2
0
mirror of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git synced 2025-09-04 20:19:47 +08:00
Commit Graph

511 Commits

Author SHA1 Message Date
Linus Torvalds
eb0ece1602 - The 6 patch series "Enable strict percpu address space checks" from
Uros Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.
 
   This has caused a small amount of fallout - two or three issues were
   reported.  In all cases the calling code was founf to be incorrect.
 
 - The 4 patch series "Some cleanup for memcg" from Chen Ridong
   implements some relatively monir cleanups for the memcontrol code.
 
 - The 17 patch series "mm: fixes for device-exclusive entries (hmm)"
   from David Hildenbrand fixes a boatload of issues which David found then
   using device-exclusive PTE entries when THP is enabled.  More work is
   needed, but this makes thins better - our own HMM selftests now succeed.
 
 - The 2 patch series "mm: zswap: remove z3fold and zbud" from Yosry
   Ahmed remove the z3fold and zbud implementations.  They have been
   deprecated for half a year and nobody has complained.
 
 - The 5 patch series "mm: further simplify VMA merge operation" from
   Lorenzo Stoakes implements numerous simplifications in this area.  No
   runtime effects are anticipated.
 
 - The 4 patch series "mm/madvise: remove redundant mmap_lock operations
   from process_madvise()" from SeongJae Park rationalizes the locking in
   the madvise() implementation.  Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.
 
 - The 12 patch series "Tiny cleanup and improvements about SWAP code"
   from Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.
 
 - The 2 patch series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak user-visible
   output.
 
 - The 2 patch series "mm/damon/paddr: fix large folios access and
   schemes handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.
 
 - The 3 patch series "mm/damon/core: fix wrong and/or useless
   damos_walk() behaviors" from SeongJae Park fixes a few issues with the
   accuracy of kdamond's walking of DAMON regions.
 
 - The 3 patch series "expose mapping wrprotect, fix fb_defio use" from
   Lorenzo Stoakes changes the interaction between framebuffer deferred-io
   and core MM.  No functional changes are anticipated - this is
   preparatory work for the future removal of page structure fields.
 
 - The 4 patch series "mm/damon: add support for hugepage_size DAMOS
   filter" from Usama Arif adds a DAMOS filter which permits the filtering
   by huge page sizes.
 
 - The 4 patch series "mm: permit guard regions for file-backed/shmem
   mappings" from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state.  The feature now covers shmem and
   file-backed mappings.
 
 - The 4 patch series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping for
   pte-mapped large folios.
 
 - The 18 patch series "reimplement per-vma lock as a refcount" from
   Suren Baghdasaryan puts the vm_lock back into the vma.  Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy.  This patchset provides small (0-10%) improvements on one
   microbenchmark.
 
 - The 5 patch series "Docs/mm/damon: misc DAMOS filters documentation
   fixes and improves" from SeongJae Park does some maintenance work on the
   DAMON docs.
 
 - The 27 patch series "hugetlb/CMA improvements for large systems" from
   Frank van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for unmapped
   pages" from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.
 
 - The 19 patch series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.
 
 - The 12 patch series "selftests/mm: Some cleanups from trying to run
   them" from Brendan Jackman fixes a pile of unrelated issues which
   Brendan encountered while runnimg our selftests.
 
 - The 2 patch series "fs/proc/task_mmu: add guard region bit to pagemap"
   from Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.
 
 - The 7 patch series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply wasn't
   being effective.
 
 - The 5 patch series "mm: cleanups for device-exclusive entries (hmm)"
   from David Hildenbrand implements a number of unrelated cleanups in this
   code.
 
 - The 5 patch series "mm: Rework generic PTDUMP configs" from Anshuman
   Khandual implements a number of preparatoty cleanups to the
   GENERIC_PTDUMP Kconfig logic.
 
 - The 8 patch series "mm/damon: auto-tune aggregation interval" from
   SeongJae Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.
 
 - The 5 patch series "Fix lazy mmu mode" from Ryan Roberts fixes some
   issues in powerpc, sparc and x86 lazy MMU implementations.  Ryan did
   this in preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.
 
 - The 2 patch series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the code
   easier to follow.
 
 - The 3 patch series "page_counter cleanup and size reduction" from
   Shakeel Butt cleans up the page_counter code and fixes a size increase
   which we accidentally added late last year.
 
 - The 3 patch series "Add a command line option that enables control of
   how many threads should be used to allocate huge pages" from Thomas
   Prescher does that.  It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.
 
 - The 3 patch series "Fix calculations in trace_balance_dirty_pages()
   for cgwb" from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.
 
 - The 9 patch series "mm/damon: make allow filters after reject filters
   useful and intuitive" from SeongJae Park improves the handling of allow
   and reject filters.  Behaviour is made more consistent and the
   documention is updated accordingly.
 
