Commit b8791381 authored by Zi Yan's avatar Zi Yan Committed by Andrew Morton
Browse files

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/20240226205534.1603748-6-zi.yan@sent.com


Signed-off-by: default avatarZi Yan <ziy@nvidia.com>
Acked-by: default avatarDavid 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: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 9a581c12

include/linux/memcontrol.h

+2 −2
Original line number Diff line number Diff line
@@ -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, 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,
@@ -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, int order)

static inline void split_page_memcg(struct page *head, int old_order, int new_order)

{

}

mm/huge_memory.c

+1 −1
Original line number Diff line number Diff line
@@ -2894,7 +2894,7 @@ static void __split_huge_page(struct page *page, struct list_head *list, 
	unsigned int nr = 1 << order;



	/* complete memcg works before add pages to LRU */

	split_page_memcg(head, order);

	split_page_memcg(head, order, 0);



	if (folio_test_anon(folio) && folio_test_swapcache(folio)) {

		offset = swp_offset(folio->swap);

mm/memcontrol.c

+6 −5
Original line number Diff line number Diff line
@@ -3606,23 +3606,24 @@ 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

mm/page_alloc.c

+2 −2
Original line number Diff line number Diff line
@@ -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, order);

	split_page_memcg(page, order);

	split_page_memcg(page, order, 0);

}

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, order);

		split_page_memcg(page, order);

		split_page_memcg(page, order, 0);

		while (page < --last)

			set_page_refcounted(last);