linux/mm/Kconfig, branch master

Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-04-15T19:59:16Z

Pull MM updates from Andrew Morton: - "maple_tree: Replace big node with maple copy" (Liam Howlett) Mainly prepararatory work for ongoing development but it does reduce stack usage and is an improvement. - "mm, swap: swap table phase III: remove swap_map" (Kairui Song) Offers memory savings by removing the static swap_map. It also yields some CPU savings and implements several cleanups. - "mm: memfd_luo: preserve file seals" (Pratyush Yadav) File seal preservation to LUO's memfd code - "mm: zswap: add per-memcg stat for incompressible pages" (Jiayuan Chen) Additional userspace stats reportng to zswap - "arch, mm: consolidate empty_zero_page" (Mike Rapoport) Some cleanups for our handling of ZERO_PAGE() and zero_pfn - "mm/kmemleak: Improve scan_should_stop() implementation" (Zhongqiu Han) A robustness improvement and some cleanups in the kmemleak code - "Improve khugepaged scan logic" (Vernon Yang) Improve khugepaged scan logic and reduce CPU consumption by prioritizing scanning tasks that access memory frequently - "Make KHO Stateless" (Jason Miu) Simplify Kexec Handover by transitioning KHO from an xarray-based metadata tracking system with serialization to a radix tree data structure that can be passed directly to the next kernel - "mm: vmscan: add PID and cgroup ID to vmscan tracepoints" (Thomas Ballasi and Steven Rostedt) Enhance vmscan's tracepointing - "mm: arch/shstk: Common shadow stack mapping helper and VM_NOHUGEPAGE" (Catalin Marinas) Cleanup for the shadow stack code: remove per-arch code in favour of a generic implementation - "Fix KASAN support for KHO restored vmalloc regions" (Pasha Tatashin) Fix a WARN() which can be emitted the KHO restores a vmalloc area - "mm: Remove stray references to pagevec" (Tal Zussman) Several cleanups, mainly udpating references to "struct pagevec", which became folio_batch three years ago - "mm: Eliminate fake head pages from vmemmap optimization" (Kiryl Shutsemau) Simplify the HugeTLB vmemmap optimization (HVO) by changing how tail pages encode their relationship to the head page - "mm/damon/core: improve DAMOS quota efficiency for core layer filters" (SeongJae Park) Improve two problematic behaviors of DAMOS that makes it less efficient when core layer filters are used - "mm/damon: strictly respect min_nr_regions" (SeongJae Park) Improve DAMON usability by extending the treatment of the min_nr_regions user-settable parameter - "mm/page_alloc: pcp locking cleanup" (Vlastimil Babka) The proper fix for a previously hotfixed SMP=n issue. Code simplifications and cleanups ensued - "mm: cleanups around unmapping / zapping" (David Hildenbrand) A bunch of cleanups around unmapping and zapping. Mostly simplifications, code movements, documentation and renaming of zapping functions - "support batched checking of the young flag for MGLRU" (Baolin Wang) Batched checking of the young flag for MGLRU. It's part cleanups; one benchmark shows large performance benefits for arm64 - "memcg: obj stock and slab stat caching cleanups" (Johannes Weiner) memcg cleanup and robustness improvements - "Allow order zero pages in page reporting" (Yuvraj Sakshith) Enhance free page reporting - it is presently and undesirably order-0 pages when reporting free memory. - "mm: vma flag tweaks" (Lorenzo Stoakes) Cleanup work following from the recent conversion of the VMA flags to a bitmap - "mm/damon: add optional debugging-purpose sanity checks" (SeongJae Park) Add some more developer-facing debug checks into DAMON core - "mm/damon: test and document power-of-2 min_region_sz requirement" (SeongJae Park) An additional DAMON kunit test and makes some adjustments to the addr_unit parameter handling - "mm/damon/core: make passed_sample_intervals comparisons overflow-safe" (SeongJae Park) Fix a hard-to-hit time overflow issue in DAMON core - "mm/damon: improve/fixup/update ratio calculation, test and documentation" (SeongJae Park) A batch of misc/minor improvements and fixups for DAMON - "mm: move vma_(kernel|mmu)_pagesize() out of hugetlb.c" (David Hildenbrand) Fix a possible issue with dax-device when CONFIG_HUGETLB=n. Some code movement was required. - "zram: recompression cleanups and tweaks" (Sergey Senozhatsky) A somewhat random mix of fixups, recompression cleanups and improvements in the zram code - "mm/damon: support multiple goal-based quota tuning algorithms" (SeongJae Park) Extend DAMOS quotas goal auto-tuning to support multiple tuning algorithms that users can select - "mm: thp: reduce unnecessary start_stop_khugepaged()" (Breno Leitao) Fix the khugpaged sysfs handling so we no longer spam the logs with reams of junk when starting/stopping khugepaged - "mm: improve map count checks" (Lorenzo Stoakes) Provide some cleanups and slight fixes in the mremap, mmap and vma code - "mm/damon: support addr_unit on default monitoring targets for modules" (SeongJae Park) Extend the use of DAMON core's addr_unit tunable - "mm: khugepaged cleanups and mTHP prerequisites" (Nico Pache) Cleanups to khugepaged and is a base for Nico's planned khugepaged mTHP support - "mm: memory hot(un)plug and SPARSEMEM cleanups" (David Hildenbrand) Code movement and cleanups in the memhotplug and sparsemem code - "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION" (David Hildenbrand) Rationalize some memhotplug Kconfig support - "change young flag check functions to return bool" (Baolin Wang) Cleanups to change all young flag check functions to return bool - "mm/damon/sysfs: fix memory leak and NULL dereference issues" (Josh Law and SeongJae Park) Fix a few potential DAMON bugs - "mm/vma: convert vm_flags_t to vma_flags_t in vma code" (Lorenzo Stoakes) Convert a lot of the existing use of the legacy vm_flags_t data type to the new vma_flags_t type which replaces it. Mainly in the vma code. - "mm: expand mmap_prepare functionality and usage" (Lorenzo Stoakes) Expand the mmap_prepare functionality, which is intended to replace the deprecated f_op->mmap hook which has been the source of bugs and security issues for some time. Cleanups, documentation, extension of mmap_prepare into filesystem drivers - "mm/huge_memory: refactor zap_huge_pmd()" (Lorenzo Stoakes) Simplify and clean up zap_huge_pmd(). Additional cleanups around vm_normal_folio_pmd() and the softleaf functionality are performed. * tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (369 commits) mm: fix deferred split queue races during migration mm/khugepaged: fix issue with tracking lock mm/huge_memory: add and use has_deposited_pgtable() mm/huge_memory: add and use normal_or_softleaf_folio_pmd() mm: add softleaf_is_valid_pmd_entry(), pmd_to_softleaf_folio() mm/huge_memory: separate out the folio part of zap_huge_pmd() mm/huge_memory: use mm instead of tlb->mm mm/huge_memory: remove unnecessary sanity checks mm/huge_memory: deduplicate zap deposited table call mm/huge_memory: remove unnecessary VM_BUG_ON_PAGE() mm/huge_memory: add a common exit path to zap_huge_pmd() mm/huge_memory: handle buggy PMD entry in zap_huge_pmd() mm/huge_memory: have zap_huge_pmd return a boolean, add kdoc mm/huge: avoid big else branch in zap_huge_pmd() mm/huge_memory: simplify vma_is_specal_huge() mm: on remap assert that input range within the proposed VMA mm: add mmap_action_map_kernel_pages[_full]() uio: replace deprecated mmap hook with mmap_prepare in uio_info drivers: hv: vmbus: replace deprecated mmap hook with mmap_prepare mm: allow handling of stacked mmap_prepare hooks in more drivers ...

