Commit Graph

1415 Commits

Author SHA1 Message Date
Linus Torvalds
5f5ef9c407 Bootconfig updates for v7.3:
- bootconfig: Support build-time command line rendering for embedded bootconfig
   . bootconfig: render descendant keys when xbc_snprint_cmdline() root has a
     value. Fix xbc_snprint_cmdline() to render descendant keys when the root
     has both a value and subkeys, and treats empty subtrees correctly.
   . bootconfig: render embedded bootconfig as a kernel cmdline at build time.
     Add build-time pipeline using tools/bootconfig -C to render the embedded
     bootconfig "kernel" subtree into .init.rodata as a cmdline string.
   . bootconfig: clean build-time tools/bootconfig from make clean.
   . bootconfig: add xbc_prepend_embedded_cmdline() helper.
     Add helper to prepend embedded bootconfig cmdline into boot_command_line
     early before parse_early_param().
   . x86/setup: prepend embedded bootconfig cmdline before parse_early_param.
     Wire early prepend helper in x86 setup_arch() so early_param handlers see
     values from the embedded bootconfig. (So this feature is currently x86 only)
   . bootconfig: skip runtime kernel.* render once prepended early.
     Avoid duplicating "kernel" keys in setup_boot_config().
   . init/main.c: use bootconfig_cmdline_requested() for the runtime opt-in.
     Refactor setup_boot_config() to share bootconfig_cmdline_requested().
   . Documentation: bootconfig: document build-time cmdline rendering.
     Document CONFIG_CMDLINE_FROM_BOOTCONFIG usage, requirements, and precedence.
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Merge tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull bootconfig updates from Masami Hiramatsu:

 - Support build-time command line building for embedded bootconfig

 - Fix xbc_snprint_cmdline() to render descendant keys when the root has
   both a value and subkeys, and treats empty subtrees correctly.

 - Add build-time pipeline using tools/bootconfig -C to render the
   embedded bootconfig "kernel" subtree into .init.rodata as a cmdline
   string.

 - Clean build-time tools/bootconfig from make clean

 - Add helper to prepend embedded bootconfig cmdline into
   boot_command_line early before parse_early_param()

 - Wire early prepend helper in x86 setup_arch() so early_param handlers
   see values from the embedded bootconfig (currently x86 only)

 - Avoid duplicating "kernel" keys in setup_boot_config()

 - Refactor setup_boot_config() to share bootconfig_cmdline_requested()

 - Document CONFIG_CMDLINE_FROM_BOOTCONFIG usage, requirements, and
   precedence

* tag 'bootconfig-v7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  init/main.c: use bootconfig_cmdline_requested() for the runtime opt-in
  bootconfig: skip runtime kernel.* render once prepended early
  x86/setup: prepend embedded bootconfig cmdline before parse_early_param
  Documentation: bootconfig: document build-time cmdline rendering
  bootconfig: add xbc_prepend_embedded_cmdline() helper
  bootconfig: clean build-time tools/bootconfig from make clean
  bootconfig: render embedded bootconfig as a kernel cmdline at build time
  bootconfig: render descendant keys when xbc_snprint_cmdline() root has a value
2026-08-25 08:59:09 -07:00
Linus Torvalds
ed3b875bea mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
 
 Total patches:       501
 Reviews/patch:       1.66
 Reviewed rate:       70%
 
 Excluding DAMON:
 
 Total patches:       356
 Reviews/patch:       2.26
 Reviewed rate:       90%
 
 Excluding DAMON and selftests:
 
 Total patches:       329
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Excluding DAMON, selftests and maple_tree:
 
 Total patches:       328
 Reviews/patch:       2.31
 Reviewed rate:       92%
 
 Summary of patch series in this merge:
 
 - The 2 patch series "mm: drop "sub" prefix from various places" from
   Dev Jain implements some page->folio conversion and a naming cleanup.
 
 - The 2 patch series "mm/kasan: remove redundant initialization for
   kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
 
 - The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
   from Chi Zhiling provides a small speedup in the pagecaache read code.
 
 - The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
   recursion" from Kaitao Cheng improves a few things in the vmalloc code -
   mainly the avoidance of GFP_KERNEL allocations when the caller asked for
   GFP_NOFS or GFP_NOIO.
 
 - The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
   stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
   kmemleak scanning code in extreme situations.
 
 - The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
   collection of unrelated cleanups to the page_owner code.  For some
   reason lots of people have been working on the page_owner code this
   cycle.
 
 - The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
   find_vma()" from Kefeng Wang simplifies and accelerates the page walking
   library function.
 
 - The 3 patch series "mm/migrate: preparatory cleanups for batch copy
   and offload" from Shivank Garg implements cleanups in the migration
   code.
 
 - The 4 patch series "mm/page_owner: add per-fd filter infrastructure
   for print_mode and NUMA filtering" from Zhen Ni provides per-fd
   filtering to page_owner in order to reduce the sometimes vast amount of
   output it can produce.
 
 - The 19 patch series "mm: Refactor bootmem gigantic hugepage
   allocation" from Muchun Song is a "set of fixes and preparatory cleanups
   around bootmem HugeTLB handling, sparse initialization ordering, and
   related vmemmap setup".
 
 - The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
   from Wenchao Hao reduces lock contention in zs_free(), which dominates
   the unmap path under memory pressure on Android (LMK kills) and on x86
   servers running zswap-heavy workloads.  Up to 1.83x improvement in
   microbenchmarking.
 
 - The 2 patch series "move alloc_tag.c file under mm/" from Suren
   Baghdasaryan does that.
 
 - The 6 patch series "samples/damon: handle damon_{start,stop}()
   failures" from SJ Park fixes improper handling of damon_start(),
   damon_stop(), and damon_call() failures across DAMON sample modules to
   prevent potential memory leaks, operation disruptions and use-after-free
   bugs.
 
 - The 11 patch series "mm/damon/sysfs: kobject_del() directories that
   users can create/remove" from SJ Park resolves an issue where delayed
   sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
   creation failures due to duplicate directory names by adding missing
   kobject_del() calls before creating new directories.
 
 - The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
   David Hildenbrand cleans up the core pte handling code.
 
 - The 3 patch series "selftests/damon: misc fixes for test bugs" from
   Kunwu Chan fixes several bugs in the DAMON selftests.
 
 - The 2 patch series "selftests/damon: fix memcg_path staging handling"
   from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
   memcg_path setup, and adds a test case for it in sysfs.py.
 
 - The 2 patch series "selftests/damon: test kdamond refresh_ms" from
   Ruslan Valiyev introduces selftest coverage for DAMON's refresh_ms sysfs
   feature by updating the test control module and verifying that scheme
   stats update automatically without manual intervention.
 
 - The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
   contains miscellaneous DAMON fixups.
 
 - The 2 patch series "mm/damon/core: detect internal variation above
   max_nr_regions/2" from Jiayuan Chen fixes DAMON's region splitting
   behavior when region counts exceed half the maximum budget by
   dynamically scaling down the split fraction as the limit approaches,
   preventing large regions from staying un-split, and adds corresponding
   KUnit test coverage.
 
 - The 6 patch series "mm: preparatory patches for PMD level swap
   entries" from Usama Arif refactors and cleans up PMD softleaf helpers,
   call sites, and architecture flags to lay the groundwork for a follow-up
   series that introduces PMD page table swap entries.
 
 - The 11 patch series "mm/damon: update, optimize, and clean up doc,
   tests, and code" from SJ Park updates DAMON design and ABI
   documentation, expands unit and selftest coverage, optimizes
   damon_commit_target_regions(), and cleans up recently added sysfs
   interface code for better readability.
 
 - The 2 patch series "mm/vmpressure: reduce CPU, memory and code
   overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
   skipping unnecessary work on cgroup v2 for userspace event notifications
   and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
   memory overhead and code complexity.
 
 - The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
   error handling" from Hongfu Li refactors pkeys shared tracing and
   assertion helpers into a common file, unifies protection key selftests
   to use consistent diagnostic logging and assertions, and enforces
   standardized MAP_FAILED return checks for mmap() calls across the tests.
 
 - The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
   Park replaces the error-prone, continuously updated nr_accesses_bp field
   in damon_region with an on-demand moving sum function
   (damon_nr_accesses_mvsum()), reducing structure memory overhead and
   avoiding state corruption bugs.
 
 - The 6 patch series "Open HugeTLB allocation routine for more generic
   use" from Ackerley Tng decouples HugeTLB folio allocation from VMA
   dependencies by introducing hugetlb_alloc_folio(), enabling subsystems
   like guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs.
 
 - The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
   from SJ Park integrates DAMON's probe_hits attribute counter into the
   pseudo moving sum infrastructure, enabling real-time, online monitoring
   without waiting for full aggregation intervals.
 
 - The 18 patch series "mm: Some cleanups for page allocator APIs" from
   Brendan Jackman simplifies and refactors the page allocator entry points
   and flags by unifying allocation paths, adding internal alloc_flags
   arguments, and eliminating redundant __ prefixed alloc_pages variants.
 
 - The 5 patch series "Fix incorrect access of hugetlb pte entries" from
   Dev Jain enforces the consistent use of huge_ptep_get() instead of
   ptep_get() for HugeTLB entries and fixes an unaligned address issue in
   arm64's huge_ptep_get() implementation.
 
 - The 8 patch series "mm/damon: validate all parameters in the core"
   from SJ Park consolidates parameter validation into the DAMON core
   specifically within damon_start() and damon_commit_ctx() to centralize
   error checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency.
 
 - The 3 patch series "tools/mm/page_owner_sort: fix filtering and
   cleanup issues" from Yichong Chen renames is_need() to filter_record()
   for clearer return semantics, fixes per-record allocation memory leaks
   and bounds output copies in search_pattern() to address an existing
   buffer issue.
 
 - The 4 patch series "memcg: bail out reclaim when memcg is dying" from
   Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
   removed while one of its memory control files is doing synchronous
   reclaim.
 
 - The 5 patch series "mm/memory-failure: add panic option for
   unrecoverable pages" from Breno Leitao introduces an opt-in
   vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics
   the kernel on unrecoverable memory errors in kernel-owned pages to
   preserve error context and prevent delayed, silent data corruption.
 
 - The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
   for simple error handling" from SJ Park refactors the DAMON core API
   functions to guarantee that all contexts are fully stopped when
   damon_start(), damon_stop(), or damon_commit() fail, eliminating the
   need for complex and error-prone caller-side cleanup code.
 
 - The 5 patch series "Keep tail page private zero at free and folio
   split" from Zi Yan adds checks to ensure tail_page->private is zero when
   freeing compound or high-order pages and when promoting tail pages
   during large folio splits.  By validating these fields at free and split
   time, it allows the removal of redundant private field clearing inside
   prep_compound_tail().
 
 - The 4 patch series "mm: drop redundant lru_add_drain in anon folio
   reuse paths" from Barry Song eliminates redundant lru_add_drain() calls
   in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead.
 
   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads.
 
 - The 3 patch series "mm: clean up folio LRU and swap declarations" from
   Jianyue Wu reorganizes folio LRU and swap code by relocating
   page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c,
   and moving MM-internal reclaim declarations into mm/internal.h.
 
 - The 15 patch series "userfaultfd: working set tracking for VM guest
   memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
   working set of VM guest memory, so a VMM can identify hot pages and
   reclaim cold ones to tiered or remote storage.
 
 - The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
   2)" from David Hildenbrand removes the remaining pieces of
   CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
   freeing of reserved vmemmap pages on the way.
 
 - The 7 patch series "mm/damon: update probe hits for runtime parameter
   commits" from SJ Park ensures that DAMON's probe_hits attribute counter
   is properly updated when monitoring intervals are changed at runtime,
   matching the behavior of nr_accesses.  To achieve this, it refactors and
   renames existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.
 
 - The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
   from xu xin resolves a severe KSM reverse-mapping performance bottleneck
   where thousands of split VMAs sharing a single anon_vma cause extended
   lock contention.  By adding an interval-filtering check during the rmap
   walk, it reduces worst-case anon_vma lock hold times from over 500ms
   down to under 2ms, preventing application freezes and latency spikes
   under memory pressure.
 
 - The 3 patch series "mm: split a couple of headers from internal.h"
   from Mike Rapoport splits declarations related to mm_init, memblock,
   vmalloc and sparse into new headers.
 
 - The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
   from xu xin applies the interval tree optimization from rmap_walk_ksm()
   to collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.  It hoists loop-invariant address
   initialization and restricts the anon_vma_interval_tree_foreach walk to
   a targeted page offset range, reducing redundant checks and improving
   lookup efficiency.
 
 - The 3 patch series "selftests/mm: avoid false failures in hugetlb and
   KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
   selftest categories that can report failures when the prerequisites for
   the tests are not satisfied.
 
 - The 19 patch series "mm/damon: introduce data attributes only
   monitoring" from SJ Park introduces attribute-weighted region management
   in DAMON, allowing users to prioritize specific data attributes (such as
   page sizes or cgroups) over or instead of access monitoring.
 
   By assigning weights to attribute probes, DAMON can completely disable
   access tracking and adjust monitoring regions based on weighted
   probe-hit counters to optimize monitoring quality for attribute-focused
   workloads.
 
 - The 8 patch series "mm/hmm: Add mmap lock-drop support for
   userfaultfd-backed mappings" from Stanislav Kinsburskii extends
   hmm_range_fault() to support userfaultfd-backed regions by allowing the
   mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.
 
   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd regions
   while preserving backward compatibility for existing callers.
 
 - The 33 patch series "mm: make VMA page offset handling more
   consistent" from Lorenzo Stoakes cleans up and standardizes how
   vma->vm_pgoff is accessed and manipulated across file-backed and
   anonymous mappings in the kernel.
 
   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming
   rmap interval tree helpers to better reflect their functionality.
 
   These changes establish a cleaner foundation for future work that will
   unify virtual page offset indexing for all anonymous and CoW'd folios.
 
 - The 3 patch series "mm: handle device-private PMDs in walk callbacks"
   from Usama Arif addresses kernel panics and state corruption caused by
   MM walk callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations.
 
   It ensures that functions which acquire pmd_trans_huge_lock() properly
   recognize device-private PMDs instead of assuming a present THP or a
   standard migration entry.
 
 - The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
   refactors try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree,
   and anonymous-swapbacked logic into dedicated functions, laying the
   structural groundwork for batched anonymous large folio unmapping.
 
 - The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
   additions" from Song Hu fixes typos and fills in missing entries in the
   DAMON sysfs ABI document.
 
 - The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
   from Gregory Price introduces an atomic sysfs state attribute and
   supporting DAX/MM infrastructure to prevent userland races when
   offlining and removing entire memory regions.
 
   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.
 
 - The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
   from Lorenzo Stoakes continues transitioning the kernel from the
   deprecated vm_flags_t type to vma_flags_t across core memory management
   infrastructure.
 
   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.
 
 - The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
   xu xin refactors mm_slot.h by introducing mm_slot_remove() to unify
   duplicate slot deletion sequences in khugepaged and KSM.  It also adds
   code documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.
 
 - The 10 patch series "mm/damon/core: hide core-private struct fields"
   from SJ Park cleans up DAMON core structures by consistently marking
   internal-only fields with private: comment tags to prevent improper
   direct access from outer layers.
 
   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.
 
 - The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
   de-ref and races" from SJ Park addresses potential infinite loops, NULL
   dereferences, and race conditions identified in DAMON.
 
   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.
 
 - The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
   RT/UP" from Brendan Jackman fixes an NMI safety flaw in
   __free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT
   kernels can bypass can_spin_trylock() checks via non-PCP or isolated
   migration paths.
 
   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.
 
 - The 4 patch series "mm/page_alloc: couple of followups for recent
   cleanups" from Brendan Jackman cleans up and updates page allocator
   nomenclature, documentation, and debug assertions.
 
   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete VM_BUG_ON()
   assertions in allocation paths.
 
 - The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
   refactors and simplifies the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.
 
   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates
   mm_struct parameters to enforce that sealing applies only to
   current->mm, and streamlines overall logic and comments with no
   functional changes intended.
 
 - The 4 patch series "mm/vmscan: fix swappiness=max and clean up
   per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
   bugs and cleans up function parameters across memory reclaim paths.
 
   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead of
   collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask
   parameter from __node_reclaim().
 
 - The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
   cleans up and simplifies the mincore code.  Most importantly, it removes
   the historical special behavior that always reports VM_PFNMAP pages as
   non-resident.
 
 - The 2 patch series "mm/huge_memory: drop dead split helper variants"
   from Kiryl Shutsemau implements two trivial cleanups in the folio split
   API.
 
 - The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
   exec expectation bugs" from SJ Park resolves minor operational and
   testing bugs in DAMON identified by Sashiko.  It initializes the
   damos->last_applied field to prevent occasional efficiency degradation
   and fixes invalid memory accesses in DAMON KUnit tests during test
   failure handling.
 
 - The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
   cleans up and refactors stable_page_flags() used by /proc/kpageflags
   without altering functionality.
 
   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
 
 - The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
   extends batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities
   to pte_install_uffd_wp_if_needed().
 
   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.
 
 - The 3 patch series "mm/early_ioremap: clarify and clean up
   early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans up the
   architecture-specific usage of __late_set_fixmap() and
   __late_clear_fixmap() after early_ioremap_reset().
 
   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset calls
   in the RISC-V and ARM64 architectures.
 
 - The 4 patch series "mm: fix reclaim storms in defrag_mode" from
   Johannes Weiner addresses severe performance regressions, swap storms,
   and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure
   in Meta production.
 
   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.
 
 - The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
   optimizes and fixes lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolating lock classes across multiple instances.
 
   It reduces memory overhead by replacing per-entry lockdep_map instances
   with a single map per struct zram, and assigns a dynamic lock_class_key
   to each instance to prevent false deadlock reports when different zram
   devices are backed by distinct filesystems.
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Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - "mm: drop "sub" prefix from various places" (Dev Jain)

   page->folio conversion and a naming cleanup

 - "mm/kasan: remove redundant initialization for kasan_flag_write_only"
   (Igor Putko)

   KASAN cleanup work

 - "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)

   Small speedup in the pagecaache read code

 - "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)

   Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
   allocations when the caller asked for GFP_NOFS or GFP_NOIO

 - "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
   Leitao)

   Avoid a soft lockup watchdog trigger from the kmemleak scanning code
   in extreme situations

 - "mm/page_owner: misc cleanups" (Ye Liu)

   Cleanups to the page_owner code. For some reason lots of people have
   been working on the page_owner code this cycle.

 - "mm: convert to walk_page_range_vma() to eliminate find_vma()"
   (Kefeng Wang)

   Simplify and accelerate the page walking library function

 - "mm/migrate: preparatory cleanups for batch copy and offload"
   (Shivank Garg)

   Cleanups in the migration code

 - "mm/page_owner: add per-fd filter infrastructure for print_mode and
   NUMA filtering" (Zhen Ni)

   Per-fd filtering to page_owner in order to reduce the sometimes vast
   amount of output it can produce

 - "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)

   Fixes and preparatory cleanups around bootmem HugeTLB handling,
   sparse initialization ordering, and related vmemmap setup

 - "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)

   Reduce lock contention in zs_free(), which dominates the unmap path
   under memory pressure on Android (LMK kills) and on x86 servers
   running zswap-heavy workloads.

   Up to 1.83x improvement in microbenchmarking.

 - "move alloc_tag.c file under mm/" (Suren Baghdasaryan)

 - "samples/damon: handle damon_{start,stop}() failures" (SJ Park)

   Fix improper handling of damon_start(), damon_stop(), and
   damon_call() failures across DAMON sample modules to prevent
   potential memory leaks, operation disruptions and use-after-free
   bugs

 - "mm/damon/sysfs: kobject_del() directories that users can
   create/remove" (SJ Park)

   Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
   causeing creation failures due to duplicate directory names by adding
   missing kobject_del() calls before creating new directories

 - "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)

   Clean up the core pte handling code

 - "selftests/damon: misc fixes for test bugs" (Kunwu Chan)

   Fix several bugs in the DAMON selftests

 - "selftests/damon: fix memcg_path staging handling" (Cheng Nie)

   Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
   add a test case for it in sysfs.py.

 - "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)

   Selftest coverage for DAMON's refresh_ms sysfs feature by updating
   the test control module and verifying that scheme stats update
   automatically without manual intervention

 - "mm/damon: five misc fixups" (Akinobu Mita)

   Miscellaneous DAMON fixups.

