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{ "id": 2226085, "url": "http://patchwork.ozlabs.org/api/covers/2226085/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/cover/20260422081420.4009847-1-songmuchun@bytedance.com/", "project": { "id": 2, "url": "http://patchwork.ozlabs.org/api/projects/2/?format=api", "name": "Linux PPC development", "link_name": "linuxppc-dev", "list_id": "linuxppc-dev.lists.ozlabs.org", "list_email": "linuxppc-dev@lists.ozlabs.org", "web_url": "https://github.com/linuxppc/wiki/wiki", "scm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git", "webscm_url": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/", "list_archive_url_format": "https://lore.kernel.org/linuxppc-dev/{}/", "commit_url_format": "https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/commit/?id={}" }, "msgid": "<20260422081420.4009847-1-songmuchun@bytedance.com>", "list_archive_url": "https://lore.kernel.org/linuxppc-dev/20260422081420.4009847-1-songmuchun@bytedance.com/", "date": "2026-04-22T08:14:15", "name": "[v4,0/5] mm: Fix vmemmap optimization accounting and initialization", "submitter": { "id": 78930, "url": "http://patchwork.ozlabs.org/api/people/78930/?format=api", "name": "Muchun Song", "email": "songmuchun@bytedance.com" }, "mbox": "http://patchwork.ozlabs.org/project/linuxppc-dev/cover/20260422081420.4009847-1-songmuchun@bytedance.com/mbox/", "series": [ { "id": 500940, "url": "http://patchwork.ozlabs.org/api/series/500940/?format=api", "web_url": "http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=500940", "date": "2026-04-22T08:14:15", "name": "mm: Fix vmemmap optimization accounting and initialization", "version": 4, "mbox": "http://patchwork.ozlabs.org/series/500940/mbox/" } ], "comments": "http://patchwork.ozlabs.org/api/covers/2226085/comments/", "headers": { "Return-Path": "\n <linuxppc-dev+bounces-19936-incoming=patchwork.ozlabs.org@lists.ozlabs.org>", "X-Original-To": [ "incoming@patchwork.ozlabs.org", "linuxppc-dev@lists.ozlabs.org" ], "Delivered-To": "patchwork-incoming@legolas.ozlabs.org", "Authentication-Results": [ "legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=bytedance.com header.i=@bytedance.com\n header.a=rsa-sha256 header.s=google header.b=KHjuJtM5;\n\tdkim-atps=neutral", "legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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Howlett\" <Liam.Howlett@oracle.com>,\n\tVlastimil Babka <vbabka@kernel.org>,\n\tMike Rapoport <rppt@kernel.org>,\n\tSuren Baghdasaryan <surenb@google.com>,\n\tMichal Hocko <mhocko@suse.com>,\n\tNicholas Piggin <npiggin@gmail.com>,\n\tChristophe Leroy <chleroy@kernel.org>,\n\taneesh.kumar@linux.ibm.com,\n\tjoao.m.martins@oracle.com,\n\tlinux-mm@kvack.org,\n\tlinuxppc-dev@lists.ozlabs.org,\n\tlinux-kernel@vger.kernel.org", "Subject": "[PATCH v4 0/5] mm: Fix vmemmap optimization accounting and\n initialization", "Date": "Wed, 22 Apr 2026 16:14:15 +0800", "Message-Id": "<20260422081420.4009847-1-songmuchun@bytedance.com>", "X-Mailer": "git-send-email 2.20.1", "X-Mailing-List": "linuxppc-dev@lists.ozlabs.org", "List-Id": "<linuxppc-dev.lists.ozlabs.org>", "List-Help": "<mailto:linuxppc-dev+help@lists.ozlabs.org>", "List-Owner": "<mailto:linuxppc-dev+owner@lists.ozlabs.org>", "List-Post": "<mailto:linuxppc-dev@lists.ozlabs.org>", "List-Archive": "<https://lore.kernel.org/linuxppc-dev/>,\n <https://lists.ozlabs.org/pipermail/linuxppc-dev/>", "List-Subscribe": "<mailto:linuxppc-dev+subscribe@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-digest@lists.ozlabs.org>,\n <mailto:linuxppc-dev+subscribe-nomail@lists.ozlabs.org>", "List-Unsubscribe": "<mailto:linuxppc-dev+unsubscribe@lists.ozlabs.org>", "Precedence": "list", "MIME-Version": "1.0", "Content-Transfer-Encoding": "8bit", "X-Spam-Status": "No, score=-0.2 required=3.0 tests=DKIM_SIGNED,DKIM_VALID,\n\tDKIM_VALID_AU,DKIM_VALID_EF,RCVD_IN_DNSWL_NONE,SPF_HELO_NONE,SPF_PASS\n\tautolearn=disabled version=4.0.1 OzLabs 8", "X-Spam-Checker-Version": "SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org" }, "content": "The series fixes several bugs in vmemmap optimization, mainly around\nincorrect page accounting and memmap initialization in DAX and memory\nhotplug paths. It also fixes pageblock migratetype initialization and\nstruct page initialization for ZONE_DEVICE compound pages.\n\nThe first three patches fix vmemmap accounting issues. The first patch\nfixes an accounting underflow in the section activation failure path.\nThe second patch passes pgmap through memory deactivation paths so the\nteardown side can determine whether vmemmap optimization was in effect.\nThe third patch uses that information to account the optimized DAX\nvmemmap size correctly.\n\nThe last two patches fix initialization issues in mm/mm_init. One makes\nsure all pageblocks in ZONE_DEVICE compound pages get their migratetype\ninitialized. The other fixes a case where DAX memory hotplug reuses an\nunoptimized early-section memmap while compound_nr_pages() still assumes\nvmemmap optimization, leaving tail struct pages uninitialized.\n\nv3 -> v4:\n- Collect Acked-by and Reviewed-by tags from Oscar Salvador.\n- Fix the build issue reported by Sashiko.\n- Add a fix for uninitialized struct pages for ZONE_DEVICE, based on\n analysis from Sashiko and verified locally.\n\nMuchun Song (5):\n mm/sparse-vmemmap: Fix vmemmap accounting underflow\n mm/sparse-vmemmap: Pass @pgmap argument to memory deactivation paths\n mm/sparse-vmemmap: Fix DAX vmemmap accounting with optimization\n mm/mm_init: Fix pageblock migratetype for ZONE_DEVICE compound pages\n mm/mm_init: Fix uninitialized struct pages for ZONE_DEVICE\n\n arch/arm64/mm/mmu.c | 5 +--\n arch/loongarch/mm/init.c | 5 +--\n arch/powerpc/mm/mem.c | 5 +--\n arch/riscv/mm/init.c | 5 +--\n arch/s390/mm/init.c | 5 +--\n arch/x86/mm/init_64.c | 5 +--\n include/linux/memory_hotplug.h | 8 +++--\n mm/memory_hotplug.c | 13 ++++----\n mm/memremap.c | 4 +--\n mm/mm_init.c | 58 +++++++++++++++++++++++-----------\n mm/sparse-vmemmap.c | 56 ++++++++++++++++++++++++--------\n 11 files changed, 114 insertions(+), 55 deletions(-)" }