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From: Muchun Song In-Reply-To: <592f65bbe05587c01a2718443a70e639cc611f3d.1768389889.git.zhengqi.arch@bytedance.com> Date: Fri, 16 Jan 2026 17:18:16 +0800 Cc: hannes@cmpxchg.org, hughd@google.com, mhocko@suse.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, david@kernel.org, lorenzo.stoakes@oracle.com, ziy@nvidia.com, harry.yoo@oracle.com, yosry.ahmed@linux.dev, imran.f.khan@oracle.com, kamalesh.babulal@oracle.com, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, chenridong@huaweicloud.com, mkoutny@suse.com, akpm@linux-foundation.org, hamzamahfooz@linux.microsoft.com, apais@linux.microsoft.com, lance.yang@linux.dev, linux-mm@kvack.org, linux-kernel@vger.kernel.org, cgroups@vger.kernel.org, Qi Zheng Content-Transfer-Encoding: 7bit Message-Id: <0924D73A-5DE4-464D-B606-B0187C72EB96@linux.dev> References: <592f65bbe05587c01a2718443a70e639cc611f3d.1768389889.git.zhengqi.arch@bytedance.com> To: Qi Zheng X-Migadu-Flow: FLOW_OUT X-Rspam-User: X-Rspamd-Server: rspam07 X-Rspamd-Queue-Id: 98B094000D X-Stat-Signature: zq8hdzfxqjtdbdszzuc1pcqsnbnpff6p X-HE-Tag: 1768555155-600850 X-HE-Meta: U2FsdGVkX1+LN/4cyBEzxidgRoGlCmQsWSF9hmHSDAe8yiESLTJb1KdyycXhmS8wKXg21Ku7l4ta8OnghvkDVmZD6IVWK59EpgooBdLrf/aBQAWNOewC77UtCikKKbofXp/sDv+pv7I+fENTA00wD43nEUYgMVcy3DMsbcUaJ4V1PpbQExSK1C+TJFlnmoRxAy4mk6ap8GdpXsMOAHGVZQdgOXrYfQ7mQUMLXR8+Mw4b/VzOpTenrMBEbKjKlm1pgwDYAhvFCBxYtLjtzqbbL+CmGLqRHdKKpFutKAEfpkTZUNVBQ/4qmXf1FmrAfvOm2IYWLajcCu3EWigLTG1hPDItSvcN9r6z44zXM3WJ0hYoQlXJRak4UluxGv1STJ9Y7VCN4z/r0X7Om7tZ7kDj0+IFjDlW7cNkhLjHsgp11QA+A8J6sNCkWMnf4lK+NVKWvnT879gcezpBXj5+F6OILZ8wnZ21QfFbM6jnYqnRLGbFRJkwO/1XsRr4Ff7Z2vGnj617wNZjXL1M2eGab+6moA3coeSmEB/H0fGrz6F/p5ykHIem4RLhgIN6iLupV2jL3LcQKWQ3vtkD8xkr0ZZ77ogzZ+ZSrvoqZ9lcKOSmrY0BDg6KedeappIqUF0WYB2ndOW9Bboz9l7EVVZgbI7d0fqIk/3cOJacVXdhH8jMWr0iFwu9qsGYo14f9H3FkGoTUezKNW8uI3BnFcogDi+V6rIcHQRwnWmRKfoVf27X/+l4TIqB4XAZY/NatJnApVix1F4bLaimxXpiOT6U4THO6o+EkWWfmLSQk7fa1xMPEa1PByZs+RPnodcuW7DhFavJB6/7xTn8TW2d+EocRDN3fSL6cCKrT26TUGuiiWuvecfxqiThH6Wy+kBxmMPBnHJtV/sy4JYM+IcF0ib2CDP8Aq7Vth/wIlWJ+SVHuy5+94ahAzbDnfT7FsxUqGuzV8vR X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Jan 14, 2026, at 19:32, Qi Zheng wrote: > > From: Qi Zheng > > In the near future, a folio will no longer pin its corresponding memory > cgroup. To ensure safety, it will only be appropriate to hold the rcu read > lock or acquire a reference to the memory cgroup returned by > folio_memcg(), thereby preventing it from being released. > > In the current patch, the rcu read lock is employed to safeguard against > the release of the memory cgroup in zswap_compress(). > > Signed-off-by: Qi Zheng > Acked-by: Johannes Weiner > Acked-by: Shakeel Butt Acked-by: Muchun Song