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Mon, 22 Sep 2025 02:42:06 -0700 (PDT) From: Julian Sun To: cgroups@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org Cc: viro@zeniv.linux.org.uk, brauner@kernel.org, jack@suse.cz, mingo@redhat.com, peterz@infradead.org, juri.lelli@redhat.com, vincent.guittot@linaro.org, dietmar.eggemann@arm.com, rostedt@goodmis.org, bsegall@google.com, mgorman@suse.de, vschneid@redhat.com, akpm@linux-foundation.org, lance.yang@linux.dev, mhiramat@kernel.org, agruenba@redhat.com, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev Subject: [PATCH 3/3] memcg: Don't trigger hung task warnings when memcg is releasing resources. Date: Mon, 22 Sep 2025 17:41:46 +0800 Message-Id: <20250922094146.708272-4-sunjunchao@bytedance.com> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250922094146.708272-1-sunjunchao@bytedance.com> References: <20250922094146.708272-1-sunjunchao@bytedance.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Hung task warning in mem_cgroup_css_free() is undesirable and unnecessary since it does not affect any user behavior and there is no misbehavior at the kernel code level. Use wb_wait_for_completion_no_hung() to eliminate the possible hung task warning. Signed-off-by: Julian Sun --- mm/memcontrol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 8dd7fbed5a94..b7d9e795dd64 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -3913,7 +3913,7 @@ static void mem_cgroup_css_free(struct cgroup_subsys_= state *css) =20 #ifdef CONFIG_CGROUP_WRITEBACK for (i =3D 0; i < MEMCG_CGWB_FRN_CNT; i++) - wb_wait_for_completion(&memcg->cgwb_frn[i].done); + wb_wait_for_completion_no_hung(&memcg->cgwb_frn[i].done); #endif if (cgroup_subsys_on_dfl(memory_cgrp_subsys) && !cgroup_memory_nosocket) static_branch_dec(&memcg_sockets_enabled_key); --=20 2.39.5