kernel/git/next/linux-next.git/mm/debug_vm_pgtable.c, branch master

mm: decouple protnone helpers from CONFIG_NUMA_BALANCING

2026-07-10T03:15:39+00:00

Patch series "userfaultfd: working set tracking for VM guest memory", v10. This series adds userfaultfd support for tracking the working set of VM guest memory, so a VMM can identify hot pages and reclaim cold ones to tiered or remote storage. This patch (of 15): pte_protnone() and pmd_protnone() detect present-but-inaccessible page table entries. This capability is useful beyond NUMA balancing -- for example, userfaultfd working set tracking uses protnone PTEs to track page access without unmapping pages. Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE infrastructure from CONFIG_NUMA_BALANCING. The six architectures that support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now select this option, and CONFIG_NUMA_BALANCING depends on it. No functional change -- the same set of architectures continues to have working protnone support, but the infrastructure is now available independently of NUMA balancing. Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) Assisted-by: Claude:claude-opus-4-6 Acked-by: SeongJae Park Acked-by: Mike Rapoport (Microsoft) Cc: Andrea Arcangeli Cc: David Hildenbrand Cc: James Houghton Cc: Jonathan Corbet Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Paolo Bonzini Cc: Peter Xu Cc: Sean Christopherson Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zi Yan Signed-off-by: Andrew Morton

mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES

2026-07-10T03:14:58+00:00

CONFIG_ARCH_ENABLE_THP_MIGRATION gates PMD-level migration entries. PMD-level device-private entries use the same migration mechanism and therefore require the same architecture support. Upcoming PMD-level swap entries can use the same PMD softleaf helpers without depending on page migration, so rename the architecture gate to CONFIG_ARCH_HAS_PMD_SOFTLEAVES. This describes the PMD entry capability rather than one current user of it. This is a pure rename: the set of selecting architectures (x86, arm64, s390, riscv, loongarch, and powerpc on PPC_BOOK3S_64) and the gating semantics are unchanged. No functional change intended. Link: https://lore.kernel.org/20260706114320.1643046-7-usama.arif@linux.dev Signed-off-by: Usama Arif Reviewed-by: Zi Yan Acked-by: David Hildenbrand (Arm) Cc: Alexandre Ghiti Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: Dev Jain Cc: "Huang, Ying" Cc: Johannes Weiner Cc: Kairui Song Cc: Kemeng Shi Cc: Kiryl Shutsemau Cc: Lance Yang Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Nhat Pham Cc: Nico Pache Cc: Rik van Riel Cc: Ryan Roberts Cc: Shakeel Butt Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm: add softleaf_to_pmd() and convert existing callers

2026-07-10T03:14:56+00:00

Patch series "mm: preparatory patches for PMD level swap entries", v2. This is the preparatory part of the PMD page table swapin work. The full PMD swap entry series has been split into two parts: 1. this preparatory series, which contains the first 6 patches. Zi [1] and Lance [2] suggested to separate this out from the core series. 2. the PMD swap entry core series, which depends on this one. I will send this once the preparatory series is merged in mm-new as v3 as the combined is currently at v2 [1]. I have not marked this prep series as v3, as its not really adding support for PMD swap entries. This series does not introduce PMD swap entries and does not install any new page-table entry type. It only cleans up existing PMD softleaf helpers and call sites so the follow-up PMD swap entry series can be smaller and easier to review. It should be safe to merge independently. The patches are either helper additions, refactors of existing open-coded logic, defensive checks that preserve current migration/device-private behavior, or a mechanical rename of the PMD softleaf Kconfig gate. The follow-up series depends on these helpers, but this series does not depend on the follow-up series. Patch breakdown: 1. mm: add softleaf_to_pmd() and convert existing callers Add the PMD counterpart to softleaf_to_pte() and convert existing swp_entry_to_pmd() users that are constructing PMD softleaf entries. 2. mm: extract mm_prepare_for_swap_entries() helper Hoist the "register mm with swapoff" double-checked-locking pattern out of try_to_unmap_one() and copy_nonpresent_pte() so future PMD-level users do not need another open-coded copy. 3. fs/proc: use softleaf_has_pfn() in pagemap PMD walker Avoid assuming every non-present PMD softleaf entry encodes a PFN. Existing migration/device-private behavior is preserved. 4. mm/huge_memory: move softleaf_to_folio() inside migration branch Keep the folio lookup in change_non_present_huge_pmd() scoped to the migration-entry branch that actually needs it. 5. mm/migrate_device: move softleaf_to_folio() inside device-private branch Apply the same ordering cleanup to migrate_vma_collect_pmd(): only derive a folio after confirming the PMD entry is device-private. 6. mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVES Rename the architecture gate to describe what it actually enables: PMD softleaf entries. Migration remains the only current user in this series; the follow-up series adds PMD swap entries. This patch (of 6): Add softleaf_to_pmd() as the PMD counterpart to softleaf_to_pte(), completing the symmetry of the softleaf abstraction for page table leaf entries. The upcoming PMD swap entry support needs to construct PMD entries from swap entries. Converting existing swp_entry_to_pmd() callers to softleaf_to_pmd() in a prep patch keeps the feature patches focused on new functionality rather than mixing refactoring with new code. Link: https://lore.kernel.org/20260706114320.1643046-1-usama.arif@linux.dev Link: https://lore.kernel.org/20260706114320.1643046-2-usama.arif@linux.dev Link: https://lore.kernel.org/all/6E99CC4E-A026-4DE3-8A5A-34216771F521@nvidia.com/ [1] Link: https://lore.kernel.org/all/b08cafbb-a4b7-4609-84ae-dbb2cfcfc8be@linux.dev/#t [2] Link: https://lore.kernel.org/all/20260602142537.198755-1-usama.arif@linux.dev/ [3] Signed-off-by: Usama Arif Acked-by: David Hildenbrand (Arm) Reviewed-by: Zi Yan Reviewed-by: Lance Yang Cc: Alexandre Ghiti Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: Dev Jain Cc: "Huang, Ying" Cc: Johannes Weiner Cc: Kairui Song Cc: Kemeng Shi Cc: Kiryl Shutsemau Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Matthew Wilcox (Oracle) Cc: Nhat Pham Cc: Nico Pache Cc: Rik van Riel Cc: Ryan Roberts Cc: Shakeel Butt Cc: Vlastimil Babka Signed-off-by: Andrew Morton

mm/debug_vm_pgtable: replace WRITE_ONCE() with pxd_clear()

2026-04-05T20:53:11+00:00

Replace WRITE_ONCE() with generic pxd_clear() to clear out the page table entries as required. Besides this does not cause any functional change as well. Link: https://lkml.kernel.org/r/20260227061204.2215395-1-anshuman.khandual@arm.com Signed-off-by: Anshuman Khandual Suggested-by: Ryan Roberts Acked-by: David Hildenbrand (Arm) Ackeed-by: SeongJae Park Cc: Ryan Roberts Signed-off-by: Andrew Morton

mm: debug_vm_pgtable: add debug_vm_pgtable_free_huge_page()

2026-01-27T04:02:27+00:00

Patch series "mm: hugetlb: allocate frozen gigantic folio", v6. Introduce alloc_contig_frozen_pages() and cma_alloc_frozen_compound() which avoid atomic operation about page refcount, and then convert to allocate frozen gigantic folio by the new helpers in hugetlb to cleanup the alloc_gigantic_folio(). This patch (of 6): Add a new helper to free huge page to be consistency to debug_vm_pgtable_alloc_huge_page(), and use HPAGE_PUD_ORDER instead of open-code. Also move the free_contig_range() under CONFIG_ALLOC_CONTIG since all caller are built with CONFIG_ALLOC_CONTIG. Link: https://lkml.kernel.org/r/20260109093136.1491549-2-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang Acked-by: David Hildenbrand Reviewed-by: Zi Yan Reviewed-by: Muchun Song Reviewed-by: Sidhartha Kumar Cc: Brendan Jackman Cc: Jane Chu Cc: Johannes Weiner Cc: Matthew Wilcox (Oracle) Cc: Oscar Salvador Cc: Vlastimil Babka Cc: Claudiu Beznea Cc: Mark Brown Signed-off-by: Andrew Morton

mm: softdirty: add pgtable_supports_soft_dirty()

2025-11-24T23:08:54+00:00

Patch series "mm: Add soft-dirty and uffd-wp support for RISC-V", v15. This patchset adds support for Svrsw60t59b [1] extension which is ratified now, also add soft dirty and userfaultfd write protect tracking for RISC-V. The patches 1 and 2 add macros to allow architectures to define their own checks if the soft-dirty / uffd_wp PTE bits are available, in other words for RISC-V, the Svrsw60t59b extension is supported on which device the kernel is running. Also patch1-2 are removing "ifdef CONFIG_MEM_SOFT_DIRTY" "ifdef CONFIG_HAVE_ARCH_USERFAULTFD_WP" and "ifdef CONFIG_PTE_MARKER_UFFD_WP" in favor of checks which if not overridden by the architecture, no change in behavior is expected. This patchset has been tested with kselftest mm suite in which soft-dirty, madv_populate, test_unmerge_uffd_wp, and uffd-unit-tests run and pass, and no regressions are observed in any of the other tests. This patch (of 6): Some platforms can customize the PTE PMD entry soft-dirty bit making it unavailable even if the architecture provides the resource. Add an API which architectures can define their specific implementations to detect if soft-dirty bit is available on which device the kernel is running. This patch is removing "ifdef CONFIG_MEM_SOFT_DIRTY" in favor of pgtable_supports_soft_dirty() checks that defaults to IS_ENABLED(CONFIG_MEM_SOFT_DIRTY), if not overridden by the architecture, no change in behavior is expected. We make sure to never set VM_SOFTDIRTY if !pgtable_supports_soft_dirty(), so we will never run into VM_SOFTDIRTY checks. [lorenzo.stoakes@oracle.com: fix VMA selftests] Link: https://lkml.kernel.org/r/dac6ddfe-773a-43d5-8f69-021b9ca4d24b@lucifer.local Link: https://lkml.kernel.org/r/20251113072806.795029-1-zhangchunyan@iscas.ac.cn Link: https://lkml.kernel.org/r/20251113072806.795029-2-zhangchunyan@iscas.ac.cn Link: https://github.com/riscv-non-isa/riscv-iommu/pull/543 [1] Signed-off-by: Chunyan Zhang Acked-by: David Hildenbrand Cc: Albert Ou Cc: Alexandre Ghiti Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Christian Brauner Cc: Conor Dooley Cc: Deepak Gupta Cc: Jan Kara Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Palmer Dabbelt Cc: Paul Walmsley Cc: Peter Xu Cc: Rob Herring Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Yuanchu Xie Cc: Alexandre Ghiti Cc: Andrew Jones Cc: Conor Dooley Signed-off-by: Andrew Morton

mm: replace remaining pte_to_swp_entry() with softleaf_from_pte()

2025-11-24T23:08:52+00:00

There are straggler invocations of pte_to_swp_entry() lying around, replace all of these with the software leaf entry equivalent - softleaf_from_pte(). With those removed, eliminate pte_to_swp_entry() altogether. No functional change intended. Link: https://lkml.kernel.org/r/d8ee5ccefe4c42d7c4fe1a2e46f285ac40421cd3.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Cc: Alexander Gordeev Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Christian Borntraeger Cc: Christian Brauner Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Dev Jain Cc: Gerald Schaefer Cc: Gregory Price Cc: Heiko Carstens Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jason Gunthorpe Cc: Joshua Hahn Cc: Kairui Song Cc: Kemeng Shi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Nhat Pham Cc: Nico Pache Cc: Oscar Salvador Cc: Pasha Tatashin Cc: Peter Xu Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Wei Xu Cc: xu xin Cc: Yuanchu Xie Cc: Zi Yan Signed-off-by: Andrew Morton

mm: eliminate further swapops predicates

2025-11-24T23:08:52+00:00

Having converted so much of the code base to software leaf entries, we can mop up some remaining cases. We replace is_pfn_swap_entry(), pfn_swap_entry_to_page(), is_writable_device_private_entry(), is_device_exclusive_entry(), is_migration_entry(), is_writable_migration_entry(), is_readable_migration_entry(), swp_offset_pfn() and pfn_swap_entry_folio() with softleaf equivalents. No functional change intended. Link: https://lkml.kernel.org/r/956bc9c031604811c0070d2f4bf2f1373f230213.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Cc: Alexander Gordeev Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Christian Borntraeger Cc: Christian Brauner Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Dev Jain Cc: Gerald Schaefer Cc: Gregory Price Cc: Heiko Carstens Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jason Gunthorpe Cc: Joshua Hahn Cc: Kairui Song Cc: Kemeng Shi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Nhat Pham Cc: Nico Pache Cc: Oscar Salvador Cc: Pasha Tatashin Cc: Peter Xu Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Wei Xu Cc: xu xin Cc: Yuanchu Xie Cc: Zi Yan Signed-off-by: Andrew Morton

mm: remove remaining is_swap_pmd() users and is_swap_pmd()

2025-11-24T23:08:51+00:00

Update copy_huge_pmd() and change_huge_pmd() to use pmd_is_valid_softleaf() - as this checks for the only valid non-present huge PMD states. Also update mm/debug_vm_pgtable.c to explicitly test for a valid leaf PMD entry (which it was not before, which was incorrect), and have it test against pmd_is_huge() and pmd_is_valid_softleaf() rather than is_swap_pmd(). With these changes done there are no further users of is_swap_pmd(), so remove it. Link: https://lkml.kernel.org/r/1628b00b00c8498bbd2c20b82117ee87845fb738.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Cc: Alexander Gordeev Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Christian Borntraeger Cc: Christian Brauner Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Dev Jain Cc: Gerald Schaefer Cc: Gregory Price Cc: Heiko Carstens Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jason Gunthorpe Cc: Joshua Hahn Cc: Kairui Song Cc: Kemeng Shi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Nhat Pham Cc: Nico Pache Cc: Oscar Salvador Cc: Pasha Tatashin Cc: Peter Xu Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Vlastimil Babka Cc: Wei Xu Cc: xu xin Cc: Yuanchu Xie Cc: Zi Yan Signed-off-by: Andrew Morton

mm: use leaf entries in debug pgtable + remove is_swap_pte()

2025-11-24T23:08:50+00:00

Remove invocations of is_swap_pte() in mm/debug_vm_pgtable.c and use softleaf_from_pte() and softleaf_is_swap() as necessary to replace this usage. We update the test code to use a 'true' swap entry throughout so we are guaranteed this is not a non-swap entry, so all asserts continue to operate correctly. With this change in place, we no longer use is_swap_pte() anywhere, so remove it. Link: https://lkml.kernel.org/r/222f352e7a99191b4bdfa77e835f2fc0dd83fa72.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes Reviewed-by: Vlastimil Babka Cc: Alexander Gordeev Cc: Alistair Popple Cc: Al Viro Cc: Arnd Bergmann Cc: Axel Rasmussen Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Byungchul Park Cc: Chengming Zhou Cc: Chris Li Cc: Christian Borntraeger Cc: Christian Brauner Cc: Claudio Imbrenda Cc: David Hildenbrand Cc: Dev Jain Cc: Gerald Schaefer Cc: Gregory Price Cc: Heiko Carstens Cc: "Huang, Ying" Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Janosch Frank Cc: Jason Gunthorpe Cc: Joshua Hahn Cc: Kairui Song Cc: Kemeng Shi Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Mathew Brost Cc: Matthew Wilcox (Oracle) Cc: Miaohe Lin Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Naoya Horiguchi Cc: Nhat Pham Cc: Nico Pache Cc: Oscar Salvador Cc: Pasha Tatashin Cc: Peter Xu Cc: Rakie Kim Cc: Rik van Riel Cc: Ryan Roberts Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: Wei Xu Cc: xu xin Cc: Yuanchu Xie Cc: Zi Yan Signed-off-by: Andrew Morton