kernel/linux.git/mm/vmstat.c, branch v7.3-rc1

mm/vmstat: add NRSWP{IN,OUT} counters

2026-08-25T01:43:15+00:00

Count how many swap I/Os we cause. Due to batching this can be different than the current counter number of pages written/read, and tracking this information is useful to see how efficient the batching is. The counters are added at the end of enum vm_event_item and the vmstat_text array under the assumption that the order of fields in /proc/vmstat is an ABI. If that is not the case, they could be grouped with the other swap counters. Link: https://lore.kernel.org/20260713093350.2154226-8-hch@lst.de Signed-off-by: Christoph Hellwig Reviewed-by: Nhat Pham Cc: Baolin Wang Cc: Baoquan He Cc: Barry Song Cc: Chris Li Cc: Kairui Song Cc: Kemeng Shi Cc: Youngjun Park Signed-off-by: Andrew Morton

mm/vmscan: add pgrotate_anon and pgrotate_file vmstat counters

2026-08-25T01:42:56+00:00

Reclaim can spend substantial work on an LRU type without immediately reclaiming or demoting a corresponding amount of memory. Record this work in PGROTATE_ANON and PGROTATE_FILE. For classic LRU reclaim: - Inactive-list reclaim adds nr_scanned - nr_reclaimed to the corresponding anon/file counter when isolation succeeds. - Active-list reclaim adds referenced executable file folios that are retained on the active list to PGROTATE_FILE. Active anon reclaim does not contribute this component. For MGLRU, add the number of initially isolated pages that remain unreclaimed after both the initial and retry passes to the counter for the selected anon/file type. These counters are distinct from the existing pgrotated vm event. pgrotated records an actual move to the inactive-list tail, primarily after reclaim-marked writeback completes or failed invalidation leaves a folio for accelerated reclaim. PGROTATE_ANON and PGROTATE_FILE measure reclaim cost and do not imply that a folio moved to an LRU tail. A subsequent patch will consume these counters for anon/file scan balancing. Link: https://lore.kernel.org/20260727162550.2032-3-usama.arif@linux.dev Signed-off-by: Usama Arif Acked-by: Shakeel Butt Acked-by: Johannes Weiner Reviewed-by: Vlastimil Babka (SUSE) Cc: Axel Rasmussen Cc: Baoquan He Cc: Chris Li Cc: David Hildenbrand Cc: David Rientjes Cc: Kairui Song Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Nhat Pham Cc: Roman Gushchin Cc: Suren Baghdasaryan Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

mm/vmstat, mm/memcontrol: add _monotonic vmstat readers

2026-08-25T01:42:55+00:00

Patch series "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance cost", v5. The anon/file scan balance heuristic in get_scan_count() is fed by two scalars in struct lruvec (anon_cost, file_cost) that every reclaim producer updates under lruvec->lru_lock. The cost-recording work itself is trivial, but it both contends for and contributes to contention on lru_lock - which is often a contention point on memory-pressured workloads. Specifically: - shrink_inactive_list() re-acquires lru_lock at function exit just to call lru_note_cost_unlock_irq(). - shrink_active_list() does the same after rotation accounting. - workingset_refault() takes folio_lruvec_lock_irq() purely to record the refault cost. - prepare_scan_control() snapshots anon_cost/file_cost under lru_lock. - lru_note_cost_unlock_irq() itself walks parent_lruvec() and re-acquires lru_lock on every ancestor, multiplying the cost of every update by memcg-hierarchy depth. This series removes those producer-side acquisitions entirely. The rotation inputs become per-LRU PGROTATE_{ANON,FILE} vmstat counters. NR_VMSCAN_WRITE already captures reclaim-driven pageout at writeout(); charge it through lruvec_stat_mod_folio() so it is available per lruvec and aggregated through the memcg hierarchy. Reclaim does not submit filesystem folios for writeback from this path, so pageout contributes only to anon cost. WORKINGSET_RESTORE_* already captures the refault input. PGROTATE_* are also useful independently of scan balancing. They are cumulative base-page events, not unique-page counts. Classic inactive reclaim records scan work that does not produce immediate reclaim or demotion, while active reclaim records referenced executable file folios retained on the active list. MGLRU records initially isolated pages that remain unreclaimed after its retry passes. Read alongside pgscan_* and pgsteal_*, their deltas identify which LRU type is consuming reclaim CPU without producing immediate yield. Unlike the existing pgrotated event, they do not imply a move to the inactive-list tail. prepare_scan_control() reads the raw cost signals without lru_lock: anon = PGROTATE_ANON + (NR_VMSCAN_WRITE + WORKINGSET_RESTORE_ANON) * SWAP_CLUSTER_MAX file = PGROTATE_FILE + WORKINGSET_RESTORE_FILE * SWAP_CLUSTER_MAX It folds the deltas into a per-lruvec accumulator. A dedicated per-lruvec cost_lock, not touched by isolate_lru_folios(), move_folios_to_lru(), or folio_add_lru(), serialises the accumulator RMW and the lrusize/4 halving check. Hierarchy aggregation is implicit in rstat propagation, so the parent_lruvec() walk and the lru_reparent_memcg() cost-splice both disappear. Moving accumulation and decay to the reclaim side also improves the cost model across reclaim gaps. With producer-side decay, events that happen while reclaim is idle still age each other before reclaim ever samples the costs. If a workload refaults a large anon set and then a smaller file set before reclaim runs again, the later file activity can age the earlier anon activity out of the cost model. The new scheme observes the whole between-reclaim delta and decays anon and file proportionally, so the scan-balance history better represents what happened since the last reclaim pass. Trade-offs: - Cost reads see rstat-aggregated values that can lag until periodic / reader-triggered flushing. - Per-lruvec footprint grows by 4 unsigned longs + a spinlock (a struct lru_cost { count, last_rotated, last_io } per side), which is a small cost. - NR_VMSCAN_WRITE now also updates the folio's lruvec/memcg stat, adding memcg stat accounting to the reclaim writeout path while preserving the existing node-level total. == Numbers == Tested on a 176-core, 256 GB host. The benchmark drives sustained swap-out/refault inside a tight memcg using vm-scalability/usemem: usemem -n 16 --prealloc --prefault --random $((256*1024*1024)) run inside a two-level memcg with memory.max=512M on the leaf (4 GB anon working set has to fit in 512 MB -> continuous shrink_inactive_list + workingset_refault). A 16 GB swap file is used. Measurement is a 30 s `perf lock record -a` window over otherwise-idle hardware. Workload rates are identical on both kernels (the bench drives the same memory pressure): baseline patched delta pgscan_direct / s 172,662 171,817 ~0% pgsteal_direct / s 67,162 66,306 ~0% workingset_refault_anon / s 40,696 39,830 ~0% perf lock contention (total wait per 30 s window): Lock Name Before After % change shrink_lruvec+0x770 722.84 ms 0 -100% (eliminated) (= lru_note_cost_unlock_irq) workingset_refault+0x167 385.26 ms 0 -100% (eliminated) (= lru_note_cost_refault) shrink_node+0x4ad 689.43 ms 26.95 ms -96% shrink_active_list 208.34 ms 15.97 ms -92% lru_add_drain_cpu+0x34 1.96 s 917.71 ms -53% Total LRU lock wait ~4.23 s ~1.66 s -61% The two specific contention sites the patch removes (shrink_lruvec+0x770 = lru_note_cost_unlock_irq; workingset_refault+0x167 = lru_note_cost_refault) are completely absent from the patched perf-lock-contention output. Secondary reductions in shrink_node, shrink_active_list, lru_add_drain_cpu and pgrefill/pgactivate look like knock-on effects from removing the cost-recording overhead and the parent_lruvec walk. The remaining ~1.66 s of LRU lock wait on the patched kernel is dominated by the per-CPU pagevec drain (lru_add_drain_cpu) and the main reclaim path in shrink_lruvec. The numbers above can be reproduced using the script in [1]. This patch (of 3): lruvec_page_state(), node_page_state(), and global_node_page_state() all clamp negative reads to zero on CONFIG_SMP so that a transient per-CPU delta skew presents as zero pages rather than as a garbage unsigned value. This is the right behaviour for non-monotonic page-count readers. It is however incorrect for callers that snapshot a monotonically- incremented event counter and compute a delta from two samples. Once the underlying signed long wraps past LONG_MAX, the clamped read drops to zero while the previously-recorded snapshot still holds the pre-wrap value; the unsigned subtraction then underflows into a ~2^31 spurious delta for 32-bit architecture and corrupts the caller's accumulator. Add non-clamping siblings that return the underlying state value cast to unsigned long: global_node_page_state_monotonic() node_page_state_monotonic() lruvec_page_state_monotonic() With both samples read via the _monotonic variant, unsigned modular subtraction stays correct across a signed-long wraparound as long as the true growth between two samples fits in unsigned long (< 2^32 on 32-bit, < 2^64 on 64-bit); the 32-bit bound is the practically-reachable one that motivates this helper. The variants are only safe for monotonically-incremented counters. Non-monotonic page-count readers must keep using the existing clamped helpers so transient negative reads still present as zero. This is a prerequisite for a later patch which replaces the producer-side anon_cost/file_cost accumulators with a read-side accumulator in prepare_scan_control() that samples monotonic per-LRU vmstat counters (PGROTATE_*, NR_VMSCAN_WRITE, WORKINGSET_RESTORE_*) via lruvec_page_state_monotonic() and folds their unsigned modular deltas into lruvec->cost[].count. Link: https://lore.kernel.org/20260727162550.2032-1-usama.arif@linux.dev Link: https://lore.kernel.org/20260727162550.2032-2-usama.arif@linux.dev Link: https://gist.github.com/uarif1/a4eb33a86c5b2d7bbc55b42f0956e884 [1] Signed-off-by: Usama Arif Acked-by: Johannes Weiner Acked-by: Shakeel Butt Acked-by: Vlastimil Babka (SUSE) Cc: Axel Rasmussen Cc: Baoquan He Cc: Chris Li Cc: David Hildenbrand Cc: David Rientjes Cc: Kairui Song Cc: Liam R. Howlett Cc: Lorenzo Stoakes Cc: Michal Hocko Cc: Mike Rapoport Cc: Muchun Song Cc: Nhat Pham Cc: Roman Gushchin Cc: Suren Baghdasaryan Cc: Wei Xu Cc: Yuanchu Xie Signed-off-by: Andrew Morton

mm: move some stuff to mm/page_alloc.h

2026-07-31T02:40:41+00:00

Some of this stuff in the public header is only used internally so shrink the scope to avoid silently growing new users. drain_local_pages() is still used from kernel/power/snapshot.c so that needs to stay behind. Link: https://lore.kernel.org/20260703-alloc-trylock-v5-7-c87b714e19d3@google.com Signed-off-by: Brendan Jackman Reviewed-by: Vlastimil Babka (SUSE) Reviewed-by: Zi Yan Signed-off-by: Andrew Morton

mm/vmstat: avoid taking zone lock in /proc/buddyinfo reads

2026-07-29T04:12:05+00:00

frag_show_print() just reads zone->free_area[order].nr_free, so it can safely do this without needing the zone->lock. Pass nolock=true from frag_show(), so that walk_zones_in_node() can skip the zone->lock acquisition. Link: https://lore.kernel.org/20260604134245.1580287-1-imran.f.khan@oracle.com Signed-off-by: Imran Khan Reviewed-by: Joshua Hahn Acked-by: Vlastimil Babka (SUSE) Reviewed-by: Lorenzo Stoakes Acked-by: David Hildenbrand (Arm) Cc: Liam R. Howlett Cc: Michal Hocko Cc: Mike Rapoport Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

