Re: [PATCH v3 13/15] mm/page_alloc: Add __alloc_frozen_pages()

[David Hildenbrand <david@xxxxxxxxxx>]

On 25.11.24 22:01, Matthew Wilcox (Oracle) wrote:
> Defer the initialisation of the page refcount to the new __alloc_pages()
> wrapper and turn the old __alloc_pages() into __alloc_frozen_pages().
>
> Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
> ---
>   mm/internal.h   |  4 ++++
>   mm/page_alloc.c | 18 ++++++++++++++----
>   2 files changed, 18 insertions(+), 4 deletions(-)
>
> diff --git a/mm/internal.h b/mm/internal.h
> index 9cc5fdc614cf..55e03f8f41d9 100644
> --- a/mm/internal.h
> +++ b/mm/internal.h
> @@ -740,6 +740,10 @@ extern bool free_pages_prepare(struct page *page, unsigned int order);
>   
>   extern int user_min_free_kbytes;
>   
> +struct page *__alloc_frozen_pages_noprof(gfp_t, unsigned int order, int nid,
> +		nodemask_t *);
> +#define __alloc_frozen_pages(...) \
> +	alloc_hooks(__alloc_frozen_pages_noprof(__VA_ARGS__))
>   void free_frozen_pages(struct page *page, unsigned int order);
>   void free_unref_folios(struct folio_batch *fbatch);
>   
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 35fb45b8b369..67b1cb757def 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -4747,8 +4747,8 @@ EXPORT_SYMBOL_GPL(alloc_pages_bulk_noprof);
>   /*
>    * This is the 'heart' of the zoned buddy allocator.
>    */
> -struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
> -				      int preferred_nid, nodemask_t *nodemask)
> +struct page *__alloc_frozen_pages_noprof(gfp_t gfp, unsigned int order,
> +		int preferred_nid, nodemask_t *nodemask)
>   {
>   	struct page *page;
>   	unsigned int alloc_flags = ALLOC_WMARK_LOW;
> @@ -4804,14 +4804,24 @@ struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
>   		free_frozen_pages(page, order);
>   		page = NULL;
>   	}
> -	if (page)
> -		set_page_refcounted(page);
>   
>   	trace_mm_page_alloc(page, order, alloc_gfp, ac.migratetype);
>   	kmsan_alloc_page(page, order, alloc_gfp);
>   
>   	return page;
>   }
> +EXPORT_SYMBOL(__alloc_frozen_pages_noprof);
> +
> +struct page *__alloc_pages_noprof(gfp_t gfp, unsigned int order,
> +		int preferred_nid, nodemask_t *nodemask)
> +{
> +	struct page *page;
> +
> +	page = __alloc_frozen_pages_noprof(gfp, order, preferred_nid, nodemask);
> +	if (page)
> +		set_page_refcounted(page);
> +	return page;
> +}
>   EXPORT_SYMBOL(__alloc_pages_noprof);
>   
>   struct folio *__folio_alloc_noprof(gfp_t gfp, unsigned int order, int preferred_nid,


Acked-by: David Hildenbrand <david@xxxxxxxxxx>

--
Cheers,

David / dhildenb