[090/131] mm: memcontrol: prepare move_account for removal of private page type counters

Commit Message

Andrew Morton June 3, 2020, 11:01 p.m. UTC

From: Johannes Weiner <[e-mail]>
Subject: mm: memcontrol: prepare move_account for removal of private page type counters

When memcg uses the generic vmstat counters, it doesn't need to do
anything at charging and uncharging time.  It does, however, need to
migrate counts when pages move to a different cgroup in move_account.

Prepare the move_account function for the arrival of NR_FILE_PAGES,
NR_ANON_MAPPED, NR_ANON_THPS etc.  by having a branch for files and a
branch for anon, which can then divided into sub-branches.

Link: http://lkml.kernel.org/r/[e-mail]
Signed-off-by: Johannes Weiner <[e-mail]>
Reviewed-by: Alex Shi <[e-mail]>
Reviewed-by: Joonsoo Kim <[e-mail]>
Cc: Hugh Dickins <[e-mail]>
Cc: "Kirill A. Shutemov" <[e-mail]>
Cc: Michal Hocko <[e-mail]>
Cc: Roman Gushchin <[e-mail]>
Cc: Shakeel Butt <[e-mail]>
Cc: Balbir Singh <[e-mail]>
Signed-off-by: Andrew Morton <[e-mail]>
---

 mm/memcontrol.c |   25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

Patch

--- a/mm/memcontrol.c~mm-memcontrol-prepare-move_account-for-removal-of-private-page-type-counters
+++ a/mm/memcontrol.c
@@ -5434,7 +5434,6 @@  static int mem_cgroup_move_account(struc
 	struct pglist_data *pgdat;
 	unsigned int nr_pages = compound ? hpage_nr_pages(page) : 1;
 	int ret;
-	bool anon;
 
 	VM_BUG_ON(from == to);
 	VM_BUG_ON_PAGE(PageLRU(page), page);
@@ -5452,25 +5451,27 @@  static int mem_cgroup_move_account(struc
 	if (page->mem_cgroup != from)
 		goto out_unlock;
 
-	anon = PageAnon(page);
-
 	pgdat = page_pgdat(page);
 	from_vec = mem_cgroup_lruvec(from, pgdat);
 	to_vec = mem_cgroup_lruvec(to, pgdat);
 
 	lock_page_memcg(page);
 
-	if (!anon && page_mapped(page)) {
-		__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
-		__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
-	}
+	if (!PageAnon(page)) {
+		if (page_mapped(page)) {
+			__mod_lruvec_state(from_vec, NR_FILE_MAPPED, -nr_pages);
+			__mod_lruvec_state(to_vec, NR_FILE_MAPPED, nr_pages);
+		}
 
-	if (!anon && PageDirty(page)) {
-		struct address_space *mapping = page_mapping(page);
+		if (PageDirty(page)) {
+			struct address_space *mapping = page_mapping(page);
 
-		if (mapping_cap_account_dirty(mapping)) {
-			__mod_lruvec_state(from_vec, NR_FILE_DIRTY, -nr_pages);
-			__mod_lruvec_state(to_vec, NR_FILE_DIRTY, nr_pages);
+			if (mapping_cap_account_dirty(mapping)) {
+				__mod_lruvec_state(from_vec, NR_FILE_DIRTY,
+						   -nr_pages);
+				__mod_lruvec_state(to_vec, NR_FILE_DIRTY,
+						   nr_pages);
+			}
 		}
 	}