 - The 5 patch series "Switch zswap to object read/write APIs" from Yosry
   Ahmed updates zswap to the new object read/write APIs and thus permits
   the removal of some legacy code from zpool and zsmalloc.
 
 - The 6 patch series "Some trivial cleanups for shmem" from Baolin Wang
   does as it claims.
 
 - The 20 patch series "fs/dax: Fix ZONE_DEVICE page reference counts"
   from Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.
 
 - The 4 patch series "refactor mremap and fix bug" from Lorenzo Stoakes
   is a preparatoty refactoring and cleanup of the mremap() code.
 
 - The 20 patch series "mm: MM owner tracking for large folios (!hugetlb)
   + CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.
 
 - The 8 patch series "mm/damon: add sysfs dirs for managing DAMOS
   filters based on handling layers" from SeongJae Park adds a couple of
   new sysfs directories to ease the management of DAMON/DAMOS filters.
 
 - The 13 patch series "arch, mm: reduce code duplication in mem_init()"
   from Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.
 
 - The 13 patch series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.
 
 - The 3 patch series "mm: page_ext: Introduce new iteration API" from
   Luiz Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.
 
 - The 8 patch series "Buddy allocator like (or non-uniform) folio split"
   from Zi Yan reworks the code to split a folio into smaller folios.  The
   main benefit is lessened memory consumption: fewer post-split folios are
   generated.
 
 - The 2 patch series "Minimize xa_node allocation during xarry split"
   from Zi Yan reduces the number of xarray xa_nodes which are generated
   during an xarray split.
 
 - The 2 patch series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.
 
 - The 3 patch series "Add tracepoints for lowmem reserves, watermarks
   and totalreserve_pages" from Martin Liu adds some more tracepoints to
   the page allocator code.
 
 - The 4 patch series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which SeongJae
   observed during his earlier madvise work.
 
 - The 3 patch series "mm/hwpoison: Fix regressions in memory failure
   handling" from Shuai Xue addresses two quite serious regressions which
   Shuai has observed in the memory-failure implementation.
 
 - The 5 patch series "mm: reliable huge page allocator" from Johannes
   Weiner makes huge page allocations cheaper and more reliable by reducing
   fragmentation.
 
 - The 5 patch series "Minor memcg cleanups & prep for memdescs" from
   Matthew Wilcox is preparatory work for the future implementation of
   memdescs.
 
 - The 4 patch series "track memory used by balloon drivers" from Nico
   Pache introduces a way to track memory used by our various balloon
   drivers.
 
 - The 2 patch series "mm/damon: introduce DAMOS filter type for active
   pages" from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.
 
 - The 2 patch series "Adding Proactive Memory Reclaim Statistics" from
   Hao Jia separates the proactive reclaim statistics from the direct
   reclaim statistics.
 
 - The 2 patch series "mm/vmscan: don't try to reclaim hwpoison folio"
   from Jinjiang Tu fixes our handling of hwpoisoned pages within the
   reclaim code.
 -----BEGIN PGP SIGNATURE-----
 
 iHQEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZ+nZaAAKCRDdBJ7gKXxA
 jsOWAPiP4r7CJHMZRK4eyJOkvS1a1r+TsIarrFZtjwvf/GIfAQCEG+JDxVfUaUSF
 Ee93qSSLR1BkNdDw+931Pu0mXfbnBw==
 =Pn2K
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:

 - The series "Enable strict percpu address space checks" from Uros
   Bizjak uses x86 named address space qualifiers to provide
   compile-time checking of percpu area accesses.

   This has caused a small amount of fallout - two or three issues were
   reported. In all cases the calling code was found to be incorrect.

 - The series "Some cleanup for memcg" from Chen Ridong implements some
   relatively monir cleanups for the memcontrol code.

 - The series "mm: fixes for device-exclusive entries (hmm)" from David
   Hildenbrand fixes a boatload of issues which David found then using
   device-exclusive PTE entries when THP is enabled. More work is
   needed, but this makes thins better - our own HMM selftests now
   succeed.

 - The series "mm: zswap: remove z3fold and zbud" from Yosry Ahmed
   remove the z3fold and zbud implementations. They have been deprecated
   for half a year and nobody has complained.

 - The series "mm: further simplify VMA merge operation" from Lorenzo
   Stoakes implements numerous simplifications in this area. No runtime
   effects are anticipated.

 - The series "mm/madvise: remove redundant mmap_lock operations from
   process_madvise()" from SeongJae Park rationalizes the locking in the
   madvise() implementation. Performance gains of 20-25% were observed
   in one MADV_DONTNEED microbenchmark.

 - The series "Tiny cleanup and improvements about SWAP code" from
   Baoquan He contains a number of touchups to issues which Baoquan
   noticed when working on the swap code.

 - The series "mm: kmemleak: Usability improvements" from Catalin
   Marinas implements a couple of improvements to the kmemleak
   user-visible output.

