On 09/08/22 12:37, Sidhartha Kumar wrote:
> Allows struct folio to store hugetlb metadata that is contained in the
> private field of the first tail page. On 32-bit, _private_1 aligns with
> page[1].private.
>
> Signed-off-by: Sidhartha Kumar <sidhartha.kumar@xxxxxxxxxx>
> ---
> include/linux/mm_types.h | 14 ++++++++++++++
> 1 file changed, 14 insertions(+)
This change is fine with me as it makes the following patches dealing
with hugetlb page subpool folio aware. I 'think' Matthew is OK with
this direction, but it would be good if he chimed in.
Acked-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx>
--
Mike Kravetz
>
> diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h
> index 8a9ee9d24973..7a33171a05b6 100644
> --- a/include/linux/mm_types.h
> +++ b/include/linux/mm_types.h
> @@ -143,6 +143,7 @@ struct page {
> atomic_t compound_pincount;
> #ifdef CONFIG_64BIT
> unsigned int compound_nr; /* 1 << compound_order */
> + unsigned long _private_1;
> #endif
> };
> struct { /* Second tail page of compound page */
> @@ -251,6 +252,7 @@ struct page {
> * @_total_mapcount: Do not use directly, call folio_entire_mapcount().
> * @_pincount: Do not use directly, call folio_maybe_dma_pinned().
> * @_folio_nr_pages: Do not use directly, call folio_nr_pages().
> + * @_private_1: Do not use directly, call folio_get_private_1().
> *
> * A folio is a physically, virtually and logically contiguous set
> * of bytes. It is a power-of-two in size, and it is aligned to that
> @@ -298,6 +300,7 @@ struct folio {
> #ifdef CONFIG_64BIT
> unsigned int _folio_nr_pages;
> #endif
> + unsigned long _private_1;
> };
>
> #define FOLIO_MATCH(pg, fl) \
> @@ -325,6 +328,7 @@ FOLIO_MATCH(compound_mapcount, _total_mapcount);
> FOLIO_MATCH(compound_pincount, _pincount);
> #ifdef CONFIG_64BIT
> FOLIO_MATCH(compound_nr, _folio_nr_pages);
> +FOLIO_MATCH(_private_1, _private_1);
> #endif
> #undef FOLIO_MATCH
>
> @@ -370,6 +374,16 @@ static inline void *folio_get_private(struct folio *folio)
> return folio->private;
> }
>
> +static inline void folio_set_private_1(struct folio *folio, unsigned long private)
> +{
> + folio->_private_1 = private;
> +}
> +
> +static inline unsigned long folio_get_private_1(struct folio *folio)
> +{
> + return folio->_private_1;
> +}
> +
> struct page_frag_cache {
> void * va;
> #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
> --
> 2.31.1
>
