mm/page_owner: change split_page_owner to take a count

The implementation of split_page_owner() prefers a count rather than the
old order of the page.  When we support a variable size THP, we won't
have the order at this point, but we will have the number of pages.
So change the interface to what the caller and callee would prefer.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SeongJae Park <sjpark@amazon.de>
Acked-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Huang Ying <ying.huang@intel.com>
Link: https://lkml.kernel.org/r/20200908195539.25896-4-willy@infradead.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/include/linux/page_owner.h b/include/linux/page_owner.h
index 8679ccd722e8985b01ba113c0f472da7f25d1aa4..3468794f83d23eac0eda53470f59fad4858dd6a7 100644 (file)
--- a/include/linux/page_owner.h
+++ b/include/linux/page_owner.h
@@ -11,7 +11,7 @@ extern struct page_ext_operations page_owner_ops;
 extern void __reset_page_owner(struct page *page, unsigned int order);
 extern void __set_page_owner(struct page *page,
                        unsigned int order, gfp_t gfp_mask);
-extern void __split_page_owner(struct page *page, unsigned int order);
+extern void __split_page_owner(struct page *page, unsigned int nr);
 extern void __copy_page_owner(struct page *oldpage, struct page *newpage);
 extern void __set_page_owner_migrate_reason(struct page *page, int reason);
 extern void __dump_page_owner(struct page *page);
@@ -31,10 +31,10 @@ 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 order)
+static inline void split_page_owner(struct page *page, unsigned int nr)
 {
        if (static_branch_unlikely(&page_owner_inited))
-               __split_page_owner(page, order);
+               __split_page_owner(page, nr);
 }
 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 65c289c13b5813480c8354d4bc20f2ca80a114db..aa612cc5b3fe6b551748b818a86462cd0a69fed0 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2454,7 +2454,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
 
        ClearPageCompound(head);
 
-       split_page_owner(head, HPAGE_PMD_ORDER);
+       split_page_owner(head, HPAGE_PMD_NR);
 
        /* See comment in __split_huge_page_tail() */
        if (PageAnon(head)) {

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 05fe1ddb033ca141c0062bb8234acc688b5f5efc..febb2d731f9e81aa7f86860cb04a26eea2ed0ffa 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3209,7 +3209,7 @@ 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, 1 << order);
 }
 EXPORT_SYMBOL_GPL(split_page);
 

diff --git a/mm/page_owner.c b/mm/page_owner.c
index 3604615094235330e0db502f492a0227192549c0..4ca3051a10358639bf50aaa6763174038a356dfd 100644 (file)
--- 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 order)
+void __split_page_owner(struct page *page, unsigned int nr)
 {
        int i;
        struct page_ext *page_ext = lookup_page_ext(page);
@@ -213,7 +213,7 @@ void __split_page_owner(struct page *page, unsigned int order)
        if (unlikely(!page_ext))
                return;
 
-       for (i = 0; i < (1 << order); i++) {
+       for (i = 0; i < nr; i++) {
                page_owner = get_page_owner(page_ext);
                page_owner->order = 0;
                page_ext = page_ext_next(page_ext);