 - The series "mm/damon/paddr: fix large folios access and schemes
   handling" from Usama Arif provides a couple of fixes for DAMON's
   handling of large folios.

 - The series "mm/damon/core: fix wrong and/or useless damos_walk()
   behaviors" from SeongJae Park fixes a few issues with the accuracy of
   kdamond's walking of DAMON regions.

 - The series "expose mapping wrprotect, fix fb_defio use" from Lorenzo
   Stoakes changes the interaction between framebuffer deferred-io and
   core MM. No functional changes are anticipated - this is preparatory
   work for the future removal of page structure fields.

 - The series "mm/damon: add support for hugepage_size DAMOS filter"
   from Usama Arif adds a DAMOS filter which permits the filtering by
   huge page sizes.

 - The series "mm: permit guard regions for file-backed/shmem mappings"
   from Lorenzo Stoakes extends the guard region feature from its
   present "anon mappings only" state. The feature now covers shmem and
   file-backed mappings.

 - The series "mm: batched unmap lazyfree large folios during
   reclamation" from Barry Song cleans up and speeds up the unmapping
   for pte-mapped large folios.

 - The series "reimplement per-vma lock as a refcount" from Suren
   Baghdasaryan puts the vm_lock back into the vma. Our reasons for
   pulling it out were largely bogus and that change made the code more
   messy. This patchset provides small (0-10%) improvements on one
   microbenchmark.

 - The series "Docs/mm/damon: misc DAMOS filters documentation fixes and
   improves" from SeongJae Park does some maintenance work on the DAMON
   docs.

 - The series "hugetlb/CMA improvements for large systems" from Frank
   van der Linden addresses a pile of issues which have been observed
   when using CMA on large machines.

 - The series "mm/damon: introduce DAMOS filter type for unmapped pages"
   from SeongJae Park enables users of DMAON/DAMOS to filter my the
   page's mapped/unmapped status.

 - The series "zsmalloc/zram: there be preemption" from Sergey
   Senozhatsky teaches zram to run its compression and decompression
   operations preemptibly.

 - The series "selftests/mm: Some cleanups from trying to run them" from
   Brendan Jackman fixes a pile of unrelated issues which Brendan
   encountered while runnimg our selftests.

 - The series "fs/proc/task_mmu: add guard region bit to pagemap" from
   Lorenzo Stoakes permits userspace to use /proc/pid/pagemap to
   determine whether a particular page is a guard page.

 - The series "mm, swap: remove swap slot cache" from Kairui Song
   removes the swap slot cache from the allocation path - it simply
   wasn't being effective.

 - The series "mm: cleanups for device-exclusive entries (hmm)" from
   David Hildenbrand implements a number of unrelated cleanups in this
   code.

 - The series "mm: Rework generic PTDUMP configs" from Anshuman Khandual
   implements a number of preparatoty cleanups to the GENERIC_PTDUMP
   Kconfig logic.

 - The series "mm/damon: auto-tune aggregation interval" from SeongJae
   Park implements a feedback-driven automatic tuning feature for
   DAMON's aggregation interval tuning.

 - The series "Fix lazy mmu mode" from Ryan Roberts fixes some issues in
   powerpc, sparc and x86 lazy MMU implementations. Ryan did this in
   preparation for implementing lazy mmu mode for arm64 to optimize
   vmalloc.

 - The series "mm/page_alloc: Some clarifications for migratetype
   fallback" from Brendan Jackman reworks some commentary to make the
   code easier to follow.

 - The series "page_counter cleanup and size reduction" from Shakeel
   Butt cleans up the page_counter code and fixes a size increase which
   we accidentally added late last year.

 - The series "Add a command line option that enables control of how
   many threads should be used to allocate huge pages" from Thomas
   Prescher does that. It allows the careful operator to significantly
   reduce boot time by tuning the parallalization of huge page
   initialization.

 - The series "Fix calculations in trace_balance_dirty_pages() for cgwb"
   from Tang Yizhou fixes the tracing output from the dirty page
   balancing code.

 - The series "mm/damon: make allow filters after reject filters useful
   and intuitive" from SeongJae Park improves the handling of allow and
   reject filters. Behaviour is made more consistent and the documention
   is updated accordingly.

 - The series "Switch zswap to object read/write APIs" from Yosry Ahmed
   updates zswap to the new object read/write APIs and thus permits the
   removal of some legacy code from zpool and zsmalloc.

 - The series "Some trivial cleanups for shmem" from Baolin Wang does as
   it claims.

 - The series "fs/dax: Fix ZONE_DEVICE page reference counts" from
   Alistair Popple regularizes the weird ZONE_DEVICE page refcount
   handling in DAX, permittig the removal of a number of special-case
   checks.

 - The series "refactor mremap and fix bug" from Lorenzo Stoakes is a
   preparatoty refactoring and cleanup of the mremap() code.

 - The series "mm: MM owner tracking for large folios (!hugetlb) +
   CONFIG_NO_PAGE_MAPCOUNT" from David Hildenbrand reworks the manner in
   which we determine whether a large folio is known to be mapped
   exclusively into a single MM.

 - The series "mm/damon: add sysfs dirs for managing DAMOS filters based
   on handling layers" from SeongJae Park adds a couple of new sysfs
   directories to ease the management of DAMON/DAMOS filters.

 - The series "arch, mm: reduce code duplication in mem_init()" from
   Mike Rapoport consolidates many per-arch implementations of
   mem_init() into code generic code, where that is practical.

 - The series "mm/damon/sysfs: commit parameters online via
   damon_call()" from SeongJae Park continues the cleaning up of sysfs
   access to DAMON internal data.

 - The series "mm: page_ext: Introduce new iteration API" from Luiz
   Capitulino reworks the page_ext initialization to fix a boot-time
   crash which was observed with an unusual combination of compile and
   cmdline options.

 - The series "Buddy allocator like (or non-uniform) folio split" from
   Zi Yan reworks the code to split a folio into smaller folios. The
   main benefit is lessened memory consumption: fewer post-split folios
   are generated.

 - The series "Minimize xa_node allocation during xarry split" from Zi
   Yan reduces the number of xarray xa_nodes which are generated during
   an xarray split.

 - The series "drivers/base/memory: Two cleanups" from Gavin Shan
   performs some maintenance work on the drivers/base/memory code.

 - The series "Add tracepoints for lowmem reserves, watermarks and
   totalreserve_pages" from Martin Liu adds some more tracepoints to the
   page allocator code.

 - The series "mm/madvise: cleanup requests validations and
   classifications" from SeongJae Park cleans up some warts which
   SeongJae observed during his earlier madvise work.

 - The series "mm/hwpoison: Fix regressions in memory failure handling"
   from Shuai Xue addresses two quite serious regressions which Shuai
   has observed in the memory-failure implementation.

 - The series "mm: reliable huge page allocator" from Johannes Weiner
   makes huge page allocations cheaper and more reliable by reducing
   fragmentation.

 - The series "Minor memcg cleanups & prep for memdescs" from Matthew
   Wilcox is preparatory work for the future implementation of memdescs.

 - The series "track memory used by balloon drivers" from Nico Pache
   introduces a way to track memory used by our various balloon drivers.

 - The series "mm/damon: introduce DAMOS filter type for active pages"
   from Nhat Pham permits users to filter for active/inactive pages,
   separately for file and anon pages.

 - The series "Adding Proactive Memory Reclaim Statistics" from Hao Jia
   separates the proactive reclaim statistics from the direct reclaim
   statistics.

 - The series "mm/vmscan: don't try to reclaim hwpoison folio" from
   Jinjiang Tu fixes our handling of hwpoisoned pages within the reclaim
   code.

* tag 'mm-stable-2025-03-30-16-52' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (431 commits)
  mm/page_alloc: remove unnecessary __maybe_unused in order_to_pindex()
  x86/mm: restore early initialization of high_memory for 32-bits
  mm/vmscan: don't try to reclaim hwpoison folio
  mm/hwpoison: introduce folio_contain_hwpoisoned_page() helper
  cgroup: docs: add pswpin and pswpout items in cgroup v2 doc
  mm: vmscan: split proactive reclaim statistics from direct reclaim statistics
  selftests/mm: speed up split_huge_page_test
  selftests/mm: uffd-unit-tests support for hugepages > 2M
  docs/mm/damon/design: document active DAMOS filter type
  mm/damon: implement a new DAMOS filter type for active pages
  fs/dax: don't disassociate zero page entries
  MM documentation: add "Unaccepted" meminfo entry
  selftests/mm: add commentary about 9pfs bugs
  fork: use __vmalloc_node() for stack allocation
  docs/mm: Physical Memory: Populate the "Zones" section
  xen: balloon: update the NR_BALLOON_PAGES state
  hv_balloon: update the NR_BALLOON_PAGES state
  balloon_compaction: update the NR_BALLOON_PAGES state
  meminfo: add a per node counter for balloon drivers
  mm: remove references to folio in __memcg_kmem_uncharge_page()
  ...
2025-04-01 09:29:18 -07:00
Linus Torvalds
aa918db707 bpf_try_alloc_pages
-----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCAAdFiEE+soXsSLHKoYyzcli6rmadz2vbToFAmfkHCQACgkQ6rmadz2v
 bTrzWhAAnDcJsGgSJ9EbElpTfgBWE7aijXo/MsPxxRhORc0uR6MnhPx1iADP4KYj
 lTGEIBgRuDG3qaM4EXpPd32rUJJHv8hot7z9zfvUgSuFNLZEHWXJtz/i4ileOxin
 08zV+zA5WL2fqamAmMRFMI37DeSWy3xU0/qlbWgNnURjPjRri6CF4rVFUWq+QMY+
 XP8ITD/6nOLUR6Bq2M18aHnk2VJWkxVP9Oi+vz1VHbOjKaJC7ATa1+Q4qMqWyTb1
 8IAYWiZR1ZPc214ITaspVzLoLb/wxHxy3QMrdAWAL6sjp0B4J8YxIq1qsBuR1FN7
 TxTRQND/+LjqrAgs5AmFqz3ndKmahjGQWnQEh/rDYJtx+sLJk9hfsMIDF8Wmxuwl
 RftdV0g9bPljR5Qgc9i8DNtEjoAbNjoP8xLjt9HfQakVl8V9jPe0bxZ5tJDf+T0M
 n/VgEjaRzdXqFOLal6Z5wl/jkIn1l1kWQuCMI2z5Z0Ls+PlYX56xdZxfK2Rh3m+e
 3W89vqj9ytJ3rZKG8DRsxukuHwnJ+Gia3XI2h/5cc8kEM5ss1Ase8oIkmrwaLd9x
 +zVXNoDCCPRQgTStwItW+2YdFmE9uijhEZh9yPwT1/rtFuKd0oSebVIpjih/bGqH
 mMN9gYO4+ArSbqku9X2lP3VjMOf6M6SZGm+PzG25PAMGzjqGqwk=
 =AHTr
 -----END PGP SIGNATURE-----