 - "mm/damon/core: detect internal variation above max_nr_regions/2"
   (Jiayuan Chen)

   Fix DAMON's region splitting behavior when region counts exceed half
   the maximum budget by dynamically scaling down the split fraction as
   the limit approaches, preventing large regions from staying un-split,
   and add corresponding KUnit test coverage

 - "mm: preparatory patches for PMD level swap entries" (Usama Arif)

   Refactor and clean up PMD softleaf helpers, call sites, and
   architecture flags to lay the groundwork for a follow-up series that
   introduces PMD page table swap entries

 - "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
   Park)

   Update DAMON design and ABI documentation, expands unit and selftest
   coverage, optimize damon_commit_target_regions(), and clean up
   recently added sysfs interface code for better readability

 - "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
   (Usama Arif)

   Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
   userspace event notifications and refactor v1-only eventfd handling
   into mm/memcontrol-v1.c to reduce memory overhead and code complexity

 - "selftests/mm: refactor pkey helpers and fix mmap error handling"
   (Hongfu Li)

   Refactor pkeys shared tracing and assertion helpers into a common
   file, unify protection key selftests to use consistent diagnostic
   logging and assertions, and enforce standardized MAP_FAILED return
   checks for mmap() calls across the tests

 - "mm/damon: optimize out nr_accesses_bp" (SJ Park)

   Replace the error-prone, continuously updated nr_accesses_bp field in
   damon_region with an on-demand moving sum function, reducing
   structure memory overhead and avoiding state corruption bugs

 - "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)

   Decouple HugeTLB folio allocation from VMA dependencies by
   introducing hugetlb_alloc_folio(), enabling subsystems like
   guest_memfd to allocate HugeTLB folios without standard VMA
   reservations or pseudo-VMAs

 - "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)

   Integrate DAMON's probe_hits attribute counter into the pseudo moving
   sum infrastructure, enabling real-time, online monitoring without
   waiting for full aggregation intervals

 - "mm: Some cleanups for page allocator APIs" (Brendan Jackman)

   Simplify and refactor the page allocator entry points and flags by
   unifying allocation paths, adding internal alloc_flags arguments, and
   eliminating redundant __ prefixed alloc_pages variants.

 - "Fix incorrect access of hugetlb pte entries" (Dev Jain)

   Enforce the consistent use of huge_ptep_get() instead of ptep_get()
   for HugeTLB entries and fixes an unaligned address issue in arm64's
   huge_ptep_get() implementation

 - "mm/damon: validate all parameters in the core" (SJ Park)

   Consolidate parameter validation into the DAMON core specifically
   within damon_start() and damon_commit_ctx() to centralize error
   checking, eliminate caller-side redundant checks and to improve
   maintenance efficiency

 - "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
   Chen)

   Rename is_need() to filter_record() for clearer return semantics, fix
   per-record allocation memory leaks and bound output copies in
   search_pattern() to address an existing buffer issue

 - "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)

   Mitigate a system-wide stall which occurs when a cgroup is removed
   while one of its memory control files is doing synchronous reclaim

 - "mm/memory-failure: add panic option for unrecoverable pages" (Breno
   Leitao)

   Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
   that immediately panics the kernel on unrecoverable memory errors in
   kernel-owned pages to preserve error context and prevent delayed,
   silent data corruption

 - "mm/damon: refactor damon_{start,stop,commit}() for simple error
   handling" (SJ Park)

   Refactor the DAMON core API functions to guarantee that all contexts
   are fully stopped when damon_start(), damon_stop(), or damon_commit()
   fail, eliminating the need for complex and error-prone caller-side
   cleanup code

 - "Keep tail page private zero at free and folio split" (Zi Yan)

   Add checks to ensure tail_page->private is zero when freeing compound
   or high-order pages and when promoting tail pages during large folio
   splits. By validating these fields at free and split time, it allows
   the removal of redundant private field clearing inside
   prep_compound_tail()

 - "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
   Song)

   Eliminate redundant lru_add_drain() calls in
   wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
   contention and system overhead

   By validating folio refcounts against the LRU cache before draining
   and removing unnecessary drains in the swap path, it achieves up to a
   30.5% reduction in drain calls during heavy swap workloads

 - "mm: clean up folio LRU and swap declarations" (Jianyue Wu)

   Reorganize folio LRU and swap code by relocating page-cluster state
   to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
   MM-internal reclaim declarations into mm/internal.h.

 - "userfaultfd: working set tracking for VM guest memory" (Kiryl
   Shutsemau)

   Add userfaultfd support for tracking the working set of VM guest
   memory, so a VMM can identify hot pages and reclaim cold ones to
   tiered or remote storage

 - "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
   Hildenbrand)

   Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
   performing some smaller cleanups around freeing of reserved vmemmap
   pages on the way.

 - "mm/damon: update probe hits for runtime parameter commits" (SJ Park)

   Ensure that DAMON's probe_hits attribute counter is properly updated
   when monitoring intervals are changed at runtime, matching the
   behavior of nr_accesses. To achieve this, it refactors and renames
   existing helper functions for shared use, applies the updates to
   probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
   maintain measurement accuracy.

 - "KSM: performance optimizations for rmap_walk_ksm" (xu xin)

   Resolve a severe KSM reverse-mapping performance bottleneck where
   thousands of split VMAs sharing a single anon_vma cause extended lock
   contention.

   By adding an interval-filtering check during the rmap walk, it
   reduces worst-case anon_vma lock hold times from over 500ms down to
   under 2ms, preventing application freezes and latency spikes under
   memory pressure.

 - "mm: split a couple of headers from internal.h" (Mike Rapoport)

   Split declarations related to mm_init, memblock, vmalloc and sparse
   into new headers

 - "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)

   Apply the interval tree optimization from rmap_walk_ksm() to
   collect_procs_ksm() to avoid iterating over non-matching VMAs during
   KSM memory error handling.

   It hoists loop-invariant address initialization and restricts the
   anon_vma_interval_tree_foreach walk to a targeted page offset range,
   reducing redundant checks and improving lookup efficiency.

 - "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
   Patil)

   Fix issues in the hugetlb and KSM MM selftest categories that can
   report failures when the prerequisites for the tests are not
   satisfied

 - "mm/damon: introduce data attributes only monitoring" (SJ Park)

   Introduce attribute-weighted region management in DAMON, allowing
   users to prioritize specific data attributes (such as page sizes or
   cgroups) over or instead of access monitoring.

   By assigning weights to attribute probes, DAMON can completely
   disable access tracking and adjust monitoring regions based on
   weighted probe-hit counters to optimize monitoring quality for
   attribute-focused workloads.

 - "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
   (Stanislav Kinsburskii)

   Extend hmm_range_fault() to support userfaultfd-backed regions by
   allowing the mmap lock to be dropped during fault handling via a new
   hmm_range_fault_locked() helper.

   By accepting a locked pointer and signaling retry status when lock
   release occurs, it enables page fault resolution in userfaultfd
   regions while preserving backward compatibility for existing callers.

 - "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)

   Clean up and standardize how vma->vm_pgoff is accessed and
   manipulated across file-backed and anonymous mappings in the kernel

   It introduces dedicated helper functions such as vma_start_pgoff(),
   vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
   renaming rmap interval tree helpers to better reflect their
   functionality.

   These changes establish a cleaner foundation for future work that
   will unify virtual page offset indexing for all anonymous and CoW'd
   folios.

 - "mm: handle device-private PMDs in walk callbacks" (Usama Arif)

   Address kernel panics and state corruption caused by MM walk
   callbacks reaching non-present device-private PMD swap entries
   created during HMM migrations

   It ensures that functions which acquire pmd_trans_huge_lock()
   properly recognize device-private PMDs instead of assuming a present
   THP or a standard migration entry.

 - "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)

   Refactor try_to_unmap_one by modularizing Hugetlb,
   anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
   functions, laying the structural groundwork for batched anonymous
   large folio unmapping.

 - "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)

   Fix typos and fills in missing entries in the DAMON sysfs ABI
   document

 - "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)

   Introduce an atomic sysfs state attribute and supporting DAX/MM
   infrastructure to prevent userland races when offlining and removing
   entire memory regions

   By adding an unplugged state alongside standard online modes, it
   enables whole-device atomic hotplug control while preserving backward
   compatibility.

 - "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)

   Continue transitioning the kernel from the deprecated vm_flags_t type
   to vma_flags_t across core memory management infrastructure.

   It replaces legacy type usage in core functions such as do_mmap(),
   unmapped area allocation, mm->def_vma_flags, and VMA operations like
   mlock, mprotect, and mremap.

 - "Two small patches to clean up mm/mm_slot.h" (xu xin)

   Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
   slot deletion sequences in khugepaged and KSM. It also adds code
   documentation explaining why mm_slot_lookup and mm_slot_insert must
   remain as preprocessor macros rather than static inline functions.

 - "mm/damon/core: hide core-private struct fields" (SJ Park)

   Clean up DAMON core structures by consistently marking internal-only
   fields with private: comment tags to prevent improper direct access
   from outer layers.

   It enforces encapsulation across core structures including
   damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
   interact through approved access APIs instead of exposing raw struct
   members.

 - "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
   (SJ Park)

   Address potential infinite loops, NULL dereferences, and race
   conditions identified in DAMON

   It fixes an infinite loop triggered by extreme user configurations, a
   NULL pointer dereference within unit tests and minor monitoring
   accuracy degradation caused by subtle runtime races.

 - "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
   Jackman)

   Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
   on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
   via non-PCP or isolated migration paths.

   It also resolves potential kernel crashes and privilege escalation
   risks triggered when BPF tracing runs in NMI context alongside memory
   hotplug or large allocation frees.

 - "mm/page_alloc: couple of followups for recent cleanups" (Brendan
   Jackman)

   Clean up and update page allocator nomenclature, documentation, and
   debug assertions.

   It aligns internal FPI_ flags with the public "nolock" naming
   convention, removes outdated internal implementation details from
   high-level page allocator comments, and eliminates obsolete
   VM_BUG_ON() assertions in allocation paths.

 - "mm/mseal: further cleanups" (Lorenzo Stoakes)

   Refactor and simplify the mseal implementation by clarifying API
   boundaries and removing unnecessary code complexity.

   It replaces generic do_mseal() usage outside the syscall with a
   dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
   eliminates mm_struct parameters to enforce that sealing applies only
   to current->mm, and streamlines overall logic and comments with no
   functional changes intended.

 - "mm/vmscan: fix swappiness=max and clean up per-node proactive
   reclaim" (Ridong Chen)

   Resolve reclaim behavior bugs and clean up function parameters across
   memory reclaim paths

   It fixes swappiness=max in both standard reclaim and MGLRU so
   unswappable anonymous memory no longer falls back to evicting page
   cache, ensures reclaim_store() returns accurate error codes instead
   of collapsing all failures into -EAGAIN, and removes the obsolete
   gfp_mask parameter from __node_reclaim().

 - "mm: mincore: misc cleanups" (Kefeng Wang)

   Clean up and simplifies the mincore code. Most importantly, it
   removes the historical special behavior that always reports VM_PFNMAP
   pages as non-resident.

 - "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)

   Two trivial cleanups in the folio split API

 - "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
   bugs" (SJ Park)

   Resolve minor operational and testing bugs in DAMON identified by
   Sashiko. It initializes the damos->last_applied field to prevent
   occasional efficiency degradation and fixes invalid memory accesses
   in DAMON KUnit tests during test failure handling.

 - "cleanup for stable_page_flags()" (Jinjiang Tu)

   Clean up and refactor stable_page_flags() used by /proc/kpageflags
   without altering functionality.

   It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
   bits, converts folio-specific flag checks to standard folio_test_*()
   helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.

 - "Batch unmap of uffd-wp file folios" (Dev Jain)

   Extend batched folio unmapping support to file folios within
   userfaultfd write-protect (uffd-wp) VMAs by adding batching
   capabilities to pte_install_uffd_wp_if_needed().

   This removes special-case restrictions on uffd-wp VMAs in
   try_to_unmap_one(), significantly simplifying the function's control
   flow and complexity.

 - "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
   (Sang-Heon Jeon)

   Clarify and clean up the architecture-specific usage of
   __late_set_fixmap() and __late_clear_fixmap() after
   early_ioremap_reset()

   It adds explicit documentation regarding when early_ioremap_reset()
   must be called and removes redundant macro definitions and reset
   calls in the RISC-V and ARM64 architectures.

 - "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)

   Address severe performance regressions, swap storms, and spurious
   OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
   production

   It updates the page allocator slowpath so non-movable allocation
   requests actively trigger direct reclaim and direct compaction at
   pageblock_order scale, allowing them to claim whole pageblocks rather
   than spinning unproductively.

 - "zram: lockmap tweaks" (Sebastian Siewior)

   Optimize and fix lockdep tracking for zram devices by consolidating
   per-entry lockmaps and isolate lock classes across multiple instances

   This reduces memory overhead by replacing per-entry lockdep_map
   instances with a single map per struct zram, and assigns a dynamic
   lock_class_key to each instance to prevent false deadlock reports
   when different zram devices are backed by distinct filesystems.

* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
  selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
  selftests/mm: unpoison pages in memory-failure teardown
  mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
  mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
  mm/zsmalloc: fix release order of locks in zs_page_migrate()
  Documentation: zram: remove sections numbering
  ksm: stop iterating VMAs when ksm_test_exit returns true
  mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
  mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
  zram: use a custom key for each zram object
  zram: move lockmap to be per-zram instead per table
  selftests/mm: fix gup_longterm EINVAL error message
  mm: page_alloc: fix non-movable reclaim storm in defrag_mode
  mm: page_alloc: move capture_control to the page allocator
  mm: compaction: support non-movable compaction for pageblock requests
  mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
  hugetlb: evaluate subpool free state while locked
  mm/damon: remove trailing semicolons after function definitions
  mm/damon/ops-common: prevent migration fallback to non-target nodes
  mm/damon: update outdated comment about DAMOS filter handling
  ...
2026-08-20 18:17:08 -07:00
Linus Torvalds
9d2ed026f0 Summary
* Documentation
 
   Fix kernel-doc warnings by adjusting in file documentation.
 
 * Consolidate do_proc_* function into do_proc_vec.
 
   Consolidate three slightly different implementations of applying a converter
   on all elements of a vector. Fixes to this function now propagate to the three
   types.
 
 * Miscellaneous
 
   Replaced CONFIG_PROC_SYSCTL with CONFIG_SYSCTL (they were the same) and
   restrict cad_pid modifications to global root (GLOBAL_ROOT_UID)
 
 * Testing
 
   This series was run through sysctl selftests/kunit test suite in x86_64. And
   went into linux-next around rc2, giving it a bit more than a month of testing.
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Merge tag 'sysctl-7.03-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Fix kernel-doc warnings by adjusting in file documentation

 - Consolidate do_proc_* function into do_proc_vec

   Consolidate three slightly different implementations of applying a
   converter on all elements of a vector. Fixes to this function now
   propagate to the three types.

 - Replace CONFIG_PROC_SYSCTL with CONFIG_SYSCTL (they were the same)
   and restrict cad_pid modifications to global root (GLOBAL_ROOT_UID)

* tag 'sysctl-7.03-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl:
  sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL
  sysctl: move the "cad_pid" entry from pid_table[] to kern_reboot_table[]
  sysctl: repair some kernel-doc comments
  sysctl: add Returns: kernel-doc for all functions
  sysctl: Update API function documentation
  sysctl: Rename proc_doulongvec_minmax_conv to proc_doulongvec_conv
  sysctl: Group proc_handler declarations and document
  sysctl: Replace do_proc_do{int,ulong,uint}vec with do_proc_vec
  sysctl: Add negp parameter to douintvec converter functions
  sysctl: Move default converter assignment out of do_proc_dointvec
2026-08-20 08:46:41 -07:00
Linus Torvalds
104a813376 VDSO updates:
- Consolidate the VDSO datastore further and provide support for
    mlock_all() and prefaulting.
 
  - Provide 32-bit legacy time related functionality only if
    CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists, but
    architecture code still exposes the legacy functionality even disabled.
 
    Clean this up by adding the missing guards and validating at build time
    that the VDSO is legacy free if disabled.
 
  - Consolidate the VDSO related config options in core and drivers, which
    removes some non-sensical dependencies and quite an amount of #ifdeffery.
 
  - Clean up the PAGE_SIZE definition maze
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Merge tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull VDSO updates from Thomas Gleixner:

 - Consolidate the VDSO datastore further and provide support for
   mlock_all() and prefaulting.

 - Provide 32-bit legacy time related functionality only if
   CONFIG_COMPAT_32BIT_TIME is enabled. The config switch exists,
   but architecture code still exposes the legacy functionality even
   disabled.

   Clean this up by adding the missing guards and validating at build
   time that the VDSO is legacy free if disabled.

 - Consolidate the VDSO related config options in core and drivers,
   which removes some non-sensical dependencies and quite an amount of
   #ifdeffery.

 - Clean up the PAGE_SIZE definition maze

* tag 'timers-vdso-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (30 commits)
  random: vDSO: Drop custom PAGE_SIZE definitions
  LoongArch: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/timer-riscv: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/arm_arch_timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  clocksource/drivers/mips-gic-timer: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  MIPS: csrc-r4k: Remove CONFIG_GENERIC_GETTIMEOFDAY ifdeffery
  vDSO: Make clockmode constants available without CONFIG_GENERIC_GETTIMEOFDAY
  kbuild: Support generated asm-headers in subdirectories
  vdso: Rename HAVE_GENERIC_VDSO to VDSO_DATASTORE
  vdso: Drop HAVE_GENERIC_VDSO from architecture kconfig files
  vdso: Automatically select HAVE_GENERIC_VDSO if necessary
  MIPS: vdso: Stop using CONFIG_HAVE_GENERIC_VDSO
  vdso: Remove the dependency on HAVE_GENERIC_VDSO from ARCH_HAS_VDSO_ARCH_DATA
  futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK
  vdso/gettimeofday: Verify COMPAT_32BIT_TIME interactions
  sparc: vdso: Respect COMPAT_32BIT_TIME
  MIPS: VDSO: Respect COMPAT_32BIT_TIME
  powerpc/vdso: Respect COMPAT_32BIT_TIME
  ARM: VDSO: Respect COMPAT_32BIT_TIME
  arm64: vdso32: Respect COMPAT_32BIT_TIME
  ...
2026-08-18 16:56:25 -07:00
Linus Torvalds
3b4128b9f3 Timers and timekeeping core updates:
- Fix a subtly inconsistency in the timekeeping code, which fails to
     account for the monotonicity adjustment in ntp_error. For small changes
     of the clocksource multiplicator (+/-1) which are typically used by the
     NTP PLL this is hardly to observe. But for larger adjustments,
     e.g. caused by a direct frequency setting through adjtimex() the
     one-time uncompensated offset is significant.
 
     Cure this by adjusting ntp_error with the resulting offset so that the
     discrepancy is smoothed away over time
 
   - Make tick length calculations correct in NTP. The timekeeping core
     takes the quantisation of the clocksource into account when calculating
     the tick length to compensate for the deviation of the nominal
     NTP_INTERVAL_LENGTH. While timekeeping gets this right, NTP is not
     aware of that, which means it operates on the nominal value and not on
     the actual value which is determined by the clock source frequency. The
     rounding of a coarse clocksource like the ACPI PM timer results in a
     +127 PPM deviation.
 
     Cure this by exposing the deviation to the NTP code so that it can
     operate on the same data as the timekeeping core. This is purely kernel
     internal. User space still sees the nominal tick lenght via adjtimex().
 
   - The accuracy of the NTP adjustments is fairly approximate as the code
     assumes that the invocations are precisely in NTP interval frequency
     ticks and the final adjustment can over and under-run.
 
     Cure this by adjusting ntp_error by the intended skew on each tick to
     achieve the desired rate.
 
   - Handle the two competing skews of time offset and time adjustment
     correctly by calculating the conflict portion between the skews and
     adjusting both accordingly.
 
   - A set of updates and improvements for the selftests
 
   - The usual small fixes and improvements all over the place
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Merge tag 'timers-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer and timekeeping core updates from Thomas Gleixner:

 - Fix a subtly inconsistency in the timekeeping code, which fails to
   account for the monotonicity adjustment in ntp_error.

   For small changes of the clocksource multiplicator (+/-1) which are
   typically used by the NTP PLL this is hard to observe. But for larger
   adjustments, e.g. caused by a direct frequency setting through
   adjtimex() the one-time uncompensated offset is significant.

   Cure this by adjusting ntp_error with the resulting offset so that
   the discrepancy is smoothed away over time

 - Make tick length calculations correct in NTP.

   The timekeeping core takes the quantisation of the clocksource into
   account when calculating the tick length to compensate for the
   deviation of the nominal NTP_INTERVAL_LENGTH.

   While timekeeping gets this right, NTP is not aware of that, which
   means it operates on the nominal value and not on the actual value
   which is determined by the clock source frequency. The rounding of a
   coarse clocksource like the ACPI PM timer results in a +127 PPM
   deviation.

   Cure this by exposing the deviation to the NTP code so that it can
   operate on the same data as the timekeeping core. This is purely
   kernel internal. User space still sees the nominal tick lenght via
   adjtimex().

 - The accuracy of the NTP adjustments is fairly approximate as the code
   assumes that the invocations are precisely in NTP interval frequency
   ticks and the final adjustment can over and under-run.

   Cure this by adjusting ntp_error by the intended skew on each tick to
   achieve the desired rate.

 - Handle the two competing skews of time offset and time adjustment
   correctly by calculating the conflict portion between the skews and
   adjusting both accordingly.

