Re: [PATCH v3 11/18] mm/huge_memory: allow splitting mappingless swap cache folios

[Zi Yan]

On Thu Aug 20, 2026 at 2:55 PM EDT, Kairui Song via B4 Relay wrote:
> From: Kairui Song <kasong@xxxxxxxxxxx>
>
> Lift the restriction that kept swap cache folios without a mapping
> from being split.  All the underlying infrastructure is sound against
> that with a few more tweaks, no reason to block it anymore.
>
> Also rename the split helper, which now handles mappingless swap
> cache folios that are yet to be anon, or may actually belong to
> shmem.  In either case there is not much difference in how they would
> be split.
>
> A non-anon swap cache folio that still has a mapping (e.g. a shmem
> swap cache folio) remains rejected up front: it would need both its
> page cache and swap cache entries updated on split, which the split
> helpers do not do, and there would be little benefit in doing so.
>
> Signed-off-by: Kairui Song <kasong@xxxxxxxxxxx>
> ---
>  mm/huge_memory.c | 38 ++++++++++++++++++++++----------------
>  1 file changed, 22 insertions(+), 16 deletions(-)
>

LGTM.

Reviewed-by: Zi Yan <ziy@xxxxxxxxxx>

-- 
Best Regards,
Yan, Zi