Merge tag 'bpf_try_alloc_pages' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next

Pull bpf try_alloc_pages() support from Alexei Starovoitov:
 "The pull includes work from Sebastian, Vlastimil and myself with a lot
  of help from Michal and Shakeel.

  This is a first step towards making kmalloc reentrant to get rid of
  slab wrappers: bpf_mem_alloc, kretprobe's objpool, etc. These patches
  make page allocator safe from any context.

  Vlastimil kicked off this effort at LSFMM 2024:

    https://lwn.net/Articles/974138/

  and we continued at LSFMM 2025:

    https://lore.kernel.org/all/CAADnVQKfkGxudNUkcPJgwe3nTZ=xohnRshx9kLZBTmR_E1DFEg@mail.gmail.com/

  Why:

  SLAB wrappers bind memory to a particular subsystem making it
  unavailable to the rest of the kernel. Some BPF maps in production
  consume Gbytes of preallocated memory. Top 5 in Meta: 1.5G, 1.2G,
  1.1G, 300M, 200M. Once we have kmalloc that works in any context BPF
  map preallocation won't be necessary.

  How:

  Synchronous kmalloc/page alloc stack has multiple stages going from
  fast to slow: cmpxchg16 -> slab_alloc -> new_slab -> alloc_pages ->
  rmqueue_pcplist -> __rmqueue, where rmqueue_pcplist was already
  relying on trylock.

  This set changes rmqueue_bulk/rmqueue_buddy to attempt a trylock and
  return ENOMEM if alloc_flags & ALLOC_TRYLOCK. It then wraps this
  functionality into try_alloc_pages() helper. We make sure that the
  logic is sane in PREEMPT_RT.

  End result: try_alloc_pages()/free_pages_nolock() are safe to call
  from any context.

  try_kmalloc() for any context with similar trylock approach will
  follow. It will use try_alloc_pages() when slab needs a new page.
  Though such try_kmalloc/page_alloc() is an opportunistic allocator,
  this design ensures that the probability of successful allocation of
  small objects (up to one page in size) is high.

  Even before we have try_kmalloc(), we already use try_alloc_pages() in
  BPF arena implementation and it's going to be used more extensively in
  BPF"

* tag 'bpf_try_alloc_pages' of git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
  mm: Fix the flipped condition in gfpflags_allow_spinning()
  bpf: Use try_alloc_pages() to allocate pages for bpf needs.
  mm, bpf: Use memcg in try_alloc_pages().
  memcg: Use trylock to access memcg stock_lock.
  mm, bpf: Introduce free_pages_nolock()
  mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation
  locking/local_lock: Introduce localtry_lock_t
2025-03-30 13:45:28 -07:00
Linus Torvalds
592329e5e9 Summary
* Move vm_table members out of kernel/sysctl.c
 
   All vm_table array members have moved to their respective subsystems leading
   to the removal of vm_table from kernel/sysctl.c. This increases modularity by
   placing the ctl_tables closer to where they are actually used and at the same
   time reducing the chances of merge conflicts in kernel/sysctl.c.
 
 * ctl_table range fixes
 
   Replace the proc_handler function that checks variable ranges in
   coredump_sysctls and vdso_table with the one that actually uses the extra{1,2}
   pointers as min/max values. This tightens the range of the values that users
   can pass into the kernel effectively preventing {under,over}flows.
 
