From: Vladimir Davydov <vdavydov@parallels.com>
Date: Thu, 12 Mar 2015 23:26:19 +0000 (-0700)
Subject: memcg: disable hierarchy support if bound to the legacy cgroup hierarchy
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=7feee590bb18ffc42636975f74c2c3120ce1901c;p=GitHub%2FLineageOS%2FG12%2Fandroid_kernel_amlogic_linux-4.9.git

memcg: disable hierarchy support if bound to the legacy cgroup hierarchy

If the memory cgroup controller is initially mounted in the scope of the
default cgroup hierarchy and then remounted to a legacy hierarchy, it will
still have hierarchy support enabled, which is incorrect.  We should
disable hierarchy support if bound to the legacy cgroup hierarchy.

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Michal Hocko <mhocko@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9fe07692eaad..b34ef4a32a3b 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -5232,7 +5232,9 @@ static void mem_cgroup_bind(struct cgroup_subsys_state *root_css)
 	 * on for the root memcg is enough.
 	 */
 	if (cgroup_on_dfl(root_css->cgroup))
-		mem_cgroup_from_css(root_css)->use_hierarchy = true;
+		root_mem_cgroup->use_hierarchy = true;
+	else
+		root_mem_cgroup->use_hierarchy = false;
 }
 
 static u64 memory_current_read(struct cgroup_subsys_state *css,