Merge tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

2026-04-19T15:01:17+00:00

Pull more MM updates from Andrew Morton: - "Eliminate Dying Memory Cgroup" (Qi Zheng and Muchun Song) Address the longstanding "dying memcg problem". A situation wherein a no-longer-used memory control group will hang around for an extended period pointlessly consuming memory - "fix unexpected type conversions and potential overflows" (Qi Zheng) Fix a couple of potential 32-bit/64-bit issues which were identified during review of the "Eliminate Dying Memory Cgroup" series - "kho: history: track previous kernel version and kexec boot count" (Breno Leitao) Use Kexec Handover (KHO) to pass the previous kernel's version string and the number of kexec reboots since the last cold boot to the next kernel, and print it at boot time - "liveupdate: prevent double preservation" (Pasha Tatashin) Teach LUO to avoid managing the same file across different active sessions - "liveupdate: Fix module unloading and unregister API" (Pasha Tatashin) Address an issue with how LUO handles module reference counting and unregistration during module unloading - "zswap pool per-CPU acomp_ctx simplifications" (Kanchana Sridhar) Simplify and clean up the zswap crypto compression handling and improve the lifecycle management of zswap pool's per-CPU acomp_ctx resources - "mm/damon/core: fix damon_call()/damos_walk() vs kdmond exit race" (SeongJae Park) Address unlikely but possible leaks and deadlocks in damon_call() and damon_walk() - "mm/damon/core: validate damos_quota_goal->nid" (SeongJae Park) Fix a couple of root-only wild pointer dereferences - "Docs/admin-guide/mm/damon: warn commit_inputs vs other params race" (SeongJae Park) Update the DAMON documentation to warn operators about potential races which can occur if the commit_inputs parameter is altered at the wrong time - "Minor hmm_test fixes and cleanups" (Alistair Popple) Bugfixes and a cleanup for the HMM kernel selftests - "Modify memfd_luo code" (Chenghao Duan) Cleanups, simplifications and speedups to the memfd_lou code - "mm, kvm: allow uffd support in guest_memfd" (Mike Rapoport) Support for userfaultfd in guest_memfd - "selftests/mm: skip several tests when thp is not available" (Chunyu Hu) Fix several issues in the selftests code which were causing breakage when the tests were run on CONFIG_THP=n kernels - "mm/mprotect: micro-optimization work" (Pedro Falcato) A couple of nice speedups for mprotect() - "MAINTAINERS: update KHO and LIVE UPDATE entries" (Pratyush Yadav) Document upcoming changes in the maintenance of KHO, LUO, memfd_luo, kexec, crash, kdump and probably other kexec-based things - they are being moved out of mm.git and into a new git tree * tag 'mm-stable-2026-04-18-02-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (121 commits) MAINTAINERS: add page cache reviewer mm/vmscan: avoid false-positive -Wuninitialized warning MAINTAINERS: update Dave's kdump reviewer email address MAINTAINERS: drop include/linux/liveupdate from LIVE UPDATE MAINTAINERS: drop include/linux/kho/abi/ from KHO MAINTAINERS: update KHO and LIVE UPDATE maintainers MAINTAINERS: update kexec/kdump maintainers entries mm/migrate_device: remove dead migration entry check in migrate_vma_collect_huge_pmd() selftests: mm: skip charge_reserved_hugetlb without killall userfaultfd: allow registration of ranges below mmap_min_addr mm/vmstat: fix vmstat_shepherd double-scheduling vmstat_update mm/hugetlb: fix early boot crash on parameters without '=' separator zram: reject unrecognized type= values in recompress_store() docs: proc: document ProtectionKey in smaps mm/mprotect: special-case small folios when applying permissions mm/mprotect: move softleaf code out of the main function mm: remove '!root_reclaim' checking in should_abort_scan() mm/sparse: fix comment for section map alignment mm/page_io: use sio->len for PSWPIN accounting in sio_read_complete() selftests/mm: transhuge_stress: skip the test when thp not available ...