 - A set of updates and improvements for the selftests

 - The usual small fixes and improvements all over the place

* tag 'timers-core-2026-08-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  selftests: timers: nsleep-lat: Check all calls to clock_nanosleep() and clock_gettime()
  selftests: timers: nsleep-lat: Reuse kselftest error numbers
  selftests: timers: nsleep-lat: Explicitly list the tested clocks
  selftests: timers: nsleep-lat: Use NSEC_PER_MSEC define for unreasonable latency
  selftests: timers: nanosleep: Report each test separately
  selftests: timers: nanosleep: Explicitly handle timer_delete() failure
  selftests: timers: nanosleep: Move all single clock tests out of the loop in main()
  selftests: timers: nanosleep: Reuse kselftest error numbers
  selftests: timers: nanosleep: Explicitly list the tested clocks
  selftests: timers: nanosleep: Drop output alignment
  selftests: timers: Use clock_name() and constants from clock-helpers.h
  selftests: Add clock-helpers.h
  timer_list: Use ktime_t over nanoseconds
  timer_list: Use standard 'long long' format placeholders
  hrtimer: Add a lockdep assertion to hrtimer_update_base()
  timekeeping: Use u32 for clock_was_set_seq
  timekeeping: Rename clockid_aux_valid() to clockid_is_aux_clock()
  hrtimer: Account nr_retries on recovered interrupt retries
  timers/itimer: Zero-init old itimerval before copy to userspace
  nohz: Replace dead select with choice default
  ...
2026-08-18 16:23:56 -07:00
Julian Braha
b17006b452 nohz: Replace dead select with choice default
'select' does not work on config options in a 'choice', so currently the
'select VIRT_CPU_ACCOUNTING_GEN' for NO_HZ_FULL is dead, with the choice
option VIRT_CPU_ACCOUNTING_GEN only being enabled when NO_HZ_FULL=y because
the other choice members depend on NO_HZ_FULL=n.

Remove the dead select, and encode this relationship as a default of the
choice, instead.

This dead select was found by kconfirm, a static analysis tool for Kconfig.

Signed-off-by: Julian Braha <julianbraha@gmail.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Bradley Morgan <include@grrlz.net>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260801160140.2391000-1-julianbraha@gmail.com
2026-08-11 15:37:23 +02:00
Leon Hwang
e474ac24a7 mm/mseal: fix mseal documentation for 32-bit kernels
mseal.o is built only for 64-bit kernels, so 32-bit kernels fall back to
sys_ni_syscall() and return -ENOSYS rather than -EPERM.

Drop architecture description in mseal.rst, since the arch feature doc has
the latest state of mseal for each architecture.

Fix the CONFIG_MSEAL_SYSTEM_MAPPINGS typo in init/Kconfig.

Link: https://lore.kernel.org/20260715131258.55499-1-leon.hwang@linux.dev
Signed-off-by: Leon Hwang <leon.hwang@linux.dev>
Acked-by: Lance Yang <lance.yang@linux.dev>
Cc: Alice Ryhl <aliceryhl@google.com>
Cc: Anand Moon <linux.amoon@gmail.com>
Cc: Doug Anderson <dianders@chromium.org>
Cc: Gary Guo <gary@garyguo.net>
Cc: Jann Horn <jannh@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Leon Hwang <leon.hwang@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Miguel Ojeda <ojeda@kernel.org>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-08-06 18:57:12 -07:00
Oleg Nesterov
8d75c338f0 sysctl: remove CONFIG_PROC_SYSCTL, it just mirrors CONFIG_SYSCTL
CONFIG_SYSCTL used to make sense as a separate hidden bool before commit
61a47c1ad3 ("sysctl: Remove the sysctl system call"); it was selected
by both CONFIG_SYSCTL_SYSCALL and CONFIG_PROC_SYSCTL.

Today CONFIG_PROC_SYSCTL is the only selector, so the two are always
equal. Kill the hidden bool, rename the PROC_SYSCTL prompt to SYSCTL,
and s/CONFIG_PROC_SYSCTL/CONFIG_SYSCTL/ tree-wide.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2026-08-05 15:28:23 +02:00
Kiryl Shutsemau (Meta)
c6f11553c0 mm: decouple protnone helpers from CONFIG_NUMA_BALANCING
Patch series "userfaultfd: working set tracking for VM guest memory", v10.

This series adds userfaultfd support for tracking the working set of VM
guest memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage.


This patch (of 15):

pte_protnone() and pmd_protnone() detect present-but-inaccessible page
table entries.  This capability is useful beyond NUMA balancing -- for
example, userfaultfd working set tracking uses protnone PTEs to track page
access without unmapping pages.

Introduce CONFIG_ARCH_HAS_PTE_PROTNONE to decouple the protnone PTE
infrastructure from CONFIG_NUMA_BALANCING.  The six architectures that
support protnone PTEs (x86_64, arm64, powerpc, s390, riscv, loongarch) now
select this option, and CONFIG_NUMA_BALANCING depends on it.

No functional change -- the same set of architectures continues to have
working protnone support, but the infrastructure is now available
independently of NUMA balancing.

Link: https://lore.kernel.org/20260708111417.173443-1-kirill@shutemov.name
Link: https://lore.kernel.org/20260708111417.173443-2-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Assisted-by: Claude:claude-opus-4-6
Acked-by: SeongJae Park <sj@kernel.org>
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: 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>
2026-08-04 19:18:36 -07:00
Thomas Weißschuh
2558084d2b futex: Remove dependency on HAVE_GENERIC_VDSO from FUTEX_ROBUST_UNLOCK
The robust futex unlock functionality has no relation to the generic
vDSO functionality.

Remove the dependency.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Vincenzo Frascino <vincenzo.frascino@arm.com>
Link: https://patch.msgid.link/20260709-vdso-have_generic_vdso-v1-1-d2e1061f268b@linutronix.de
2026-07-15 10:49:02 +02:00
Breno Leitao
fc9d904704 bootconfig: render embedded bootconfig as a kernel cmdline at build time
Add the build-time pipeline that renders the "kernel" subtree of
CONFIG_BOOT_CONFIG_EMBED_FILE into a flat cmdline string and stashes
it in .init.rodata as embedded_kernel_cmdline[]. A follow-up patch
adds the runtime helper that prepends this string to boot_command_line
during early architecture setup so parse_early_param() sees the values.

The build wires up:
  tools/bootconfig -C kernel - userspace tool already shared with
                               lib/bootconfig.c, used here in -C mode
                               to render a bootconfig file to a cmdline
  lib/embedded-cmdline.S     - .incbin's the rendered text plus a NUL
                               (listed under the EXTRA BOOT CONFIG
                               MAINTAINERS entry)
  lib/Makefile rule          - runs tools/bootconfig at build time
  Makefile prepare dep       - ensures tools/bootconfig is built first,
                               same pattern as tools/objtool and
                               tools/bpf/resolve_btfids

Drop the test target from tools/bootconfig/Makefile's default 'all'
recipe so that hooking the binary into the kernel build does not run
test-bootconfig.sh on every prepare. The tests stay available as
'make -C tools/bootconfig test', matching the convention of
tools/objtool and tools/bpf/resolve_btfids whose 'all' targets only
build the binary.

Require BOOT_CONFIG_EMBED_FILE to be non-empty before the new option
can be enabled, otherwise tools/bootconfig -C runs against an empty
file and prints a parse error on every kernel build.

The feature gates on CONFIG_ARCH_SUPPORTS_CMDLINE_FROM_BOOTCONFIG, a
silent symbol arches select once they've wired the prepend call into
setup_arch(). No arch selects it in this patch, so the user-visible
CONFIG_CMDLINE_FROM_BOOTCONFIG is not yet enableable; when an arch
later opts in, the runtime behavior is added by the follow-up patches.

tools/bootconfig also installs on target systems, so its own Makefile
keeps $(CC) and stays cross-buildable as a standalone tool. The kernel
build, which runs the tool on the build host during prepare, instead
forces CC=$(HOSTCC) from a dedicated tools/bootconfig rule and clears
CROSS_COMPILE= in the sub-make. Without that clear, an LLVM=1 cross
build would inherit CROSS_COMPILE and tools/scripts/Makefile.include
would inject --target=/--sysroot= flags into the host clang invocation,
producing a target binary that fails to exec ("Exec format error").

embedded-cmdline.S places the rendered string in its own .init.rodata
subsection (.init.rodata.embed_cmdline) with the "a" (allocatable,
read-only) flag and %progbits. lib/bootconfig-data.S already places
the embedded bootconfig blob in .init.rodata with the "aw" flag
(xbc_init() rewrites separators in place, so that data must be
writable). Using a distinct subsection name avoids the ld.lld section-
type mismatch that would otherwise arise from mixing "a" and "aw"
under the same name; the linker's "*(.init.rodata .init.rodata.*)"
glob still folds both into the init image and frees them after boot.

A follow-up patch wires the build-time tools/bootconfig into the
top-level clean target.

Link: https://lore.kernel.org/all/20260626-bootconfig_using_tools-v7-3-24ab72139c29@debian.org/

Reviewed-by: Nicolas Schier <n.schier@fritz.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Signed-off-by: Masami Hiramatsu (Google) <mhiramat@kernel.org>
2026-07-02 21:15:45 +09:00
Miguel Ojeda
608045a91d rust: allow suspicious_runtime_symbol_definitions lint for Rust >= 1.98
Starting with Rust 1.98.0 (expected 2026-08-20), Rust is introducing a
couple new lints, `invalid_runtime_symbol_definitions` (deny-by-default)
and `suspicious_runtime_symbol_definitions` (warn-by-default), which check
the signature of items whose symbol name is a runtime symbol expected by
`core`.

Our build hits the second one, i.e. the warning:

    error: suspicious definition of the runtime `strlen` symbol used by the standard library
         --> rust/bindings/bindings_generated.rs:20018:5
          |
    20018 |     pub fn strlen(s: *const ffi::c_char) -> usize;
          |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
          |
          = note: expected `unsafe extern "C" fn(*const i8) -> usize`
                  found    `unsafe extern "C" fn(*const u8) -> usize`
          = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]`
          = help: allow this lint if the signature is compatible
          = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings`
          = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]`

    error: suspicious definition of the runtime `strlen` symbol used by the standard library
         --> rust/uapi/uapi_generated.rs:14236:5
          |
    14236 |     pub fn strlen(s: *const ffi::c_char) -> usize;
          |     ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
          |
          = note: expected `unsafe extern "C" fn(*const i8) -> usize`
                  found    `unsafe extern "C" fn(*const u8) -> usize`
          = help: either fix the signature or remove any attributes like `#[unsafe(no_mangle)]`, `#[unsafe(export_name = "strlen")]`, or `#[link_name = "strlen"]`
          = help: allow this lint if the signature is compatible
          = note: `-D suspicious-runtime-symbol-definitions` implied by `-D warnings`
          = help: to override `-D warnings` add `#[allow(suspicious_runtime_symbol_definitions)]`

Thus `allow` the lint in `bindings` and `uapi`.

A more targeted alternative to avoid `allow`ing it would be to pass
`--blocklist-function strlen` to `bindgen`, but we would perhaps need
to adjust if other C headers end up adding more (or Rust checking more).
Since it is just the less critical one that we hit, and since eventually
this should be properly fixed by getting upstream Rust to provide a flag
like GCC/Clang's `-funsigned-char` [2][3], just `allow` it for now.

Cc: Urgau <urgau@numericable.fr>
Cc: stable@vger.kernel.org # Needed in 6.12.y and later (Rust is pinned in older LTSs).
Link: https://github.com/rust-lang/rust/pull/155521 [1]
Link: https://github.com/rust-lang/rust/issues/138446 [2]
Link: https://github.com/Rust-for-Linux/linux/issues/355 [3]
Reviewed-by: Gary Guo <gary@garyguo.net>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Link: https://patch.msgid.link/20260615143225.471756-1-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-29 13:02:15 +02:00
Linus Torvalds
2e05544060 mm.git review status for mm-hotfixes-stable..mm-nonmm-stable
Everything:
 
 Total patches:       108
 Reviews/patch:       0.84
 Reviewed rate:       75%
 
 Patch series in this merge:
 
 - The 2 patch series "taskstats: fix TGID dead-thread stat retention"
   from Yiyang Chen fixes a taskstats TGID aggregation bug where fields
   added in the TGID query path were not preserved after thread exit, and
   adds a kselftest covering the regression.
 
 - The 2 patch series "lib/tests: string_helpers: Slight improvements"
   from Andy Shevchenko improves lib/tests/string_helpers_kunit.c a little.
 
 - The 2 patch series "lib/base64: decode fixes" from Josh Law addreesses
   minor issues in lib/base64.c.
 
 - The 3 patch series "selftests/filelock: Make output more kselftestish"
   from Mark Brown makes the output from the ofdlocks test a bit easier for
   tooling to work with, and also ignores the generated file.
 
 - The 3 patch series "uaccess: unify inline vs outline
   copy_{from,to}_user() selection" from Yury Norov simplifies the usercopy
   code by removing the selectability of inlining copy_{from,to}_user().
 
 - The 5 patch series "ocfs2: validate inline xattr header consumers"
   from ZhengYuan Huang fixes a number of possible issues in the ocfs2
   xattr code.
 
 - The 8 patch series "lib and lib/cmdline enhancements" from Dmitry
   Antipov provides additional robustness checking in the cmdline handling
   code and its in-kernel testing and selftests.
 
 - The 18 patch series "cleanup the RAID6 P/Q library" from Christoph
   Hellwig cleans up the RAID6 P/Q library to match the recent updates to
   the RAID 5 XOR library and other CRC/crypto libraries.
 
 - The 3 patch series "ocfs2: harden inode validators against forged
   metadata" from Michael Bommarito adds three structural checks to OCFS2
   dinode validation so malformed on-disk fields are rejected before
   ocfs2_populate_inode() copies them into the in-core inode.
 
 - The 2 patch series "lib/raid: replace __get_free_pages() call with
   kmalloc()" from Mike Rapoport cleans up the lib/raid code by using
   kmalloc() in more places.
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Merge tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull non-MM updates from Andrew Morton:

 - "taskstats: fix TGID dead-thread stat retention" (Yiyang Chen)

   Fix a taskstats TGID aggregation bug where fields added in the TGID
   query path were not preserved after thread exit, and adds a kselftest
   covering the regression.

 - "lib/tests: string_helpers: Slight improvements" (Andy Shevchenko)

   Improve lib/tests/string_helpers_kunit.c a little

 - "lib/base64: decode fixes" (Josh Law)

   Address minor issues in lib/base64.c

 - "selftests/filelock: Make output more kselftestish" (Mark Brown)

   Make the output from the ofdlocks test a bit easier for tooling to
   work with. Also ignore the generated file

 - "uaccess: unify inline vs outline copy_{from,to}_user() selection"
   (Yury Norov)

   Simplify the usercopy code by removing the selectability of inlining
   copy_{from,to}_user().

 - "ocfs2: validate inline xattr header consumers" (ZhengYuan Huang)

   Fix a number of possible issues in the ocfs2 xattr code

 - "lib and lib/cmdline enhancements" (Dmitry Antipov)

   Provide additional robustness checking in the cmdline handling code
   and its in-kernel testing and selftests

 - "cleanup the RAID6 P/Q library" (Christoph Hellwig)

   Clean up the RAID6 P/Q library to match the recent updates to the
   RAID 5 XOR library and other CRC/crypto libraries

 - "ocfs2: harden inode validators against forged metadata" (Michael
   Bommarito)

   Add three structural checks to OCFS2 dinode validation so malformed
   on-disk fields are rejected before ocfs2_populate_inode() copies them
   into the in-core inode

 - "lib/raid: replace __get_free_pages() call with kmalloc()" (Mike
   Rapoport)

   Clean up the lib/raid code by using kmalloc() in more places

* tag 'mm-nonmm-stable-2026-06-21-10-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (108 commits)
  ocfs2: fix circular locking dependency in ocfs2_dio_end_io_write
  ocfs2: fix NULL h_transaction deref in ocfs2_assure_trans_credits
  lib: interval_tree_test: validate benchmark parameters
  ocfs2: avoid moving extents to occupied clusters
  treewide: fix transposed "sign" typos and update spelling.txt
  ocfs2: fix UBSAN array-index-out-of-bounds in ocfs2_sum_rightmost_rec
  fat: reject BPB volumes whose data area starts beyond total sectors
  selftests/uevent: increase __UEVENT_BUFFER_SIZE to avoid ENOBUFS on busy systems
  lib/test_firmware: allocate the configured into_buf size
  fs: efs: remove unneeded debug prints
  checkpatch: cuppress warnings when Reported-by: is followed by Link:
  MAINTAINERS: add Alexander as a kcov reviewer
  mailmap: update Alexander Sverdlin's Email addresses
  fs: fat: inode: replace sprintf() with scnprintf()
  ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent
  ocfs2: fix race between ocfs2_control_install_private() and ocfs2_control_release()
  ocfs2/dlm: require a ref for locking_state debugfs open
  ocfs2: reject FITRIM ranges shorter than a cluster
  ocfs2: validate fast symlink target during inode read
  ocfs2: add journal NULL check in ocfs2_checkpoint_inode()
  ...
2026-06-21 13:20:19 -07:00
Linus Torvalds
f8115f0e8a slab changes for 7.2
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Merge tag 'slab-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab

Pull slab updates from Vlastimil Babka:

 - Support for "allocation tokens" (currently available in Clang 22+)
   for smarter partitioning of kmalloc caches based on the allocated
   object type, which can be enabled instead of the "random"
   per-caller-address-hash partitioning.

   It should be able to deterministically separate types containing a
   pointer from those that do not (Marco Elver)

 - Improvements and simplification of the kmem_cache_alloc_bulk() and
   mempool_alloc_bulk() API. This includes adaptation of callers
   (Christoph Hellwig)

 - Performance improvements and cleanups related mostly to sheaves
   refill (Hao Li, Shengming Hu, Vlastimil Babka)

 - Several fixups for the slabinfo tool (Xuewen Wang)

* tag 'slab-for-7.2' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
  mm/slab: do not limit zeroing to orig_size when only red zoning is enabled
  mm/slub: preserve original size in _kmalloc_nolock_noprof retry path
  mm: simplify the mempool_alloc_bulk API
  mm/slab: improve kmem_cache_alloc_bulk
  mm/slub: detach and reattach partial slabs in batch
  mm/slub: introduce helpers for node partial slab state
  mm/slub: use empty sheaf helpers for oversized sheaves
  tools/mm/slabinfo: remove redundant slab->partial assignment
  tools/mm/slabinfo: remove dead assignment in get_obj_and_str()
  tools/mm/slabinfo: Fix trace disable logic inversion
  MAINTAINERS: add slab-related scripts and tools to SLAB ALLOCATOR
  mm/slub: fix typo in sheaves comment
  mm, slab: simplify returning slab in __refill_objects_node()
  mm, slab: add an optimistic __slab_try_return_freelist()
  slab: fix kernel-docs for mm-api
  slab: improve KMALLOC_PARTITION_RANDOM randomness
  slab: support for compiler-assisted type-based slab cache partitioning
  mm/slub: defer freelist construction until after bulk allocation from a new slab
2026-06-16 08:44:43 +05:30
Linus Torvalds
2cbf335f8c Scheduler updates for v7.2:
SMP load-balancing updates:
 
  - A large series to introduce infrastructure for cache-aware load
    balancing, with the goal of co-locating tasks that share data
    within the same Last Level Cache (LLC) domain. By improving cache
    locality, the scheduler can reduce cache bouncing and cache misses,
    ultimately improving data access efficiency.
 
    Implemented by Chen Yu and Tim Chen, based on early prototype work
    by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
    Shrikanth Hegde.
 
  - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)
 
 Fair scheduler updates:
 
  - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
    SMT awareness (Andrea Righi, K Prateek Nayak)
 
  - A series to optimize cfs_rq and sched_entity allocation for
    better data locality (Zecheng Li)
 
  - A preparatory series to change fair/cgroup scheduling to a single
    runqueue, without the final change (Peter Zijlstra)
 
  - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)
 
  - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)
 
  - Optimize update_tg_load_avg()'s rate-limiting code
    (Rik van Riel)
 
  - Allow account_cfs_rq_runtime() to throttle current hierarchy
    (K Prateek Nayak)
 
  - Update util_est after updating util_avg during dequeue, to fix
    the util signal update logic, which reduces signal noise
    (Vincent Guittot)
 
 Scheduler topology updates:
 
  - Allow multiple domains to claim sched_domain_shared (K Prateek Nayak)
 
  - Add parameter to split LLC (Peter Zijlstra)
 
 Core scheduler updates:
 
  - Use trace_call__<tp>() to save a static branch (Gabriele Monaco)
 
 Scheduler statistics updates:
 
  - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation guard
    (Nicolas Pitre)
 
 Deadline scheduler updates:
 
  - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)
 
  - Fix replenishment logic for non-deferred servers
    (Yuri Andriaccio)
 
 RT scheduling updates:
 
  - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)
 
  - Update default bandwidth for real-time tasks to 1.0
    (Yuri Andriaccio)
 
 Proxy scheduling updates:
 
  - A series to implement Optimized Donor Migration for Proxy Execution
    (John Stultz, Peter Zijlstra)
 
  - Various proxy scheduling cleanups and fixes
    (Peter Zijlstra, K Prateek Nayak)
 
 Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
 Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
 Peter Zijlstra, Liang Luo and Yiyang Chen.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "SMP load-balancing updates:

   - A large series to introduce infrastructure for cache-aware load
     balancing, with the goal of co-locating tasks that share data
     within the same Last Level Cache (LLC) domain. By improving cache
     locality, the scheduler can reduce cache bouncing and cache misses,
     ultimately improving data access efficiency.

     Implemented by Chen Yu and Tim Chen, based on early prototype work
     by Peter Zijlstra, with fixes by Jianyong Wu, Peter Zijlstra and
     Shrikanth Hegde.

   - A series to simplify CONFIG_SCHED_SMT ifdef usage (Shrikanth Hegde)

  Fair scheduler updates:

   - A series to improve SD_ASYM_CPUCAPACITY scheduling by introducing
     SMT awareness (Andrea Righi, K Prateek Nayak)

   - A series to optimize cfs_rq and sched_entity allocation for better
     data locality (Zecheng Li)

   - A preparatory series to change fair/cgroup scheduling to a single
     runqueue, without the final change (Peter Zijlstra)

   - Auto-manage ext/fair dl_server bandwidth (Andrea Righi)

   - Fix cpu_util runnable_avg arithmetic (Hongyan Xia)

   - Optimize update_tg_load_avg()'s rate-limiting code (Rik van Riel)

   - Allow account_cfs_rq_runtime() to throttle current hierarchy
     (K Prateek Nayak)

   - Update util_est after updating util_avg during dequeue, to fix the
     util signal update logic, which reduces signal noise (Vincent
     Guittot)

  Scheduler topology updates:

   - Allow multiple domains to claim sched_domain_shared (K Prateek
     Nayak)

   - Add parameter to split LLC (Peter Zijlstra)

  Core scheduler updates:

   - Use trace_call__<tp>() to save a static branch (Gabriele Monaco)

  Scheduler statistics updates:

   - Drop now-stale mul_u64_u64_div_u64() cputime over-approximation
     guard (Nicolas Pitre)

  Deadline scheduler updates:

   - Reject debugfs dl_server writes for offline CPUs (Andrea Righi)

   - Fix replenishment logic for non-deferred servers (Yuri Andriaccio)

  RT scheduling updates:

   - Turn RT_PUSH_IPI default off for non PREEMPT_RT (Steven Rostedt)

   - Update default bandwidth for real-time tasks to 1.0 (Yuri
     Andriaccio)

  Proxy scheduling updates:

   - A series to implement Optimized Donor Migration for Proxy Execution
     (John Stultz, Peter Zijlstra)

   - Various proxy scheduling cleanups and fixes (Peter Zijlstra,
     K Prateek Nayak)

  Misc fixes, improvements and cleanups by Aaron Lu, Andrea Righi,
  Zenghui Yu, Chen Yu, Guanyou.Chen, John Stultz, Shrikanth Hegde,
  Peter Zijlstra, Liang Luo and Yiyang Chen"

* tag 'sched-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (91 commits)
  sched/fair: Fix newidle vs core-sched
  sched/deadline: Use task_on_rq_migrating() helper
  sched/core: Combine separate 'else' and 'if' statements
  sched/fair: Fix cpu_util runnable_avg arithmetic
  sched/fair: Unify cfs_rq throttling via account_cfs_rq_runtime()
  sched/fair: Move the throttled tasks to a local list in tg_unthrottle_up()
  sched/fair: Call update_curr() before unthrottling the hierarchy
  sched/fair: Use throttled_csd_list for local unthrottle
  sched/fair: Convert cfs bandwidth throttling to use guards
  sched/fair: Allocate cfs_tg_state with percpu allocator
  sched/fair: Remove task_group->se pointer array
  sched/fair: Co-locate cfs_rq and sched_entity in cfs_tg_state
  sched: restore timer_slack_ns when resetting RT policy on fork
  MAINTAINERS: Fix spelling mistake in Peter's name
  sched: Simplify ttwu_runnable()
  sched/proxy: Remove superfluous clear_task_blocked_in()
  sched/proxy: Remove PROXY_WAKING
  sched/proxy: Switch proxy to use p->is_blocked
  sched/proxy: Only return migrate when needed
  sched: Be more strict about p->is_blocked
  ...
2026-06-15 14:50:18 +05:30
Linus Torvalds
764e77d868 Locking updates for v7.2:
Futex updates:
 
  - Optimize futex hash bucket access patterns (Peter Zijlstra)
 
  - Large series to address the robust futex unlock race for real,
    by Thomas Gleixner:
 
     "The robust futex unlock mechanism is racy in respect
      to the clearing of the robust_list_head::list_op_pending
      pointer because unlock and clearing the pointer are not
      atomic. The race window is between the unlock and clearing the
      pending op pointer. If the task is forced to exit in this
      window, exit will access a potentially invalid pending op
      pointer when cleaning up the robust list. That happens if
      another task manages to unmap the object containing the lock
      before the cleanup, which results in an UAF. In the worst case
      this UAF can lead to memory corruption when unrelated content
      has been mapped to the same address by the time the access
      happens.
 
      User space can't solve this problem without help from the kernel.
      This series provides the kernel side infrastructure to help it
      along:
 
       1) Combined unlock, pointer clearing, wake-up for the
          contended case
 
       2) VDSO based unlock and pointer clearing helpers with a
          fix-up function in the kernel when user space was interrupted
          within the critical section.
 
     ... with help by André Almeida:
 
      - Add a note about robust list race condition (André Almeida)
      - Add self-tests for robust release operations (André Almeida)
 
 Context analysis updates:
 
  - Implement context analysis for 'struct rt_mutex'.
    (Bart Van Assche)
  - Bump required Clang version to 23 (Marco Elver)
 
 Guard infrastructure updates:
 
  - Series to remove NULL check from unconditional guards
    (Dmitry Ilvokhin)
 
 Lockdep updates:
 
  - Restore self-test migrate_disable() and sched_rt_mutex
    state on PREEMPT_RT (Karl Mehltretter)
 
 Membarriers updates:
 
  - Use per-CPU mutexes for targeted commands (Aniket Gattani)
  - Modernize membarrier_global_expedited with cleanup guards
    (Aniket Gattani)
  - Add rseq stress test for CFS throttle interactions (Aniket Gattani)
 
 percpu-rwsems updates:
 
  - Extract __percpu_up_read() to optimize inlining overhead
    (Dmitry Ilvokhin)
 
 Seqlocks updates:
 
  - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)
 
 Lock tracing:
 
  - Add contended_release tracepoint to sleepable locks
    such as mutexes, percpu-rwsems, rtmutexes, rwsems
    and semaphores. (Dmitry Ilvokhin)
 
 MAINTAINERS updates:
 
  - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)
 
 Misc updates and fixes by Randy Dunlap, YE WEI-HONG,
 Fabricio Parra, Dmitry Ilvokhin and Peter Zijlstra.
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip

Pull locking updates from Ingo Molnar:
 "Futex updates:

   - Optimize futex hash bucket access patterns (Peter Zijlstra)

   - Large series to address the robust futex unlock race for real, by
     Thomas Gleixner:

      "The robust futex unlock mechanism is racy in respect to the
       clearing of the robust_list_head::list_op_pending pointer because
       unlock and clearing the pointer are not atomic.

       The race window is between the unlock and clearing the pending op
       pointer. If the task is forced to exit in this window, exit will
       access a potentially invalid pending op pointer when cleaning up
       the robust list.

       That happens if another task manages to unmap the object
       containing the lock before the cleanup, which results in an UAF.

       In the worst case this UAF can lead to memory corruption when
       unrelated content has been mapped to the same address by the time
       the access happens.

       User space can't solve this problem without help from the kernel.
       This series provides the kernel side infrastructure to help it
       along:

        1) Combined unlock, pointer clearing, wake-up for the
           contended case

        2) VDSO based unlock and pointer clearing helpers with a
           fix-up function in the kernel when user space was interrupted
           within the critical section.

      ... with help by André Almeida:

        - Add a note about robust list race condition (André Almeida)
        - Add self-tests for robust release operations (André Almeida)

  Context analysis updates:

   - Implement context analysis for 'struct rt_mutex'. (Bart Van Assche)
   - Bump required Clang version to 23 (Marco Elver)

  Guard infrastructure updates:

   - Series to remove NULL check from unconditional guards (Dmitry
     Ilvokhin)

  Lockdep updates:

   - Restore self-test migrate_disable() and sched_rt_mutex state on
     PREEMPT_RT (Karl Mehltretter)

  Membarriers updates:

   - Use per-CPU mutexes for targeted commands (Aniket Gattani)
   - Modernize membarrier_global_expedited with cleanup guards (Aniket
     Gattani)
   - Add rseq stress test for CFS throttle interactions (Aniket Gattani)

  percpu-rwsems updates:

   - Extract __percpu_up_read() to optimize inlining overhead (Dmitry
     Ilvokhin)

  Seqlocks updates:

   - Allow UBSAN_ALIGNMENT to fail optimizing (Heiko Carstens)

  Lock tracing:

   - Add contended_release tracepoint to sleepable locks such as
     mutexes, percpu-rwsems, rtmutexes, rwsems and semaphores (Dmitry
     Ilvokhin)

  MAINTAINERS updates:

   - MAINTAINERS: Add RUST [SYNC] entry (Boqun Feng)

  Misc updates and fixes by Randy Dunlap, YE WEI-HONG, Fabricio Parra,
  Dmitry Ilvokhin and Peter Zijlstra"

* tag 'locking-core-2026-06-14' of gitolite.kernel.org:pub/scm/linux/kernel/git/tip/tip: (36 commits)
  locking: Add contended_release tracepoint to sleepable locks
  locking/percpu-rwsem: Extract __percpu_up_read()
  tracing/lock: Remove unnecessary linux/sched.h include
  futex: Optimize futex hash bucket access patterns
  rust: sync: completion: Mark inline complete_all and wait_for_completion
  MAINTAINERS: Add RUST [SYNC] entry
  cleanup: Specify nonnull argument index
  selftests: futex: Add tests for robust release operations
  Documentation: futex: Add a note about robust list race condition
  x86/vdso: Implement __vdso_futex_robust_try_unlock()
  x86/vdso: Prepare for robust futex unlock support
  futex: Provide infrastructure to plug the non contended robust futex unlock race
  futex: Add robust futex unlock IP range
  futex: Add support for unlocking robust futexes
  futex: Cleanup UAPI defines
  x86: Select ARCH_MEMORY_ORDER_TSO
  uaccess: Provide unsafe_atomic_store_release_user()
  futex: Provide UABI defines for robust list entry modifiers
  futex: Move futex related mm_struct data into a struct
  futex: Make futex_mm_init() void
  ...
2026-06-15 14:21:14 +05:30
Linus Torvalds
b079329b86 Rust changes for v7.2
Toolchain and infrastructure:
 
  - Introduce support for the 'zerocopy' library [1][2]:
 
        Fast, safe, compile error. Pick two.
 
        Zerocopy makes zero-cost memory manipulation effortless. We write
        `unsafe` so you don't have to.
 
    It essentially provides derivable traits (e.g. 'FromBytes') and
    macros (e.g. 'transmute!') for safely converting between byte
    sequences and other types. Having such support allows us to remove
    some 'unsafe' code.
 
    It is among the most downloaded Rust crates and it is also used by
    the Rust compiler itself.
 
    It is licensed under "BSD-2-Clause OR Apache-2.0 OR MIT".
 
    The crates are imported essentially as-is (only +2/-3 lines needed
    to be adapted), plus SPDX identifiers. Upstream has since added the
    SPDX identifiers as well as one of the tweaks at my request, thus
    reducing our future diffs on updates -- I keep the details in one of
    our usual live lists [3].
 
    In total, it is about ~39k lines added, ~32k without counting
    'benches/' which are just for documentation purposes.
 
    The series includes a few Kbuild and rust-analyzer improvements and
    an example patch using it in Nova, removing one 'unsafe impl'.
 
    I checked that the codegen of an isolated example function (similar
    to the Nova patch on top) is essentially identical. It also turns out
    that (for that particular case) the 'zerocopy' version, even with
    'debug-assertions' enabled, has no remaining panics, unlike a few in
    the current code (since the compiler can prove the remaining
    'ub_checks' statically).
 
    So their "fast, safe" does indeed check out -- at least in that case.
 
    Link: https://github.com/google/zerocopy [1]
    Link: https://docs.rs/zerocopy [2]
    Link: https://github.com/Rust-for-Linux/linux/issues/1239 [3]
 
  - Support AutoFDO. This allows Rust code to be profiled and optimized
    based on the profile. Tested with Rust Binder: ~13% slower without
    AutoFDO in the binderAddInts benchmark (using an app-launch benchmark
    for the profile).
 
  - Support Software Tag-Based KASAN.
 
    In addition, fix KASAN Kconfig by requiring Clang.
 
  - Add Kconfig options for each existing Rust KUnit test suite, such as
    'CONFIG_RUST_BITMAP_KUNIT_TEST'. They are placed within a new menu,
    'CONFIG_RUST_KUNIT_TESTS', in the new 'rust/kernel/Kconfig.test'
    file.
 
  - Support the upcoming Rust 1.98.0 release (expected 2026-08-20): lint
    cleanups and an unstable flag rename.
 
  - Disable 'rustdoc' documentation inlining for all prelude items, which
    bloats the generated documentation.
 
  - Ignore (in Git) and clean (in Kbuild) the (rarely) 'rustc'-generated
    '*.long-type-*.txt' files.
 
 'kernel' crate:
 
  - Add new 'bitfield' module with the 'bitfield!' macro (extracted from
    the existing 'register!' one), which declares integer types that are
    split into distinct bit fields of arbitrary length.
 
    Each field is a 'Bounded' of the appropriate bit width (ensuring
    values are properly validated and avoiding implicit data loss) and
    gets several generated getters and setters (infallible, 'const' and
    fallible) as well as associated constants ('_MASK', '_SHIFT' and
    '_RANGE'). It also supports fields that can be converted from/to
    custom types, either fallibly ('?=>') or infallibly ('=>').
 
    For instance:
 
        bitfield! {
            struct Rgb(u16) {
                15:11 blue;
                10:5 green;
                4:0 red;
            }
        }
 
        // Compile-time checks.
        let color = Rgb::zeroed().with_const_green::<0x1f>();
 
        assert_eq!(color.green(), 0x1f);
        assert_eq!(color.into_raw(), 0x1f << Rgb::GREEN_SHIFT);
 
    Add as well documentation and a test suite for it, as usual; and
    update the 'register!' macro to use it.
 
    It will be maintained by Alexandre Courbot (with Yury Norov as
    reviewer) under a new 'MAINTAINERS' entry: 'RUST [BITFIELD]'.
 
  - 'ptr' module: rework index projection syntax into keyworded syntax
    and introduce panicking variant.
 
    The keyword syntax ('build:', 'try:', 'panic:') is more explicit and
    paves the way of perhaps adding more flavors in the future, e.g. an
    'unsafe' index projection.
 
    For instance, projections now look like this:
 
        fn f(p: *const [u8; 32]) -> Result {
            // Ok, within bounds, checked at build time.
            project!(p, [build: 1]);
 
            // Build error.
            project!(p, [build: 128]);
 
            // `OutOfBound` runtime error (convertible to `ERANGE`).
            project!(p, [try: 128]);
 
            // Runtime panic.
            project!(p, [panic: 128]);
 
            Ok(())
        }
 
    Update as well the users, which now look like e.g.
 
        // Pointer to the first entry of the GSP message queue.
        let data = project!(self.0.as_ptr(), .gspq.msgq.data[build: 0]);
 
  - 'build_assert' module: make the module the home of its macros instead
    of rendering them twice.
 
  - 'sync' module: add 'UniqueArc::as_ptr()' associated function.
 
  - 'alloc' module:
 
     + Fix the 'Vec::reserve()' doctest to properly account for the
       existing vector length in the capacity assertion.
 
     + Fix an incorrect operator in the 'Vec::extend_with()' 'SAFETY'
       comment; add a doc test demonstrating basic usage and the
       zero-length case.
 
  - Clean imports across several modules to follow the "kernel vertical"
    import style in order to minimize conflicts.
 
 'pin-init' crate:
 
  - User visible changes:
 
     + Do not generate 'non_snake_case' warnings for identifiers that are
       syntactically just users of a field name. This would allow all
       '#[allow(non_snake_case)]' in nova-core to be removed, which Gary
       will send to the nova tree next cycle.
 
     + Filter non-cfg attributes out properly in derived structs. This
       improves pin-init compatibility with other derive macros.
 
     + Insert projection types' where clause properly.
 
  - Other changes:
 
     + Bump MSRV to 1.82, plus associated cleanups.
 
     + Overhaul how init slots are projected. The new approach is easier
       to justify with safety comments.
 
     + Mark more functions as inline, which should help mitigate the
       super-long symbol name issue due to lack of inlining.
 
 rust-analyzer:
 
  - Support '--envs' for passing env vars for crates like 'zerocopy'.
 
 'MAINTAINERS':
 
  - Add the following reviewers to the 'RUST' entry:
 
     + Daniel Almeida
     + Tamir Duberstein
     + Alexandre Courbot
     + Onur Özkan
 
    They have been involved in the Rust for Linux project for about
    7 collective years and bring expertise across several domains, which
    will be very useful to have around in the future.
 
    Thanks everyone for stepping up!
 
 And some other fixes, cleanups and improvements.
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Merge tag 'rust-7.2' of gitolite.kernel.org:pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "This one is big due to the vendoring of the `zerocopy` library, which
  allows us to replace a bunch of `unsafe` code dealing with conversions
  between byte sequences and other types with safe alternatives. More
  details on that below (and in its merge commit).

  Toolchain and infrastructure:

   - Introduce support for the 'zerocopy' library [1][2]:

         Fast, safe, compile error. Pick two.

         Zerocopy makes zero-cost memory manipulation effortless. We write
         `unsafe` so you don't have to.

     It essentially provides derivable traits (e.g. 'FromBytes') and
     macros (e.g. 'transmute!') for safely converting between byte
     sequences and other types. Having such support allows us to remove
     some 'unsafe' code.

     It is among the most downloaded Rust crates and it is also used by
     the Rust compiler itself.

     It is licensed under "BSD-2-Clause OR Apache-2.0 OR MIT".

     The crates are imported essentially as-is (only +2/-3 lines needed
     to be adapted), plus SPDX identifiers. Upstream has since added the
     SPDX identifiers as well as one of the tweaks at my request, thus
     reducing our future diffs on updates -- I keep the details in one
     of our usual live lists [3].

     In total, it is about ~39k lines added, ~32k without counting
     'benches/' which are just for documentation purposes.

     The series includes a few Kbuild and rust-analyzer improvements and
     an example patch using it in Nova, removing one 'unsafe impl'.

     I checked that the codegen of an isolated example function (similar
     to the Nova patch on top) is essentially identical. It also turns
     out that (for that particular case) the 'zerocopy' version, even
     with 'debug-assertions' enabled, has no remaining panics, unlike a
     few in the current code (since the compiler can prove the remaining
     'ub_checks' statically).

     So their "fast, safe" does indeed check out -- at least in that
     case.

   - Support AutoFDO. This allows Rust code to be profiled and optimized
     based on the profile. Tested with Rust Binder: ~13% slower without
     AutoFDO in the binderAddInts benchmark (using an app-launch
     benchmark for the profile).

   - Support Software Tag-Based KASAN.

     In addition, fix KASAN Kconfig by requiring Clang.

   - Add Kconfig options for each existing Rust KUnit test suite, such
     as 'CONFIG_RUST_BITMAP_KUNIT_TEST'.

     They are placed within a new menu, 'CONFIG_RUST_KUNIT_TESTS', in
     the new 'rust/kernel/Kconfig.test' file.

   - Support the upcoming Rust 1.98.0 release (expected 2026-08-20):
     lint cleanups and an unstable flag rename.

   - Disable 'rustdoc' documentation inlining for all prelude items,
     which bloats the generated documentation.

   - Ignore (in Git) and clean (in Kbuild) the (rarely) 'rustc'-generated
     '*.long-type-*.txt' files.

  'kernel' crate:

   - Add new 'bitfield' module with the 'bitfield!' macro (extracted
     from the existing 'register!' one), which declares integer types
     that are split into distinct bit fields of arbitrary length.

     Each field is a 'Bounded' of the appropriate bit width (ensuring
     values are properly validated and avoiding implicit data loss) and
     gets several generated getters and setters (infallible, 'const' and
     fallible) as well as associated constants ('_MASK', '_SHIFT' and
     '_RANGE'). It also supports fields that can be converted from/to
     custom types, either fallibly ('?=>') or infallibly ('=>').

     For instance:

         bitfield! {
             struct Rgb(u16) {
                 15:11 blue;
                 10:5 green;
                 4:0 red;
             }
         }

         // Compile-time checks.
         let color = Rgb::zeroed().with_const_green::<0x1f>();

         assert_eq!(color.green(), 0x1f);
         assert_eq!(color.into_raw(), 0x1f << Rgb::GREEN_SHIFT);

     Add as well documentation and a test suite for it, as usual; and
     update the 'register!' macro to use it.

     It will be maintained by Alexandre Courbot (with Yury Norov as
     reviewer) under a new 'MAINTAINERS' entry: 'RUST [BITFIELD]'.

   - 'ptr' module: rework index projection syntax into keyworded syntax
     and introduce panicking variant.

     The keyword syntax ('build:', 'try:', 'panic:') is more explicit
     and paves the way of perhaps adding more flavors in the future,
     e.g. an 'unsafe' index projection.

     For instance, projections now look like this:

         fn f(p: *const [u8; 32]) -> Result {
             // Ok, within bounds, checked at build time.
             project!(p, [build: 1]);

             // Build error.
             project!(p, [build: 128]);

             // `OutOfBound` runtime error (convertible to `ERANGE`).
             project!(p, [try: 128]);

             // Runtime panic.
             project!(p, [panic: 128]);

             Ok(())
         }

     Update as well the users, which now look like e.g.

         // Pointer to the first entry of the GSP message queue.
         let data = project!(self.0.as_ptr(), .gspq.msgq.data[build: 0]);

   - 'build_assert' module: make the module the home of its macros
     instead of rendering them twice.

   - 'sync' module: add 'UniqueArc::as_ptr()' associated function.

   - 'alloc' module:

       - Fix the 'Vec::reserve()' doctest to properly account for the
         existing vector length in the capacity assertion.

       - Fix an incorrect operator in the 'Vec::extend_with()' 'SAFETY'
         comment; add a doc test demonstrating basic usage and the
         zero-length case.

   - Clean imports across several modules to follow the "kernel
     vertical" import style in order to minimize conflicts.

  'pin-init' crate:

   - User visible changes:

       - Do not generate 'non_snake_case' warnings for identifiers that
         are syntactically just users of a field name. This would allow
         all '#[allow(non_snake_case)]' in nova-core to be removed,
         which Gary will send to the nova tree next cycle.

       - Filter non-cfg attributes out properly in derived structs. This
         improves pin-init compatibility with other derive macros.

       - Insert projection types' where clause properly.

   - Other changes:

       - Bump MSRV to 1.82, plus associated cleanups.

       - Overhaul how init slots are projected. The new approach is
         easier to justify with safety comments.

       - Mark more functions as inline, which should help mitigate the
         super-long symbol name issue due to lack of inlining.

  rust-analyzer:

   - Support '--envs' for passing env vars for crates like 'zerocopy'.

  'MAINTAINERS':

   - Add the following reviewers to the 'RUST' entry:
       - Daniel Almeida
       - Tamir Duberstein
       - Alexandre Courbot
       - Onur Özkan

     They have been involved in the Rust for Linux project for about 7
     collective years and bring expertise across several domains, which
     will be very useful to have around in the future.

     Thanks everyone for stepping up!

  And some other fixes, cleanups and improvements"

Link: https://github.com/google/zerocopy [1]
Link: https://docs.rs/zerocopy [2]
Link: https://github.com/Rust-for-Linux/linux/issues/1239 [3]

* tag 'rust-7.2' of gitolite.kernel.org:pub/scm/linux/kernel/git/ojeda/linux: (86 commits)
  MAINTAINERS: add Onur Özkan as Rust reviewer
  MAINTAINERS: add Alexandre Courbot as Rust reviewer
  MAINTAINERS: add Tamir Duberstein as Rust reviewer
  MAINTAINERS: add Daniel Almeida as Rust reviewer
  kbuild: rust: clean `zerocopy-derive` in `mrproper`
  rust: make `build_assert` module the home of related macros
  rust: str: clean unused import for Rust >= 1.98
  rust: str: use the "kernel vertical" imports style
  rust: aref: use the "kernel vertical" imports style
  rust: page: use the "kernel vertical" imports style
  gpu: nova-core: firmware: parse `FalconUCodeDescV2` via `zerocopy`
  rust: prelude: add `zerocopy{,_derive}::FromBytes`
  rust: zerocopy-derive: enable support in kbuild
  rust: zerocopy-derive: add `README.md`
  rust: zerocopy-derive: avoid generating non-ASCII identifiers
  rust: zerocopy-derive: add SPDX License Identifiers
  rust: zerocopy-derive: import crate
  rust: zerocopy: enable support in kbuild
  rust: zerocopy: add `README.md`
  rust: zerocopy: remove float `Display` support
  ...
2026-06-15 09:25:48 +05:30
Yury Norov
e74b7a3f5a rust: tests: add Kconfig for KUnit test
There are 6 individual Rust KUnit test suites (plus the doctests one). All
the tests are compiled unconditionally now, which adds ~200 kB to the
kernel image for me on x86_64. As Rust matures, this bloating will
inevitably grow.

Add Kconfig.test which includes a RUST_KUNIT_TESTS menu, and all
individual tests under it.

As usual, new tests are all enabled if KUNIT_ALL_TESTS=y.

Suggested-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Yury Norov <ynorov@nvidia.com>
Reviewed-by: David Gow <david@davidgow.net>
Acked-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260417031531.315281-3-ynorov@nvidia.com
[ Fixed capitalization. Used singular for "API" for consistency.
  Reworded to clarify these are suites and that there exists
  the doctests one (which is the biggest at the moment by
  far). - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-06-08 02:30:33 +02:00
Thomas Gleixner
042df0c1d4 futex: Add robust futex unlock IP range
There will be a VDSO function to unlock robust futexes in user space. The
unlock sequence is racy vs. clearing the list_pending_op pointer in the
tasks robust list head. To plug this race the kernel needs to know the
instruction window. As the VDSO is per MM the addresses are stored in
mm_struct::futex.

Architectures which implement support for this have to update these
addresses when the VDSO is (re)mapped and indicate the pending op pointer
size which is matching the IP.

Arguably this could be resolved by chasing mm->context->vdso->image, but
that's architecture specific and requires to touch quite some cache
lines. Having it in mm::futex reduces the cache line impact and avoids
having yet another set of architecture specific functionality.

To support multi size robust list applications (gaming) this provides two
ranges when COMPAT is enabled.

Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: André Almeida <andrealmeid@igalia.com>
Link: https://patch.msgid.link/20260602090535.718926819@kernel.org
2026-06-03 11:38:51 +02:00
Anand Moon
97bd80a918 treewide: fix indentation and whitespace in Kconfig files
Clean up inconsistent indentation (mixing tabs and spaces) and remove
extraneous whitespace in several Kconfig files across the tree.  This is a
purely cosmetic change to improve readability.

Adjust indentation from spaces to tab (+optional two spaces) as in
coding style with command like:

$ sed -e 's/^        /\t/' -i */Kconfig

Link: https://lore.kernel.org/20260407053945.14116-1-linux.amoon@gmail.com
Signed-off-by: Anand Moon <linux.amoon@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>			[fs]
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>	[mm]
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>		[mm]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2026-05-28 21:24:42 -07:00
Nathan Chancellor
f3de78cb19
kbuild: Remove check for broken scoping with clang < 17 in CC_HAS_ASM_GOTO_OUTPUT
Now that the minimum supported version of LLVM for building the kernel
has been raised to 17.0.1, the check added to CC_HAS_ASM_GOTO_OUTPUT by
commit e2ffa15b9b ("kbuild: Disable CC_HAS_ASM_GOTO_OUTPUT on clang <
17") can be removed, as the issue it detects is guaranteed to be fixed.

Acked-by: Nicolas Schier <nsc@kernel.org>
Link: https://patch.msgid.link/20260517-bump-minimum-supported-llvm-version-to-17-v2-14-b3b8cda46bdd@kernel.org
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
2026-05-27 15:20:06 -07:00
Alice Ryhl
72d33b8bfe rust: kasan: add support for Software Tag-Based KASAN
This adds support for Software Tag-Based KASAN (KASAN_SW_TAGS) when
CONFIG_RUST is enabled. This requires that rustc includes support for
the kernel-hwaddress sanitizer, which is available since 1.96.0 [1].

Unlike with clang, we need to pass -Zsanitizer-recover in addition to
-Zsanitizer because the option is not implied automatically.

The kasan makefile uses different names for the flags depending on
whether CC is clang or gcc, but as we require that CC is clang when
using KASAN, we do not need to try to handle mixed gcc/llvm builds when
Rust is enabled.

Link: https://github.com/rust-lang/rust/pull/153049 [1]
Reviewed-by: Danilo Krummrich <dakr@kernel.org>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-2-e07964d14363@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-05-27 01:54:22 +02:00
Alice Ryhl
5b271543d0 rust: kasan: KASAN+RUST requires clang
Kernel KASAN involves passing various llvm/gcc specific arguments to
the C and Rust compiler. Since these arguments differ between llvm and
gcc, it's not safe to mix an llvm-based rustc with a gcc build when
kasan is enabled.

Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Gary Guo <gary@garyguo.net>
Cc: stable@vger.kernel.org
Fixes: e3117404b4 ("kbuild: rust: Enable KASAN support")
Link: https://patch.msgid.link/20260408-kasan-rust-sw-tags-v3-1-e07964d14363@google.com
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-05-27 01:54:22 +02:00
Peter Zijlstra
a26d9208c1 Merge branch 'sched/cache'
Merge the cache aware balancer topic branch.

# Conflicts:
#	kernel/sched/topology.c
2026-05-19 12:18:01 +02:00
Marco Elver
feb662d916 slab: support for compiler-assisted type-based slab cache partitioning
Rework the general infrastructure around RANDOM_KMALLOC_CACHES into more
flexible KMALLOC_PARTITION_CACHES, with the former being a partitioning
mode of the latter.

Introduce a new mode, KMALLOC_PARTITION_TYPED, which leverages a feature
available in Clang 22 and later, called "allocation tokens" via
__builtin_infer_alloc_token() [1]. Unlike KMALLOC_PARTITION_RANDOM
(formerly RANDOM_KMALLOC_CACHES), this mode deterministically assigns a
slab cache to an allocation of type T, regardless of allocation site.

The builtin __builtin_infer_alloc_token(<malloc-args>, ...) instructs
the compiler to infer an allocation type from arguments commonly passed
to memory-allocating functions and returns a type-derived token ID. The
implementation passes kmalloc-args to the builtin: the compiler performs
best-effort type inference, and then recognizes common patterns such as
`kmalloc(sizeof(T), ...)`, `kmalloc(sizeof(T) * n, ...)`, but also
`(T *)kmalloc(...)`. Where the compiler fails to infer a type the
fallback token (default: 0) is chosen.

Note: kmalloc_obj(..) APIs fix the pattern how size and result type are
expressed, and therefore ensures there's not much drift in which
patterns the compiler needs to recognize. Specifically, kmalloc_obj()
and friends expand to `(TYPE *)KMALLOC(__obj_size, GFP)`, which the
compiler recognizes via the cast to TYPE*.

Clang's default token ID calculation is described as [1]:

   typehashpointersplit: This mode assigns a token ID based on the hash
   of the allocated type's name, where the top half ID-space is reserved
   for types that contain pointers and the bottom half for types that do
   not contain pointers.

Separating pointer-containing objects from pointerless objects and data
allocations can help mitigate certain classes of memory corruption
exploits [2]: attackers who gains a buffer overflow on a primitive
buffer cannot use it to directly corrupt pointers or other critical
metadata in an object residing in a different, isolated heap region.

It is important to note that heap isolation strategies offer a
best-effort approach, and do not provide a 100% security guarantee,
albeit achievable at relatively low performance cost. Note that this
also does not prevent cross-cache attacks: while waiting for future
features like SLAB_VIRTUAL [3] to provide physical page isolation, this
feature should be deployed alongside SHUFFLE_PAGE_ALLOCATOR and
init_on_free=1 to mitigate cross-cache attacks and page-reuse attacks as
much as possible today.

With all that, my kernel (x86 defconfig) shows me a histogram of slab
cache object distribution per /proc/slabinfo (after boot):

  <slab cache>      <objs> <hist>
  kmalloc-part-15    1465  ++++++++++++++
  kmalloc-part-14    2988  +++++++++++++++++++++++++++++
  kmalloc-part-13    1656  ++++++++++++++++
  kmalloc-part-12    1045  ++++++++++
  kmalloc-part-11    1697  ++++++++++++++++
  kmalloc-part-10    1489  ++++++++++++++
  kmalloc-part-09     965  +++++++++
  kmalloc-part-08     710  +++++++
  kmalloc-part-07     100  +
  kmalloc-part-06     217  ++
  kmalloc-part-05     105  +
  kmalloc-part-04    4047  ++++++++++++++++++++++++++++++++++++++++
  kmalloc-part-03     183  +
  kmalloc-part-02     283  ++
  kmalloc-part-01     316  +++
  kmalloc            1422  ++++++++++++++

The above /proc/slabinfo snapshot shows me there are 6673 allocated
objects (slabs 00 - 07) that the compiler claims contain no pointers or
it was unable to infer the type of, and 12015 objects that contain
pointers (slabs 08 - 15). On a whole, this looks relatively sane.

Additionally, when I compile my kernel with -Rpass=alloc-token, which
provides diagnostics where (after dead-code elimination) type inference
failed, I see 186 allocation sites where the compiler failed to identify
a type (down from 966 when I sent the RFC [4]). Some initial review
confirms these are mostly variable sized buffers, but also include
structs with trailing flexible length arrays.

Link: https://clang.llvm.org/docs/AllocToken.html [1]
Link: https://blog.dfsec.com/ios/2025/05/30/blasting-past-ios-18/ [2]
Link: https://lwn.net/Articles/944647/ [3]
Link: https://lore.kernel.org/all/20250825154505.1558444-1-elver@google.com/ [4]
Link: https://discourse.llvm.org/t/rfc-a-framework-for-allocator-partitioning-hints/87434
Acked-by: GONG Ruiqi <gongruiqi1@huawei.com>
Co-developed-by: Harry Yoo (Oracle) <harry@kernel.org>
Signed-off-by: Harry Yoo (Oracle) <harry@kernel.org>
Signed-off-by: Marco Elver <elver@google.com>
Reviewed-by: Harry Yoo (Oracle) <harry@kernel.org>
Link: https://patch.msgid.link/20260511200136.3201646-1-elver@google.com
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
2026-05-14 10:44:09 +02:00
Linus Torvalds
334fbe734e mm.git review status for linus..mm-stable
Everything:
 
 Total patches:       368
 Reviews/patch:       1.56
 Reviewed rate:       74%
 
 Excluding DAMON:
 
 Total patches:       316
 Reviews/patch:       1.77
 Reviewed rate:       81%
 
 Excluding DAMON and zram:
 
 Total patches:       306
 Reviews/patch:       1.81
 Reviewed rate:       82%
 
 Excluding DAMON, zram and maple_tree:
 
 Total patches:       276
 Reviews/patch:       2.01
 Reviewed rate:       91%
 
 Significant patch series in this merge:
 
 - The 30 patch series "maple_tree: Replace big node with maple copy"
   from Liam Howlett is mainly prepararatory work for ongoing development
   but it does reduce stack usage and is an improvement.
 
 - The 12 patch series "mm, swap: swap table phase III: remove swap_map"
   from Kairui Song offers memory savings by removing the static swap_map.
   It also yields some CPU savings and implements several cleanups.
 
 - The 2 patch series "mm: memfd_luo: preserve file seals" from Pratyush
   Yadav adds file seal preservation to LUO's memfd code.
 
 - The 2 patch series "mm: zswap: add per-memcg stat for incompressible
   pages" from Jiayuan Chen adds additional userspace stats reportng to
   zswap.
 
 - The 4 patch series "arch, mm: consolidate empty_zero_page" from Mike
   Rapoport implements some cleanups for our handling of ZERO_PAGE() and
   zero_pfn.
 
 - The 2 patch series "mm/kmemleak: Improve scan_should_stop()
   implementation" from Zhongqiu Han provides an robustness improvement and
   some cleanups in the kmemleak code.
 
 - The 4 patch series "Improve khugepaged scan logic" from Vernon Yang
   "improves the khugepaged scan logic and reduces CPU consumption by
   prioritizing scanning tasks that access memory frequently".
 
 - The 2 patch series "Make KHO Stateless" from Jason Miu simplifies
   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"
 
 - The 3 patch series "mm: vmscan: add PID and cgroup ID to vmscan
   tracepoints" from Thomas Ballasi and Steven Rostedt enhances vmscan's
   tracepointing.
 
 - The 5 patch series "mm: arch/shstk: Common shadow stack mapping helper
   and VM_NOHUGEPAGE" from Catalin Marinas is a cleanup for the shadow
   stack code: remove per-arch code in favour of a generic implementation.
 
 - The 2 patch series "Fix KASAN support for KHO restored vmalloc
   regions" from Pasha Tatashin fixes a WARN() which can be emitted the KHO
   restores a vmalloc area.
 
 - The 4 patch series "mm: Remove stray references to pagevec" from Tal
   Zussman provides several cleanups, mainly udpating references to "struct
   pagevec", which became folio_batch three years ago.
 
 - The 17 patch series "mm: Eliminate fake head pages from vmemmap
   optimization" from Kiryl Shutsemau simplifies the HugeTLB vmemmap
   optimization (HVO) by changing how tail pages encode their relationship
   to the head page.
 
 - The 2 patch series "mm/damon/core: improve DAMOS quota efficiency for
   core layer filters" from SeongJae Park improves two problematic
   behaviors of DAMOS that makes it less efficient when core layer filters
   are used.
 
 - The 3 patch series "mm/damon: strictly respect min_nr_regions" from
   SeongJae Park improves DAMON usability by extending the treatment of the
   min_nr_regions user-settable parameter.
 
 - The 3 patch series "mm/page_alloc: pcp locking cleanup" from Vlastimil
   Babka is a proper fix for a previously hotfixed SMP=n issue.  Code
   simplifications and cleanups ennsed.
 
 - The 16 patch series "mm: cleanups around unmapping / zapping" from
   David Hildenbrand implements "a bunch of cleanups around unmapping and
   zapping.  Mostly simplifications, code movements, documentation and
   renaming of zapping functions".
 
 - The 6 patch series "support batched checking of the young flag for
   MGLRU" from Baolin Wang supports batched checking of the young flag for
   MGLRU.  It's part cleanups; one benchmark shows large performance
   benefits for arm64.
 
 - The 5 patch series "memcg: obj stock and slab stat caching cleanups"
   from Johannes Weiner provides memcg cleanup and robustness improvements.
 
 - The 5 patch series "Allow order zero pages in page reporting" from
   Yuvraj Sakshith enhances page_reporting's free page reporting - it is
   presently and undesirably order-0 pages when reporting free memory.
 
 - The 6 patch series "mm: vma flag tweaks" from Lorenzo Stoakes is
   cleanup work following from the recent conversion of the VMA flags to a
   bitmap.
 
 - The 10 patch series "mm/damon: add optional debugging-purpose sanity
   checks" from SeongJae Park adds some more developer-facing debug checks
   into DAMON core.
 
 - The 2 patch series "mm/damon: test and document power-of-2
   min_region_sz requirement" from SeongJae Park adds an additional DAMON
   kunit test and makes some adjustments to the addr_unit parameter
   handling.
 
 - The 3 patch series "mm/damon/core: make passed_sample_intervals
   comparisons overflow-safe" from SeongJae Park fixes a hard-to-hit time
   overflow issue in DAMON core.
 
 - The 7 patch series "mm/damon: improve/fixup/update ratio calculation,
   test and documentation" from SeongJae Park is a "batch of misc/minor
   improvements and fixups" for DAMON.
 
 - The 4 patch series "mm: move vma_(kernel|mmu)_pagesize() out of
   hugetlb.c" from David Hildenbrand fixes a possible issue with dax-device
   when CONFIG_HUGETLB=n.  Some code movement was required.
 
 - The 6 patch series "zram: recompression cleanups and tweaks" from
   Sergey Senozhatsky provides "a somewhat random mix of fixups,
   recompression cleanups and improvements" in the zram code.
 
 - The 11 patch series "mm/damon: support multiple goal-based quota
   tuning algorithms" from SeongJae Park extend DAMOS quotas goal
   auto-tuning to support multiple tuning algorithms that users can select.
 
 - The 4 patch series "mm: thp: reduce unnecessary
   start_stop_khugepaged()" from Breno Leitao fixes the khugpaged sysfs
   handling so we no longer spam the logs with reams of junk when
   starting/stopping khugepaged.
 
 - The 3 patch series "mm: improve map count checks" from Lorenzo Stoakes
   provides some cleanups and slight fixes in the mremap, mmap and vma
   code.
 
 - The 5 patch series "mm/damon: support addr_unit on default monitoring
   targets for modules" from SeongJae Park extends the use of DAMON core's
   addr_unit tunable.
 
 - The 5 patch series "mm: khugepaged cleanups and mTHP prerequisites"
   from Nico Pache provides cleanups in the khugepaged and is a base for
   Nico's planned khugepaged mTHP support.
 
 - The 15 patch series "mm: memory hot(un)plug and SPARSEMEM cleanups"
   from David Hildenbrand implements code movement and cleanups in the
   memhotplug and sparsemem code.
 
 - The 2 patch series "mm: remove CONFIG_ARCH_ENABLE_MEMORY_HOTREMOVE and
   cleanup CONFIG_MIGRATION" from David Hildenbrand rationalizes some
   memhotplug Kconfig support.
 
 - The 6 patch series "change young flag check functions to return bool"
   from Baolin Wang is "a cleanup patchset to change all young flag check
   functions to return bool".
 
 - The 3 patch series "mm/damon/sysfs: fix memory leak and NULL
   dereference issues" from Josh Law and SeongJae Park fixes a few
   potential DAMON bugs.
 
 - The 25 patch series "mm/vma: convert vm_flags_t to vma_flags_t in vma
   code" from "converts 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.
 
 - The 21 patch series "mm: expand mmap_prepare functionality and usage"
   from Lorenzo Stoakes "expands 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.
 
 - The 13 patch series "mm/huge_memory: refactor zap_huge_pmd()" from
   Lorenzo Stoakes simplifies and cleans up zap_huge_pmd().  Additional
   cleanups around vm_normal_folio_pmd() and the softleaf functionality are
   performed.
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Merge tag 'mm-stable-2026-04-13-21-45' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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
  ...
2026-04-15 12:59:16 -07:00
Linus Torvalds
5bdb4078e1 sched_ext: Changes for v7.1
- Cgroup sub-scheduler groundwork. Multiple BPF schedulers can be
   attached to cgroups and the dispatch path is made hierarchical. This
   involves substantial restructuring of the core dispatch, bypass,
   watchdog, and dump paths to be per-scheduler, along with new
   infrastructure for scheduler ownership enforcement, lifecycle
   management, and cgroup subtree iteration. The enqueue path is not yet
   updated and will follow in a later cycle.
 
 - scx_bpf_dsq_reenq() generalized to support any DSQ including remote
   local DSQs and user DSQs. Built on top of this, SCX_ENQ_IMMED
   guarantees that tasks dispatched to local DSQs either run immediately
   or get reenqueued back through ops.enqueue(), giving schedulers tighter
   control over queueing latency. Also useful for opportunistic CPU
   sharing across sub-schedulers.
 
 - ops.dequeue() was only invoked when the core knew a task was in BPF
   data structures, missing scheduling property change events and skipping
   callbacks for non-local DSQ dispatches from ops.select_cpu(). Fixed to
   guarantee exactly one ops.dequeue() call when a task leaves BPF
   scheduler custody.
 
 - Kfunc access validation moved from runtime to BPF verifier time,
   removing runtime mask enforcement.
 
 - Idle SMT sibling prioritization in the idle CPU selection path.
 
 - Documentation, selftest, and tooling updates. Misc bug fixes and
   cleanups.
 
 - Merges from tip/sched-core, cgroup/for-7.1, and for-7.0-fixes to
   resolve dependencies and conflicts for the above changes.
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Merge tag 'sched_ext-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext

Pull sched_ext updates from Tejun Heo:

 - cgroup sub-scheduler groundwork

   Multiple BPF schedulers can be attached to cgroups and the dispatch
   path is made hierarchical. This involves substantial restructuring of
   the core dispatch, bypass, watchdog, and dump paths to be
   per-scheduler, along with new infrastructure for scheduler ownership
   enforcement, lifecycle management, and cgroup subtree iteration

   The enqueue path is not yet updated and will follow in a later cycle

 - scx_bpf_dsq_reenq() generalized to support any DSQ including remote
   local DSQs and user DSQs

   Built on top of this, SCX_ENQ_IMMED guarantees that tasks dispatched
   to local DSQs either run immediately or get reenqueued back through
   ops.enqueue(), giving schedulers tighter control over queueing
   latency

   Also useful for opportunistic CPU sharing across sub-schedulers

 - ops.dequeue() was only invoked when the core knew a task was in BPF
   data structures, missing scheduling property change events and
   skipping callbacks for non-local DSQ dispatches from ops.select_cpu()

   Fixed to guarantee exactly one ops.dequeue() call when a task leaves
   BPF scheduler custody

 - Kfunc access validation moved from runtime to BPF verifier time,
   removing runtime mask enforcement

 - Idle SMT sibling prioritization in the idle CPU selection path

 - Documentation, selftest, and tooling updates. Misc bug fixes and
   cleanups

* tag 'sched_ext-for-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/sched_ext: (134 commits)
  tools/sched_ext: Add explicit cast from void* in RESIZE_ARRAY()
  sched_ext: Make string params of __ENUM_set() const
  tools/sched_ext: Kick home CPU for stranded tasks in scx_qmap
  sched_ext: Drop spurious warning on kick during scheduler disable
  sched_ext: Warn on task-based SCX op recursion
  sched_ext: Rename scx_kf_allowed_on_arg_tasks() to scx_kf_arg_task_ok()
  sched_ext: Remove runtime kfunc mask enforcement
  sched_ext: Add verifier-time kfunc context filter
  sched_ext: Drop redundant rq-locked check from scx_bpf_task_cgroup()
  sched_ext: Decouple kfunc unlocked-context check from kf_mask
  sched_ext: Fix ops.cgroup_move() invocation kf_mask and rq tracking
  sched_ext: Track @p's rq lock across set_cpus_allowed_scx -> ops.set_cpumask
  sched_ext: Add select_cpu kfuncs to scx_kfunc_ids_unlocked
  sched_ext: Drop TRACING access to select_cpu kfuncs
  selftests/sched_ext: Fix wrong DSQ ID in peek_dsq error message
  sched_ext: Documentation: improve accuracy of task lifecycle pseudo-code
  selftests/sched_ext: Improve runner error reporting for invalid arguments
  sched_ext: Documentation: Fix scx_bpf_move_to_local kfunc name
  sched_ext: Documentation: Add ops.dequeue() to task lifecycle
  tools/sched_ext: Fix off-by-one in scx_sdt payload zeroing
  ...
2026-04-15 10:54:24 -07:00
Linus Torvalds
f21f7b5162 Update to the VDSO subsystem:
- Make the handling of compat functions consistent and more robust
 
      - Rework the underlying data store so that it is dynamically
        allocated, which allows the conversion of the last holdout SPARC64
        to the generic VDSO implementation
 
      - Rework the SPARC64 VDSO to utilize the generic implementation
 
      - Mop up the left overs of the non-generic VDSO support in the core
        code.
 
      - Expand the VDSO selftest and make them more robust
 
      - Allow time namespaces to be enabled independently of the generic
        VDSO support, which was not possible before due to SPARC64 not
        using it.
 
      - Various cleanups and improvements in the related code.
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Merge tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull vdso updates from Thomas Gleixner:

 - Make the handling of compat functions consistent and more robust

 - Rework the underlying data store so that it is dynamically allocated,
   which allows the conversion of the last holdout SPARC64 to the
   generic VDSO implementation

 - Rework the SPARC64 VDSO to utilize the generic implementation

 - Mop up the left overs of the non-generic VDSO support in the core
   code

 - Expand the VDSO selftest and make them more robust

 - Allow time namespaces to be enabled independently of the generic VDSO
   support, which was not possible before due to SPARC64 not using it

 - Various cleanups and improvements in the related code

* tag 'timers-vdso-2026-04-12' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (51 commits)
  timens: Use task_lock guard in timens_get*()
  timens: Use mutex guard in proc_timens_set_offset()
  timens: Simplify some calls to put_time_ns()
  timens: Add a __free() wrapper for put_time_ns()
  timens: Remove dependency on the vDSO
  vdso/timens: Move functions to new file
  selftests: vDSO: vdso_test_correctness: Add a test for time()
  selftests: vDSO: vdso_test_correctness: Use facilities from parse_vdso.c
  selftests: vDSO: vdso_test_correctness: Handle different tv_usec types
  selftests: vDSO: vdso_test_correctness: Drop SYS_getcpu fallbacks
  selftests: vDSO: vdso_test_gettimeofday: Remove nolibc checks
  Revert "selftests: vDSO: parse_vdso: Use UAPI headers instead of libc headers"
  random: vDSO: Remove ifdeffery
  random: vDSO: Trim vDSO includes
  vdso/datapage: Trim down unnecessary includes
  vdso/datapage: Remove inclusion of gettimeofday.h
  vdso/helpers: Explicitly include vdso/processor.h
  vdso/gettimeofday: Add explicit includes
  random: vDSO: Add explicit includes
  MIPS: vdso: Explicitly include asm/vdso/vdso.h
  ...
2026-04-14 10:53:44 -07:00
Linus Torvalds
5d0d362330 Kbuild/Kconfig updates for 7.1
Kbuild changes
 ==============
 
   * tools/build: Reject unexpected values for LLVM=
 
   * kbuild: uapi: remove usage of toolchain headers
 
   * kbuild: Switch from '-fms-extensions' to '-fms-anonymous-structs'
     when available (currently: clang >= 23.0.0)
 
   * kbuild: Reduce the number of compiler-generated suffixes for clang
     thin-lto build
 
   * kbuild: reduce output spam ("GEN Makefile") when building out of tree
 
   * check-uapi: improve portability for testing headers
 
   * uapi: also test UAPI headers against C++ compilers
 
   * kbuild: vdso_install: drop build ID architecture allow-list
 
   * checksyscalls: only run when necessary
 
   * Documentation: kbuild: Update the debug information notes in
     reproducible-builds.rst
 
   * kconfig: forbid multiple entries with the same symbol in a choice
 
   * kbuild: expand inlining hints with -fdiagnostics-show-inlining-chain
 
 Kconfig changes
 ===============
 
   * kconfig: Error out on duplicated kconfig inclusion
 
 Cc: Alexander Coffin <alex@cyberialabs.net>
 Cc: Ard Biesheuvel <ardb@kernel.org>
 Cc: Arnd Bergmann <arnd@arndb.de>
 Cc: Bill Wendling <morbo@google.com>
 Cc: David Howells <dhowells@redhat.com>
 Cc: Dodji Seketeli <dodji@seketeli.org>
 Cc: H. Peter Anvin <hpa@zytor.com>
 Cc: Helge Deller <deller@gmx.de>
 Cc: John Moon <john@jmoon.dev>
 Cc: Jonathan Corbet <corbet@lwn.net>
 Cc: Josh Poimboeuf <jpoimboe@kernel.org>
 Cc: Justin Stitt <justinstitt@google.com>
 Cc: Kees Cook <kees@kernel.org>
 Cc: Masahiro Yamada <masahiroy@kernel.org>
 Cc: Nathan Chancellor <nathan@kernel.org>
 Cc: Nick Desaulniers <nick.desaulniers+lkml@gmail.com>
 Cc: Shuah Khan <skhan@linuxfoundation.org>
 Cc: Song Liu <song@kernel.org>
 Cc: Thomas Weißschuh <linux@weissschuh.net>
 Cc: Yonghong Song <yonghong.song@linux.dev>
 Cc: kernel-team@fb.com
 Cc: linux-arm-kernel@lists.infradead.org
 Cc: linux-efi@vger.kernel.org
 Cc: linux-hexagon@vger.kernel.org
 Cc: linux-kbuild@vger.kernel.org
 Cc: linux-kernel@vger.kernel.org
 Cc: linux-parisc@vger.kernel.org
 Cc: linux-s390@vger.kernel.org
 Cc: linuxppc-dev@lists.ozlabs.org
 Cc: llvm@lists.linux.dev
 Cc: loongarch@lists.linux.dev
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Merge tag 'kbuild-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild/Kconfig updates from Nicolas Schier:
 "Kbuild:
   - reject unexpected values for LLVM=
   - uapi: remove usage of toolchain headers
   - switch from '-fms-extensions' to '-fms-anonymous-structs' when
     available (currently: clang >= 23.0.0)
   - reduce the number of compiler-generated suffixes for clang thin-lto
     build
   - reduce output spam ("GEN Makefile") when building out of tree
   - improve portability for testing headers
   - also test UAPI headers against C++ compilers
   - drop build ID architecture allow-list in vdso_install
   - only run checksyscalls when necessary
   - update the debug information notes in reproducible-builds.rst
   - expand inlining hints with -fdiagnostics-show-inlining-chain

  Kconfig:
   - forbid multiple entries with the same symbol in a choice
   - error out on duplicated kconfig inclusion"

* tag 'kbuild-7.1-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (35 commits)
  kbuild: expand inlining hints with -fdiagnostics-show-inlining-chain
  kconfig: forbid multiple entries with the same symbol in a choice
  Documentation: kbuild: Update the debug information notes in reproducible-builds.rst
  checksyscalls: move instance functionality into generic code
  checksyscalls: only run when necessary
  checksyscalls: fail on all intermediate errors
  checksyscalls: move path to reference table to a variable
  kbuild: vdso_install: drop build ID architecture allow-list
  kbuild: vdso_install: gracefully handle images without build ID
  kbuild: vdso_install: hide readelf warnings
  kbuild: vdso_install: split out the readelf invocation
  kbuild: uapi: also test UAPI headers against C++ compilers
  kbuild: uapi: provide a C++ compatible dummy definition of NULL
  kbuild: uapi: handle UML in architecture-specific exclusion lists
  kbuild: uapi: move all include path flags together
  kbuild: uapi: move some compiler arguments out of the command definition
  check-uapi: use dummy libc includes
  check-uapi: honor ${CROSS_COMPILE} setting
  check-uapi: link into shared objects
  kbuild: reduce output spam when building out of tree
  ...
2026-04-14 09:18:40 -07:00
Linus Torvalds
26ff969926 Rust changes for v7.1
Toolchain and infrastructure:
 
  - Bump the minimum Rust version to 1.85.0 (and 'bindgen' to 0.71.1).
 
    As proposed in LPC 2025 and the Maintainers Summit [1], we are going
    to follow Debian Stable's Rust versions as our minimum versions.
 
    Debian Trixie was released on 2025-08-09 with a Rust 1.85.0 and
    'bindgen' 0.71.1 toolchain, which is a fair amount of time for e.g.
    kernel developers to upgrade.
 
    Other major distributions support a Rust version that is high enough
    as well, including:
 
      + Arch Linux.
      + Fedora Linux.
      + Gentoo Linux.
      + Nix.
      + openSUSE Slowroll and openSUSE Tumbleweed.
      + Ubuntu 25.10 and 26.04 LTS. In addition, 24.04 LTS using
        their versioned packages.
 
    The merged patch series comes with the associated cleanups and
    simplifications treewide that can be performed thanks to both bumps,
    as well as documentation updates.
 
    In addition, start using 'bindgen''s '--with-attribute-custom-enum'
    feature to set the 'cfi_encoding' attribute for the 'lru_status' enum
    used in Binder.
 
    Link: https://lwn.net/Articles/1050174/ [1]
 
  - Add experimental Kconfig option ('CONFIG_RUST_INLINE_HELPERS') that
    inlines C helpers into Rust.
 
    Essentially, it performs a step similar to LTO, but just for the
    helpers, i.e. very local and fast.
 
    It relies on 'llvm-link' and its '--internalize' flag, and requires
    a compatible LLVM between Clang and 'rustc' (i.e. same major version,
    'CONFIG_RUSTC_CLANG_LLVM_COMPATIBLE'). It is only enabled for two
    architectures for now.
 
    The result is a measurable speedup in different workloads that
    different users have tested. For instance, for the null block driver,
    it amounts to a 2%.
 
  - Support global per-version flags.
 
    While we already have per-version flags in many places, we didn't
    have a place to set global ones that depend on the compiler version,
    i.e. in 'rust_common_flags', which sometimes is needed to e.g. tweak
    the lints set per version.
 
    Use that to allow the 'clippy::precedence' lint for Rust < 1.86.0,
    since it had a change in behavior.
 
  - Support overriding the crate name and apply it to Rust Binder, which
    wanted the module to be called 'rust_binder'.
 
  - Add the remaining '__rust_helper' annotations (started in the
    previous cycle).
 
 'kernel' crate:
 
  - Introduce the 'const_assert!' macro: a more powerful version of
    'static_assert!' that can refer to generics inside functions or
    implementation bodies, e.g.:
 
        fn f<const N: usize>() {
            const_assert!(N > 1);
        }
 
        fn g<T>() {
            const_assert!(size_of::<T>() > 0, "T cannot be ZST");
        }
 
    In addition, reorganize our set of build-time assertion macros
    ('{build,const,static_assert}!') to live in the 'build_assert'
    module.
 
    Finally, improve the docs as well to clarify how these are different
    from one another and how to pick the right one to use, and their
    equivalence (if any) to the existing C ones for extra clarity.
 
  - 'sizes' module: add 'SizeConstants' trait.
 
    This gives us typed 'SZ_*' constants (avoiding casts) for use in
    device address spaces where the address width depends on the hardware
    (e.g. 32-bit MMIO windows, 64-bit GPU framebuffers, etc.), e.g.:
 
        let gpu_heap = 14 * u64::SZ_1M;
        let mmio_window = u32::SZ_16M;
 
  - 'clk' module: implement 'Send' and 'Sync' for 'Clk' and thus simplify
    the users in Tyr and PWM.
 
  - 'ptr' module: add 'const_align_up'.
 
  - 'str' module: improve the documentation of the 'c_str!' macro to
    explain that one should only use it for non-literal cases (for the
    other case we instead use C string literals, e.g. 'c"abc"').
 
  - Disallow the use of 'CStr::{as_ptr,from_ptr}' and clean one such use
    in the 'task' module.
 
  - 'sync' module: finish the move of 'ARef' and 'AlwaysRefCounted'
    outside of the 'types' module, i.e. update the last remaining
    instances and finally remove the re-exports.
 
  - 'error' module: clarify that 'from_err_ptr' can return 'Ok(NULL)',
    including runtime-tested examples.
 
    The intention is to hopefully prevent UB that assumes the result of
    the function is not 'NULL' if successful. This originated from a case
    of UB I noticed in 'regulator' that created a 'NonNull' on it.
 
 Timekeeping:
 
  - Expand the example section in the 'HrTimer' documentation.
 
  - Mark the 'ClockSource' trait as unsafe to ensure valid values for
    'ktime_get()'.
 
  - Add 'Delta::from_nanos()'.
 
 'pin-init' crate:
 
  - Replace the 'Zeroable' impls for 'Option<NonZero*>' with impls of
    'ZeroableOption' for 'NonZero*'.
 
  - Improve feature gate handling for unstable features.
 
  - Declutter the documentation of implementations of 'Zeroable' for
    tuples.
 
  - Replace uses of 'addr_of[_mut]!' with '&raw [mut]'.
 
 rust-analyzer:
 
  - Add type annotations to 'generate_rust_analyzer.py'.
 
  - Add support for scripts written in Rust ('generate_rust_target.rs',
    'rustdoc_test_builder.rs', 'rustdoc_test_gen.rs').
 
  - Refactor 'generate_rust_analyzer.py' to explicitly identify host and
    target crates, improve readability, and reduce duplication.
 
 And some other fixes, cleanups and improvements.
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Merge tag 'rust-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux

Pull Rust updates from Miguel Ojeda:
 "Toolchain and infrastructure:

   - Bump the minimum Rust version to 1.85.0 (and 'bindgen' to 0.71.1).

     As proposed in LPC 2025 and the Maintainers Summit [1], we are
     going to follow Debian Stable's Rust versions as our minimum
     versions.

     Debian Trixie was released on 2025-08-09 with a Rust 1.85.0 and
     'bindgen' 0.71.1 toolchain, which is a fair amount of time for e.g.
     kernel developers to upgrade.

     Other major distributions support a Rust version that is high
     enough as well, including:

       + Arch Linux.
       + Fedora Linux.
       + Gentoo Linux.
       + Nix.
       + openSUSE Slowroll and openSUSE Tumbleweed.
       + Ubuntu 25.10 and 26.04 LTS. In addition, 24.04 LTS using
         their versioned packages.

     The merged patch series comes with the associated cleanups and
     simplifications treewide that can be performed thanks to both
     bumps, as well as documentation updates.

     In addition, start using 'bindgen''s '--with-attribute-custom-enum'
     feature to set the 'cfi_encoding' attribute for the 'lru_status'
     enum used in Binder.

     Link: https://lwn.net/Articles/1050174/ [1]

   - Add experimental Kconfig option ('CONFIG_RUST_INLINE_HELPERS') that
     inlines C helpers into Rust.

     Essentially, it performs a step similar to LTO, but just for the
     helpers, i.e. very local and fast.

     It relies on 'llvm-link' and its '--internalize' flag, and requires
     a compatible LLVM between Clang and 'rustc' (i.e. same major
     version, 'CONFIG_RUSTC_CLANG_LLVM_COMPATIBLE'). It is only enabled
     for two architectures for now.

     The result is a measurable speedup in different workloads that
     different users have tested. For instance, for the null block
     driver, it amounts to a 2%.

   - Support global per-version flags.

     While we already have per-version flags in many places, we didn't
     have a place to set global ones that depend on the compiler
     version, i.e. in 'rust_common_flags', which sometimes is needed to
     e.g. tweak the lints set per version.

     Use that to allow the 'clippy::precedence' lint for Rust < 1.86.0,
     since it had a change in behavior.

   - Support overriding the crate name and apply it to Rust Binder,
     which wanted the module to be called 'rust_binder'.

   - Add the remaining '__rust_helper' annotations (started in the
     previous cycle).

  'kernel' crate:

   - Introduce the 'const_assert!' macro: a more powerful version of
     'static_assert!' that can refer to generics inside functions or
     implementation bodies, e.g.:

         fn f<const N: usize>() {
             const_assert!(N > 1);
         }

         fn g<T>() {
             const_assert!(size_of::<T>() > 0, "T cannot be ZST");
         }

     In addition, reorganize our set of build-time assertion macros
     ('{build,const,static_assert}!') to live in the 'build_assert'
     module.

     Finally, improve the docs as well to clarify how these are
     different from one another and how to pick the right one to use,
     and their equivalence (if any) to the existing C ones for extra
     clarity.

   - 'sizes' module: add 'SizeConstants' trait.

     This gives us typed 'SZ_*' constants (avoiding casts) for use in
     device address spaces where the address width depends on the
     hardware (e.g. 32-bit MMIO windows, 64-bit GPU framebuffers, etc.),
     e.g.:

         let gpu_heap = 14 * u64::SZ_1M;
         let mmio_window = u32::SZ_16M;

   - 'clk' module: implement 'Send' and 'Sync' for 'Clk' and thus
     simplify the users in Tyr and PWM.

   - 'ptr' module: add 'const_align_up'.

   - 'str' module: improve the documentation of the 'c_str!' macro to
     explain that one should only use it for non-literal cases (for the
     other case we instead use C string literals, e.g. 'c"abc"').

   - Disallow the use of 'CStr::{as_ptr,from_ptr}' and clean one such
     use in the 'task' module.

   - 'sync' module: finish the move of 'ARef' and 'AlwaysRefCounted'
     outside of the 'types' module, i.e. update the last remaining
     instances and finally remove the re-exports.

   - 'error' module: clarify that 'from_err_ptr' can return 'Ok(NULL)',
     including runtime-tested examples.

     The intention is to hopefully prevent UB that assumes the result of
     the function is not 'NULL' if successful. This originated from a
     case of UB I noticed in 'regulator' that created a 'NonNull' on it.

  Timekeeping:

   - Expand the example section in the 'HrTimer' documentation.

   - Mark the 'ClockSource' trait as unsafe to ensure valid values for
     'ktime_get()'.

   - Add 'Delta::from_nanos()'.

  'pin-init' crate:

   - Replace the 'Zeroable' impls for 'Option<NonZero*>' with impls of
     'ZeroableOption' for 'NonZero*'.

   - Improve feature gate handling for unstable features.

   - Declutter the documentation of implementations of 'Zeroable' for
     tuples.

   - Replace uses of 'addr_of[_mut]!' with '&raw [mut]'.

  rust-analyzer:

   - Add type annotations to 'generate_rust_analyzer.py'.

   - Add support for scripts written in Rust ('generate_rust_target.rs',
     'rustdoc_test_builder.rs', 'rustdoc_test_gen.rs').

   - Refactor 'generate_rust_analyzer.py' to explicitly identify host
     and target crates, improve readability, and reduce duplication.

  And some other fixes, cleanups and improvements"

* tag 'rust-7.1' of git://git.kernel.org/pub/scm/linux/kernel/git/ojeda/linux: (79 commits)
  rust: sizes: add SizeConstants trait for device address space constants
  rust: kernel: update `file_with_nul` comment
  rust: kbuild: allow `clippy::precedence` for Rust < 1.86.0
  rust: kbuild: support global per-version flags
  rust: declare cfi_encoding for lru_status
  docs: rust: general-information: use real example
  docs: rust: general-information: simplify Kconfig example
  docs: rust: quick-start: remove GDB/Binutils mention
  docs: rust: quick-start: remove Nix "unstable channel" note
  docs: rust: quick-start: remove Gentoo "testing" note
  docs: rust: quick-start: add Ubuntu 26.04 LTS and remove subsection title
  docs: rust: quick-start: update minimum Ubuntu version
  docs: rust: quick-start: update Ubuntu versioned packages
  docs: rust: quick-start: openSUSE provides `rust-src` package nowadays
  rust: kbuild: remove "dummy parameter" workaround for `bindgen` < 0.71.1
  rust: kbuild: update `bindgen --rust-target` version and replace comment
  rust: rust_is_available: remove warning for `bindgen` < 0.69.5 && libclang >= 19.1
  rust: rust_is_available: remove warning for `bindgen` 0.66.[01]
  rust: bump `bindgen` minimum supported version to 0.71.1 (Debian Trixie)
  rust: block: update `const_refs_to_static` MSRV TODO comment
  ...
2026-04-13 09:54:20 -07:00
Peter Zijlstra (Intel)
df0d984759 sched/cache: Introduce infrastructure for cache-aware load balancing
Adds infrastructure to enable cache-aware load balancing,
which improves cache locality by grouping tasks that share resources
within the same cache domain. This reduces cache misses and improves
overall data access efficiency.

In this initial implementation, threads belonging to the same process
are treated as entities that likely share working sets. The mechanism
tracks per-process CPU occupancy across cache domains and attempts to
migrate threads toward cache-hot domains where their process already
has active threads, thereby enhancing locality.

This provides a basic model for cache affinity. While the current code
targets the last-level cache (LLC), the approach could be extended to
other domain types such as clusters (L2) or node-internal groupings.

At present, the mechanism selects the CPU within an LLC that has the
highest recent runtime. Subsequent patches in this series will use this
information in the load-balancing path to guide task placement toward
preferred LLCs.

In the future, more advanced policies could be integrated through NUMA
balancing-for example, migrating a task to its preferred LLC when spare
capacity exists, or swapping tasks across LLCs to improve cache affinity.
Grouping of tasks could also be generalized from that of a process
to be that of a NUMA group, or be user configurable.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Chen Yu <yu.c.chen@intel.com>
Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/6269a53221b9439b9ca00d18a9d1946fb64d8cff.1775065312.git.tim.c.chen@linux.intel.com
2026-04-09 15:49:47 +02:00
Miguel Ojeda
93553d9922 rust: kbuild: remove "dummy parameter" workaround for bindgen < 0.71.1
Until the version bump of `bindgen`, we needed to pass a dummy parameter
to avoid failing the `--version` call.

Thus remove it.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-22-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07 10:00:24 +02:00
Miguel Ojeda
4ab22c543f rust: remove RUSTC_HAS_COERCE_POINTEE and simplify code
With the Rust version bump in place, the `RUSTC_HAS_COERCE_POINTEE`
Kconfig (automatic) option is always true.

Thus remove the option and simplify the code.

In particular, this includes removing our use of the predecessor unstable
features we used with Rust < 1.84.0 (`coerce_unsized`, `dispatch_from_dyn`
and `unsize`).

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-11-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07 10:00:23 +02:00
Miguel Ojeda
9b398d0565 rust: remove RUSTC_HAS_SLICE_AS_FLATTENED and simplify code
With the Rust version bump in place, the `RUSTC_HAS_SLICE_AS_FLATTENED`
Kconfig (automatic) option is always true.

Thus remove the option and simplify the code.

In particular, this includes removing the `slice` module which contained
the temporary slice helpers, i.e. the `AsFlattened` extension trait and
its `impl`s.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-10-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07 10:00:23 +02:00
Miguel Ojeda
b28711ac98 rust: simplify RUSTC_VERSION Kconfig conditions
With the Rust version bump in place, several Kconfig conditions based on
`RUSTC_VERSION` are always true.

Thus simplify them.

The minimum supported major LLVM version by our new Rust minimum version
is now LLVM 18, instead of LLVM 16. However, there are no possible
cleanups for `RUSTC_LLVM_VERSION`.

Reviewed-by: Tamir Duberstein <tamird@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Link: https://patch.msgid.link/20260405235309.418950-9-ojeda@kernel.org
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-04-07 10:00:23 +02:00
David Hildenbrand (Arm)
6ebf98d71f mm: introduce CONFIG_NUMA_MIGRATION and simplify CONFIG_MIGRATION
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>
2026-04-05 13:53:33 -07:00
Gary Guo
e90f97ce20 kbuild: rust: add CONFIG_RUSTC_CLANG_LLVM_COMPATIBLE
This config detects if Rust and Clang have matching LLVM major version.
All IR or bitcode operations (e.g. LTO) rely on LLVM major version to be
matching, otherwise it may generate errors, or worse, miscompile
silently due to change of IR semantics.

It's usually suggested to use the exact same LLVM version, but this can
be difficult to guarantee. Rust's suggestion [1] is also major-version
only, so I think this check is sufficient for the kernel.

Link: https://doc.rust-lang.org/rustc/linker-plugin-lto.html [1]
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Signed-off-by: Gary Guo <gary@garyguo.net>
Signed-off-by: Matthew Maurer <mmaurer@google.com>
Signed-off-by: Alice Ryhl <aliceryhl@google.com>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Tested-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Tested-by: Nicolas Schier <nsc@kernel.org>
Tested-by: Andreas Hindborg <a.hindborg@kernel.org>
Link: https://patch.msgid.link/20260203-inline-helpers-v2-1-beb8547a03c9@google.com
[ Fixed typo. - Miguel ]
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>
2026-03-30 02:03:52 +02:00
Thomas Weißschuh
1b6c89285d timens: Remove dependency on the vDSO
Previously, missing time namespace support in the vDSO meant that time
namespaces needed to be disabled globally. This was expressed in a hard
dependency on the generic vDSO library. This also meant that architectures
without any vDSO or only a stub vDSO could not enable time namespaces.
Now that all architectures using a real vDSO are using the generic library,
that dependency is not necessary anymore.

Remove the dependency and let all architectures enable time namespaces.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260326-vdso-timens-decoupling-v2-2-c82693a7775f@linutronix.de
2026-03-26 15:44:23 +01:00
Linus Torvalds
d2a43e7f89 hardening fixes for v7.0-rc6
- fix required Clang version for CC_HAS_COUNTED_BY_PTR (Nathan Chancellor)
 
 - update Coccinelle script used for kmalloc_obj
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Merge tag 'hardening-v7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux

Pull hardening fixes from Kees Cook:

 - fix required Clang version for CC_HAS_COUNTED_BY_PTR (Nathan
   Chancellor)

 - update Coccinelle script used for kmalloc_obj

* tag 'hardening-v7.0-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux:
  init/Kconfig: Require a release version of clang-22 for CC_HAS_COUNTED_BY_PTR
  coccinelle: kmalloc_obj: Remove default GFP_KERNEL arg
2026-03-25 14:47:18 -07:00
Cheng-Yang Chou
e73b1d7210 sched_ext: Fix build errors and unused label warning in non-cgroup configs
When building with SCHED_CLASS_EXT=y but CGROUPS=n, clang reports errors
for undeclared cgroup_put() and cgroup_get() calls, and a warning for the
unused err_stop_helper label.

EXT_SUB_SCHED is def_bool y depending only on SCHED_CLASS_EXT, but it
fundamentally requires cgroups (cgroup_path, cgroup_get, cgroup_put,
cgroup_id, etc.). Add the missing CGROUPS dependency to EXT_SUB_SCHED in
init/Kconfig.

Guard cgroup_put() and cgroup_get() in the common paths with:
  #if defined(CONFIG_EXT_GROUP_SCHED) || defined(CONFIG_EXT_SUB_SCHED)

Guard the err_stop_helper label with #ifdef CONFIG_EXT_SUB_SCHED since
all gotos targeting it are inside that same ifdef block.

Tested with both CGROUPS enabled and disabled.

Fixes: ebeca1f930 ("sched_ext: Introduce cgroup sub-sched support")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202603210903.IrKhPd6k-lkp@intel.com/
Signed-off-by: Cheng-Yang Chou <yphbchou0911@gmail.com>
Acked-by: Andrea Righi <arighi@nvidia.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
2026-03-22 10:02:11 -10:00
Nathan Chancellor
7a618ca9b9 init/Kconfig: Require a release version of clang-22 for CC_HAS_COUNTED_BY_PTR
Commit 150a04d817 ("compiler_types.h: Attributes: Add __counted_by_ptr
macro") used Clang 22.0.0 as a minimum supported version for
__counted_by_ptr, which made sense while 22.0.0 was the version of
LLVM's main branch to allow developers to easily test and develop uses
of __counted_by_ptr in their code. However, __counted_by_ptr requires a
change [1] merged towards the end of the 22 development cycle to avoid
errors when applied to void pointers.

  In file included from fs/xfs/xfs_attr_inactive.c:18:
  fs/xfs/libxfs/xfs_attr.h:59:2: error: 'counted_by' cannot be applied to a pointer with pointee of unknown size because 'void' is an incomplete type
     59 |         void                    *buffer __counted_by_ptr(bufsize);
        |         ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is disruptive for deployed prerelease clang-22 builds (such as
Android LLVM) or when bisecting between llvmorg-21-init and the fix.

Require a released version of clang-22 (i.e., 21.1.0 or newer) to
enabled __counted_by_ptr to ensure all fixes needed for proper support
are present.

Fixes: 150a04d817 ("compiler_types.h: Attributes: Add __counted_by_ptr macro")
Link: f29955a594 [1]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260318-counted_by_ptr-release-clang-22-v1-1-e017da246df0@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2026-03-20 11:51:48 -07:00
Nathan Chancellor
0d3fccf68d
kbuild: Use '-fms-anonymous-structs' if it is available
Clang recently added '-fms-anonymous-structs' [1] to specifically enable
the Microsoft tagged anonymous structure / union extension, for which
the kernel added '-fms-extensions' in commit c4781dc3d1 ("Kbuild:
enable -fms-extensions"). Switch to this more narrow option if it is
available, which would have helped avoid the issue addressed by
commit a6773e6932 ("jfs: Rename _inline to avoid conflict with clang's
'-fms-extensions'"). GCC has talked about adding a similar flag [2] as
well but potentially naming it differently.

Move the selection of the flag to Kconfig to make it easier to use
cc-option (as CC_FLAGS_DIALECT may be used in arch Makefiles, which may
be too early for cc-option in Kbuild) and customize based on compiler
flag names.

Link: c391efe6fb [1]
Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=123623 [2]
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Reviewed-by: Nicolas Schier <nsc@kernel.org>
Reviewed-by: Kees Cook <kees@kernel.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Acked-by: Helge Deller <deller@gmx.de>  # parisc
Link: https://patch.msgid.link/20260223-fms-anonymous-structs-v1-2-8ee406d3c36c@kernel.org
Signed-off-by: Nicolas Schier <nsc@kernel.org>
2026-03-12 12:52:37 +01:00
Tejun Heo
ebeca1f930 sched_ext: Introduce cgroup sub-sched support
A system often runs multiple workloads especially in multi-tenant server
environments where a system is split into partitions servicing separate
more-or-less independent workloads each requiring an application-specific
scheduler. To support such and other use cases, sched_ext is in the process
of growing multiple scheduler support.

When partitioning a system in terms of CPUs for such use cases, an
oft-taken approach is hard partitioning the system using cpuset. While it
would be possible to tie sched_ext multiple scheduler support to cpuset
partitions, such an approach would have fundamental limitations stemming
from the lack of dynamism and flexibility.

Users often don't care which specific CPUs are assigned to which workload
and want to take advantage of optimizations which are enabled by running
workloads on a larger machine - e.g. opportunistic over-commit, improving
latency critical workload characteristics while maintaining bandwidth
fairness, employing control mechanisms based on different criteria than
on-CPU time for e.g. flexible memory bandwidth isolation, packing similar
parts from different workloads on same L3s to improve cache efficiency,
and so on.

As this sort of dynamic behaviors are impossible or difficult to implement
with hard partitioning, sched_ext is implementing cgroup sub-sched support
where schedulers can be attached to the cgroup hierarchy and a parent
scheduler is responsible for controlling the CPUs that each child can use
at any given moment. This makes CPU distribution dynamically controlled by
BPF allowing high flexibility.

This patch adds the skeletal sched_ext cgroup sub-sched support:

- sched_ext_ops.sub_cgroup_id and .sub_attach/detach() are added. Non-zero
  sub_cgroup_id indicates that the scheduler is to be attached to the
  identified cgroup. A sub-sched is attached to the cgroup iff the nearest
  ancestor scheduler implements .sub_attach() and grants the attachment. Max
  nesting depth is limited by SCX_SUB_MAX_DEPTH.

- When a scheduler exits, all its descendant schedulers are exited
  together. Also, cgroup.scx_sched added which points to the effective
  scheduler instance for the cgroup. This is updated on scheduler
  init/exit and inherited on cgroup online. When a cgroup is offlined, the
  attached scheduler is automatically exited.

- Sub-sched support is gated on CONFIG_EXT_SUB_SCHED which is
  automatically enabled if both SCX and cgroups are enabled. Sub-sched
  support is not tied to the CPU controller but rather the cgroup
  hierarchy itself. This is intentional as the support for cpu.weight and
  cpu.max based resource control is orthogonal to sub-sched support. Note
  that CONFIG_CGROUPS around cgroup subtree iteration support for
  scx_task_iter is replaced with CONFIG_EXT_SUB_SCHED for consistency.

- This allows loading sub-scheds and most framework operations such as
  propagating disable down the hierarchy work. However, sub-scheds are not
  operational yet and all tasks stay with the root sched. This will serve
  as the basis for building up full sub-sched support.

- DSQs point to the scx_sched they belong to.

- scx_qmap is updated to allow attachment of sub-scheds and also serving
  as sub-scheds.

- scx_is_descendant() is added but not yet used in this patch. It is used by
  later changes in the series and placed here as this is where the function
  belongs.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Andrea Righi <arighi@nvidia.com>
2026-03-06 07:58:03 -10:00
Linus Torvalds
3ad66a34cc io_uring-7.0-20260305
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Merge tag 'io_uring-7.0-20260305' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux

Pull io_uring fixes from Jens Axboe:

 - Fix a typo in the mock_file help text

 - Fix a comment regarding IORING_SETUP_TASKRUN_FLAG in the
   io_uring.h UAPI header

 - Use READ_ONCE() for reading refill queue entries

 - Reject SEND_VECTORIZED for fixed buffer sends, as it isn't
   implemented. Currently this flag is silently ignored

   This is in preparation for making these work, but first we
   need a fixup so that older kernels will correctly reject them

 - Ensure "0" means default for the rx page size

* tag 'io_uring-7.0-20260305' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux:
  io_uring/zcrx: use READ_ONCE with user shared RQEs
  io_uring/mock: Fix typo in help text
  io_uring/net: reject SEND_VECTORIZED when unsupported
  io_uring: correct comment for IORING_SETUP_TASKRUN_FLAG
  io_uring/zcrx: don't set rx_page_size when not requested
2026-03-06 08:31:36 -08:00
J. Neuschäfer
9e7dc228bb io_uring/mock: Fix typo in help text
Fix the spelling of "subsystem".

Signed-off-by: J. Neuschäfer <j.ne@posteo.net>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2026-03-03 19:42:53 -07:00
Nathan Chancellor
f709859f33 init/Kconfig: Adjust fixed clang version for __builtin_counted_by_ref
Commit d39a1d7486 ("compiler_types: Disable __builtin_counted_by_ref
for Clang") used 22.0.0 as the fixed version for a compiler crash but
the fix was only merged in main (23.0.0) and release/22.x (22.1.0). With
the current fixed version number, prerelease or Android LLVM 22 builds
will still be able to hit the compiler crash when building the kernel.
This can be particularly disruptive when bisecting LLVM.

Use 21.1.0 as the fixed version number to ensure the fix for this crash
is always present.

Fixes: d39a1d7486 ("compiler_types: Disable __builtin_counted_by_ref for Clang")
Signed-off-by: Nathan Chancellor <nathan@kernel.org>
Link: https://patch.msgid.link/20260223-fix-clang-version-builtin-counted-by-ref-v1-1-3ea478a24f0a@kernel.org
Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-23 14:35:16 -08:00
Kees Cook
d39a1d7486 compiler_types: Disable __builtin_counted_by_ref for Clang
Unfortunately, there is a corner case of __builtin_counted_by_ref()
usage that crashes[1] Clang since support was introduced in Clang 19.
Disable it prior to Clang 22. Found while tested kmalloc_obj treewide
refactoring (via kmalloc_flex() usage).

Link: https://github.com/llvm/llvm-project/issues/182575 [1]
Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:01:14 -08:00
Linus Torvalds
41f1a08645 Kbuild/Kconfig updates for 7.0
Kbuild changes
 ==============
 
 * Drop '*_probe' pattern from modpost section check allowlist, which hid
   legitimate warnings (Johan Hovold)
 
 * Disable -Wtype-limits altogether, instead of enabling at W=2 (Vincent
   Mailhol)
 
 * Improve UAPI testing to skip testing headers that require a libc when
   CONFIG_CC_CAN_LINK is not set, opening up testing of headers with no
   libc dependencies to more environments (Thomas Weißschuh)
 
 * Update gendwarfksyms documentation with required dependencies (Jihan
   LIN)
 
 * Reject invalid LLVM= values to avoid unintentionally falling back to
   system toolchain (Thomas Weißschuh)
 
 * Add a script to help run the kernel build process in a container for
   consistent environments and testing (Guillaume Tucker)
 
 * Simplify kallsyms by getting rid of the relative base (Ard Biesheuvel)
 
 * Performance and usability improvements to scripts/make_fit.py (Simon
   Glass)
 
 * Minor various clean ups and fixes
 
 Kconfig changes
 ===============
 
 * Move XPM icons to individual files, clearing up GTK deprecation
   warnings (Rostislav Krasny)
 
 * Support
 
     depends on FOO if BAR
 
   as syntactic sugar for
 
     depends on FOO || !BAR' (Nicolas Pitre, Graham Roff)
 
 * Refactor merge_config.sh to use awk over shell/sed/grep, dramatically
   speeding up processing large number of config fragments (Anders
   Roxell, Mikko Rapeli)
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Merge tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux

Pull Kbuild/Kconfig updates from Nathan Chancellor:
 "Kbuild:

   - Drop '*_probe' pattern from modpost section check allowlist, which
     hid legitimate warnings (Johan Hovold)

   - Disable -Wtype-limits altogether, instead of enabling at W=2
     (Vincent Mailhol)

   - Improve UAPI testing to skip testing headers that require a libc
     when CONFIG_CC_CAN_LINK is not set, opening up testing of headers
     with no libc dependencies to more environments (Thomas Weißschuh)

   - Update gendwarfksyms documentation with required dependencies
     (Jihan LIN)

   - Reject invalid LLVM= values to avoid unintentionally falling back
     to system toolchain (Thomas Weißschuh)

   - Add a script to help run the kernel build process in a container
     for consistent environments and testing (Guillaume Tucker)

   - Simplify kallsyms by getting rid of the relative base (Ard
     Biesheuvel)

   - Performance and usability improvements to scripts/make_fit.py
     (Simon Glass)

   - Minor various clean ups and fixes

  Kconfig:

   - Move XPM icons to individual files, clearing up GTK deprecation
     warnings (Rostislav Krasny)

   - Support

        depends on FOO if BAR

     as syntactic sugar for

        depends on FOO || !BAR

     (Nicolas Pitre, Graham Roff)

   - Refactor merge_config.sh to use awk over shell/sed/grep,
     dramatically speeding up processing large number of config
     fragments (Anders Roxell, Mikko Rapeli)"

* tag 'kbuild-7.0-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kbuild/linux: (39 commits)
  kbuild: remove dependency of run-command on config
  scripts/make_fit: Compress dtbs in parallel
  scripts/make_fit: Support a few more parallel compressors
  kbuild: Support a FIT_EXTRA_ARGS environment variable
  scripts/make_fit: Move dtb processing into a function
  scripts/make_fit: Support an initial ramdisk
  scripts/make_fit: Speed up operation
  rust: kconfig: Don't require RUST_IS_AVAILABLE for rustc-option
  MAINTAINERS: Add scripts/install.sh into Kbuild entry
  modpost: Amend ppc64 save/restfpr symnames for -Os build
  MIPS: tools: relocs: Ship a definition of R_MIPS_PC32
  streamline_config.pl: remove superfluous exclamation mark
  kbuild: dummy-tools: Add python3
  scripts: kconfig: merge_config.sh: warn on duplicate input files
  scripts: kconfig: merge_config.sh: use awk in checks too
  scripts: kconfig: merge_config.sh: refactor from shell/sed/grep to awk
  kallsyms: Get rid of kallsyms relative base
  mips: Add support for PC32 relocations in vmlinux
  Documentation: dev-tools: add container.rst page
  scripts: add tool to run containerized builds
  ...
2026-02-11 13:40:35 -08:00
Linus Torvalds
36ae1c45b2 Scheduler changes for v7.0:
Scheduler Kconfig space updates:
 
  - Further consolidate configurable preemption modes: reduce
    the number of architectures that are allowed to offer
    PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number
    of preemption models from four to just two: 'full' and 'lazy'
    on up-to-date architectures (arm64, loongarch, powerpc,
    riscv, s390, x86).
 
    None and voluntary are only available as legacy features
    on platforms that don't implement lazy preemption yet,
    or which don't even support preemption.
 
    The goal is to eventually remove cond_resched() and
    voluntary preemption altogether.
 
    (Peter Zijlstra)
 
 RSEQ based 'scheduler time slice extension' support:
 
 This allows a thread to request a time slice extension when it
 enters a critical section to avoid contention on a resource when
 the thread is scheduled out inside of the critical section.
 
  - Add fields and constants for time slice extension
  - Provide static branch for time slice extensions
  - Add statistics for time slice extensions
  - Add prctl() to enable time slice extensions
  - Implement sys_rseq_slice_yield()
  - Implement syscall entry work for time slice extensions
  - Implement time slice extension enforcement timer
  - Reset slice extension when scheduled
  - Implement rseq_grant_slice_extension()
  - entry: Hook up rseq time slice extension
  - selftests: Implement time slice extension test
 
    (Thomas Gleixner)
 
  - Allow registering RSEQ with slice extension
  - Move slice_ext_nsec to debugfs
  - Lower default slice extension
  - selftests/rseq: Add rseq slice histogram script
 
    (Peter Zijlstra)
 
 Scheduler performance/scalability improvements:
 
  - Update rq->avg_idle when a task is moved to an idle CPU,
    which improves the scalability of various workloads.
    (Shubhang Kaushik)
 
  - Reorder fields in 'struct rq' for better caching
    (Blake Jones)
 
  - Fair scheduler SMP NOHZ balancing code speedups:
 
    - Move checking for nohz cpus after time check
    - Change likelyhood of nohz.nr_cpus
    - Remove nohz.nr_cpus and use weight of cpumask instead
 
      (Shrikanth Hegde)
 
  - Avoid false sharing for sched_clock_irqtime (Wangyang Guo)
 
  - Drop useless cpumask_empty() in find_energy_efficient_cpu()
  - Simplify task_numa_find_cpu()
  - Use cpumask_weight_and() in sched_balance_find_dst_group()
 
    (Yury Norov)
 
 DL scheduler updates:
 
  - Add a deadline server for sched_ext tasks (by Andrea Righi and
    Joel Fernandes, with fixes by Peter Zijlstra)
 
 RT scheduler updates:
 
  - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang)
 
 Entry code updates and performance improvements, which is part of the
 scheduler tree in this cycle due to interdependencies with the RSEQ
 based time slice extension work:
 
   - Remove unused syscall argument from syscall_trace_enter()
   - Rework syscall_exit_to_user_mode_work() for architecture reuse
   - Add arch_ptrace_report_syscall_entry/exit()
   - Inline syscall_exit_work() and syscall_trace_enter()
 
     (Jinjie Ruan)
 
 Scheduler core updates:
 
  - Rework sched_class::wakeup_preempt() and rq_modified_*()
  - Avoid rq->lock bouncing in sched_balance_newidle()
  - Rename rcu_dereference_check_sched_domain() =>
           rcu_dereference_sched_domain()
  - <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper
 
    (Peter Zijlstra)
 
 Fair scheduler updates/refactoring:
 
  - Fold the sched_avg update
  - Change rcu_dereference_check_sched_domain() to rcu-sched
  - Switch to rcu_dereference_all()
  - Remove superfluous rcu_read_lock()
  - Limit hrtick work
 
    (Peter Zijlstra)
 
  - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks
  - Clean up comments in 'struct cfs_rq'
  - Separate se->vlag from se->vprot
  - Rename cfs_rq::avg_load to cfs_rq::sum_weight
  - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions
  - Introduce and use the vruntime_cmp() and vruntime_op() wrappers
    for wrapped-signed aritmetics
  - Sort out 'blocked_load*' namespace noise
 
    (Ingo Molnar)
 
 Scheduler debugging code updates:
 
  - Export hidden tracepoints to modules (Gabriele Monaco)
 
  - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
    (Fushuai Wang)
 
  - Add assertions to QUEUE_CLASS (Peter Zijlstra)
 
  - hrtimer: Fix tracing oddity (Thomas Gleixner)
 
 Misc fixes and cleanups:
 
  - Re-evaluate scheduling when migrating queued tasks out of
    throttled cgroups (Zicheng Qu)
 
  - Remove task_struct->faults_disabled_mapping (Christoph Hellwig)
 
  - Fix math notation errors in avg_vruntime comment (Zhan Xusheng)
 
  - sched/cpufreq: Use %pe format for PTR_ERR() printing (zenghongling)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull scheduler updates from Ingo Molnar:
 "Scheduler Kconfig space updates:

   - Further consolidate configurable preemption modes (Peter Zijlstra)

     Reduce the number of architectures that are allowed to offer
     PREEMPT_NONE and PREEMPT_VOLUNTARY, reducing the number of
     preemption models from four to just two: 'full' and 'lazy' on
     up-to-date architectures (arm64, loongarch, powerpc, riscv, s390,
     x86).

     None and voluntary are only available as legacy features on
     platforms that don't implement lazy preemption yet, or which don't
     even support preemption.

     The goal is to eventually remove cond_resched() and voluntary
     preemption altogether.

  RSEQ based 'scheduler time slice extension' support (Thomas Gleixner
  and Peter Zijlstra):

  This allows a thread to request a time slice extension when it enters
  a critical section to avoid contention on a resource when the thread
  is scheduled out inside of the critical section.

   - Add fields and constants for time slice extension
   - Provide static branch for time slice extensions
   - Add statistics for time slice extensions
   - Add prctl() to enable time slice extensions
   - Implement sys_rseq_slice_yield()
   - Implement syscall entry work for time slice extensions
   - Implement time slice extension enforcement timer
   - Reset slice extension when scheduled
   - Implement rseq_grant_slice_extension()
   - entry: Hook up rseq time slice extension
   - selftests: Implement time slice extension test
   - Allow registering RSEQ with slice extension
   - Move slice_ext_nsec to debugfs
   - Lower default slice extension
   - selftests/rseq: Add rseq slice histogram script

  Scheduler performance/scalability improvements:

   - Update rq->avg_idle when a task is moved to an idle CPU, which
     improves the scalability of various workloads (Shubhang Kaushik)

   - Reorder fields in 'struct rq' for better caching (Blake Jones)

   - Fair scheduler SMP NOHZ balancing code speedups (Shrikanth Hegde):
      - Move checking for nohz cpus after time check
      - Change likelyhood of nohz.nr_cpus
      - Remove nohz.nr_cpus and use weight of cpumask instead

   - Avoid false sharing for sched_clock_irqtime (Wangyang Guo)

   - Cleanups (Yury Norov):
      - Drop useless cpumask_empty() in find_energy_efficient_cpu()
      - Simplify task_numa_find_cpu()
      - Use cpumask_weight_and() in sched_balance_find_dst_group()

  DL scheduler updates:

   - Add a deadline server for sched_ext tasks (by Andrea Righi and Joel
     Fernandes, with fixes by Peter Zijlstra)

  RT scheduler updates:

   - Skip currently executing CPU in rto_next_cpu() (Chen Jinghuang)

  Entry code updates and performance improvements (Jinjie Ruan)

  This is part of the scheduler tree in this cycle due to inter-
  dependencies with the RSEQ based time slice extension work:

    - Remove unused syscall argument from syscall_trace_enter()
    - Rework syscall_exit_to_user_mode_work() for architecture reuse
    - Add arch_ptrace_report_syscall_entry/exit()
    - Inline syscall_exit_work() and syscall_trace_enter()

  Scheduler core updates (Peter Zijlstra):

   - Rework sched_class::wakeup_preempt() and rq_modified_*()
   - Avoid rq->lock bouncing in sched_balance_newidle()
   - Rename rcu_dereference_check_sched_domain() =>
            rcu_dereference_sched_domain()
   - <linux/compiler_types.h>: Add the __signed_scalar_typeof() helper

  Fair scheduler updates/refactoring (Peter Zijlstra and Ingo Molnar):

   - Fold the sched_avg update
   - Change rcu_dereference_check_sched_domain() to rcu-sched
   - Switch to rcu_dereference_all()
   - Remove superfluous rcu_read_lock()
   - Limit hrtick work
   - Join two #ifdef CONFIG_FAIR_GROUP_SCHED blocks
   - Clean up comments in 'struct cfs_rq'
   - Separate se->vlag from se->vprot
   - Rename cfs_rq::avg_load to cfs_rq::sum_weight
   - Rename cfs_rq::avg_vruntime to ::sum_w_vruntime & helper functions
   - Introduce and use the vruntime_cmp() and vruntime_op() wrappers for
     wrapped-signed aritmetics
   - Sort out 'blocked_load*' namespace noise

  Scheduler debugging code updates:

   - Export hidden tracepoints to modules (Gabriele Monaco)

   - Convert copy_from_user() + kstrtouint() to kstrtouint_from_user()
     (Fushuai Wang)

   - Add assertions to QUEUE_CLASS (Peter Zijlstra)

   - hrtimer: Fix tracing oddity (Thomas Gleixner)

  Misc fixes and cleanups:

   - Re-evaluate scheduling when migrating queued tasks out of throttled
     cgroups (Zicheng Qu)

   - Remove task_struct->faults_disabled_mapping (Christoph Hellwig)

   - Fix math notation errors in avg_vruntime comment (Zhan Xusheng)

   - sched/cpufreq: Use %pe format for PTR_ERR() printing
     (zenghongling)"

* tag 'sched-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (64 commits)
  sched: Re-evaluate scheduling when migrating queued tasks out of throttled cgroups
  sched/cpufreq: Use %pe format for PTR_ERR() printing
  sched/rt: Skip currently executing CPU in rto_next_cpu()
  sched/clock: Avoid false sharing for sched_clock_irqtime
  selftests/sched_ext: Add test for DL server total_bw consistency
  selftests/sched_ext: Add test for sched_ext dl_server
  sched/debug: Fix dl_server (re)start conditions
  sched/debug: Add support to change sched_ext server params
  sched_ext: Add a DL server for sched_ext tasks
  sched/debug: Stop and start server based on if it was active
  sched/debug: Fix updating of ppos on server write ops
  sched/deadline: Clear the defer params
  entry: Inline syscall_exit_work() and syscall_trace_enter()
  entry: Add arch_ptrace_report_syscall_entry/exit()
  entry: Rework syscall_exit_to_user_mode_work() for architecture reuse
  entry: Remove unused syscall argument from syscall_trace_enter()
  sched: remove task_struct->faults_disabled_mapping
  sched: Update rq->avg_idle when a task is moved to an idle CPU
  selftests/rseq: Add rseq slice histogram script
  hrtimer: Fix trace oddity
  ...
2026-02-10 12:50:10 -08:00
Linus Torvalds
4d84667627 Performance events changes for v7.0:
x86 PMU driver updates:
 
  - Add support for the core PMU for Intel Diamond Rapids (DMR) CPUs.
    Compared to previous iterations of the Intel PMU code, there's
    been a lot of changes, which center around three main areas:
 
     - Introduce the OFF-MODULE RESPONSE (OMR) facility to
       replace the Off-Core Response (OCR) facility
 
     - New PEBS data source encoding layout
 
     - Support the new "RDPMC user disable" feature
 
    (Dapeng Mi)
 
  - Likewise, a large series adds uncore PMU support for
    Intel Diamond Rapids (DMR) CPUs, which center around these
    four main areas:
 
     - DMR may have two Integrated I/O and Memory Hub (IMH) dies,
       separate from the compute tile (CBB) dies.  Each CBB and
       each IMH die has its own discovery domain.
 
     - Unlike prior CPUs that retrieve the global discovery table
       portal exclusively via PCI or MSR, DMR uses PCI for IMH PMON
       discovery and MSR for CBB PMON discovery.
 
     - DMR introduces several new PMON types: SCA, HAMVF, D2D_ULA,
       UBR, PCIE4, CRS, CPC, ITC, OTC, CMS, and PCIE6.
 
     - IIO free-running counters in DMR are MMIO-based, unlike SPR.
 
    (Zide Chen)
 
  - Also add support for Add missing PMON units for Intel Panther Lake,
    and support Nova Lake (NVL), which largely maps to Panther Lake.
    (Zide Chen)
 
  - KVM integration: Add support for mediated vPMUs (by Kan Liang
    and Sean Christopherson, with fixes and cleanups by Peter Zijlstra,
    Sandipan Das and Mingwei Zhang)
 
  - Add Intel cstate driver to support for Wildcat Lake (WCL)
    CPUs, which are a low-power variant of Panther Lake.
    (Zide Chen)
 
  - Add core, cstate and MSR PMU support for the Airmont NP Intel CPU
    (aka MaxLinear Lightning Mountain), which maps to the existing
    Airmont code. (Martin Schiller)
 
 Performance enhancements:
 
  - core: Speed up kexec shutdown by avoiding unnecessary
    cross CPU calls. (Jan H. Schönherr)
 
  - core: Fix slow perf_event_task_exit() with LBR callstacks
    (Namhyung Kim)
 
 User-space stack unwinding support:
 
  - Various cleanups and refactorings in preparation to generalize
    the unwinding code for other architectures. (Jens Remus)
 
 Uprobes updates:
 
  - Transition from kmap_atomic to kmap_local_page (Keke Ming)
 
  - Fix incorrect lockdep condition in filter_chain() (Breno Leitao)
 
  - Fix XOL allocation failure for 32-bit tasks (Oleg Nesterov)
 
 Misc fixes and cleanups:
 
  - s390: Remove kvm_types.h from Kbuild (Randy Dunlap)
 
  - x86/intel/uncore: Convert comma to semicolon (Chen Ni)
 
  - x86/uncore: Clean up const mismatch (Greg Kroah-Hartman)
 
  - x86/ibs: Fix typo in dc_l2tlb_miss comment (Xiang-Bin Shi)
 
 Signed-off-by: Ingo Molnar <mingo@kernel.org>
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Merge tag 'perf-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull performance event updates from Ingo Molnar:
 "x86 PMU driver updates:

   - Add support for the core PMU for Intel Diamond Rapids (DMR) CPUs
     (Dapeng Mi)

     Compared to previous iterations of the Intel PMU code, there's been
     a lot of changes, which center around three main areas:

      - Introduce the OFF-MODULE RESPONSE (OMR) facility to replace the
        Off-Core Response (OCR) facility

      - New PEBS data source encoding layout

      - Support the new "RDPMC user disable" feature

   - Likewise, a large series adds uncore PMU support for Intel Diamond
     Rapids (DMR) CPUs (Zide Chen)

     This centers around these four main areas:

      - DMR may have two Integrated I/O and Memory Hub (IMH) dies,
        separate from the compute tile (CBB) dies. Each CBB and each IMH
        die has its own discovery domain.

      - Unlike prior CPUs that retrieve the global discovery table
        portal exclusively via PCI or MSR, DMR uses PCI for IMH PMON
        discovery and MSR for CBB PMON discovery.

      - DMR introduces several new PMON types: SCA, HAMVF, D2D_ULA, UBR,
        PCIE4, CRS, CPC, ITC, OTC, CMS, and PCIE6.

      - IIO free-running counters in DMR are MMIO-based, unlike SPR.

   - Also add support for Add missing PMON units for Intel Panther Lake,
     and support Nova Lake (NVL), which largely maps to Panther Lake.
     (Zide Chen)

   - KVM integration: Add support for mediated vPMUs (by Kan Liang and
     Sean Christopherson, with fixes and cleanups by Peter Zijlstra,
     Sandipan Das and Mingwei Zhang)

   - Add Intel cstate driver to support for Wildcat Lake (WCL) CPUs,
     which are a low-power variant of Panther Lake (Zide Chen)

   - Add core, cstate and MSR PMU support for the Airmont NP Intel CPU
     (aka MaxLinear Lightning Mountain), which maps to the existing
     Airmont code (Martin Schiller)

  Performance enhancements:

   - Speed up kexec shutdown by avoiding unnecessary cross CPU calls
     (Jan H. Schönherr)

   - Fix slow perf_event_task_exit() with LBR callstacks (Namhyung Kim)

  User-space stack unwinding support:

   - Various cleanups and refactorings in preparation to generalize the
     unwinding code for other architectures (Jens Remus)

  Uprobes updates:

   - Transition from kmap_atomic to kmap_local_page (Keke Ming)

   - Fix incorrect lockdep condition in filter_chain() (Breno Leitao)

   - Fix XOL allocation failure for 32-bit tasks (Oleg Nesterov)

  Misc fixes and cleanups:

   - s390: Remove kvm_types.h from Kbuild (Randy Dunlap)

   - x86/intel/uncore: Convert comma to semicolon (Chen Ni)

   - x86/uncore: Clean up const mismatch (Greg Kroah-Hartman)

   - x86/ibs: Fix typo in dc_l2tlb_miss comment (Xiang-Bin Shi)"

* tag 'perf-core-2026-02-09' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (58 commits)
  s390: remove kvm_types.h from Kbuild
  uprobes: Fix incorrect lockdep condition in filter_chain()
  x86/ibs: Fix typo in dc_l2tlb_miss comment
  x86/uprobes: Fix XOL allocation failure for 32-bit tasks
  perf/x86/intel/uncore: Convert comma to semicolon
  perf/x86/intel: Add support for rdpmc user disable feature
  perf/x86: Use macros to replace magic numbers in attr_rdpmc
  perf/x86/intel: Add core PMU support for Novalake
  perf/x86/intel: Add support for PEBS memory auxiliary info field in NVL
  perf/x86/intel: Add core PMU support for DMR
  perf/x86/intel: Add support for PEBS memory auxiliary info field in DMR
  perf/x86/intel: Support the 4 new OMR MSRs introduced in DMR and NVL
  perf/core: Fix slow perf_event_task_exit() with LBR callstacks
  perf/core: Speed up kexec shutdown by avoiding unnecessary cross CPU calls
  uprobes: use kmap_local_page() for temporary page mappings
  arm/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
  mips/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
  arm64/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
  riscv/uprobes: use kmap_local_page() in arch_uprobe_copy_ixol()
  perf/x86/intel/uncore: Add Nova Lake support
  ...
2026-02-10 12:00:46 -08:00