Folios always use memcg_data to refer to the mem_cgroup while pages allocated with GFP_ACCOUNT have a pointer to the obj_cgroup. Since the caller already knows what it has, split the function into two and then we don't need to check. Move the assignment of split folio memcg_data to the point where we set up the other parts of the new folio. That leaves folio_split_memcg() just handling the memcg accounting. Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx> --- include/linux/memcontrol.h | 7 +++++++ mm/huge_memory.c | 16 ++++------------ mm/memcontrol.c | 17 +++++++++++++---- 3 files changed, 24 insertions(+), 16 deletions(-) diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 57664e2a8fb7..2b4246dc4284 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -1039,6 +1039,8 @@ static inline void memcg_memory_event_mm(struct mm_struct *mm, } void split_page_memcg(struct page *head, int old_order, int new_order); +void folio_split_memcg(struct folio *folio, unsigned old_order, + unsigned new_order); static inline u64 cgroup_id_from_mm(struct mm_struct *mm) { @@ -1463,6 +1465,11 @@ static inline void split_page_memcg(struct page *head, int old_order, int new_or { } +static inline void folio_split_memcg(struct folio *folio, unsigned old_order, + unsigned new_order) +{ +} + static inline u64 cgroup_id_from_mm(struct mm_struct *mm) { return 0; diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 14b1963898a7..514db6a5eee7 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -3394,6 +3394,9 @@ static void __split_folio_to_order(struct folio *folio, int old_order, folio_set_young(new_folio); if (folio_test_idle(folio)) folio_set_idle(new_folio); +#ifdef CONFIG_MEMCG + new_folio->memcg_data = folio->memcg_data; +#endif folio_xchg_last_cpupid(new_folio, folio_last_cpupid(folio)); } @@ -3525,18 +3528,7 @@ static int __split_unmapped_folio(struct folio *folio, int new_order, } } - /* - * Reset any memcg data overlay in the tail pages. - * folio_nr_pages() is unreliable until prep_compound_page() - * was called again. - */ -#ifdef NR_PAGES_IN_LARGE_FOLIO - folio->_nr_pages = 0; -#endif - - - /* complete memcg works before add pages to LRU */ - split_page_memcg(&folio->page, old_order, split_order); + folio_split_memcg(folio, old_order, split_order); split_page_owner(&folio->page, old_order, split_order); pgalloc_tag_split(folio, old_order, split_order); diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 87544df4c3b8..102109d0ee87 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3101,10 +3101,19 @@ void split_page_memcg(struct page *head, int old_order, int new_order) 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), old_nr / new_nr - 1); - else - css_get_many(&folio_memcg(folio)->css, old_nr / new_nr - 1); + obj_cgroup_get_many(__folio_objcg(folio), old_nr / new_nr - 1); +} + +void folio_split_memcg(struct folio *folio, unsigned old_order, + unsigned new_order) +{ + unsigned new_refs; + + if (mem_cgroup_disabled() || !folio_memcg_charged(folio)) + return; + + new_refs = (1 << (old_order - new_order)) - 1; + css_get_many(&__folio_memcg(folio)->css, new_refs); } unsigned long mem_cgroup_usage(struct mem_cgroup *memcg, bool swap) -- 2.47.2