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b=n7SeFapVpA0FVa0rBcWMRcqmtGXhKF4SUKqa6WYkxg3xN0Hzhk+bD4Sky5jqyzz8i XrqwGPUGg1xCPw7eLbUS5wdpQeBTknZ8sef8am4JZu5wQad/bJvSThYaWvVQWHBHZn onA9ZqZCPSsmKqrx5TWnRVy7wi9D6Ji2AbfoUcYM= Date: Wed, 4 Feb 2026 19:13:09 -0800 From: Andrew Morton To: Wei Yang Cc: david@kernel.org, lorenzo.stoakes@oracle.com, riel@surriel.com, Liam.Howlett@oracle.com, vbabka@suse.cz, harry.yoo@oracle.com, jannh@google.com, ziy@nvidia.com, gavinguo@igalia.com, baolin.wang@linux.alibaba.com, linux-mm@kvack.org, Lance Yang , stable@vger.kernel.org Subject: Re: [Patch v2] mm/huge_memory: fix early failure try_to_migrate() when split huge pmd for shared thp Message-Id: <20260204191309.5c61a11ddfbb71f6a1672c12@linux-foundation.org> In-Reply-To: <20260205030421.zz72iie5bwvgxlsj@master> References: <20260204004219.6524-1-richard.weiyang@gmail.com> <20260204114217.6da3e05ee5fbfac3a5f4c16a@linux-foundation.org> <20260205030421.zz72iie5bwvgxlsj@master> X-Mailer: Sylpheed 3.8.0beta1 (GTK+ 2.24.33; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-Stat-Signature: r431eprzzim135wum9rztf4xojb6u56s X-Rspamd-Queue-Id: 3EB0C2000A X-Rspam-User: X-Rspamd-Server: rspam04 X-HE-Tag: 1770261192-414851 X-HE-Meta: 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 emCeXtgR CSJiUB15kYIk33Hp8a4EFGjjuqKfZKsPgDm00b4XLjI/9Qa3442eA2R0FYv7i5j8TkI9MY4+nWeA83sY= 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 Thu, 5 Feb 2026 03:04:21 +0000 Wei Yang wrote: > >> Cc: Gavin Guo > >> Cc: "David Hildenbrand (Red Hat)" > >> Cc: Zi Yan > >> Cc: Baolin Wang > >> Cc: Lance Yang > >> Cc: > > > >Why cc:stable? In other words, what is the userspace-visible runtime > >effect of this bug? > > On memory pressure or failure, we would try to split folio to reclaim or limit > bad memory. If failed to split it, we will leave some memory unusable. > > I would put this in change log, if it looks good to you. > > As David mentioned some change in comment and change log, do you prefer a v3? v3 would be good please. If the patch(set) was large and had been under test for significant time then I think a delta is preferable. But that isn't the case here.