 * Misc fixes
 
   Correct grammar errors and typos in test messages. Update sysctl files in
   MAINTAINERS. Constified and removed array size in declaration for
   alignment_tbl
 
 * Testing
 
   - These have all been in linux-next for at least 1 month
   - They have gone through 0-day
   - Ran all these through sysctl selftests in x86_64
 -----BEGIN PGP SIGNATURE-----
 
 iQGzBAABCgAdFiEErkcJVyXmMSXOyyeQupfNUreWQU8FAmfhV8EACgkQupfNUreW
 QU/udAv/VCXGkndQsJ5biXpXYFnokX0gIEaYzzHiqrFycZqr8ys0/wWzc+ar1LjF
 Jvanl2uKB0mUviLKt7Gk0+Hri+PJlYIrbx+5K5eo2wsKUUxFykqLLm59y/orPODl
 gyPQjKNpHJb7COsnEc3Lrq/fvol4NPHlcBPXG8NwehccTeBHZ1ninfo+pSnxh3o8
 kI3GSLLxD4K9AgBl5QuVWH4gU7o//u7lUkKzy03NW+2jmuRv3dRcYF7IdgMINNee
 AeXnygdSBxLzECBvmkfNdyg+AmL8hdsmzbsIh7UuJDvxLlQOInVLZa+sXBotCOIc
 TImCrr1Ws1OuGrD0kpH+21tJvc8pNFWt61QlulObQdrLndWHdZEGyGOusLpXTwbn
 jIWZmMvzk1foSwdgzwPFzUqPEpW3FrBVDo4Z4kenBDrCp56QTX7hGRvkNYJNKvot
 Ue+i8BeHR/Gm/p+UMqgsSTOaNJXTqZhFqwJQVzxU/9LN/vkS0On6fbjgBd5X6Pn+
 a5dlc9gy
 =0bcX
 -----END PGP SIGNATURE-----

Merge tag 'sysctl-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl

Pull sysctl updates from Joel Granados:

 - Move vm_table members out of kernel/sysctl.c

   All vm_table array members have moved to their respective subsystems
   leading to the removal of vm_table from kernel/sysctl.c. This
   increases modularity by placing the ctl_tables closer to where they
   are actually used and at the same time reducing the chances of merge
   conflicts in kernel/sysctl.c.

 - ctl_table range fixes

   Replace the proc_handler function that checks variable ranges in
   coredump_sysctls and vdso_table with the one that actually uses the
   extra{1,2} pointers as min/max values. This tightens the range of the
   values that users can pass into the kernel effectively preventing
   {under,over}flows.

 - Misc fixes

   Correct grammar errors and typos in test messages. Update sysctl
   files in MAINTAINERS. Constified and removed array size in
   declaration for alignment_tbl

* tag 'sysctl-6.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/sysctl/sysctl: (22 commits)
  selftests/sysctl: fix wording of help messages
  selftests: fix spelling/grammar errors in sysctl/sysctl.sh
  MAINTAINERS: Update sysctl file list in MAINTAINERS
  sysctl: Fix underflow value setting risk in vm_table
  coredump: Fixes core_pipe_limit sysctl proc_handler
  sysctl: remove unneeded include
  sysctl: remove the vm_table
  sh: vdso: move the sysctl to arch/sh/kernel/vsyscall/vsyscall.c
  x86: vdso: move the sysctl to arch/x86/entry/vdso/vdso32-setup.c
  fs: dcache: move the sysctl to fs/dcache.c
  sunrpc: simplify rpcauth_cache_shrink_count()
  fs: drop_caches: move sysctl to fs/drop_caches.c
  fs: fs-writeback: move sysctl to fs/fs-writeback.c
  mm: nommu: move sysctl to mm/nommu.c
  security: min_addr: move sysctl to security/min_addr.c
  mm: mmap: move sysctl to mm/mmap.c
  mm: util: move sysctls to mm/util.c
  mm: vmscan: move vmscan sysctls to mm/vmscan.c
  mm: swap: move sysctl to mm/swap.c
  mm: filemap: move sysctl to mm/filemap.c
  ...
2025-03-26 21:02:05 -07:00
Mike Rapoport (Microsoft)
09bdc4fe70 mm/mm_init: rename __init_reserved_page_zone to __init_page_from_nid
__init_reserved_page_zone() function finds the zone for pfn and nid and
performs initialization of a struct page with that zone and nid.  There is
nothing in that function about reserved pages and it is misnamed.

Rename it to __init_page_from_nid() to better reflect what the function
does.

Link: https://lkml.kernel.org/r/20250225083017.567649-2-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Frank van der Linden <fvdl@google.com>
Cc: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-21 22:03:11 -07:00
Johannes Weiner
a211c6550e mm: page_alloc: defrag_mode kswapd/kcompactd watermarks
The previous patch added pageblock_order reclaim to kswapd/kcompactd,
which helps, but produces only one block at a time.  Allocation stalls and
THP failure rates are still higher than they could be.