mm/vmstat: fix vmstat_shepherd double-scheduling vmstat_update

2026-04-18T07:10:55+00:00

vmstat_shepherd uses delayed_work_pending() to check whether vmstat_update is already scheduled for a given CPU before queuing it. However, delayed_work_pending() only tests WORK_STRUCT_PENDING_BIT, which is cleared the moment a worker thread picks up the work to execute it. This means that while vmstat_update is actively running on a CPU, delayed_work_pending() returns false. If need_update() also returns true at that point (per-cpu counters not yet zeroed mid-flush), the shepherd queues a second invocation with delay=0, causing vmstat_update to run again immediately after finishing. On a 72-CPU system this race is readily observable: before the fix, many CPUs show invocation gaps well below 500 jiffies (the minimum round_jiffies_relative() can produce), with the most extreme cases reaching 0 jiffies—vmstat_update called twice within the same jiffy. Fix this by replacing delayed_work_pending() with work_busy(), which returns non-zero for both WORK_BUSY_PENDING (timer armed or work queued) and WORK_BUSY_RUNNING (work currently executing). The shepherd now correctly skips a CPU in all busy states. After the fix, all sub-jiffy and most sub-100-jiffie gaps disappear. The remaining early invocations have gaps in the 700–999 jiffie range, attributable to round_jiffies_relative() aligning to a nearer jiffie-second boundary rather than to this race. Each spurious vmstat_update invocation has a measurable side effect: refresh_cpu_vm_stats() calls decay_pcp_high() for every zone, which drains idle per-CPU pages back to the buddy allocator via free_pcppages_bulk(), taking the zone spinlock each time. Eliminating the double-scheduling therefore reduces zone lock contention directly. On a 72-CPU stress-ng workload measured with perf lock contention: free_pcppages_bulk contention count: ~55% reduction free_pcppages_bulk total wait time: ~57% reduction free_pcppages_bulk max wait time: ~47% reduction Note: work_busy() is inherently racy—between the check and the subsequent queue_delayed_work_on() call, vmstat_update can finish execution, leaving the work neither pending nor running. In that narrow window the shepherd can still queue a second invocation. After the fix, this residual race is rare and produces only occasional small gaps, a significant improvement over the systematic double-scheduling seen with delayed_work_pending(). Link: https://lore.kernel.org/20260409-vmstat-v2-1-e9d9a6db08ad@debian.org Fixes: 7b8da4c7f07774 ("vmstat: get rid of the ugly cpu_stat_off variable") Signed-off-by: Breno Leitao Reviewed-by: Vlastimil Babka (SUSE) Acked-by: Michal Hocko Reviewed-by: Dmitry Ilvokhin Cc: Christoph Lameter Cc: David Hildenbrand Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mike Rapoport Cc: Shakeel Butt Cc: Suren Baghdasaryan Signed-off-by: Andrew Morton

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

2026-04-15T19:59:16+00:00

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: add gpu active/reclaim per-node stat counters (v2)

2026-04-07T20:52:47+00:00

While discussing memcg intergration with gpu memory allocations, it was pointed out that there was no numa/system counters for GPU memory allocations. With more integrated memory GPU server systems turning up, and more requirements for memory tracking it seems we should start closing the gap. Add two counters to track GPU per-node system memory allocations. The first is currently allocated to GPU objects, and the second is for memory that is stored in GPU page pools that can be reclaimed, by the shrinker. Cc: Christian Koenig Cc: Matthew Brost Cc: Johannes Weiner Cc: linux-mm@kvack.org Cc: Andrew Morton Acked-by: Zi Yan Acked-by: Shakeel Butt Acked-by: Andrew Morton Acked-by: Christian König Signed-off-by: Dave Airlie

mm: vmalloc: streamline vmalloc memory accounting

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

Use a vmstat counter instead of a custom, open-coded atomic. This has the added benefit of making the data available per-node, and prepares for cleaning up the memcg accounting as well. Link: https://lkml.kernel.org/r/20260223160147.3792777-1-hannes@cmpxchg.org Acked-by: Shakeel Butt Signed-off-by: Johannes Weiner Reviewed-by: Roman Gushchin Reviewed-by: Vishal Moola (Oracle) Reviewed-by: Uladzislau Rezki (Sony) Cc: Joshua Hahn Cc: Michal Hocko Cc: Muchun Song Signed-off-by: Andrew Morton