From 90261d5d8d72c1375460741187eaeeeee90860a6 Mon Sep 17 00:00:00 2001
From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Date: Mon, 8 Aug 2022 14:56:00 +0200
Subject: [PATCH 167/183] mm/memcg: Add a comment regarding the release `obj'.

Please fold into
    mm/memcg: Protect memcg_stock with a local_lock_t

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[do: backported to v5.15]
Signed-off-by: David Oberhollenzer <goliath@infraroot.at>
Signed-off-by: Clark Williams <williams@redhat.com>
Signed-off-by: Clark Williams <clrkwllms@kernel.org>
---
 mm/memcontrol.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 76d1e28ab2c1..7eeeb19b00b2 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -3253,6 +3253,10 @@ static struct obj_cgroup *drain_obj_stock(struct memcg_stock_pcp *stock)
 	}
 
 	stock->cached_objcg = NULL;
+	/*
+	 * The `old' objects needs to be released by the caller via
+	 * obj_cgroup_put() outside of memcg_stock_pcp::stock_lock.
+	 */
 	return old;
 }
 
-- 
2.47.1

