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

Zi Yan
2024-02-26T20:56:26Z

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);
--
2.43.0