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From: Muchun Song In-Reply-To: <20260513104640.b0f02b844c57f92bc954878e@linux-foundation.org> Date: Thu, 14 May 2026 10:34:56 +0800 Cc: Muchun Song , David Hildenbrand , Oscar Salvador , Michael Ellerman , Madhavan Srinivasan , Lorenzo Stoakes , "Liam R . Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Nicholas Piggin , Christophe Leroy , Ackerley Tng , Frank van der Linden , aneesh.kumar@linux.ibm.com, joao.m.martins@oracle.com, linux-mm@kvack.org, linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org Content-Transfer-Encoding: quoted-printable Message-Id: <72F6690C-D94B-4398-87C7-4611A96C50AC@linux.dev> References: <20260513130542.35604-1-songmuchun@bytedance.com> <20260513104640.b0f02b844c57f92bc954878e@linux-foundation.org> To: Andrew Morton X-Migadu-Flow: FLOW_OUT > On May 14, 2026, at 01:46, Andrew Morton = wrote: >=20 > On Wed, 13 May 2026 21:04:28 +0800 Muchun Song = wrote: >=20 >> In this series, HVO is redefined as Hugepage Vmemmap Optimization: a >> general vmemmap optimization model for large hugepage-backed = mappings, >> rather than a HugeTLB-only implementation detail. >>=20 >> The existing code grew around the original HugeTLB-specific HVO path, >> while device DAX developed similar but separate vmemmap optimization >> handling. As a result, the current implementation carries duplicated >> logic, boot-time special cases, and subsystem-specific interfaces = around >> what is fundamentally the same sparse-vmemmap optimization. >>=20 >> This series generalizes that optimization into a common framework = used >> by both HugeTLB and device DAX. >>=20 >> The first few patches include some minor bug fixes found during = AI-aided >> review of the current code. These fixes are not the main goal of the >> series, but the later refactoring and unification work depends on = them, >> so they are included here as preparatory changes. >>=20 >> The series then reworks the relevant early boot and sparse >> initialization paths, introduces a generic section-based = sparse-vmemmap >> optimization infrastructure, switches HugeTLB and device DAX over to = the >> shared implementation, and removes the old special-case code. >>=20 >> ... >>=20 >> 46 files changed, 743 insertions(+), 1812 deletions(-) >=20 > Gulp. Sorry for a so big series to refactor lots of things. >=20 > I think the first 15ish patches (little fixes and cleanups and > refactorings) are ready to go in immediately? Overall, I believe the first 12 patches (excluding the bugfixes) have already been reviewed by Mike and are theoretically ready to be merged. >=20 > Perhaps you could prepare such things as a separate series. Or tell = me > which ones are suitable and I'll fudge up a [0/N]? I'd prefer to group the first 19 patches into a single series (titled "Refactor bootmem gigantic hugepage allocation"). Therefore, I suggest waiting for feedback from other maintainers/reviewers; once patches 13-19 pass review, I will send them out as a standalone series. Muchun, Thanks.