kernel/linux.git/include/linux/pgtable.h, branch v6.19.11

Merge tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2025-12-05T21:52:43+00:00

Pull MM updates from Andrew Morton: "__vmalloc()/kvmalloc() and no-block support" (Uladzislau Rezki) Rework the vmalloc() code to support non-blocking allocations (GFP_ATOIC, GFP_NOWAIT) "ksm: fix exec/fork inheritance" (xu xin) Fix a rare case where the KSM MMF_VM_MERGE_ANY prctl state is not inherited across fork/exec "mm/zswap: misc cleanup of code and documentations" (SeongJae Park) Some light maintenance work on the zswap code "mm/page_owner: add debugfs files 'show_handles' and 'show_stacks_handles'" (Mauricio Faria de Oliveira) Enhance the /sys/kernel/debug/page_owner debug feature by adding unique identifiers to differentiate the various stack traces so that userspace monitoring tools can better match stack traces over time "mm/page_alloc: pcp->batch cleanups" (Joshua Hahn) Minor alterations to the page allocator's per-cpu-pages feature "Improve UFFDIO_MOVE scalability by removing anon_vma lock" (Lokesh Gidra) Address a scalability issue in userfaultfd's UFFDIO_MOVE operation "kasan: cleanups for kasan_enabled() checks" (Sabyrzhan Tasbolatov) "drivers/base/node: fold node register and unregister functions" (Donet Tom) Clean up the NUMA node handling code a little "mm: some optimizations for prot numa" (Kefeng Wang) Cleanups and small optimizations to the NUMA allocation hinting code "mm/page_alloc: Batch callers of free_pcppages_bulk" (Joshua Hahn) Address long lock hold times at boot on large machines. These were causing (harmless) softlockup warnings "optimize the logic for handling dirty file folios during reclaim" (Baolin Wang) Remove some now-unnecessary work from page reclaim "mm/damon: allow DAMOS auto-tuned for per-memcg per-node memory usage" (SeongJae Park) Enhance the DAMOS auto-tuning feature "mm/damon: fixes for address alignment issues in DAMON_LRU_SORT and DAMON_RECLAIM" (Quanmin Yan) Fix DAMON_LRU_SORT and DAMON_RECLAIM with certain userspace configuration "expand mmap_prepare functionality, port more users" (Lorenzo Stoakes) Enhance the new(ish) file_operations.mmap_prepare() method and port additional callsites from the old ->mmap() over to ->mmap_prepare() "Fix stale IOTLB entries for kernel address space" (Lu Baolu) Fix a bug (and possible security issue on non-x86) in the IOMMU code. In some situations the IOMMU could be left hanging onto a stale kernel pagetable entry "mm/huge_memory: cleanup __split_unmapped_folio()" (Wei Yang) Clean up and optimize the folio splitting code "mm, swap: misc cleanup and bugfix" (Kairui Song) Some cleanups and a minor fix in the swap discard code "mm/damon: misc documentation fixups" (SeongJae Park) "mm/damon: support pin-point targets removal" (SeongJae Park) Permit userspace to remove a specific monitoring target in the middle of the current targets list "mm: MISC follow-up patches for linux/pgalloc.h" (Harry Yoo) A couple of cleanups related to mm header file inclusion "mm/swapfile.c: select swap devices of default priority round robin" (Baoquan He) improve the selection of swap devices for NUMA machines "mm: Convert memory block states (MEM_*) macros to enums" (Israel Batista) Change the memory block labels from macros to enums so they will appear in kernel debug info "ksm: perform a range-walk to jump over holes in break_ksm" (Pedro Demarchi Gomes) Address an inefficiency when KSM unmerges an address range "mm/damon/tests: fix memory bugs in kunit tests" (SeongJae Park) Fix leaks and unhandled malloc() failures in DAMON userspace unit tests "some cleanups for pageout()" (Baolin Wang) Clean up a couple of minor things in the page scanner's writeback-for-eviction code "mm/hugetlb: refactor sysfs/sysctl interfaces" (Hui Zhu) Move hugetlb's sysfs/sysctl handling code into a new file "introduce VM_MAYBE_GUARD and make it sticky" (Lorenzo Stoakes) Make the VMA guard regions