Re: [PATCH v2 1/3] Revert "mm/khugepaged: remove definition of struct khugepaged_mm_slot"

[Baolin Wang <baolin.wang@linux.alibaba.com>]

On 11/6/26 4:57 AM, Lorenzo Stoakes (ARM) wrote:
> This partially reverts commit b4c9ffb54b32 ("mm/khugepaged: remove
> definition of struct khugepaged_mm_slot"), as a subsequent commit needs to
> resurrect this type to store additional data alongside the mm_slot.
> 
> The stated intent of the commit was to address a NULL check in
> __khugepaged_exit():
> 
> 	mm_slot = mm_slot_entry(slot, struct khugepaged_mm_slot, slot);
> 
> slot can be NULL and mm_slot_entry() is an alias for container_of(), so
> this is container_of() a NULL value.
> 
> This was benign as there was only 1 field in khugepaged_mm_slot (offsetting
> NULL at 0 results in NULL), however it was right to fix this, so retain the
> fix.
> 
> It also unwrapped KMEM_CACHE() in khugepaged_init(). This was a mistake,
> and was itself reverted in commit c14bdcc9f274 ("mm/khugepaged: use
> KMEM_CACHE()"). Therefore, retain the KMEM_CACHE() form in this revert.
> 
> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
> Reviewed-by: Lance Yang <lance.yang@linux.dev>
> Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
> ---

LGTM.
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>