mm/memcg: use order instead of nr in split_page_memcg()

We do not have non power of two pages, using nr is error prone if nr is
not power-of-two.  Use page order instead.

Link: https://lkml.kernel.org/r/20240226205534.1603748-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: "Matthew Wilcox (Oracle)" <willy@infradead.org>
Cc: Michal Koutny <mkoutny@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zach O'Keefe <zokeefe@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 4e4caeaea4041bf92cc807be8da4258568dc8264..173bbb53c1ec707df8ceb4a13a465294750608ad 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1163,7 +1163,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
        rcu_read_unlock();
 }
 
-void split_page_memcg(struct page *head, unsigned int nr);
+void split_page_memcg(struct page *head, int order);
 
 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
                                                gfp_t gfp_mask,
@@ -1621,7 +1621,7 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
 {
 }
 
-static inline void split_page_memcg(struct page *head, unsigned int nr)
+static inline void split_page_memcg(struct page *head, int order)
 {
 }
 

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 9840f312c08f40db4d649242eb712de9dea8c4b6..96ac7c62c37557319892e33f17af65731f74f75d 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2889,11 +2889,12 @@ static void __split_huge_page(struct page *page, struct list_head *list,
        struct lruvec *lruvec;
        struct address_space *swap_cache = NULL;
        unsigned long offset = 0;
-       unsigned int nr = thp_nr_pages(head);
        int i, nr_dropped = 0;
+       int order = folio_order(folio);
+       unsigned int nr = 1 << order;
 
        /* complete memcg works before add pages to LRU */
-       split_page_memcg(head, nr);
+       split_page_memcg(head, order);
 
        if (folio_test_anon(folio) && folio_test_swapcache(folio)) {
                offset = swp_offset(folio->swap);

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index cb216d30a22152528dd628a636d3c1cb8af70eac..db9a3fb26a996179f208609d2a71646d02b35f12 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3606,11 +3606,12 @@ void obj_cgroup_uncharge(struct obj_cgroup *objcg, size_t size)
 /*
  * Because page_memcg(head) is not set on tails, set it now.
  */
-void split_page_memcg(struct page *head, unsigned int nr)
+void split_page_memcg(struct page *head, int order)
 {
        struct folio *folio = page_folio(head);
        struct mem_cgroup *memcg = folio_memcg(folio);
        int i;
+       unsigned int nr = 1 << order;
 
        if (mem_cgroup_disabled() || !memcg)
                return;

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5ab921e3d7d1988f51b61ba94dda7c390b3f55e7..44ffe1304878f26cb559a3df24fdbb4bbd29e7f3 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2617,7 +2617,7 @@ 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_memcg(page, 1 << order);
+       split_page_memcg(page, order);
 }
 EXPORT_SYMBOL_GPL(split_page);
 
@@ -4802,7 +4802,7 @@ static void *make_alloc_exact(unsigned long addr, unsigned int order,
                struct page *last = page + nr;
 
                split_page_owner(page, 1 << order);
-               split_page_memcg(page, 1 << order);
+               split_page_memcg(page, order);
                while (page < --last)
                        set_page_refcounted(last);