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

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