To adequately reflect ALLOC_NOFRAGMENT demand for pageblocks, change the
watermarking for kswapd & kcompactd: instead of targeting the high
watermark in order-0 pages and checking for one suitable block, simply
require that the high watermark is entirely met in pageblocks.

To this end, track the number of free pages within contiguous pageblocks,
then change pgdat_balanced() and compact_finished() to check watermarks
against this new value.

This further reduces THP latencies and allocation stalls, and improves THP
success rates against the previous patch:

                                       DEFRAGMODE-ASYNC DEFRAGMODE-ASYNC-WMARKS
Hugealloc Time mean               34300.36 (    +0.00%)   28904.00 (   -15.73%)
Hugealloc Time stddev             36390.42 (    +0.00%)   33464.37 (    -8.04%)
Kbuild Real time                    196.13 (    +0.00%)     196.59 (    +0.23%)
Kbuild User time                   1234.74 (    +0.00%)    1231.67 (    -0.25%)
Kbuild System time                   62.62 (    +0.00%)      59.10 (    -5.54%)
THP fault alloc                   57054.53 (    +0.00%)   63223.67 (   +10.81%)
THP fault fallback                11581.40 (    +0.00%)    5412.47 (   -53.26%)
Direct compact fail                 107.80 (    +0.00%)      59.07 (   -44.79%)
Direct compact success                4.53 (    +0.00%)       2.80 (   -31.33%)
Direct compact success rate %         3.20 (    +0.00%)       3.99 (   +18.66%)
Compact daemon scanned migrate  5461033.93 (    +0.00%) 2267500.33 (   -58.48%)
Compact daemon scanned free     5824897.93 (    +0.00%) 2339773.00 (   -59.83%)
Compact direct scanned migrate    58336.93 (    +0.00%)   47659.93 (   -18.30%)
Compact direct scanned free       32791.87 (    +0.00%)   40729.67 (   +24.21%)
Compact total migrate scanned   5519370.87 (    +0.00%) 2315160.27 (   -58.05%)
Compact total free scanned      5857689.80 (    +0.00%) 2380502.67 (   -59.36%)
Alloc stall                        2424.60 (    +0.00%)     638.87 (   -73.62%)
Pages kswapd scanned            2657018.33 (    +0.00%) 4002186.33 (   +50.63%)
Pages kswapd reclaimed           559583.07 (    +0.00%)  718577.80 (   +28.41%)
Pages direct scanned             722094.07 (    +0.00%)  355172.73 (   -50.81%)
Pages direct reclaimed           107257.80 (    +0.00%)   31162.80 (   -70.95%)
Pages total scanned             3379112.40 (    +0.00%) 4357359.07 (   +28.95%)
Pages total reclaimed            666840.87 (    +0.00%)  749740.60 (   +12.43%)
Swap out                          77238.20 (    +0.00%)  110084.33 (   +42.53%)
Swap in                           11712.80 (    +0.00%)   24457.00 (  +108.80%)
File refaults                    143438.80 (    +0.00%)  188226.93 (   +31.22%)

Also of note is that compaction work overall is reduced.  The reason for
this is that when free pageblocks are more readily available, allocations
are also much more likely to get physically placed in LRU order, instead
of being forced to scavenge free space here and there.  This means that
reclaim by itself has better chances of freeing up whole blocks, and the
system relies less on compaction.

Comparing all changes to the vanilla kernel:

                                                VANILLA DEFRAGMODE-ASYNC-WMARKS
Hugealloc Time mean               52739.45 (    +0.00%)   28904.00 (   -45.19%)
Hugealloc Time stddev             56541.26 (    +0.00%)   33464.37 (   -40.81%)
Kbuild Real time                    197.47 (    +0.00%)     196.59 (    -0.44%)
Kbuild User time                   1240.49 (    +0.00%)    1231.67 (    -0.71%)
Kbuild System time                   70.08 (    +0.00%)      59.10 (   -15.45%)
THP fault alloc                   46727.07 (    +0.00%)   63223.67 (   +35.30%)
THP fault fallback                21910.60 (    +0.00%)    5412.47 (   -75.29%)
Direct compact fail                 195.80 (    +0.00%)      59.07 (   -69.48%)
Direct compact success                7.93 (    +0.00%)       2.80 (   -57.46%)
Direct compact success rate %         3.51 (    +0.00%)       3.99 (   +10.49%)
Compact daemon scanned migrate  3369601.27 (    +0.00%) 2267500.33 (   -32.71%)
Compact daemon scanned free     5075474.47 (    +0.00%) 2339773.00 (   -53.90%)
Compact direct scanned migrate   161787.27 (    +0.00%)   47659.93 (   -70.54%)
Compact direct scanned free      163467.53 (    +0.00%)   40729.67 (   -75.08%)
Compact total migrate scanned   3531388.53 (    +0.00%) 2315160.27 (   -34.44%)
Compact total free scanned      5238942.00 (    +0.00%) 2380502.67 (   -54.56%)
Alloc stall                        2371.07 (    +0.00%)     638.87 (   -73.02%)
Pages kswapd scanned            2160926.73 (    +0.00%) 4002186.33 (   +85.21%)
Pages kswapd reclaimed           533191.07 (    +0.00%)  718577.80 (   +34.77%)
Pages direct scanned             400450.33 (    +0.00%)  355172.73 (   -11.31%)
Pages direct reclaimed            94441.73 (    +0.00%)   31162.80 (   -67.00%)
Pages total scanned             2561377.07 (    +0.00%) 4357359.07 (   +70.12%)
Pages total reclaimed            627632.80 (    +0.00%)  749740.60 (   +19.46%)
Swap out                          47959.53 (    +0.00%)  110084.33 (  +129.53%)
Swap in                            7276.00 (    +0.00%)   24457.00 (  +236.10%)
File refaults                    138043.00 (    +0.00%)  188226.93 (   +36.35%)

