linux-kernel - [PATCH RFC 2/4] mm: kmem: remove redundant checks from get_obj_cgroup_from

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Message-ID: <20200827175215.319780-3-guro@fb.com>
Date:   Thu, 27 Aug 2020 10:52:13 -0700
From:   Roman Gushchin <guro@...com>
To:     <linux-mm@...ck.org>
CC:     Andrew Morton <akpm@...ux-foundation.org>,
        =Shakeel Butt <shakeelb@...gle.com>,
        Johannes Weiner <hannes@...xchg.org>,
        Michal Hocko <mhocko@...nel.org>, <kernel-team@...com>,
        <linux-kernel@...r.kernel.org>, Roman Gushchin <guro@...com>
Subject: [PATCH RFC 2/4] mm: kmem: remove redundant checks from get_obj_cgroup_from_current()

There are checks for current->mm and current->active_memcg
in get_obj_cgroup_from_current(), but these checks are redundant:
memcg_kmem_bypass() called just above performs same checks.

Signed-off-by: Roman Gushchin <guro@...com>
---
 mm/memcontrol.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9c08d8d14bc0..5d847257a639 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -2919,9 +2919,6 @@ __always_inline struct obj_cgroup *get_obj_cgroup_from_current(void)
 	if (memcg_kmem_bypass())
 		return NULL;
 
-	if (unlikely(!current->mm && !current->active_memcg))
-		return NULL;
-
 	rcu_read_lock();
 	if (unlikely(current->active_memcg))
 		memcg = rcu_dereference(current->active_memcg);
-- 
2.26.2