Re: [PATCH v5 6/8] mm: page_owner: add support for splitting to any order in split page_owner.

David Hildenbrand
2024-02-28T10:31:59Z

On 26.02.24 21:55, Zi Yan wrote:
> From: Zi Yan <ziy@nvidia.com>
>
> It adds a new_order parameter to set new page order in page owner.
> It prepares for upcoming changes to support split huge page to any
> lower order.
>
> Signed-off-by: Zi Yan <ziy@nvidia.com>
> ---
> include/linux/page_owner.h | 13 ++++++++-----
> mm/huge_memory.c | 2 +-
> mm/page_alloc.c | 4 ++--
> mm/page_owner.c | 7 +++----
> 4 files changed, 14 insertions(+), 12 deletions(-)
>
> diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
> index 2b39c8e19d98..debdc25f08b9 100644
> --- a/include/linux/page_owner.h
> +++ b/include/linux/page_owner.h
> @@ -11,7 +11,8 @@ extern struct page_ext_operations page_owner_ops;
> extern void __reset_page_owner(struct page *page, unsigned short order);
> extern void __set_page_owner(struct page *page,
> unsigned short order, gfp_t gfp_mask);
> -extern void __split_page_owner(struct page *page, int order);
> +extern void __split_page_owner(struct page *page, int old_order,
> + int new_order);
> extern void __folio_copy_owner(struct folio *newfolio, struct folio *old);
> extern void __set_page_owner_migrate_reason(struct page *page, int reason);
> extern void __dump_page_owner(const struct page *page);
> @@ -31,10 +32,11 @@ static inline void set_page_owner(struct page *page,
> __set_page_owner(page, order, gfp_mask);
> }
>
> -static inline void split_page_owner(struct page *page, int order)
> +static inline void split_page_owner(struct page *page, int old_order,
> + int new_order)
> {
> if (static_branch_unlikely(&page_owner_inited))
> - __split_page_owner(page, order);
> + __split_page_owner(page, old_order, new_order);
> }
> static inline void folio_copy_owner(struct folio *newfolio, struct folio *old)
> {
> @@ -56,10 +58,11 @@ static inline void reset_page_owner(struct page *page, unsigned short order)
> {
> }
> static inline void set_page_owner(struct page *page,
> - unsigned int order, gfp_t gfp_mask)
> + unsigned short order, gfp_t gfp_mask)
> {
> }
> -static inline void split_page_owner(struct page *page, int order)
> +static inline void split_page_owner(struct page *page, int old_order,
> + int new_order)
> {
> }
> static inline void folio_copy_owner(struct folio *newfolio, struct folio *folio)
> diff --git a/mm/huge_memory.c b/mm/huge_memory.c
> index 5d4b7c17b9bc..b2df788c11fa 100644
> --- a/mm/huge_memory.c
> +++ b/mm/huge_memory.c
> @@ -2933,7 +2933,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
> unlock_page_lruvec(lruvec);
> /* Caller disabled irqs, so they are still disabled here */
>
> - split_page_owner(head, order);
> + split_page_owner(head, order, 0);
>
> /* See comment in __split_huge_page_tail() */
> if (PageAnon(head)) {
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index c31a468fe317..cc41341c08f4 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -2652,7 +2652,7 @@ void split_page(struct page *page, unsigned int order)
>
> for (i = 1; i < (1 << order); i++)
> set_page_refcounted(page + i);
> - split_page_owner(page, order);
> + split_page_owner(page, order, 0);
> split_page_memcg(page, order, 0);
> }
> EXPORT_SYMBOL_GPL(split_page);
> @@ -4839,7 +4839,7 @@ static void *make_alloc_exact(unsigned long addr, unsigned int order,
> struct page *page = virt_to_page((void *)addr);
> struct page *last = page + nr;
>
> - split_page_owner(page, order);
> + split_page_owner(page, order, 0);
> split_page_memcg(page, order, 0);
> while (page < --last)
> set_page_refcounted(last);
> diff --git a/mm/page_owner.c b/mm/page_owner.c
> index b678f7a6e702..033e349f6479 100644
> --- a/mm/page_owner.c
> +++ b/mm/page_owner.c
> @@ -306,19 +306,18 @@ void __set_page_owner_migrate_reason(struct page *page, int reason)
> page_ext_put(page_ext);
> }
>
> -void __split_page_owner(struct page *page, int order)
> +void __split_page_owner(struct page *page, int old_order, int new_order)
> {
> int i;
> struct page_ext *page_ext = page_ext_get(page);
> struct page_owner *page_owner;
> - unsigned int nr = 1 << order;
>
> if (unlikely(!page_ext))
> return;
>
> - for (i = 0; i < nr; i++) {
> + for (i = 0; i < (1 << old_order); i++) {
> page_owner = get_page_owner(page_ext);
> - page_owner->order = 0;
> + page_owner->order = new_order;
> page_ext = page_ext_next(page_ext);
> }
> page_ext_put(page_ext);

Acked-by: David Hildenbrand <david@redhat.com>

--
Cheers,

David / dhildenb