The patch titled
Subject: mm: memcontrol: change ug->dummy_page only if memcg changed
has been added to the -mm tree. Its filename is
mm-memcontrol-change-ug-dummy_page-only-if-memcg-changed.patch
This patch should soon appear at
https://ozlabs.org/~akpm/mmots/broken-out/mm-memcontrol-change-ug-dummy_page-only-if-memcg-changed.patch
and later at
https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcontrol-change-ug-dummy_page-only-if-memcg-changed.patch
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------------------------------------------------------
From: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Subject: mm: memcontrol: change ug->dummy_page only if memcg changed
Just like assignment to ug->memcg, we only need to update ug->dummy_page
if memcg changed. So move it to there. This is a very small
optimization.
Link: https://lkml.kernel.org/r/20210319163821.20704-5-songmuchun@xxxxxxxxxxxxx
Signed-off-by: Muchun Song <songmuchun@xxxxxxxxxxxxx>
Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxxxx>
Cc: Roman Gushchin <guro@xxxxxx>
Cc: Vladimir Davydov <vdavydov.dev@xxxxxxxxx>
Cc: Xiongchun Duan <duanxiongchun@xxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/memcontrol.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
--- a/mm/memcontrol.c~mm-memcontrol-change-ug-dummy_page-only-if-memcg-changed
+++ a/mm/memcontrol.c
@@ -6843,6 +6843,7 @@ static void uncharge_page(struct page *p
uncharge_gather_clear(ug);
}
ug->memcg = page_memcg(page);
+ ug->dummy_page = page;
/* pairs with css_put in uncharge_batch */
css_get(&ug->memcg->css);
@@ -6856,7 +6857,6 @@ static void uncharge_page(struct page *p
else
ug->pgpgout++;
- ug->dummy_page = page;
page->memcg_data = 0;
css_put(&ug->memcg->css);
}
_
Patches currently in -mm which might be from songmuchun@xxxxxxxxxxxxx are
mm-memcontrol-fix-kernel-stack-account.patch
mm-memcontrol-slab-fix-obtain-a-reference-to-a-freeing-memcg.patch
mm-memcontrol-introduce-obj_cgroup_uncharge_pages.patch
mm-memcontrol-directly-access-page-memcg_data-in-mm-page_allocc.patch
mm-memcontrol-change-ug-dummy_page-only-if-memcg-changed.patch
mm-memcontrol-use-obj_cgroup-apis-to-charge-kmem-pages.patch
mm-memcontrol-inline-__memcg_kmem_uncharge-into-obj_cgroup_uncharge_pages.patch
mm-memcontrol-move-pagememcgkmem-to-the-scope-of-config_memcg_kmem.patch