available in /proc/pid/smaps and improves the mergeability of guarded VMAs "mm: perform guard region install/remove under VMA lock" (Lorenzo Stoakes) Reduce mmap lock contention for callers performing VMA guard region operations "vma_start_write_killable" (Matthew Wilcox) Start work on permitting applications to be killed when they are waiting on a read_lock on the VMA lock "mm/damon/tests: add more tests for online parameters commit" (SeongJae Park) Add additional userspace testing of DAMON's "commit" feature "mm/damon: misc cleanups" (SeongJae Park) "make VM_SOFTDIRTY a sticky VMA flag" (Lorenzo Stoakes) Address the possible loss of a VMA's VM_SOFTDIRTY flag when that VMA is merged with another "mm: support device-private THP" (Balbir Singh) Introduce support for Transparent Huge Page (THP) migration in zone device-private memory "Optimize folio split in memory failure" (Zi Yan) "mm/huge_memory: Define split_type and consolidate split support checks" (Wei Yang) Some more cleanups in the folio splitting code "mm: remove is_swap_[pte, pmd]() + non-swap entries, introduce leaf entries" (Lorenzo Stoakes) Clean up our handling of pagetable leaf entries by introducing the concept of 'software leaf entries', of type softleaf_t "reparent the THP split queue" (Muchun Song) Reparent the THP split queue to its parent memcg. This is in preparation for addressing the long-standing "dying memcg" problem, wherein dead memcg's linger for too long, consuming memory resources "unify PMD scan results and remove redundant cleanup" (Wei Yang) A little cleanup in the hugepage collapse code "zram: introduce writeback bio batching" (Sergey Senozhatsky) Improve zram writeback efficiency by introducing batched bio writeback support "memcg: cleanup the memcg stats interfaces" (Shakeel Butt) Clean up our handling of the interrupt safety of some memcg stats "make vmalloc gfp flags usage more apparent" (Vishal Moola) Clean up vmalloc's handling of incoming GFP flags "mm: Add soft-dirty and uffd-wp support for RISC-V" (Chunyan Zhang) Teach soft dirty and userfaultfd write protect tracking to use RISC-V's Svrsw60t59b extension "mm: swap: small fixes and comment cleanups" (Youngjun Park) Fix a small bug and clean up some of the swap code "initial work on making VMA flags a bitmap" (Lorenzo Stoakes) Start work on converting the vma struct's flags to a bitmap, so we stop running out of them, especially on 32-bit "mm/swapfile: fix and cleanup swap list iterations" (Youngjun Park) Address a possible bug in the swap discard code and clean things up a little [ This merge also reverts commit ebb9aeb980e5 ("vfio/nvgrace-gpu: register device memory for poison handling") because it looks broken to me, I've asked for clarification - Linus ] * tag 'mm-stable-2025-12-03-21-26' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (321 commits) mm: fix vma_start_write_killable() signal handling mm/swapfile: use plist_for_each_entry in __folio_throttle_swaprate mm/swapfile: fix list iteration when next node is removed during discard fs/proc/task_mmu.c: fix make_uffd_wp_huge_pte() huge pte handling mm/kfence: add reboot notifier to disable KFENCE on shutdown memcg: remove inc/dec_lruvec_kmem_state helpers selftests/mm/uffd: initialize char variable to Null mm: fix DEBUG_RODATA_TEST indentation in Kconfig mm: introduce VMA flags bitmap type tools/testing/vma: eliminate dependency on vma->__vm_flags mm: simplify and rename mm flags function for clarity mm: declare VMA flags by bit zram: fix a spelling mistake mm/page_alloc: optimize lowmem_reserve max lookup using its semantic monotonicity mm/vmscan: skip increasing kswapd_failures when reclaim was boosted pagemap: update BUDDY flag documentation mm: swap: remove scan_swap_map_slots() references from comments mm: swap: change swap_alloc_slow() to void mm, swap: remove redundant comment for read_swap_cache_async mm, swap: use SWP_SOLIDSTATE to determine if swap is rotational ...

