On Wed, Nov 11, 2020 at 03:40:05PM -0500, 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 | 7 ++++--- mm/huge_memory.c | 2 +- mm/page_alloc.c | 2 +- mm/page_owner.c | 6 +++--- 4 files changed, 9 insertions(+), 8 deletions(-)
diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h index 3468794f83d2..215cbb159568 100644 --- a/include/linux/page_owner.h +++ b/include/linux/page_owner.h @@ -31,10 +31,11 @@ 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, unsigned int nr) +static inline void split_page_owner(struct page *page, unsigned int nr,
unsigned int new_order){ if (static_branch_unlikely(&page_owner_inited))
__split_page_owner(page, nr);
__split_page_owner(page, nr, new_order);} static inline void copy_page_owner(struct page *oldpage, struct page *newpage) { @@ -60,7 +61,7 @@ static inline void set_page_owner(struct page *page, { } static inline void split_page_owner(struct page *page,
unsigned int order)
unsigned int nr, unsigned int new_order)
With the addition of the new argument it's a bit hard to understand what the function is supposed to do. It seems like nr == page_order(page), is it right? Maybe we can pass old_order and new_order? Or just the page and the new order?
{ } static inline void copy_page_owner(struct page *oldpage, struct page *newpage) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index f599f5b9bf7f..8b7d771ee962 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -2459,7 +2459,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, ClearPageCompound(head);
- split_page_owner(head, nr);
- split_page_owner(head, nr, 1);
/* See comment in __split_huge_page_tail() */ if (PageAnon(head)) { diff --git a/mm/page_alloc.c b/mm/page_alloc.c index d77220615fd5..a9eead0e091a 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3284,7 +3284,7 @@ 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, 1 << order);
- split_page_owner(page, 1 << order, 1);
} EXPORT_SYMBOL_GPL(split_page); diff --git a/mm/page_owner.c b/mm/page_owner.c index b735a8eafcdb..2b7f7e9056dc 100644 --- a/mm/page_owner.c +++ b/mm/page_owner.c @@ -204,7 +204,7 @@ void __set_page_owner_migrate_reason(struct page *page, int reason) page_owner->last_migrate_reason = reason; } -void __split_page_owner(struct page *page, unsigned int nr) +void __split_page_owner(struct page *page, unsigned int nr, unsigned int new_order) { int i; struct page_ext *page_ext = lookup_page_ext(page); @@ -213,9 +213,9 @@ void __split_page_owner(struct page *page, unsigned int nr) if (unlikely(!page_ext)) return;
- for (i = 0; i < nr; i++) {
- for (i = 0; i < nr; i += (1 << new_order)) { page_owner = get_page_owner(page_ext);
page_owner->order = 0;
page_owner->order = new_order;
I believe there cannot be any leftovers because nr is always a power of 2. Is it true? Converting nr argument to order (if it's possible) will make it obvious.
Other than that the patch looks good to me.
Thanks!