mm: introduce CONFIG_NUMA_MIGRATION and simplify CONFIG_MIGRATION

2026-04-05T20:53:33Z

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) Reviewed-by: Lorenzo Stoakes (Oracle) Acked-by: Zi Yan Reviewed-by: Jonathan Cameron Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Alistair Popple Cc: "Borislav Petkov (AMD)" Cc: Byungchul Park Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Gregory Price Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: "Huang, Ying" Cc: Ingo Molnar Cc: Joshua Hahn Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Matthew Brost Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Rakie Kim Cc: Sebastian Andrzej Siewior Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: WANG Xuerui Cc: Will Deacon Signed-off-by: Andrew Morton

mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE

2026-04-05T20:53:33Z

Patch series "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and cleanup CONFIG_MIGRATION". While working on memory hotplug code cleanups, I realized that CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE is not really required anymore. Changing that revealed some rather nasty looking CONFIG_MIGRATION handling. Let's clean that up by introducing a dedicated CONFIG_NUMA_MIGRATION option and reducing the dependencies that CONFIG_MIGRATION has. This patch (of 2): All architectures that select CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE also select CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG. So we can just remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE. For CONFIG_MIGRATION, make it depend on CONFIG_MEMORY_HOTREMOVE instead, and make CONFIG_MEMORY_HOTREMOVE select CONFIG_MIGRATION (just like CONFIG_CMA and CONFIG_COMPACTION already do). We'll clean up CONFIG_MIGRATION next. Link: https://lkml.kernel.org/r/20260319-config_migration-v1-0-42270124966f@kernel.org Link: https://lkml.kernel.org/r/20260319-config_migration-v1-1-42270124966f@kernel.org Signed-off-by: David Hildenbrand (Arm) Acked-by: Zi Yan Reviewed-by: Lorenzo Stoakes (Oracle) Reviewed-by: Joshua Hahn Reviewed-by: Gregory Price Reviewed-by: Mike Rapoport (Microsoft) Reviewed-by: Jonathan Cameron Cc: Albert Ou Cc: Alexander Gordeev Cc: Alexandre Ghiti Cc: Alistair Popple Cc: "Borislav Petkov (AMD)" Cc: Byungchul Park Cc: Catalin Marinas Cc: Christian Borntraeger Cc: Heiko Carstens Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: "Huang, Ying" Cc: Ingo Molnar Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Matthew Brost Cc: Michael Ellerman Cc: Michal Hocko Cc: Nicholas Piggin Cc: Palmer Dabbelt Cc: Rakie Kim Cc: Sebastian Andrzej Siewior Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Sven Schnelle Cc: Vasily Gorbik Cc: WANG Xuerui Cc: Will Deacon Signed-off-by: Andrew Morton

mm/Kconfig: make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP

2026-04-05T20:53:31Z

Ever since commit f8f03eb5f0f9 ("mm: stop making SPARSEMEM_VMEMMAP user-selectable"), an architecture that supports CONFIG_SPARSEMEM_VMEMMAP (by selecting SPARSEMEM_VMEMMAP_ENABLE) can no longer enable CONFIG_SPARSEMEM without CONFIG_SPARSEMEM_VMEMMAP. Right now, CONFIG_MEMORY_HOTPLUG is guarded by CONFIG_SPARSEMEM. However, CONFIG_ARCH_ENABLE_MEMORY_HOTPLUG is only enabled by * arm64: which selects SPARSEMEM_VMEMMAP_ENABLE * loongarch: which selects SPARSEMEM_VMEMMAP_ENABLE * powerpc (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE * riscv (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE * s390 with SPARSEMEM: which selects SPARSEMEM_VMEMMAP_ENABLE * x86 (64bit): which selects SPARSEMEM_VMEMMAP_ENABLE So, we can make CONFIG_MEMORY_HOTPLUG depend on CONFIG_SPARSEMEM_VMEMMAP without affecting any setups. Link: https://lkml.kernel.org/r/20260320-sparsemem_cleanups-v2-4-096addc8800d@kernel.org Signed-off-by: David Hildenbrand (Arm) Reviewed-by: Lorenzo Stoakes (Oracle) Reviewed-by: Mike Rapoport (Microsoft) Cc: Axel Rasmussen Cc: Liam Howlett Cc: Michal Hocko Cc: Oscar Salvador Cc: Sidhartha Kumar Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

slab,rcu: disable KVFREE_RCU_BATCHED for strict grace period

2026-03-25T08:39:01Z

Disable CONFIG_KVFREE_RCU_BATCHED in CONFIG_RCU_STRICT_GRACE_PERIOD builds so that kernel fuzzers have an easier time finding use-after-free involving kfree_rcu(). The intent behind CONFIG_RCU_STRICT_GRACE_PERIOD is that RCU should invoke callbacks and free objects as soon as possible (at a large performance cost) so that kernel fuzzers and such have an easier time detecting use-after-free bugs in objects with RCU lifetime. CONFIG_KVFREE_RCU_BATCHED is a performance optimization that queues RCU-freed objects in ways that CONFIG_RCU_STRICT_GRACE_PERIOD can't expedite; for example, the following testcase doesn't trigger a KASAN splat when CONFIG_KVFREE_RCU_BATCHED is enabled: ``` struct foo_struct { struct rcu_head rcu; int a; }; struct foo_struct *foo = kmalloc(sizeof(*foo), GFP_KERNEL | __GFP_NOFAIL | __GFP_ZERO); pr_info("%s: calling kfree_rcu()\n", __func__); kfree_rcu(foo, rcu); msleep(10); pr_info("%s: start UAF access\n", __func__); READ_ONCE(foo->a); pr_info("%s: end UAF access\n", __func__); ``` Signed-off-by: Jann Horn Acked-by: David Rientjes Reviewed-by: Joel Fernandes Acked-by: Harry Yoo (Oracle) Link: https://patch.msgid.link/20260324-kasan-kfree-rcu-v1-1-ac58a7a13d03@google.com Signed-off-by: Vlastimil Babka (SUSE)

Merge tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-02-12T19:32:37Z

Pull MM updates from Andrew Morton: - "powerpc/64s: do not re-activate batched TLB flush" makes arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev) It adds a generic enter/leave layer and switches architectures to use it. Various hacks were removed in the process. - "zram: introduce compressed data writeback" implements data compression for zram writeback (Richard Chang and Sergey Senozhatsky) - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous page ranges for hugepages. Large improvements during demand faulting are demonstrated (David Hildenbrand) - "memcg cleanups" tidies up some memcg code (Chen Ridong) - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos stats" improves DAMOS stat's provided information, deterministic control, and readability (SeongJae Park) - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few issues in the hugetlb cgroup charging selftests (Li Wang) - "Fix va_high_addr_switch.sh test failure - again" addresses several issues in the va_high_addr_switch test (Chunyu Hu) - "mm/damon/tests/core-kunit: extend existing test scenarios" improves the KUnit test coverage for DAMON (Shu Anzai) - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to transiently return -EAGAIN (Shivank Garg) - "arch, mm: consolidate hugetlb early reservation" reworks and consolidates a pile of straggly code related to reservation of hugetlb memory from bootmem and creation of CMA areas for hugetlb (Mike Rapoport) - "mm: clean up anon_vma implementation" cleans up the anon_vma implementation in various ways (Lorenzo Stoakes) - "tweaks for __alloc_pages_slowpath()" does a little streamlining of the page allocator's slowpath code (Vlastimil Babka) - "memcg: separate private and public ID namespaces" cleans up the memcg ID code and prevents the internal-only private IDs from being exposed to userspace (Shakeel Butt) - "mm: hugetlb: allocate frozen gigantic folio" cleans up the allocation of frozen folios and avoids some atomic refcount operations (Kefeng Wang) - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement of memory betewwn the active and inactive LRUs and adds auto-tuning of the ratio-based quotas and of monitoring intervals (SeongJae Park) - "Support page table check on PowerPC" makes CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan) - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes nodes_and() and nodes_andnot() propagate the return values from the underlying bit operations, enabling some cleanup in calling code (Yury Norov) - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up some DAMON internal interfaces (SeongJae Park) - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work in khupaged and fixes a scan limit accounting issue (Shivank Garg) - "mm: balloon infrastructure cleanups" goes to town on the balloon infrastructure and its page migration function. Mainly cleanups, also some locking simplification (David Hildenbrand) - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds additional tracepoints to the page reclaim code (Jiayuan Chen) - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is part of Marco's kernel-wide migration from the legacy workqueue APIs over to the preferred unbound workqueues (Marco Crivellari) - "Various mm kselftests improvements/fixes" provides various unrelated improvements/fixes for the mm kselftests (Kevin Brodsky) - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic folio allocation, mainly by avoiding unnecessary work in pfn_range_valid_contig() (Kefeng Wang) - "selftests/damon: improve leak detection and wss estimation reliability" improves the reliability of two of the DAMON selftests (SeongJae Park) - "mm/damon: cleanup kdamond, damon_call(), damos filter and DAMON_MIN_REGION" does some cleanup work in the core DAMON code (SeongJae Park) - "Docs/mm/damon: update intro, modules, maintainer profile, and misc" performs maintenance work on the DAMON documentation (SeongJae Park) - "mm: add and use vma_assert_stabilised() helper" refactors and cleans up the core VMA code. The main aim here is to be able to use the mmap write lock's lockdep state to perform various assertions regarding the locking which the VMA code requires (Lorenzo Stoakes) - "mm, swap: swap table phase II: unify swapin use" removes some old swap code (swap cache bypassing and swap synchronization) which wasn't working very well. Various other cleanups and simplifications were made. The end result is a 20% speedup in one benchmark (Kairui Song) - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM available on 64-bit alpha, loongarch, mips, parisc, and um. Various cleanups were performed along the way (Qi Zheng) * tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits) mm/memory: handle non-split locks correctly in zap_empty_pte_table() mm: move pte table reclaim code to memory.c mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config um: mm: enable MMU_GATHER_RCU_TABLE_FREE parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE mips: mm: enable MMU_GATHER_RCU_TABLE_FREE LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles zsmalloc: make common caches global mm: add SPDX id lines to some mm source files mm/zswap: use %pe to print error pointers mm/vmscan: use %pe to print error pointers mm/readahead: fix typo in comment mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file() mm: refactor vma_map_pages to use vm_insert_pages mm/damon: unify address range representation with damon_addr_range mm/cma: replace snprintf with strscpy in cma_new_area ...