mm: softdirty: add pgtable_supports_soft_dirty()

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

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

mm: add spurious fault fixing support for huge pmd

2025-11-19T16:01:48+00:00

The page faults may be spurious because of the racy access to the page table. For example, a non-populated virtual page is accessed on 2 CPUs simultaneously, thus the page faults are triggered on both CPUs. However, it's possible that one CPU (say CPU A) cannot find the reason for the page fault if the other CPU (say CPU B) has changed the page table before the PTE is checked on CPU A. Most of the time, the spurious page faults can be ignored safely. However, if the page fault is for the write access, it's possible that a stale read-only TLB entry exists in the local CPU and needs to be flushed on some architectures. This is called the spurious page fault fixing. In the current kernel, there is spurious fault fixing support for pte, but not for huge pmd because no architectures need it. But in the next patch in the series, we will change the write protection fault handling logic on arm64, so that some stale huge pmd entries may remain in the TLB. These entries need to be flushed via the huge pmd spurious fault fixing mechanism. Signed-off-by: Huang Ying Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Acked-by: Zi Yan Cc: Will Deacon Cc: Andrew Morton Cc: Vlastimil Babka Cc: Baolin Wang Cc: Ryan Roberts Cc: Yang Shi Cc: Christoph Lameter (Ampere) Cc: Dev Jain Cc: Barry Song Cc: Anshuman Khandual Cc: Kefeng Wang Cc: Kevin Brodsky Cc: Yin Fengwei Cc: linux-arm-kernel@lists.infradead.org Cc: linux-kernel@vger.kernel.org Cc: linux-mm@kvack.org Signed-off-by: Catalin Marinas

include/linux/pgtable.h: convert arch_enter_lazy_mmu_mode() and friends to static inlines

2025-09-21T21:22:35+00:00

For all the usual reasons, plus a new one. Calling (void)arch_enter_lazy_mmu_mode(); deservedly blows up. Cc: Balbir Singh Signed-off-by: Andrew Morton

mm/memory: convert print_bad_pte() to print_bad_page_map()

2025-09-13T23:54:52+00:00

print_bad_pte() looks like something that should actually be a WARN or similar, but historically it apparently has proven to be useful to detect corruption of page tables even on production systems -- report the issue and keep the system running to make it easier to actually detect what is going wrong (e.g., multiple such messages might shed a light). As we want to unify vm_normal_page_*() handling for PTE/PMD/PUD, we'll have to take care of print_bad_pte() as well. Let's prepare for using print_bad_pte() also for non-PTEs by adjusting the implementation and renaming the function to print_bad_page_map(). Provide print_bad_pte() as a simple wrapper. Document the implicit locking requirements for the page table re-walk. To make the function a bit more readable, factor out the ratelimit check into is_bad_page_map_ratelimited() and place the printing of page table content into __print_bad_page_map_pgtable(). We'll now dump information from each level in a single line, and just stop the table walk once we hit something that is not a present page table. The report will now look something like (dumping pgd to pmd values): [ 77.943408] BUG: Bad page map in process XXX pte:80000001233f5867 [ 77.944077] addr:00007fd84bb1c000 vm_flags:08100071 anon_vma: ... [ 77.945186] pgd:10a89f067 p4d:10a89f067 pud:10e5a2067 pmd:105327067 Not using pgdp_get(), because that does not work properly on some arm configs where pgd_t is an array. Note that we are dumping all levels even when levels are folded for simplicity. [david@redhat.com: drop warning] Link: https://lkml.kernel.org/r/923b279c-de33-44dd-a923-2959afad8626@redhat.com Link: https://lkml.kernel.org/r/20250811112631.759341-9-david@redhat.com Signed-off-by: David Hildenbrand Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Baolin Wang Cc: Barry Song Cc: Christian Brauner Cc: Christophe Leroy Cc: Dan Williams Cc: David Vrabel Cc: Dev Jain Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Juegren Gross Cc: Lance Yang Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mariano Pache Cc: Matthew Wilcox (Oracle) Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oleksandr Tyshchenko Cc: Oscar Salvador Cc: Ryan Roberts Cc: Stefano Stabellini Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Yang Cc: Zi Yan Signed-off-by: Andrew Morton

mm/rmap: convert "enum rmap_level" to "enum pgtable_level"

2025-09-13T23:54:52+00:00

Let's factor it out, and convert all checks for unsupported levels to BUILD_BUG(). The code is written in a way such that force-inlining will optimize out the levels. [nathan@kernel.org: always inline __folio_rmap_sanity_checks()] Link: https://lkml.kernel.org/r/20250814-rmap-fix-build_bug-conversion-v1-1-fb7b10a0b362@kernel.org Link: https://lkml.kernel.org/r/20250811112631.759341-8-david@redhat.com Signed-off-by: David Hildenbrand Signed-off-by: Nathan Chancellor Reviewed-by: Lorenzo Stoakes Cc: Alistair Popple Cc: Al Viro Cc: Baolin Wang Cc: Barry Song Cc: Christian Brauner Cc: Christophe Leroy Cc: Dan Williams Cc: David Vrabel Cc: Dev Jain Cc: Hugh Dickins Cc: Jan Kara Cc: Jann Horn Cc: Juegren Gross Cc: Lance Yang Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Mariano Pache Cc: Matthew Wilcox (Oracle) Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oleksandr Tyshchenko Cc: Oscar Salvador Cc: Ryan Roberts Cc: Stefano Stabellini Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Yang Cc: Zi Yan Cc: Nathan Chancellor Signed-off-by: Andrew Morton

mm: introduce and use {pgd,p4d}_populate_kernel()

2025-08-28T05:45:44+00:00

Introduce and use {pgd,p4d}_populate_kernel() in core MM code when populating PGD and P4D entries for the kernel address space. These helpers ensure proper synchronization of page tables when updating the kernel portion of top-level page tables. Until now, the kernel has relied on each architecture to handle synchronization of top-level page tables in an ad-hoc manner. For example, see commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes"). However, this approach has proven fragile for following reasons: 1) It is easy to forget to perform the necessary page table synchronization when introducing new changes. For instance, commit 4917f55b4ef9 ("mm/sparse-vmemmap: improve memory savings for compound devmaps") overlooked the need to synchronize page tables for the vmemmap area. 2) It is also easy to overlook that the vmemmap and direct mapping areas must not be accessed before explicit page table synchronization. For example, commit 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges")) caused crashes by accessing the vmemmap area before calling sync_global_pgds(). To address this, as suggested by Dave Hansen, introduce _kernel() variants of the page table population helpers, which invoke architecture-specific hooks to properly synchronize page tables. These are introduced in a new header file, include/linux/pgalloc.h, so they can be called from common code. They reuse existing infrastructure for vmalloc and ioremap. Synchronization requirements are determined by ARCH_PAGE_TABLE_SYNC_MASK, and the actual synchronization is performed by arch_sync_kernel_mappings(). This change currently targets only x86_64, so only PGD and P4D level helpers are introduced. Currently, these helpers are no-ops since no architecture sets PGTBL_{PGD,P4D}_MODIFIED in ARCH_PAGE_TABLE_SYNC_MASK. In theory, PUD and PMD level helpers can be added later if needed by other architectures. For now, 32-bit architectures (x86-32 and arm) only handle PGTBL_PMD_MODIFIED, so p*d_populate_kernel() will never affect them unless we introduce a PMD level helper. [harry.yoo@oracle.com: fix KASAN build error due to p*d_populate_kernel()] Link: https://lkml.kernel.org/r/20250822020727.202749-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-3-harry.yoo@oracle.com Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo Suggested-by: Dave Hansen Acked-by: Kiryl Shutsemau Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Cc: Alexander Potapenko Cc: Alistair Popple Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: "Aneesh Kumar K.V" Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: bibo mao Cc: Borislav Betkov Cc: Christoph Lameter (Ampere) Cc: Dennis Zhou Cc: Dev Jain Cc: Dmitriy Vyukov Cc: Gwan-gyeong Mun Cc: Ingo Molnar Cc: Jane Chu Cc: Joao Martins Cc: Joerg Roedel Cc: John Hubbard Cc: Kevin Brodsky Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Tejun Heo Cc: Thomas Gleinxer Cc: Thomas Huth Cc: "Uladzislau Rezki (Sony)" Cc: Vincenzo Frascino Cc: Vlastimil Babka Cc: Signed-off-by: Andrew Morton

