+ mm-memcg-retrieve-parent-memcg-from-cssparent.patch added to -mm tree

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: mm/memcg: retrieve parent memcg from css.parent
has been added to the -mm tree.  Its filename is
     mm-memcg-retrieve-parent-memcg-from-cssparent.patch

This patch should soon appear at
    https://ozlabs.org/~akpm/mmots/broken-out/mm-memcg-retrieve-parent-memcg-from-cssparent.patch
and later at
    https://ozlabs.org/~akpm/mmotm/broken-out/mm-memcg-retrieve-parent-memcg-from-cssparent.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/process/submit-checklist.rst when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Wei Yang <richard.weiyang@gmail.com>
Subject: mm/memcg: retrieve parent memcg from css.parent

The parent we get from page_counter is correct, while this is two
different hierarchy.

Let's retrieve the parent memcg from css.parent just like parent_cs(),
blkcg_parent(), etc.

Link: https://lkml.kernel.org/r/20220201004643.8391-2-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Roman Gushchin <guro@fb.com>
Reviewed-by: Shakeel Butt <shakeelb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vladimir Davydov <vdavydov.dev@gmail.com>
Cc: Yang Shi <shy828301@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 include/linux/memcontrol.h |    4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

--- a/include/linux/memcontrol.h~mm-memcg-retrieve-parent-memcg-from-cssparent
+++ a/include/linux/memcontrol.h
@@ -841,9 +841,7 @@ static inline struct mem_cgroup *lruvec_
  */
 static inline struct mem_cgroup *parent_mem_cgroup(struct mem_cgroup *memcg)
 {
-	if (!memcg->memory.parent)
-		return NULL;
-	return mem_cgroup_from_counter(memcg->memory.parent, memory);
+	return mem_cgroup_from_css(memcg->css.parent);
 }
 
 static inline bool mem_cgroup_is_descendant(struct mem_cgroup *memcg,
_

Patches currently in -mm which might be from richard.weiyang@gmail.com are

mm-memcg-mem_cgroup_per_node-is-already-set-to-0-on-allocation.patch
mm-memcg-retrieve-parent-memcg-from-cssparent.patch
mm-page_alloc-add-same-penalty-is-enough-to-get-round-robin-order.patch
mm-page_alloc-add-penalty-to-local_node.patch
memcg-do-not-tweak-node-in-alloc_mem_cgroup_per_node_info.patch