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b=Uo442GsciOK6onkG1AEsLvJdq82PjiY/TBiBo++AW/LvKuUBvogNKTQIAkLXRTJEp /uh310z1gCJDOwPp4LEuI/kBJbsEe1xBWfLWRy8MWvQJcswA1W8g20B8iAcB99NpB5 MjVcUluBaJR+DtHDC1+f2goXJCvmu/qm8Ah6ZfsbIUQ8fS7S/j0I2SPbRpzZ7icrMD 1cs6lighWRCPLvN9QXZ0tT1g7+M1x9LmXHM/BSbpyMj+bt0wAfI3ORJE2mWu9+9l3V DnqsxRmWDy5ArNPDyCZmU5OE7A1PIAdqnTVzM3kJWTxPhsaVULXxyEGRGAAi8RMkpE U2UFx57k5KbXA== Date: Thu, 26 Mar 2026 16:51:44 +0900 From: "Harry Yoo (Oracle)" To: Michal Hocko Cc: Qi Zheng , hannes@cmpxchg.org, hughd@google.com, roman.gushchin@linux.dev, shakeel.butt@linux.dev, muchun.song@linux.dev, david@kernel.org, ljs@kernel.org, ziy@nvidia.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, bhe@redhat.com, usamaarif642@gmail.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Qi Zheng Subject: Re: [PATCH v2 0/4] fix unexpected type conversions and potential overflows Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Rspamd-Server: rspam05 X-Rspamd-Queue-Id: 75702180006 X-Stat-Signature: ft7cih6911ij9tw89kcgwhr19dmokm7c X-Rspam-User: X-HE-Tag: 1774511507-360871 X-HE-Meta: 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 p3tEXAif dwwOAPmiyAMLKp8HTbXAoTQnLSialFDhOxamzo1TnCp525/q8mqBpsMm7Vw/MqQCDXmd0frXm1O7VkT+5H/I7amh8zei+uVq2dR97u3QWEKPlB2j0+3UC+aj1Ca9kRRLVe6HJBmodS3tjFP2x5fliMX7XUqcR0HyOkWp7sX8tY5OBVNvQAaAV7TG0rR8ITjVA1SubqU/8LK2M+UF/Hhatk3YPPWIapGzFwSFCkoJG09ftgbqPPKU0L3UWofxqh9velmotwhsAm4ejKmgBEQm5rOckTW9DTUg8hKYAlPPUDFtOjuI= Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Thu, Mar 26, 2026 at 08:14:36AM +0100, Michal Hocko wrote: > On Wed 25-03-26 22:13:21, Qi Zheng wrote: > > From: Qi Zheng > > > > Hi all, > > > > As Harry Yoo pointed out [1], in scenarios where massive state updates occur > > (e.g., during the reparenting of LRU folios), the values passed to memcg stat > > update functions can accumulate and exceed the upper limit of a 32-bit integer. > > Is this a real problem without reparenting? In other words is this a > follow up for that work or something that we need on its own? This is not a problem (as discussed in [1]) without reparenting. [1] https://lore.kernel.org/linux-mm/138d9363-ab0c-4f5c-bedc-b326f5aaee91@linux.dev -- Cheers, Harry / Hyeonggon