mm: move page table sync declarations to linux/pgtable.h

2025-08-28T05:45:44+00:00

During our internal testing, we started observing intermittent boot failures when the machine uses 4-level paging and has a large amount of persistent memory: BUG: unable to handle page fault for address: ffffe70000000034 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] SMP NOPTI RIP: 0010:__init_single_page+0x9/0x6d Call Trace: __init_zone_device_page+0x17/0x5d memmap_init_zone_device+0x154/0x1bb pagemap_range+0x2e0/0x40f memremap_pages+0x10b/0x2f0 devm_memremap_pages+0x1e/0x60 dev_dax_probe+0xce/0x2ec [device_dax] dax_bus_probe+0x6d/0xc9 [... snip ...] It turns out that the kernel panics while initializing vmemmap (struct page array) when the vmemmap region spans two PGD entries, because the new PGD entry is only installed in init_mm.pgd, but not in the page tables of other tasks. And looking at __populate_section_memmap(): if (vmemmap_can_optimize(altmap, pgmap)) // does not sync top level page tables r = vmemmap_populate_compound_pages(pfn, start, end, nid, pgmap); else // sync top level page tables in x86 r = vmemmap_populate(start, end, nid, altmap); In the normal path, vmemmap_populate() in arch/x86/mm/init_64.c synchronizes the top level page table (See commit 9b861528a801 ("x86-64, mem: Update all PGDs for direct mapping and vmemmap mapping changes")) so that all tasks in the system can see the new vmemmap area. However, when vmemmap_can_optimize() returns true, the optimized path skips synchronization of top-level page tables. This is because vmemmap_populate_compound_pages() is implemented in core MM code, which does not handle synchronization of the top-level page tables. Instead, the core MM has historically relied on each architecture to perform this synchronization manually. We're not the first party to encounter a crash caused by not-sync'd top level page tables: earlier this year, Gwan-gyeong Mun attempted to address the issue [1] [2] after hitting a kernel panic when x86 code accessed the vmemmap area before the corresponding top-level entries were synced. At that time, the issue was believed to be triggered only when struct page was enlarged for debugging purposes, and the patch did not get further updates. It turns out that current approach of relying on each arch to handle the page table sync manually is fragile because 1) it's easy to forget to sync the top level page table, and 2) it's also easy to overlook that the kernel should not access the vmemmap and direct mapping areas before the sync. # The solution: Make page table sync more code robust and harder to miss To address this, Dave Hansen suggested [3] [4] introducing {pgd,p4d}_populate_kernel() for updating kernel portion of the page tables and allow each architecture to explicitly perform synchronization when installing top-level entries. With this approach, we no longer need to worry about missing the sync step, reducing the risk of future regressions. The new interface reuses existing ARCH_PAGE_TABLE_SYNC_MASK, PGTBL_P*D_MODIFIED and arch_sync_kernel_mappings() facility used by vmalloc and ioremap to synchronize page tables. pgd_populate_kernel() looks like this: static inline void pgd_populate_kernel(unsigned long addr, pgd_t *pgd, p4d_t *p4d) { pgd_populate(&init_mm, pgd, p4d); if (ARCH_PAGE_TABLE_SYNC_MASK & PGTBL_PGD_MODIFIED) arch_sync_kernel_mappings(addr, addr); } It is worth noting that vmalloc() and apply_to_range() carefully synchronizes page tables by calling p*d_alloc_track() and arch_sync_kernel_mappings(), and thus they are not affected by this patch series. This series was hugely inspired by Dave Hansen's suggestion and hence added Suggested-by: Dave Hansen. Cc stable because lack of this series opens the door to intermittent boot failures. This patch (of 3): Move ARCH_PAGE_TABLE_SYNC_MASK and arch_sync_kernel_mappings() to linux/pgtable.h so that they can be used outside of vmalloc and ioremap. Link: https://lkml.kernel.org/r/20250818020206.4517-1-harry.yoo@oracle.com Link: https://lkml.kernel.org/r/20250818020206.4517-2-harry.yoo@oracle.com Link: https://lore.kernel.org/linux-mm/20250220064105.808339-1-gwan-gyeong.mun@intel.com [1] Link: https://lore.kernel.org/linux-mm/20250311114420.240341-1-gwan-gyeong.mun@intel.com [2] Link: https://lore.kernel.org/linux-mm/d1da214c-53d3-45ac-a8b6-51821c5416e4@intel.com [3] Link: https://lore.kernel.org/linux-mm/4d800744-7b88-41aa-9979-b245e8bf794b@intel.com [4] Fixes: 8d400913c231 ("x86/vmemmap: handle unpopulated sub-pmd ranges") Signed-off-by: Harry Yoo Acked-by: Kiryl Shutsemau Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: "Uladzislau Rezki (Sony)" Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand Cc: Alexander Potapenko Cc: Alistair Popple Cc: Andrey Konovalov Cc: Andrey Ryabinin Cc: Andy Lutomirski Cc: "Aneesh Kumar K.V" Cc: Anshuman Khandual Cc: Ard Biesheuvel Cc: Arnd Bergmann Cc: bibo mao Cc: Borislav Betkov Cc: Christoph Lameter (Ampere) Cc: Dennis Zhou Cc: Dev Jain Cc: Dmitriy Vyukov Cc: Gwan-gyeong Mun Cc: Ingo Molnar Cc: Jane Chu Cc: Joao Martins Cc: Joerg Roedel Cc: John Hubbard Cc: Kevin Brodsky Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Peter Xu Cc: Peter Zijlstra Cc: Qi Zheng Cc: Ryan Roberts Cc: Suren Baghdasaryan Cc: Tejun Heo Cc: Thomas Gleinxer Cc: Thomas Huth Cc: Vincenzo Frascino Cc: Vlastimil Babka Cc: Dave Hansen Cc: Signed-off-by: Andrew Morton

