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From: Muchun Song In-Reply-To: <9624988a-366e-4884-9408-3f3b88c27290@kernel.org> Date: Tue, 7 Jul 2026 16:09:35 +0800 Cc: Sourav Panda , osalvador@suse.de, akpm@linux-foundation.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, mst@redhat.com, mhklinux@outlook.com, fvdl@google.com, gthelen@google.com, mike.kravetz@oracle.com, pasha.tatashin@soleen.com, rientjes@google.com, riel@surriel.com, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-doc@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <48E0B0E2-4CE2-40B5-A7C3-9DEEF9F49C41@linux.dev> References: <20260707064235.1386552-1-souravpanda@google.com> <9624988a-366e-4884-9408-3f3b88c27290@kernel.org> To: "David Hildenbrand (Arm)" X-Migadu-Flow: FLOW_OUT X-Rspamd-Server: rspam06 X-Rspamd-Queue-Id: B1334120006 X-Stat-Signature: qd1feconpp56gb1a56s37g5mbmiuq9xe X-Rspam-User: X-HE-Tag: 1783411819-513040 X-HE-Meta: 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 wY4abvJc vfpMKahfZ5UMVUYjJyaetzKUh2kMhH4eB7v5AyrdMQl7ItnBqXAAcTv4sYIhDkKNEfo8pHAhck2e1tE6b0W2nExJqguVhxGBw1JLLunmyJSVA6Q2APShGlGapKlVcxfBhvpclVplfbdM1pHsTD1WAB6mMybJQETpyQctd7EMztWmXtQN7x/gi7MxAaV9/R40GdSg5P5MJfVL+SqeCHSXit5/YdZF3UFDmBWET2kjijTMLHIeKr+7TkRqfmnuK09Oh9L+V Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: > On Jul 7, 2026, at 15:29, David Hildenbrand (Arm) = wrote: >=20 > On 7/7/26 08:42, Sourav Panda wrote: >> Overview >> This patch series introduces a dynamic, NUMA-aware HugePage Cache, >> backed by a kernel shrinker to safely return memory under pressure, = and >> integrates it with Free Page Reporting (virtio-balloon) for HugeTLB, >> specifically targeting gigantic (1GB) hugepages. The goal is to solve >> the tradeoff between allocation latency and memory >> fungibility in virtualized and heterogeneous cloud environments. >=20 > Hi, >=20 > in general, we consider hugetlb nowadays to be mostly in feature = freeze, as we > realized a while ago that adding more special casing on top of = something too > special for all of MM is only going to hurt us more in the long run. >=20 > We want to have less special casing and less special sauce, not more. >=20 > Now, there is nothing wrong in making hugetlb be less special, by = making it use > more of core infrastructure etc. +1 HugeTLB is already complex today, and the last thing we want is to = compound this complexity by piling more features on top of it. I fully share your = view that we should avoid going down this direction. Thanks, Muchun >=20 > But optimizing for surplus hugetlb pages by teaching hugetlb about new = caches > and its custom free-page-reporting support rather looks like the wrong = direction > for me? >=20 > --=20 > Cheers, >=20 > David