Re: [PATCH] mm: huge_memory: add the missing folio_test_pmd_mappable() for THP split statistics

[David Hildenbrand]

On 29.03.24 07:59, Baolin Wang wrote:
> Now the mTHP can also be split or added into the deferred list, so add
> folio_test_pmd_mappable() validation for PMD mapped THP, to avoid confusion
> with PMD mapped THP related statistics.
>
> Signed-off-by: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx>
> ---
>   mm/huge_memory.c | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 1683de78c313..3ca9282a0dc9 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -3109,7 +3109,8 @@ int split_huge_page_to_list_to_order(struct page *page, struct list_head *list,
>   		i_mmap_unlock_read(mapping);
>   out:
>   	xas_destroy(&xas);
> -	count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
> +	if (folio_test_pmd_mappable(folio))
> +		count_vm_event(!ret ? THP_SPLIT_PAGE : THP_SPLIT_PAGE_FAILED);
>   	return ret;
>   }
>   
> @@ -3171,7 +3172,8 @@ void deferred_split_folio(struct folio *folio)
>   
>   	spin_lock_irqsave(&ds_queue->split_queue_lock, flags);
>   	if (list_empty(&folio->_deferred_list)) {
> -		count_vm_event(THP_DEFERRED_SPLIT_PAGE);
> +		if (folio_test_pmd_mappable(folio))
> +			count_vm_event(THP_DEFERRED_SPLIT_PAGE);
>   		list_add_tail(&folio->_deferred_list, &ds_queue->split_queue);
>   		ds_queue->split_queue_len++;
>   #ifdef CONFIG_MEMCG

Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb