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2026-08-24mm/migrate: calculate large folio page index using PFNLorenzo Stoakes (ARM)
Rather than having to figure out the page index to use using linear_page_index(), calculate it using PFN. This is a more natural fit as the linear page index is immaterial to determining the folio page index. Derive the page index from the offset between migration entry PFN and folio PFN - pvmw.pfn (set via DEFINE_FOLIO_VMA_WALK() which uses folio_pfn() to obtain it). Additionally remove a not so useful comment and clean the code layout up. No functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-13-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Suggested-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-24mm/huge_memory: update remove_migration_pmd() to accept a folioLorenzo Stoakes (ARM)
This function does not need to accept a page and requiring it to is unnecessary and misleading. make_[writable, readable]_device_private_entry() must be passed a PMD-aligned PFN as they immediately used to obtain a softleaf PMD entry and the same argument applies to folio_add_[anon, file]_rmap_pmd(). While we are here, update a VM_BUG_ON() to a VM_WARN_ON_ONCE(). No functional change intended. Link: https://lore.kernel.org/20260813-b4-scalable-cow-virt-pgoff-v5-12-c21581c0c3c8@kernel.org Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Adrian Hunter <adrian.hunter@intel.com> Cc: Alexander Deucher <alexander.deucher@amd.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Boris Brezillon <boris.brezillon@collabora.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christan König <christian.koenig@amd.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Dave Airlie <airlied@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price (Meta) <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Huang Ray <Ray.Huang@amd.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ian Rogers <irogers@google.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: James Clark <james.clark@linaro.org> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jiri Olsa <jolsa@kernel.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kees Cook <kees@kernel.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Liviu Dudau <liviu.dudau@arm.com> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com> Cc: Marc Rutland <mark.rutland@arm.com> Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org> Cc: Matthew Auld <matthew.auld@intel.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Maxime Ripard <mripard@kernel.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Namhyung kim <namhyung@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Rodrigo Vivi <rodrigo.vivi@intel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Steven Price <steven.price@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: Thomas Zimemrmann <tzimmermann@suse.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()Breno Leitao
migrate_pages_batch() unmaps each folio before moving it, and every unmap runs the mmu_notifier invalidate callbacks. On KVM hosts try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() -> tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps the CPU busy for a long time. The loop already calls cond_resched(), but on PREEMPTION kernels that is a no-op, and involuntary preemption is not a Tasks-RCU quiescent state. A long batch therefore never reports a quiescent state, and the migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the Tasks-RCU grace period for minutes, which is common at Meta fleet: INFO: rcu_tasks detected stalls on tasks: 0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task Call Trace: tdp_mmu_zap_leafs tdp_mmu_next_root gfn_to_pfn_cache_invalidate_start kvm_mmu_notifier_invalidate_range_start __mmu_notifier_invalidate_range_start try_to_migrate_one try_to_migrate migrate_pages_batch migrate_pages compact_zone compact_node kcompactd kthread Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even when cond_resched() does nothing. This has also been discussed at [1] Link: https://lore.kernel.org/20260727-kcompact-v1-1-bdfefddd6874@debian.org Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04mm: preserve RWP marker across PTE rewritesKiryl Shutsemau (Meta)
The uffd PTE bit must survive any kernel path that rewrites a PTE on a VM_UFFD_RWP VMA, otherwise the marker that carries PAGE_NONE semantics is silently dropped and the next access leaks past RWP tracking. Wire the preservation through every path that rewrites a VM_UFFD_RWP PTE. Swap and device-exclusive: do_swap_page(), restore_exclusive_pte(), and unuse_pte() (swapoff()) re-apply PAGE_NONE when the swap PTE carries the uffd bit and the VMA has VM_UFFD_RWP. Migration: remove_migration_pte() and remove_migration_pmd() do the same after the migration entry is replaced with a real PTE/PMD. Fork: __copy_present_ptes(), copy_present_page(), copy_nonpresent_pte(), copy_huge_pmd(), copy_huge_non_present_pmd(), and copy_hugetlb_page_range() keep the uffd bit on the child when the destination VMA has VM_UFFD_RWP, matching the existing VM_UFFD_WP handling. Add VM_UFFD_RWP to VM_COPY_ON_FORK so the flag itself propagates. mprotect(): change_pte_range() and change_huge_pmd() restore PAGE_NONE after pte_modify()/pmd_modify() have recomputed the base protection from a (possibly user-changed) vm_page_prot. pte_modify() preserves _PAGE_UFFD, so the bit stays; we just have to force PAGE_NONE back on top. Link: https://lore.kernel.org/20260708111417.173443-8-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau <kas@kernel.org> Assisted-by: Claude:claude-opus-4-6 Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@kernel.org> Cc: James Houghton <jthoughton@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04mm: rename uffd-wp PTE accessors to uffdKiryl Shutsemau (Meta)
Userfaultfd RWP will reuse the uffd-wp PTE bit to mark access-tracking PTEs, alongside the write-protected ones it already marks. The bit's meaning now depends on the VMA flag (WP or RWP), not on its name. Rename the kernel-internal names that describe the bit: - pte/pmd/huge_pte accessors (and swap variants) - pgtable_supports_uffd() capability query - SCAN_PTE_UFFD khugepaged enum The ftrace string emitted by mm_khugepaged_scan_pmd for this enum is kept as "pte_uffd_wp" so existing trace-based tooling keeps matching. Pure mechanical rename -- no behavior change. Link: https://lore.kernel.org/20260708111417.173443-4-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau <kas@kernel.org> Assisted-by: Claude:claude-opus-4-6 Reviewed-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: David Hildenbrand <david@kernel.org> Cc: James Houghton <jthoughton@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Peter Xu <peterx@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-04Merge branch 'mm-hotfixes-stable' into mm-stable in order to pick upAndrew Morton
vmscan.c changes which are required by "memcg: bail out proactive reclaim when memcg is dying".
2026-07-30mm/migrate: use huge_ptep_get() in remove_migration_pte()Dev Jain
remove_migration_pte() converts migration entries back to present PTEs after folio migration completes. For hugetlb folios, page_vma_mapped_walk() returns the pte pointer to the hugetlb folio in pvmw.pte, but the code reads it with ptep_get(). On arches which provide their own huge_ptep_get() to dereference a huge pte pointer, accessing via ptep_get() would cause pte_pfn(), pte_present() etc to misbehave. It is not clear whether this has a trivially visible effect to userspace. Use huge_ptep_get() to dereference a huge pte pointer. Link: https://lore.kernel.org/20260703114202.365553-5-dev.jain@arm.com Fixes: 290408d4a250 ("hugetlb: hugepage migration core") Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: Muchun Song <muchun.song@linux.dev> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Andi Kleen <ak@linux.intel.com> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Gregory Price <gourry@gourry.net> Cc: Harry Yoo <harry@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jann Horn <jannh@google.com> Cc: Josh Poimboeuf <jpoimboe@kernel.org> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Jun'ichi "Nick" Nomura <j-nomura@ce.jp.nec.com> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Mel Gorman <mel@csn.ul.ie> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-30mm: split out internal page_alloc.hBrendan Jackman
internal.h is a bit bloated, seems like time for a page_alloc.h. Where it wasn't obvious, the heuristic for deciding what goes into this new header was "does it support/correspond to a definition in mm/page_alloc.c?" Only need to include it from ~20 .c files out of ~150 so this does seem like a genuine reduction in scopes, which is nice. And there's no circular internal.h<->page_alloc.h dependency, so it seems worthwhile to split this up before that inevitably emerges! Link: https://lore.kernel.org/20260703-alloc-trylock-v5-4-c87b714e19d3@google.com Signed-off-by: Brendan Jackman <jackmanb@google.com> Suggested-by: "David Hildenbrand (Arm)" <david@kernel.org> Link: https://lore.kernel.org/all/41e92bab-6882-401a-8de9-154adbdcfb36@kernel.org/ Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-30mm: rename ARCH_ENABLE_THP_MIGRATION to ARCH_HAS_PMD_SOFTLEAVESUsama Arif
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 <usama.arif@linux.dev> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <baoquan.he@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Kiryl Shutsemau <kas@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28mm/migrate: use migrate_info field instead of privateShivank Garg
Add an unsigned long migrate_info member to the struct folio union and use it to store migration state (anon_vma pointer and FOLIO_WAS_* markers) instead of using folio->private. While at it, switch to bitwise OR. No functional change. [rdunlap@infradead.org: add missing kernel-doc for @migrate_info] Link: https://lore.kernel.org/20260717022146.1290242-1-rdunlap@infradead.org Link: https://lore.kernel.org/20260701-migrate-cleanups-prep-v2-3-d9e8f17130b1@amd.com Signed-off-by: Shivank Garg <shivankg@amd.com> Suggested-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Jonathan Cameron <jic23@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: SJ Park <sj@kernel.org> Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28mm/migrate: fix stale list name in migrate_folios_move() commentShivank Garg
The return-value description in migrate_folios_move() still refers to unmap_folios, but that list no longer exists. Update this name to src_folios. Link: https://lore.kernel.org/20260701-migrate-cleanups-prep-v2-2-d9e8f17130b1@amd.com Signed-off-by: Shivank Garg <shivankg@amd.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jonathan Cameron <jic23@kernel.org> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28mm/migrate: rename page to folio leftoversShivank Garg
Patch series "mm/migrate: preparatory cleanups for batch copy and offload", v2. This is a small set of mm/migrate cleanups split out of the batch-copy and offload RFC [1], so they can be reviewed and merged independently ahead of that larger series. No functional change intended. This patch (of 3): Rename migrate_folio_undo_src()'s page_was_mapped parameter to was_mapped, unmap_and_move_huge_page() to unmap_and_move_hugetlb_folio(), its page_was_mapped variable to was_mapped and fix stale "page" wording in its comments. Also fix migrate_folio() kerneldoc to say "folio" instead of "page". Link: https://lore.kernel.org/20260701-migrate-cleanups-prep-v2-0-d9e8f17130b1@amd.com Link: https://lore.kernel.org/20260701-migrate-cleanups-prep-v2-1-d9e8f17130b1@amd.com Link: https://lore.kernel.org/all/20260428155043.39251-2-shivankg@amd.com [1] Signed-off-by: Shivank Garg <shivankg@amd.com> Suggested-by: Dev Jain <dev.jain@arm.com> Suggested-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: SJ Park <sj@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Jonathan Cameron <jic23@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28mm: use enum migrate_reason instead of int for migration reason parametersYe Liu
Replace all 'int reason' function parameters that carry migrate_reason values with the proper 'enum migrate_reason' type. This makes the intent explicit and leverages compiler type checking. The affected subsystems are: - page_owner: __folio_set_owner_migrate_reason(), folio_set_owner_migrate_reason() - migrate: migrate_pages(), migrate_pages_sync(), migrate_pages_batch(), migrate_folios_move(), migrate_hugetlbs(), unmap_and_move_huge_page() - hugetlb: move_hugetlb_state(), htlb_allow_alloc_fallback() - trace: mm_migrate_pages and mm_migrate_pages_start events The 'short last_migrate_reason' struct field and internal helper parameter in page_owner are intentionally left as 'short' since they store per-page metadata where size matters. No functional change. Link: https://lore.kernel.org/20260714015117.78351-4-ye.liu@linux.dev Signed-off-by: Ye Liu <ye.liu@linux.dev> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka (SUSE) <vbabka@kernel.org> Reviewed-by: Lorenzo Stoakes <ljs@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Brendan Jackman <jackmanb@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-07-28mm/migrate: exclude hugetlb folios from MTHP_STAT_NR_ANON accountingNico Pache
__folio_migrate_mapping() increments MTHP_STAT_NR_ANON for the destination folio when `folio_test_anon(folio) && folio_test_large(folio)` is true. However, hugetlb folios satisfy both conditions despite having a completely separate accounting system — they use hugetlb_add_anon_rmap() which does not touch mTHP stats, and their free path also bypasses the mTHP decrement in __free_pages_prepare(). This causes MTHP_STAT_NR_ANON to be incremented on each hugetlb migration without a corresponding decrement, permanently inflating the nr_anon counter. Add a !folio_test_hugetlb() check to __folio_migrate_mapping() so that only actual mTHP folios are counted. Link: https://lore.kernel.org/20260717064502.1980173-3-npache@redhat.com Fixes: 5d65c8d758f2 ("mm: count the number of anonymous THPs per size") Co-developed-by: David Hildenbrand <david@kernel.org> Signed-off-by: David Hildenbrand <david@kernel.org> Signed-off-by: Nico Pache <npache@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-04mm/migrate: find_mm_struct: fix race between security checks and suid execOleg Nesterov
The target task can execute a setuid binary between ptrace_may_access() and get_task_mm(). Protect this critical section with exec_update_lock. I don't think cpuset_mems_allowed(task) should be called under exec_update_lock, but this patch just tries to add the minimal fix. Perhaps we can later add a common helper which can be used by find_mm_struct() and kernel_migrate_pages(). Link: https://lore.kernel.org/ahWxQ3JxdR5ff2qf@redhat.com Signed-off-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Gregory Price <gourry@gourry.net> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: David Hildenbrand <david@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kees Cook <kees@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-06-04mm: remove mentions of PageWritebackMatthew Wilcox (Oracle)
Update two comments to refer to writeback in general instead of the specific flag. Convert the large comment in memory.c to be entirely folio-based. Link: https://lore.kernel.org/20260526195650.353196-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-05-28mm/migrate: rename PAGE_ migration flags to FOLIO_Shivank Garg
These flags only track folio-specific state during migration and are not used for movable_ops pages. Rename the enum values and the old_page_state variable to match. No functional change. Link: https://lore.kernel.org/20260324190706.964555-4-shivankg@amd.com Signed-off-by: Shivank Garg <shivankg@amd.com> Suggested-by: David Hildenbrand <david@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Huang Ying <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Shivank Garg <shivankg@amd.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-18mm: migrate: prevent memory cgroup release in folio_migrate_mapping()Muchun Song
In the near future, a folio will no longer pin its corresponding memory cgroup. To ensure safety, it will only be appropriate to hold the rcu read lock or acquire a reference to the memory cgroup returned by folio_memcg(), thereby preventing it from being released. In __folio_migrate_mapping(), the rcu read lock is employed to safeguard against the release of the memory cgroup in folio_migrate_mapping(). This serves as a preparatory measure for the reparenting of the LRU pages. Link: https://lore.kernel.org/0f156c2f1188f256855617953f8305f43e066065.1772711148.git.zhengqi.arch@bytedance.com Signed-off-by: Muchun Song <songmuchun@bytedance.com> Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Allen Pais <apais@linux.microsoft.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baoquan He <bhe@redhat.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chen Ridong <chenridong@huawei.com> Cc: David Hildenbrand <david@kernel.org> Cc: Hamza Mahfooz <hamzamahfooz@linux.microsoft.com> Cc: Hugh Dickins <hughd@google.com> Cc: Imran Khan <imran.f.khan@oracle.com> Cc: Kamalesh Babulal <kamalesh.babulal@oracle.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Koutný <mkoutny@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yosry Ahmed <yosry@kernel.org> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05mm: fix deferred split queue races during migrationLance Yang
migrate_folio_move() records the deferred split queue state from src and replays it on dst. Replaying it after remove_migration_ptes(src, dst, 0) makes dst visible before it is requeued, so a concurrent rmap-removal path can mark dst partially mapped and trip the WARN in deferred_split_folio(). Move the requeue before remove_migration_ptes() so dst is back on the deferred split queue before it becomes visible again. Because migration still holds dst locked at that point, teach deferred_split_scan() to requeue a folio when folio_trylock() fails. Otherwise a fully mapped underused folio can be dequeued by the shrinker and silently lost from split_queue. [ziy@nvidia.com: move the comment] Link: https://lkml.kernel.org/r/FB71A764-0F10-4E5A-B4A0-BA4C7F138408@nvidia.com Link: https://syzkaller.appspot.com/bug?extid=a7067a757858ac8eb085 Link: https://lkml.kernel.org/r/20260401131032.13011-1-lance.yang@linux.dev Fixes: 8a8ca142a488 ("mm: migrate: requeue destination folio on deferred split queue") Signed-off-by: Lance Yang <lance.yang@linux.dev> Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: syzbot+a7067a757858ac8eb085@syzkaller.appspotmail.com Closes: https://lore.kernel.org/linux-mm/69ccb65b.050a0220.183828.003a.GAE@google.com/ Suggested-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: David Hildenbrand <david@kernel.org> Cc: Deepanshu Kartikey <kartikey406@gmail.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Nico Pache <npache@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Usama Arif <usama.arif@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05mm: introduce CONFIG_NUMA_MIGRATION and simplify CONFIG_MIGRATIONDavid Hildenbrand (Arm)
CONFIG_MEMORY_HOTREMOVE, CONFIG_COMPACTION and CONFIG_CMA all select CONFIG_MIGRATION, because they require it to work (users). Only CONFIG_NUMA_BALANCING and CONFIG_BALLOON_MIGRATION depend on CONFIG_MIGRATION. CONFIG_BALLOON_MIGRATION is not an actual user, but an implementation of migration support, so the dependency is correct (CONFIG_BALLOON_MIGRATION does not make any sense without CONFIG_MIGRATION). However, kconfig-language.rst clearly states "In general use select only for non-visible symbols". So far CONFIG_MIGRATION is user-visible ... and the dependencies rather confusing. The whole reason why CONFIG_MIGRATION is user-visible is because of CONFIG_NUMA: some users might want CONFIG_NUMA but not page migration support. Let's clean all that up by introducing a dedicated CONFIG_NUMA_MIGRATION config option for that purpose only. Make CONFIG_NUMA_BALANCING that so far depended on CONFIG_NUMA && CONFIG_MIGRATION to depend on CONFIG_MIGRATION instead. CONFIG_NUMA_MIGRATION will depend on CONFIG_NUMA && CONFIG_MMU. CONFIG_NUMA_MIGRATION is user-visible and will default to "y". We use that default so new configs will automatically enable it, just like it was the case with CONFIG_MIGRATION. The downside is that some configs that used to have CONFIG_MIGRATION=n might get it re-enabled by CONFIG_NUMA_MIGRATION=y, which shouldn't be a problem. CONFIG_MIGRATION is now a non-visible config option. Any code that select CONFIG_MIGRATION (as before) must depend directly or indirectly on CONFIG_MMU. CONFIG_NUMA_MIGRATION is responsible for any NUMA migration code, which is mempolicy migration code, memory-tiering code, and move_pages() code in migrate.c. CONFIG_NUMA_BALANCING uses its functionality. Note that this implies that with CONFIG_NUMA_MIGRATION=n, move_pages() will not be available even though CONFIG_MIGRATION=y, which is an expected change. In migrate.c, we can remove the CONFIG_NUMA check as both CONFIG_NUMA_MIGRATION and CONFIG_NUMA_BALANCING depend on it. With this change, CONFIG_MIGRATION is an internal config, all users of migration selects CONFIG_MIGRATION, and only CONFIG_BALLOON_MIGRATION depends on it. Link: https://lkml.kernel.org/r/20260319-config_migration-v1-2-42270124966f@kernel.org Signed-off-by: David Hildenbrand (Arm) <david@kernel.org> Reviewed-by: Lorenzo Stoakes (Oracle) <ljs@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com> Cc: Albert Ou <aou@eecs.berkeley.edu> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alexandre Ghiti <alex@ghiti.fr> Cc: Alistair Popple <apopple@nvidia.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Byungchul Park <byungchul@sk.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Steven Rostedt <rostedt@goodmis.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: WANG Xuerui <kernel@xen0n.name> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05mm: migrate: requeue destination folio on deferred split queueUsama Arif
During folio migration, __folio_migrate_mapping() removes the source folio from the deferred split queue, but the destination folio is never re-queued. This causes underutilized THPs to escape the shrinker after NUMA migration, since they silently drop off the deferred split list. Fix this by recording whether the source folio was on the deferred split queue and its partially mapped state before move_to_new_folio() unqueues it, and re-queuing the destination folio after a successful migration if it was. By the time migrate_folio_move() runs, partially mapped folios without a pin have already been split by migrate_pages_batch(). So only two cases remain on the deferred list at this point: 1. Partially mapped folios with a pin (split failed). 2. Fully mapped but potentially underused folios. The recorded partially_mapped state is forwarded to deferred_split_folio() so that the destination folio is correctly re-queued in both cases. Because THPs are removed from the deferred_list, THP shinker cannot split the underutilized THPs in time. As a result, users will show less free memory than before. Link: https://lkml.kernel.org/r/20260312104723.1351321-1-usama.arif@linux.dev Fixes: dafff3f4c850 ("mm: split underused THPs") Signed-off-by: Usama Arif <usama.arif@linux.dev> Reported-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: SeongJae Park <sj@kernel.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nico Pache <npache@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-04-05mm: rename my_zero_pfn() to zero_pfn()Mike Rapoport (Microsoft)
my_zero_pfn() is a silly name. Rename zero_pfn variable to zero_page_pfn and my_zero_pfn() function to zero_pfn(). While on it, move extern declarations of zero_page_pfn outside the functions that use it and add a comment about what ZERO_PAGE is. Link: https://lkml.kernel.org/r/20260211103141.3215197-3-rppt@kernel.org Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Acked-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Andreas Larsson <andreas@gaisler.com> Cc: "Borislav Petkov (AMD)" <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christophe Leroy (CS GROUP) <chleroy@kernel.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David S. Miller <davem@davemloft.net> Cc: Dinh Nguyen <dinguyen@kernel.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Magnus Lindholm <linmag7@gmail.com> Cc: Matt Turner <mattst88@gmail.com> Cc: Max Filippov <jcmvbkbc@gmail.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Michal Simek <monstr@monstr.eu> Cc: Palmer Dabbelt <palmer@dabbelt.com> Cc: Richard Weinberger <richard@nod.at> Cc: Russell King <linux@armlinux.org.uk> Cc: Stafford Horne <shorne@gmail.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vineet Gupta <vgupta@kernel.org> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-03-02mm: Fix a hmm_range_fault() livelock / starvation problemThomas Hellström
If hmm_range_fault() fails a folio_trylock() in do_swap_page, trying to acquire the lock of a device-private folio for migration, to ram, the function will spin until it succeeds grabbing the lock. However, if the process holding the lock is depending on a work item to be completed, which is scheduled on the same CPU as the spinning hmm_range_fault(), that work item might be starved and we end up in a livelock / starvation situation which is never resolved. This can happen, for example if the process holding the device-private folio lock is stuck in migrate_device_unmap()->lru_add_drain_all() sinc lru_add_drain_all() requires a short work-item to be run on all online cpus to complete. A prerequisite for this to happen is: a) Both zone device and system memory folios are considered in migrate_device_unmap(), so that there is a reason to call lru_add_drain_all() for a system memory folio while a folio lock is held on a zone device folio. b) The zone device folio has an initial mapcount > 1 which causes at least one migration PTE entry insertion to be deferred to try_to_migrate(), which can happen after the call to lru_add_drain_all(). c) No or voluntary only preemption. This all seems pretty unlikely to happen, but indeed is hit by the "xe_exec_system_allocator" igt test. Resolve this by waiting for the folio to be unlocked if the folio_trylock() fails in do_swap_page(). Rename migration_entry_wait_on_locked() to softleaf_entry_wait_unlock() and update its documentation to indicate the new use-case. Future code improvements might consider moving the lru_add_drain_all() call in migrate_device_unmap() to be called *after* all pages have migration entries inserted. That would eliminate also b) above. v2: - Instead of a cond_resched() in hmm_range_fault(), eliminate the problem by waiting for the folio to be unlocked in do_swap_page() (Alistair Popple, Andrew Morton) v3: - Add a stub migration_entry_wait_on_locked() for the !CONFIG_MIGRATION case. (Kernel Test Robot) v4: - Rename migrate_entry_wait_on_locked() to softleaf_entry_wait_on_locked() and update docs (Alistair Popple) v5: - Add a WARN_ON_ONCE() for the !CONFIG_MIGRATION version of softleaf_entry_wait_on_locked(). - Modify wording around function names in the commit message (Andrew Morton) Suggested-by: Alistair Popple <apopple@nvidia.com> Fixes: 1afaeb8293c9 ("mm/migrate: Trylock device page in do_swap_page") Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Jason Gunthorpe <jgg@mellanox.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Leon Romanovsky <leon@kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Matthew Brost <matthew.brost@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: linux-mm@kvack.org Cc: <dri-devel@lists.freedesktop.org> Signed-off-by: Thomas Hellström <thomas.hellstrom@linux.intel.com> Cc: <stable@vger.kernel.org> # v6.15+ Reviewed-by: John Hubbard <jhubbard@nvidia.com> #v3 Reviewed-by: Alistair Popple <apopple@nvidia.com> Link: https://patch.msgid.link/20260210115653.92413-1-thomas.hellstrom@linux.intel.com (cherry picked from commit a69d1ab971a624c6f112cea61536569d579c3215) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
2026-01-31mm: rename CONFIG_BALLOON_COMPACTION to CONFIG_BALLOON_MIGRATIONDavid Hildenbrand (Red Hat)
While compaction depends on migration, the other direction is not the case. So let's make it clearer that this is all about migration of balloon pages. Adjust all comments/docs in the core to talk about "migration" instead of "compaction". While at it add some "/* CONFIG_BALLOON_MIGRATION */". Link: https://lkml.kernel.org/r/20260119230133.3551867-23-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pérez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-26migrate: replace RMP_ flags with TTU_ flagsMatthew Wilcox (Oracle)
Instead of translating between RMP_ and TTU_ flags, remove the RMP_ flags and just use the TTU_ flag space; there's plenty available. Possibly we should rename these to RMAP_ flags, and maybe even pass them in through rmap_walk_arg, but that can be done later. Link: https://lkml.kernel.org/r/20260109041345.3863089-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ying Huang <ying.huang@linux.alibaba.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-01-19migrate: correct lock ordering for hugetlb file foliosMatthew Wilcox (Oracle)
Syzbot has found a deadlock (analyzed by Lance Yang): 1) Task (5749): Holds folio_lock, then tries to acquire i_mmap_rwsem(read lock). 2) Task (5754): Holds i_mmap_rwsem(write lock), then tries to acquire folio_lock. migrate_pages() -> migrate_hugetlbs() -> unmap_and_move_huge_page() <- Takes folio_lock! -> remove_migration_ptes() -> __rmap_walk_file() -> i_mmap_lock_read() <- Waits for i_mmap_rwsem(read lock)! hugetlbfs_fallocate() -> hugetlbfs_punch_hole() <- Takes i_mmap_rwsem(write lock)! -> hugetlbfs_zero_partial_page() -> filemap_lock_hugetlb_folio() -> filemap_lock_folio() -> __filemap_get_folio <- Waits for folio_lock! The migration path is the one taking locks in the wrong order according to the documentation at the top of mm/rmap.c. So expand the scope of the existing i_mmap_lock to cover the calls to remove_migration_ptes() too. This is (mostly) how it used to be after commit c0d0381ade79. That was removed by 336bf30eb765 for both file & anon hugetlb pages when it should only have been removed for anon hugetlb pages. Link: https://lkml.kernel.org/r/20260109041345.3863089-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Fixes: 336bf30eb765 ("hugetlbfs: fix anon huge page migration race") Reported-by: syzbot+2d9c96466c978346b55f@syzkaller.appspotmail.com Link: https://lore.kernel.org/all/68e9715a.050a0220.1186a4.000d.GAE@google.com Debugged-by: Lance Yang <lance.yang@linux.dev> Acked-by: David Hildenbrand (Red Hat) <david@kernel.org> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24memcg: remove __mod_lruvec_stateShakeel Butt
__mod_lruvec_state() is already safe against irqs, so there is no need to have a separate interface (i.e. mod_lruvec_state) which wraps calls to it with irq disabling and reenabling. Let's rename __mod_lruvec_state() to mod_lruvec_state(). Link: https://lkml.kernel.org/r/20251110232008.1352063-4-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: replace remaining pte_to_swp_entry() with softleaf_from_pte()Lorenzo Stoakes
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 <lorenzo.stoakes@oracle.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: eliminate further swapops predicatesLorenzo Stoakes
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 <lorenzo.stoakes@oracle.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: remove is_hugetlb_entry_[migration, hwpoisoned]()Lorenzo Stoakes
We do not need to have explicit helper functions for these, it adds a level of confusion and indirection when we can simply use software leaf entry logic here instead and spell out the special huge_pte_none() case we must consider. No functional change intended. Link: https://lkml.kernel.org/r/0e92d6924d3de88cd014ce1c53e20edc08fc152e.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: replace pmd_to_swp_entry() with softleaf_from_pmd()Lorenzo Stoakes
Introduce softleaf_from_pmd() to do the equivalent operation for PMDs that softleaf_from_pte() fulfils, and cascade changes through code base accordingly, introducing helpers as necessary. We are then able to eliminate pmd_to_swp_entry(), is_pmd_migration_entry(), is_pmd_device_private_entry() and is_pmd_non_present_folio_entry(). This further establishes the use of leaf operations throughout the code base and further establishes the foundations for eliminating is_swap_pmd(). No functional change intended. [lorenzo.stoakes@oracle.com: check writable, not readable/writable, per Vlastimil] Link: https://lkml.kernel.org/r/cd97b6ec-00f9-45a4-9ae0-8f009c212a94@lucifer.local Link: https://lkml.kernel.org/r/3fb431699639ded8fdc63d2210aa77a38c8891f1.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: SeongJae Park <sj@kernel.org>\ Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm: avoid unnecessary uses of is_swap_pte()Lorenzo Stoakes
There's an established convention in the kernel that we treat PTEs as containing swap entries (and the unfortunately named non-swap swap entries) should they be neither empty (i.e. pte_none() evaluating true) nor present (i.e. pte_present() evaluating true). However, there is some inconsistency in how this is applied, as we also have the is_swap_pte() helper which explicitly performs this check: /* check whether a pte points to a swap entry */ static inline int is_swap_pte(pte_t pte) { return !pte_none(pte) && !pte_present(pte); } As this represents a predicate, and it's logical to assume that in order to establish that a PTE entry can correctly be manipulated as a swap/non-swap entry, this predicate seems as if it must first be checked. But we instead, we far more often utilise the established convention of checking pte_none() / pte_present() before operating on entries as if they were swap/non-swap. This patch works towards correcting this inconsistency by removing all uses of is_swap_pte() where we are already in a position where we perform pte_none()/pte_present() checks anyway or otherwise it is clearly logical to do so. We also take advantage of the fact that pte_swp_uffd_wp() is only set on swap entries. Additionally, update comments referencing to is_swap_pte() and non_swap_entry(). No functional change intended. Link: https://lkml.kernel.org/r/17fd6d7f46a846517fd455fadd640af47fcd7c55.1762812360.git.lorenzo.stoakes@oracle.com Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Chris Li <chrisl@kernel.org> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Gregory Price <gourry@gourry.net> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Jann Horn <jannh@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Lance Yang <lance.yang@linux.dev> Cc: Leon Romanovsky <leon@kernel.org> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Nico Pache <npache@redhat.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Pasha Tatashin <pasha.tatashin@soleen.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: SeongJae Park <sj@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Wei Xu <weixugc@google.com> Cc: xu xin <xu.xin16@zte.com.cn> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-24mm/huge_memory: implement device-private THP splittingBalbir Singh
Add support for splitting device-private THP folios, enabling fallback to smaller page sizes when large page allocation or migration fails. Key changes: - split_huge_pmd(): Handle device-private PMD entries during splitting - Preserve RMAP_EXCLUSIVE semantics for anonymous exclusive folios - Skip RMP_USE_SHARED_ZEROPAGE for device-private entries as they don't support shared zero page semantics Link: https://lkml.kernel.org/r/20251001065707.920170-6-balbirs@nvidia.com Signed-off-by: Balbir Singh <balbirs@nvidia.com> Cc: David Hildenbrand <david@redhat.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: "Liam R. Howlett" <Liam.Howlett@oracle.com> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Lyude Paul <lyude@redhat.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: David Airlie <airlied@gmail.com> Cc: Simona Vetter <simona@ffwll.ch> Cc: Ralph Campbell <rcampbell@nvidia.com> Cc: Mika Penttilä <mpenttil@redhat.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Francois Dugast <francois.dugast@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-20migrate: optimise alloc_migration_target()Matthew Wilcox (Oracle)
Extract the zone number directly from the folio instead of using the folio's zone number to look up the zone and asking the zone what its number is. [ziy@nvidia.com: fix folio_zonenum() return type] Link: https://lkml.kernel.org/r/26E8FF35-503E-4F14-98F7-7B4FA25FBD37@nvidia.com Link: https://lkml.kernel.org/r/20251106201452.2292631-2-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Zi Yan <ziy@nvidia.com> Cc: David Hildenbrand <david@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-11-16mm/migrate, swap: drop usage of folio_indexKairui Song
This helper was used when swap cache was mixed with page cache. Now they are completely separate from each other, access to the swap cache is all wrapped by the swap_cache_* helpers, which expect the folio's swap entry as a parameter. This helper is no longer used, remove the last redundant user and drop it. Link: https://lkml.kernel.org/r/20251024-swap-clean-after-swap-table-p1-v2-4-a709469052e7@tencent.com Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Acked-by: Nhat Pham <nphamcs@gmail.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-15mm: prevent poison consumption when splitting THPQiuxu Zhuo
When performing memory error injection on a THP (Transparent Huge Page) mapped to userspace on an x86 server, the kernel panics with the following trace. The expected behavior is to terminate the affected process instead of panicking the kernel, as the x86 Machine Check code can recover from an in-userspace #MC. mce: [Hardware Error]: CPU 0: Machine Check Exception: f Bank 3: bd80000000070134 mce: [Hardware Error]: RIP 10:<ffffffff8372f8bc> {memchr_inv+0x4c/0xf0} mce: [Hardware Error]: TSC afff7bbff88a ADDR 1d301b000 MISC 80 PPIN 1e741e77539027db mce: [Hardware Error]: PROCESSOR 0:d06d0 TIME 1758093249 SOCKET 0 APIC 0 microcode 80000320 mce: [Hardware Error]: Run the above through 'mcelog --ascii' mce: [Hardware Error]: Machine check: Data load in unrecoverable area of kernel Kernel panic - not syncing: Fatal local machine check The root cause of this panic is that handling a memory failure triggered by an in-userspace #MC necessitates splitting the THP. The splitting process employs a mechanism, implemented in try_to_map_unused_to_zeropage(), which reads the pages in the THP to identify zero-filled pages. However, reading the pages in the THP results in a second in-kernel #MC, occurring before the initial memory_failure() completes, ultimately leading to a kernel panic. See the kernel panic call trace on the two #MCs. First Machine Check occurs // [1] memory_failure() // [2] try_to_split_thp_page() split_huge_page() split_huge_page_to_list_to_order() __folio_split() // [3] remap_page() remove_migration_ptes() remove_migration_pte() try_to_map_unused_to_zeropage() // [4] memchr_inv() // [5] Second Machine Check occurs // [6] Kernel panic [1] Triggered by accessing a hardware-poisoned THP in userspace, which is typically recoverable by terminating the affected process. [2] Call folio_set_has_hwpoisoned() before try_to_split_thp_page(). [3] Pass the RMP_USE_SHARED_ZEROPAGE remap flag to remap_page(). [4] Try to map the unused THP to zeropage. [5] Re-access pages in the hw-poisoned THP in the kernel. [6] Triggered in-kernel, leading to a panic kernel. In Step[2], memory_failure() sets the poisoned flag on the page in the THP by TestSetPageHWPoison() before calling try_to_split_thp_page(). As suggested by David Hildenbrand, fix this panic by not accessing to the poisoned page in the THP during zeropage identification, while continuing to scan unaffected pages in the THP for possible zeropage mapping. This prevents a second in-kernel #MC that would cause kernel panic in Step[4]. Thanks to Andrew Zaborowski for his initial work on fixing this issue. Link: https://lkml.kernel.org/r/20251015064926.1887643-1-qiuxu.zhuo@intel.com Link: https://lkml.kernel.org/r/20251011075520.320862-1-qiuxu.zhuo@intel.com Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Reported-by: Farrah Chen <farrah.chen@intel.com> Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Tested-by: Farrah Chen <farrah.chen@intel.com> Tested-by: Qiuxu Zhuo <qiuxu.zhuo@intel.com> Acked-by: Lance Yang <lance.yang@linux.dev> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: Barry Song <baohua@kernel.org> Cc: Dev Jain <dev.jain@arm.com> Cc: Jiaqi Yan <jiaqiyan@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Mariano Pache <npache@redhat.com> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07mm/rmap: fix soft-dirty and uffd-wp bit loss when remapping zero-filled mTHP ↵Lance Yang
subpage to shared zeropage When splitting an mTHP and replacing a zero-filled subpage with the shared zeropage, try_to_map_unused_to_zeropage() currently drops several important PTE bits. For userspace tools like CRIU, which rely on the soft-dirty mechanism for incremental snapshots, losing the soft-dirty bit means modified pages are missed, leading to inconsistent memory state after restore. As pointed out by David, the more critical uffd-wp bit is also dropped. This breaks the userfaultfd write-protection mechanism, causing writes to be silently missed by monitoring applications, which can lead to data corruption. Preserve both the soft-dirty and uffd-wp bits from the old PTE when creating the new zeropage mapping to ensure they are correctly tracked. Link: https://lkml.kernel.org/r/20250930081040.80926-1-lance.yang@linux.dev Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Lance Yang <lance.yang@linux.dev> Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jann Horn <jannh@google.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Peter Xu <peterx@redhat.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-10-07mm/thp: fix MTE tag mismatch when replacing zero-filled subpagesLance Yang
When both THP and MTE are enabled, splitting a THP and replacing its zero-filled subpages with the shared zeropage can cause MTE tag mismatch faults in userspace. Remapping zero-filled subpages to the shared zeropage is unsafe, as the zeropage has a fixed tag of zero, which may not match the tag expected by the userspace pointer. KSM already avoids this problem by using memcmp_pages(), which on arm64 intentionally reports MTE-tagged pages as non-identical to prevent unsafe merging. As suggested by David[1], this patch adopts the same pattern, replacing the memchr_inv() byte-level check with a call to pages_identical(). This leverages existing architecture-specific logic to determine if a page is truly identical to the shared zeropage. Having both the THP shrinker and KSM rely on pages_identical() makes the design more future-proof, IMO. Instead of handling quirks in generic code, we just let the architecture decide what makes two pages identical. [1] https://lore.kernel.org/all/ca2106a3-4bb2-4457-81af-301fd99fbef4@redhat.com Link: https://lkml.kernel.org/r/20250922021458.68123-1-lance.yang@linux.dev Fixes: b1f202060afe ("mm: remap unused subpages to shared zeropage when splitting isolated thp") Signed-off-by: Lance Yang <lance.yang@linux.dev> Reported-by: Qun-wei Lin <Qun-wei.Lin@mediatek.com> Closes: https://lore.kernel.org/all/a7944523fcc3634607691c35311a5d59d1a3f8d4.camel@mediatek.com Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: andrew.yang <andrew.yang@mediatek.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Charlie Jenkins <charlie@rivosinc.com> Cc: Chinwen Chang <chinwen.chang@mediatek.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Kairui Song <ryncsn@gmail.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mariano Pache <npache@redhat.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Palmer Dabbelt <palmer@rivosinc.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Samuel Holland <samuel.holland@sifive.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21mm, swap: use the swap table for the swap cache and switch APIKairui Song
Introduce basic swap table infrastructures, which are now just a fixed-sized flat array inside each swap cluster, with access wrappers. Each cluster contains a swap table of 512 entries. Each table entry is an opaque atomic long. It could be in 3 types: a shadow type (XA_VALUE), a folio type (pointer), or NULL. In this first step, it only supports storing a folio or shadow, and it is a drop-in replacement for the current swap cache. Convert all swap cache users to use the new sets of APIs. Chris Li has been suggesting using a new infrastructure for swap cache for better performance, and that idea combined well with the swap table as the new backing structure. Now the lock contention range is reduced to 2M clusters, which is much smaller than the 64M address_space. And we can also drop the multiple address_space design. All the internal works are done with swap_cache_get_* helpers. Swap cache lookup is still lock-less like before, and the helper's contexts are same with original swap cache helpers. They still require a pin on the swap device to prevent the backing data from being freed. Swap cache updates are now protected by the swap cluster lock instead of the XArray lock. This is mostly handled internally, but new __swap_cache_* helpers require the caller to lock the cluster. So, a few new cluster access and locking helpers are also introduced. A fully cluster-based unified swap table can be implemented on top of this to take care of all count tracking and synchronization work, with dynamic allocation. It should reduce the memory usage while making the performance even better. Link: https://lkml.kernel.org/r/20250916160100.31545-12-ryncsn@gmail.com Co-developed-by: Chris Li <chrisl@kernel.org> Signed-off-by: Chris Li <chrisl@kernel.org> Signed-off-by: Kairui Song <kasong@tencent.com> Acked-by: Chris Li <chrisl@kernel.org> Suggested-by: Chris Li <chrisl@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: kernel test robot <oliver.sang@intel.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-21mm, swap: wrap swap cache replacement with a helperKairui Song
There are currently three swap cache users that are trying to replace an existing folio with a new one: huge memory splitting, migration, and shmem replacement. What they are doing is quite similar. Introduce a common helper for this. In later commits, this can be easily switched to use the swap table by updating this helper. The newly added helper also makes the swap cache API better defined, and make debugging easier by adding a few more debug checks. Migration and shmem replace are meant to clone the folio, including content, swap entry value, and flags. And splitting will adjust each sub folio's swap entry according to order, which could be non-uniform in the future. So document it clearly that it's the caller's responsibility to set up the new folio's swap entries and flags before calling the helper. The helper will just follow the new folio's entry value. This also prepares for replacing high-order folios in the swap cache. Currently, only splitting to order 0 is allowed for swap cache folios. Using the new helper, we can handle high-order folio splitting better. Link: https://lkml.kernel.org/r/20250916160100.31545-11-ryncsn@gmail.com Signed-off-by: Kairui Song <kasong@tencent.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Chris Li <chrisl@kernel.org> Suggested-by: Chris Li <chrisl@kernel.org> Cc: Baoquan He <bhe@redhat.com> Cc: Barry Song <baohua@kernel.org> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kemeng Shi <shikemeng@huaweicloud.com> Cc: kernel test robot <oliver.sang@intel.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: Zi Yan <ziy@nvidia.com> Cc: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13treewide: remove MIGRATEPAGE_SUCCESSDavid Hildenbrand
At this point MIGRATEPAGE_SUCCESS is misnamed for all folio users, and now that we remove MIGRATEPAGE_UNMAP, it's really the only "success" return value that the code uses and expects. Let's just get rid of MIGRATEPAGE_SUCCESS completely and just use "0" for success. Link: https://lkml.kernel.org/r/20250811143949.1117439-3-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> [mm] Acked-by: Dave Kleikamp <dave.kleikamp@oracle.com> [jfs] Acked-by: David Sterba <dsterba@suse.com> [btrfs] Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Reviewed-by: Byungchul Park <byungchul@sk.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Lance Yang <lance.yang@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-13mm/migrate: remove MIGRATEPAGE_UNMAPDavid Hildenbrand
migrate_folio_unmap() is the only user of MIGRATEPAGE_UNMAP. We want to remove MIGRATEPAGE_* completely. It's rather weird to have a generic MIGRATEPAGE_UNMAP, documented to be returned from address-space callbacks, when it's only used for an internal helper. Let's start by having only a single "success" return value for migrate_folio_unmap() -- 0 -- by moving the "folio was already freed" check into the single caller. There is a remaining comment for PG_isolated, which we renamed to PG_movable_ops_isolated recently and forgot to update. While we might still run into that case with zsmalloc, it's something we want to get rid of soon. So let's just focus that optimization on real folios only for now by excluding movable_ops pages. Note that concurrent freeing can happen at any time and this "already freed" check is not relevant for correctness. [david@redhat.com: no need to pass "reason" to migrate_folio_unmap(), per Lance] Link: https://lkml.kernel.org/r/3bb725f8-28d7-4aa2-b75f-af40d5cab280@redhat.com Link: https://lkml.kernel.org/r/20250811143949.1117439-2-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lance Yang <lance.yang@linux.dev> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Byungchul Park <byungchul@sk.com> Cc: Chris Mason <clm@fb.com> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dave Kleikamp <shaggy@kernel.org> Cc: David Sterba <dsterba@suse.com> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Josef Bacik <josef@toxicpanda.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: Dave Kleikamp <dave.kleikamp@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-08-19mm/migrate: fix NULL movable_ops if CONFIG_ZSMALLOC=mHuacai Chen
After commit 84caf98838a3e5f4bdb34 ("mm: stop storing migration_ops in page->mapping") we get such an error message if CONFIG_ZSMALLOC=m: WARNING: CPU: 3 PID: 42 at mm/migrate.c:142 isolate_movable_ops_page+0xa8/0x1c0 CPU: 3 UID: 0 PID: 42 Comm: kcompactd0 Not tainted 6.16.0-rc5+ #2133 PREEMPT pc 9000000000540bd8 ra 9000000000540b84 tp 9000000100420000 sp 9000000100423a60 a0 9000000100193a80 a1 000000000000000c a2 000000000000001b a3 ffffffffffffffff a4 ffffffffffffffff a5 0000000000000267 a6 0000000000000000 a7 9000000100423ae0 t0 00000000000000f1 t1 00000000000000f6 t2 0000000000000000 t3 0000000000000001 t4 ffffff00010eb834 t5 0000000000000040 t6 900000010c89d380 t7 90000000023fcc70 t8 0000000000000018 u0 0000000000000000 s9 ffffff00010eb800 s0 ffffff00010eb800 s1 000000000000000c s2 0000000000043ae0 s3 0000800000000000 s4 900000000219cc40 s5 0000000000000000 s6 ffffff00010eb800 s7 0000000000000001 s8 90000000025b4000 ra: 9000000000540b84 isolate_movable_ops_page+0x54/0x1c0 ERA: 9000000000540bd8 isolate_movable_ops_page+0xa8/0x1c0 CRMD: 000000b0 (PLV0 -IE -DA +PG DACF=CC DACM=CC -WE) PRMD: 00000004 (PPLV0 +PIE -PWE) EUEN: 00000000 (-FPE -SXE -ASXE -BTE) ECFG: 00071c1d (LIE=0,2-4,10-12 VS=7) ESTAT: 000c0000 [BRK] (IS= ECode=12 EsubCode=0) PRID: 0014c010 (Loongson-64bit, Loongson-3A5000) CPU: 3 UID: 0 PID: 42 Comm: kcompactd0 Not tainted 6.16.0-rc5+ #2133 PREEMPT Stack : 90000000021fd000 0000000000000000 9000000000247720 9000000100420000 90000001004236a0 90000001004236a8 0000000000000000 90000001004237e8 90000001004237e0 90000001004237e0 9000000100423550 0000000000000001 0000000000000001 90000001004236a8 725a84864a19e2d9 90000000023fcc58 9000000100420000 90000000024c6848 9000000002416848 0000000000000001 0000000000000000 000000000000000a 0000000007fe0000 ffffff00010eb800 0000000000000000 90000000021fd000 0000000000000000 900000000205cf30 000000000000008e 0000000000000009 ffffff00010eb800 0000000000000001 90000000025b4000 0000000000000000 900000000024773c 00007ffff103d748 00000000000000b0 0000000000000004 0000000000000000 0000000000071c1d ... Call Trace: [<900000000024773c>] show_stack+0x5c/0x190 [<90000000002415e0>] dump_stack_lvl+0x70/0x9c [<90000000004abe6c>] isolate_migratepages_block+0x3bc/0x16e0 [<90000000004af408>] compact_zone+0x558/0x1000 [<90000000004b0068>] compact_node+0xa8/0x1e0 [<90000000004b0aa4>] kcompactd+0x394/0x410 [<90000000002b3c98>] kthread+0x128/0x140 [<9000000001779148>] ret_from_kernel_thread+0x28/0xc0 [<9000000000245528>] ret_from_kernel_thread_asm+0x10/0x88 The reason is that defined(CONFIG_ZSMALLOC) evaluates to 1 only when CONFIG_ZSMALLOC=y, we should use IS_ENABLED(CONFIG_ZSMALLOC) instead. But when I use IS_ENABLED(CONFIG_ZSMALLOC), page_movable_ops() cannot access zsmalloc_mops because zsmalloc_mops is in a module. To solve this problem, we define a set_movable_ops() interface to register and unregister offline_movable_ops / zsmalloc_movable_ops in mm/migrate.c, and call them at mm/balloon_compaction.c & mm/zsmalloc.c. Since offline_movable_ops / zsmalloc_movable_ops are always accessible, all #ifdef / #endif are removed in page_movable_ops(). Link: https://lkml.kernel.org/r/20250817151759.2525174-1-chenhuacai@loongson.cn Fixes: 84caf98838a3 ("mm: stop storing migration_ops in page->mapping") Signed-off-by: Huacai Chen <chenhuacai@loongson.cn> Acked-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Huacai Chen <chenhuacai@kernel.org> Cc: Huacai Chen <chenhuacai@loongson.cn> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19mm/page_owner: convert set_page_owner_migrate_reason() to foliosSidhartha Kumar
Both callers of set_page_owner_migrate_reason() use folios. Convert the function to take a folio directly and move the &folio->page conversion inside __set_page_owner_migrate_reason(). Link: https://lkml.kernel.org/r/20250711145910.90135-1-sidhartha.kumar@oracle.com Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com> Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com> Reviewed-by: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-19mm/migrate: remove the -EEXIST conversion for move_pages()Wei Yang
The -EEXIST conversion is introduced in commit 65462462ffb2 ("mm/gup: follow_pfn_pte(): -EEXIST cleanup"), since follow_page() may call follow_pfn_pte() which may return -EEXIST. But after commit 7dff875c9436 ("mm/migrate: convert add_page_for_migration() from follow_page() to folio_walk"), it use folio_walk instead. This limit the error code and won't return -EEXIST. Remove the error code conversion here. Link: https://lkml.kernel.org/r/20250707065711.18056-1-richard.weiyang@gmail.com Signed-off-by: Wei Yang <richard.weiyang@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Gregory Price <gourry@gourry.net> Cc: Ying Huang <ying.huang@linux.alibaba.com> Cc: Alistair Popple <apopple@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm: rename PG_isolated to PG_movable_ops_isolatedDavid Hildenbrand
Let's rename the flag to make it clearer where it applies (not folios ...). While at it, define the flag only with CONFIG_MIGRATION. Link: https://lkml.kernel.org/r/20250704102524.326966-22-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm: stop storing migration_ops in page->mappingDavid Hildenbrand
... instead, look them up statically based on the page type. Maybe in the future we want a registration interface? At least for now, it can be easily handled using the two page types that actually support page migration. The remaining usage of page->mapping is to flag such pages as actually being movable (having movable_ops), which we will change next. Link: https://lkml.kernel.org/r/20250704102524.326966-20-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm: remove __folio_test_movable()David Hildenbrand
Convert to page_has_movable_ops(). While at it, cleanup relevant code a bit. The data_race() in migrate_folio_unmap() is questionable: we already hold a page reference, and concurrent modifications can no longer happen (iow: __ClearPageMovable() no longer exists). Drop it for now, we'll rework page_has_movable_ops() soon either way to no longer rely on page->mapping. Wherever we cast from folio to page now is a clear sign that this code has to be decoupled. Link: https://lkml.kernel.org/r/20250704102524.326966-19-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm: rename __PageMovable() to page_has_movable_ops()David Hildenbrand
Let's make it clearer that we are talking about movable_ops pages. While at it, convert a VM_BUG_ON to a VM_WARN_ON_ONCE_PAGE. Link: https://lkml.kernel.org/r/20250704102524.326966-17-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-07-13mm/migration: remove PageMovable()David Hildenbrand
Previously, if __ClearPageMovable() were invoked on a page, this would cause __PageMovable() to return false, but due to the continued existence of page movable ops, PageMovable() would have returned true. With __ClearPageMovable() gone, the two are exactly equivalent. So we can replace PageMovable() checks by __PageMovable(). In fact, __PageMovable() cannot change until a page is freed, so we can turn some PageMovable() into sanity checks for __PageMovable(). Link: https://lkml.kernel.org/r/20250704102524.326966-16-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Harry Yoo <harry.yoo@oracle.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Brendan Jackman <jackmanb@google.com> Cc: Byungchul Park <byungchul@sk.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: Christian Brauner <brauner@kernel.org> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Eugenio Pé rez <eperezma@redhat.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: Gregory Price <gourry@gourry.net> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Jan Kara <jack@suse.cz> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jason Wang <jasowang@redhat.com> Cc: Jerrin Shaji George <jerrin.shaji-george@broadcom.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Madhavan Srinivasan <maddy@linux.ibm.com> Cc: Mathew Brost <matthew.brost@intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: "Michael S. Tsirkin" <mst@redhat.com> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Cc: Naoya Horiguchi <nao.horiguchi@gmail.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Peter Xu <peterx@redhat.com> Cc: Qi Zheng <zhengqi.arch@bytedance.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Xuan Zhuo <xuanzhuo@linux.alibaba.com> Cc: xu xin <xu.xin16@zte.com.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>