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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 Subject: Re: [PATCH v2 00/69] mm: Generalize HVO for HugeTLB and device DAX Message-ID: References: <20260513130542.35604-1-songmuchun@bytedance.com> <20260513104640.b0f02b844c57f92bc954878e@linux-foundation.org> X-Mailing-List: linuxppc-dev@lists.ozlabs.org List-Id: List-Help: List-Owner: List-Post: List-Archive: , List-Subscribe: , , List-Unsubscribe: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20260513104640.b0f02b844c57f92bc954878e@linux-foundation.org> X-Spamd-Result: default: False [-8.30 / 50.00]; REPLY(-4.00)[]; BAYES_HAM(-3.00)[100.00%]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; FUZZY_RATELIMITED(0.00)[rspamd.com]; RCVD_VIA_SMTP_AUTH(0.00)[]; FREEMAIL_ENVRCPT(0.00)[gmail.com]; MISSING_XM_UA(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCVD_TLS_ALL(0.00)[]; DKIM_SIGNED(0.00)[suse.de:s=susede2_rsa,suse.de:s=susede2_ed25519]; RCVD_COUNT_TWO(0.00)[2]; FREEMAIL_CC(0.00)[bytedance.com,kernel.org,linux.dev,ellerman.id.au,linux.ibm.com,oracle.com,google.com,suse.com,gmail.com,kvack.org,lists.ozlabs.org,vger.kernel.org]; RCPT_COUNT_TWELVE(0.00)[21]; FROM_HAS_DN(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_SOME(0.00)[] On Wed, May 13, 2026 at 10:46:40AM -0700, Andrew Morton wrote: > On Wed, 13 May 2026 21:04:28 +0800 Muchun Song wrote: > > > 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. > > > > 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. > > > > This series generalizes that optimization into a common framework used > > by both HugeTLB and device DAX. > > > > 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. > > > > 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. > > > > ... > > > > 46 files changed, 743 insertions(+), 1812 deletions(-) > > Gulp. > > I think the first 15ish patches (little fixes and cleanups and > refactorings) are ready to go in immediately? I plan to have a (partial ) look at this tomorrow/Friday, but splitting this series in fixes-that-can-go-straight-away and the feature itself would make more sense and help ease the review. Head tends to spin a bit when the patchset grows beyond certain number of patches :-D. Would that be possible Munchun? -- Oscar Salvador SUSE Labs