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From: Muchun Song In-Reply-To: <20260512085546.368911-1-18810879172@163.com> Date: Tue, 12 May 2026 17:10:03 +0800 Cc: akpm@linux-foundation.org, david@fromorbit.com, qi.zheng@linux.dev, roman.gushchin@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, wangxuewen Content-Transfer-Encoding: quoted-printable Message-Id: <616E5E26-BB36-43CD-B086-0F238903B1BF@linux.dev> References: <20260512085546.368911-1-18810879172@163.com> To: wangxuewen <18810879172@163.com> X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: EC97B1C0003 X-Stat-Signature: fcupkr717g87tzn5fwneanu7hn6p8b5j X-HE-Tag: 1778577050-767752 X-HE-Meta: U2FsdGVkX1+BDn1qRUzawLbr/8MTCo8O3DDmhTfa1APrqHRvERuo1e7SVXCM4bC4ftWJQE6tozGqbWsBk4LcT2891rELYy5/Coj9D/XgvYpHI3g0R851HLJdiSj3lq/qiVPwIjaWOWgM/qfpVrdd16jtlU41XyQija4SC2C37xX+YJ7Eo6epGszNCK18uaEtWEFxEn1oCcWmeGsOIgY5eHRXOy1oSRbbavtuZSTW4s5TD8xGMR+9MxDzhqb4RbQh7KI+mwMp1K+U2+OlkauD/Whi/h+BdZZ711efwWwx7Us9nVbHzg2udSYetJirJ4v5H4nTJ5Ew+o6vjx0GI/phpfsYt8gEZaGjgv1qqO47I6Wsc/6X0piw5Z+wmVZ0/MVwweYPmbDLw+bm2IsHoRn2L95QeJj2513LivZT3UNFieR3syW89zCqhPtIQ8hot2t+eMWbvePjMd7y3A2ZKSwiMe4JR+f/gwNNVAtsXPCQ2Yh1o3pfmILV7SHS0QHhMJX3YEtY7XgHVDO7J6WBdwTAPEJBrqUHTeU+zzKKztfisOItPGHjgyyhwoWez1yqQz7A9FVFUKIpHbiGv6hf+iIY51qQqg8hilZlMp5/9WuH/3RJnZzNPiZpr3KeGXYbTEggvzmTG3vzcC5h1pyyE1Y3I055EijytjLZ/nmObB0/uO3DtoLmFp5rTeyngCWwrYfL3u4Cihi0EGzBoTT/e/LWbcg53S7oboDjhLk2SkdgXqFZ1JCtvf4oIqnJrXixNzke9gkt4jpmRnDovkF0yvIlpOijWWcIX0IDJHPn0ZOdV3VuHUQG5Jz+yiVA/5Xv2dqsAM39N/gOc3C5mp4HvLCcaiei0UKCw3pkUhv7T4Q8Fp6+dRA5ssbuQJ+avgdWgIGW0Hb9N35Njdx0vM5Q/3tCp347egj3+b84jUVnjqUj0I5XFKIZZXWj8g88M2Xkwzyw4+Tx2eyztXXRwdr1X5x xdNVjjYr p4OlArJimV/hWF4JfBGavWP4X4lTvkVY8JiPCiMP1S7fh7O9hUJILbm0MVcV5teV4IcsK0wRd2ATpCnXN6AV+Put+asRpMZf+FVakLMxpiTT4OjrkH7oGwfiKtmO8qXLMmTzHxzPQCjJ0W0a27r17CInas3RPe51YEqZyr0bX/+PCBKUY5Rvrd6YZxLFQ4At+YqLPLuqgA7z5bqyjToJw/xIgHriIPT9Pc9p50b/ZYCogNpz2JUHgsQ87HQKb3IO2fnQWXIelP//OXxxVnVmaBd6NkfVdjXjyTZXhoU5KXnZ+6tWfpKAvTl7dAg== Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On May 12, 2026, at 16:55, wangxuewen <18810879172@163.com> wrote: >=20 > Use guard(mutex) to automatically handle shrinker_mutex locking and > unlocking in shrinker_memcg_alloc(). This removes the explicit > mutex_unlock() call, the goto-based error path, and the redundant > ret variable, resulting in cleaner and more concise code. >=20 > Signed-off-by: wangxuewen > --- > mm/shrinker.c | 11 ++++------- > 1 file changed, 4 insertions(+), 7 deletions(-) >=20 > diff --git a/mm/shrinker.c b/mm/shrinker.c > index 76b3f750cf65..1274130323bf 100644 > --- a/mm/shrinker.c > +++ b/mm/shrinker.c > @@ -222,22 +222,19 @@ static int shrinker_memcg_alloc(struct shrinker = *shrinker) > if (mem_cgroup_kmem_disabled() && !(shrinker->flags & = SHRINKER_NONSLAB)) > return -ENOSYS; >=20 > - mutex_lock(&shrinker_mutex); > + guard(mutex)(&shrinker_mutex); > id =3D idr_alloc(&shrinker_idr, shrinker, 0, 0, GFP_KERNEL); > if (id < 0) > - goto unlock; > + return id; >=20 > if (id >=3D shrinker_nr_max) { > if (expand_shrinker_info(id)) { > idr_remove(&shrinker_idr, id); > - goto unlock; > + return -ENOMEM; > } > } > shrinker->id =3D id; > - ret =3D 0; > -unlock: > - mutex_unlock(&shrinker_mutex); > - return ret; One small thing: since ret is no longer used after this change, it should be dropped from the declaration to avoid an unused-variable warning: - int id, ret =3D -ENOMEM; + int id; Otherwise looks good to me. Thanks, Muchun > + return 0; > } >=20 > static void shrinker_memcg_remove(struct shrinker *shrinker) > --=20 > 2.25.1 >=20