Merge tag 'slab-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

2026-02-11T22:12:50Z

Pull slab updates from Vlastimil Babka: - The percpu sheaves caching layer was introduced as opt-in in 6.18 and now we enable it for all caches and remove the previous cpu (partial) slab caching mechanism. Besides the lower locking overhead and much more likely fastpath when freeing, this removes the rather complicated code related to the cpu slab lockless fastpaths (using this_cpu_try_cmpxchg128/64) and all its complications for PREEMPT_RT or kmalloc_nolock(). The lockless slab freelist+counters update operation using try_cmpxchg128/64 remains and is crucial for freeing remote NUMA objects, and to allow flushing objects from sheaves to slabs mostly without the node list_lock (Vlastimil Babka) - Eliminate slabobj_ext metadata overhead when possible. Instead of using kmalloc() to allocate the array for memcg and/or allocation profiling tag pointers, use leftover space in a slab or per-object padding due to alignment (Harry Yoo) - Various followup improvements to the above (Hao Li) * tag 'slab-for-7.0' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (39 commits) slub: let need_slab_obj_exts() return false if SLAB_NO_OBJ_EXT is set mm/slab: only allow SLAB_OBJ_EXT_IN_OBJ for unmergeable caches mm/slab: place slabobj_ext metadata in unused space within s->size mm/slab: move [__]ksize and slab_ksize() to mm/slub.c mm/slab: save memory by allocating slabobj_ext array from leftover mm/memcontrol,alloc_tag: handle slabobj_ext access under KASAN poison mm/slab: use stride to access slabobj_ext mm/slab: abstract slabobj_ext access via new slab_obj_ext() helper ext4: specify the free pointer offset for ext4_inode_cache mm/slab: allow specifying free pointer offset when using constructor mm/slab: use unsigned long for orig_size to ensure proper metadata align slub: clarify object field layout comments mm/slab: avoid allocating slabobj_ext array from its own slab slub: avoid list_lock contention from __refill_objects_any() mm/slub: cleanup and repurpose some stat items mm/slub: remove DEACTIVATE_TO_* stat items slab: remove frozen slab checks from __slab_free() slab: update overview comments slab: refill sheaves from all nodes slab: remove unused PREEMPT_RT specific macros ...

mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE

2026-02-06T23:47:19Z

The PT_RECLAIM can work on all architectures that support MMU_GATHER_RCU_TABLE_FREE, except for those that have selected HAVE_ARCH_TLB_REMOVE_TABLE,so make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE && !HAVE_ARCH_TLB_REMOVE_TABLE. BTW, change PT_RECLAIM to be enabled by default, since nobody should want to turn it off. Link: https://lkml.kernel.org/r/83b034810935a9ff18e425b085e065bb0acb28f3.1769515122.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: David Hildenbrand (Red Hat) Cc: Andreas Larsson Cc: "Aneesh Kumar K.V" Cc: Anton Ivanov Cc: Borislav Petkov Cc: Dave Hansen Cc: Dev Jain Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Johannes Berg Cc: Lance Yang Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: Magnus Lindholm Cc: Matt Turner Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Richard Henderson Cc: Richard Weinberger Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: WANG Xuerui Cc: Wei Yang Cc: Will Deacon Signed-off-by: Andrew Morton

mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config

2026-02-06T23:47:19Z

For architectures that define __HAVE_ARCH_TLB_REMOVE_TABLE, the page tables at the pmd/pud level are generally not of struct ptdesc type, and do not have pt_rcu_head member, thus these architectures cannot support PT_RECLAIM. In preparation for enabling PT_RECLAIM on more architectures, convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config, so that we can make conditional judgments in Kconfig. Link: https://lkml.kernel.org/r/5ebfa3d4b56e63c6906bda5eccaa9f7194d3a86b.1769515122.git.zhengqi.arch@bytedance.com Signed-off-by: Qi Zheng Acked-by: David Hildenbrand (Arm) Tested-by: Andreas Larsson [sparc, UP&SMP] Acked-by: Andreas Larsson [sparc] Cc: "Aneesh Kumar K.V" Cc: Anton Ivanov Cc: Borislav Petkov Cc: Dave Hansen Cc: Dev Jain Cc: Helge Deller Cc: "H. Peter Anvin" Cc: Huacai Chen Cc: Ingo Molnar Cc: "James E.J. Bottomley" Cc: Johannes Berg Cc: Lance Yang Cc: "Liam R. Howlett" Cc: Lorenzo Stoakes Cc: Magnus Lindholm Cc: Matt Turner Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Peter Zijlstra Cc: Richard Henderson Cc: Richard Weinberger Cc: Suren Baghdasaryan Cc: Thomas Bogendoerfer Cc: Thomas Gleixner Cc: Vlastimil Babka Cc: WANG Xuerui Cc: Wei Yang Cc: Will Deacon Signed-off-by: Andrew Morton

mm: rename CONFIG_MEMORY_BALLOON -> CONFIG_BALLOON

2026-01-31T22:22:36Z

Let's make it consistent with the naming of the files but also with the naming of CONFIG_BALLOON_MIGRATION. While at it, add a "/* CONFIG_BALLOON */". Link: https://lkml.kernel.org/r/20260119230133.3551867-24-david@kernel.org Signed-off-by: David Hildenbrand (Red Hat) Reviewed-by: Lorenzo Stoakes Acked-by: Michael S. Tsirkin Cc: Arnd Bergmann Cc: Christophe Leroy Cc: Eugenio Pérez Cc: Greg Kroah-Hartman Cc: Jason Wang Cc: Jerrin Shaji George Cc: Jonathan Corbet Cc: Liam Howlett Cc: Madhavan Srinivasan Cc: Michael Ellerman Cc: Michal Hocko Cc: Mike Rapoport Cc: Nicholas Piggin Cc: Oscar Salvador Cc: SeongJae Park Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Xuan Zhuo Cc: Zi Yan Signed-off-by: Andrew Morton