mm: memcg: make memcg huge page split support any order split

It sets memcg information for the pages after the split.  A new parameter
new_order is added to tell the order of subpages in the new page, always 0
for now.  It prepares for upcoming changes to support split huge page to
any lower order.

Link: https://lkml.kernel.org/r/20230403201839.4097845-4-zi.yan@sent.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Koutný <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 958838c4c91516e76e30c2b575b4738d5d3e7550..5a3c7fad7733951b5252c0e398c07c7233616774 100644 (file)
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -1152,7 +1152,7 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm,
        rcu_read_unlock();
 }
 
-void split_page_memcg(struct page *head, int order);
+void split_page_memcg(struct page *head, int old_order, int new_order);
 
 unsigned long mem_cgroup_soft_limit_reclaim(pg_data_t *pgdat, int order,
                                                gfp_t gfp_mask,
@@ -1593,7 +1593,7 @@ void count_memcg_event_mm(struct mm_struct *mm, enum vm_event_item idx)
 {
 }
 
-static inline void split_page_memcg(struct page *head, int order)
+static inline void split_page_memcg(struct page *head, int old_order, int new_order)
 {
 }
 

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 7c5a8301159f490041192d018bb5b841a359d42c..ef57dcd7824bac584da542255afcdac0c2cc4f9c 100644 (file)
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2524,7 +2524,7 @@ static void __split_huge_page(struct page *page, struct list_head *list,
        int i;
 
        /* complete memcg works before add pages to LRU */
-       split_page_memcg(head, order);
+       split_page_memcg(head, order, 0);
 
        if (PageAnon(head) && PageSwapCache(head)) {
                swp_entry_t entry = { .val = page_private(head) };

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 42248f0bf4021c65a3054f2be683a627fb25b698..74432369bf5855919a9b17a202a38a09b8738539 100644 (file)
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3441,23 +3441,24 @@ 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, int order)
+void split_page_memcg(struct page *head, int old_order, int new_order)
 {
        struct folio *folio = page_folio(head);
        struct mem_cgroup *memcg = folio_memcg(folio);
        int i;
-       unsigned int nr = 1 << order;
+       unsigned int old_nr = 1 << old_order;
+       unsigned int new_nr = 1 << new_order;
 
        if (mem_cgroup_disabled() || !memcg)
                return;
 
-       for (i = 1; i < nr; i++)
+       for (i = new_nr; i < old_nr; i += new_nr)
                folio_page(folio, i)->memcg_data = folio->memcg_data;
 
        if (folio_memcg_kmem(folio))
-               obj_cgroup_get_many(__folio_objcg(folio), nr - 1);
+               obj_cgroup_get_many(__folio_objcg(folio), old_nr / new_nr - 1);
        else
-               css_get_many(&memcg->css, nr - 1);
+               css_get_many(&memcg->css, old_nr / new_nr - 1);
 }
 
 #ifdef CONFIG_SWAP

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 279019f727f93b02abd10ed2cb003b282e717284..4943116bdf5d51f0e3f0d571ee637c860b66e7f2 100644 (file)
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2781,7 +2781,7 @@ 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_memcg(page, order);
+       split_page_memcg(page, order, 0);
 }
 EXPORT_SYMBOL_GPL(split_page);
 
@@ -4997,7 +4997,7 @@ static void *make_alloc_exact(unsigned long addr, unsigned int order,
                struct page *last = page + nr;
 
                split_page_owner(page, order);
-               split_page_memcg(page, order);
+               split_page_memcg(page, order, 0);
                while (page < --last)
                        set_page_refcounted(last);