards,
Yan, Zi