From: Andrew Morton <akpm@linux-foundation.org>
To: Qi Zheng <qi.zheng@linux.dev>
Cc: hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev,
shakeel.butt@linux.dev, muchun.song@linux.dev, yosry@kernel.org,
cgroups@vger.kernel.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org,
Qi Zheng <zhengqi.arch@bytedance.com>
Subject: Re: [PATCH v2] mm: memcontrol: fix rcu unbalance in get_non_dying_memcg_end()
Date: Tue, 28 Apr 2026 15:12:53 -0700 [thread overview]
Message-ID: <20260428151253.bdfb08401ebb74c438df0e52@linux-foundation.org> (raw)
In-Reply-To: <20260428103108.45719-1-qi.zheng@linux.dev>
On Tue, 28 Apr 2026 18:31:08 +0800 Qi Zheng <qi.zheng@linux.dev> wrote:
> Currently, get_non_dying_memcg_start() and get_non_dying_memcg_end() both
> evaluate cgroup_subsys_on_dfl(memory_cgrp_subsys) independently to
> determine whether to acquire or release the RCU read lock.
Sashiko review
(https://sashiko.dev/#/patchset/20260428103108.45719-1-qi.zheng@linux.dev)
is correct.
mm/memcontrol.c: In function 'mod_memcg_state':
mm/memcontrol.c:881:9: error: 'rcu_locked' is used uninitialized [-Werror=uninitialized]
881 | get_non_dying_memcg_end(rcu_locked);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/memcontrol.c:874:14: note: 'rcu_locked' was declared here
874 | bool rcu_locked;
| ^~~~~~~~~~
In function 'mod_memcg_lruvec_state',
inlined from 'mod_lruvec_state' at mm/memcontrol.c:973:3:
mm/memcontrol.c:952:9: error: 'rcu_locked' is used uninitialized [-Werror=uninitialized]
952 | get_non_dying_memcg_end(rcu_locked);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/memcontrol.c:944:14: note: 'rcu_locked' was declared here
944 | bool rcu_locked;
| ^~~~~~~~~~
In function 'mod_memcg_state',
inlined from 'mem_cgroup_sk_uncharge' at mm/memcontrol.c:5392:2:
mm/memcontrol.c:881:9: error: 'rcu_locked' is used uninitialized [-Werror=uninitialized]
881 | get_non_dying_memcg_end(rcu_locked);
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
mm/memcontrol.c:874:14: note: 'rcu_locked' was declared here
874 | bool rcu_locked;
| ^~~~~~~~~~
next prev parent reply other threads:[~2026-04-28 22:12 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-04-28 10:31 [PATCH v2] mm: memcontrol: fix rcu unbalance in get_non_dying_memcg_end() Qi Zheng
2026-04-28 11:19 ` Muchun Song
2026-04-28 22:12 ` Andrew Morton [this message]
2026-04-29 2:48 ` Qi Zheng
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