mm: add get_and_clear_ptes() and clear_ptes()

2025-08-02T19:06:10+00:00

Patch series "Optimizations for khugepaged", v4. If the underlying folio mapped by the ptes is large, we can process those ptes in a batch using folio_pte_batch(). For arm64 specifically, this results in a 16x reduction in the number of ptep_get() calls, since on a contig block, ptep_get() on arm64 will iterate through all 16 entries to collect a/d bits. Next, ptep_clear() will cause a TLBI for every contig block in the range via contpte_try_unfold(). Instead, use clear_ptes() to only do the TLBI at the first and last contig block of the range. For split folios, there will be no pte batching; the batch size returned by folio_pte_batch() will be 1. For pagetable split folios, the ptes will still point to the same large folio; for arm64, this results in the optimization described above, and for other arches, a minor improvement is expected due to a reduction in the number of function calls and batching atomic operations. This patch (of 3): Let's add variants to be used where "full" does not apply -- which will be the majority of cases in the future. "full" really only applies if we are about to tear down a full MM. Use get_and_clear_ptes() in existing code, clear_ptes() users will be added next. Link: https://lkml.kernel.org/r/20250724052301.23844-2-dev.jain@arm.com Signed-off-by: David Hildenbrand Signed-off-by: Dev Jain Reviewed-by: Baolin Wang Reviewed-by: Barry Song Reviewed-by: Lorenzo Stoakes Reviewed-by: Zi Yan Cc: Liam Howlett Cc: Mariano Pache Cc: Ryan Roberts Signed-off-by: Andrew Morton

mm: add batched versions of ptep_modify_prot_start/commit

2025-07-25T02:12:40+00:00

Batch ptep_modify_prot_start/commit in preparation for optimizing mprotect, implementing them as a simple loop over the corresponding single pte helpers. Architecture may override these helpers. Link: https://lkml.kernel.org/r/20250718090244.21092-4-dev.jain@arm.com Signed-off-by: Dev Jain Reviewed-by: Lorenzo Stoakes Reviewed-by: Barry Song Reviewed-by: Ryan Roberts Reviewed-by: Zi Yan Cc: Anshuman Khandual Cc: Catalin Marinas Cc: Christophe Leroy Cc: David Hildenbrand Cc: Hugh Dickins Cc: Jann Horn Cc: Joey Gouly Cc: Kevin Brodsky Cc: Lance Yang Cc: Liam Howlett Cc: Matthew Wilcox (Oracle) Cc: Peter Xu Cc: Vlastimil Babka Cc: Will Deacon Cc: Yang Shi Cc: Yicong Yang Cc: Zhenhua Huang Signed-off-by: Andrew Morton