THP allocation latencies and %sys time are down dramatically.

THP allocation failures are down from nearly 50% to 8.5%.  And to recall
previous data points, the success rates are steady and reliable without
the cumulative deterioration of fragmentation events.

Compaction work is down overall.  Direct compaction work especially is
drastically reduced.  As an aside, its success rate of 4% indicates there
is room for improvement.  For now it's good to rely on it less.

Reclaim work is up overall, however direct reclaim work is down.  Part of
the increase can be attributed to a higher use of THPs, which due to
internal fragmentation increase the memory footprint.  This is not
necessarily an unexpected side-effect for users of THP.

However, taken both points together, there may well be some opportunities
for fine tuning in the reclaim/compaction coordination.

[hannes@cmpxchg.org: fix squawks from rebasing]
  Link: https://lkml.kernel.org/r/20250314210558.GD1316033@cmpxchg.org
Link: https://lkml.kernel.org/r/20250313210647.1314586-6-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:07:07 -07:00
Mike Rapoport (Microsoft)
8afa901c14 arch, mm: make releasing of memory to page allocator more explicit
The point where the memory is released from memblock to the buddy
allocator is hidden inside arch-specific mem_init()s and the call to
memblock_free_all() is needlessly duplicated in every artiste cure and
after introduction of arch_mm_preinit() hook, mem_init() implementation on
many architecture only contains the call to memblock_free_all().

Pull memblock_free_all() call into mm_core_init() and drop mem_init() on
relevant architectures to make it more explicit where the free memory is
released from memblock to the buddy allocator and to reduce code
duplication in architecture specific code.

Link: https://lkml.kernel.org/r/20250313135003.836600-14-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Dave Hansen <dave.hansen@linux.intel.com>	[x86]
Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>	[m68k]
Tested-by: Mark Brown <broonie@kernel.org>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Guo Ren (csky) <guoren@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jiaxun Yang <jiaxun.yang@flygoat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russel King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleinxer <tglx@linutronix.de>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:53 -07:00
David Hildenbrand
749492229e mm: stop maintaining the per-page mapcount of large folios (CONFIG_NO_PAGE_MAPCOUNT)
Everything is in place to stop using the per-page mapcounts in large
folios: the mapcount of tail pages will always be logically 0 (-1 value),
just like it currently is for hugetlb folios already, and the page
mapcount of the head page is either 0 (-1 value) or contains a page type
(e.g., hugetlb).

Maintaining _nr_pages_mapped without per-page mapcounts is impossible, so
that one also has to go with CONFIG_NO_PAGE_MAPCOUNT.

There are two remaining implications:

(1) Per-node, per-cgroup and per-lruvec stats of "NR_ANON_MAPPED"
    ("mapped anonymous memory") and "NR_FILE_MAPPED"
    ("mapped file memory"):

    As soon as any page of the folio is mapped -- folio_mapped() -- we
    now account the complete folio as mapped. Once the last page is
    unmapped -- !folio_mapped() -- we account the complete folio as
    unmapped.

    This implies that ...

    * "AnonPages" and "Mapped" in /proc/meminfo and
      /sys/devices/system/node/*/meminfo
    * cgroup v2: "anon" and "file_mapped" in "memory.stat" and
      "memory.numa_stat"
    * cgroup v1: "rss" and "mapped_file" in "memory.stat" and
      "memory.numa_stat

    ... can now appear higher than before. But note that these folios do
    consume that memory, simply not all pages are actually currently
    mapped.

    It's worth nothing that other accounting in the kernel (esp. cgroup
    charging on allocation) is not affected by this change.

    [why oh why is "anon" called "rss" in cgroup v1]

 (2) Detecting partial mappings

     Detecting whether anon THPs are partially mapped gets a bit more
     unreliable. As long as a single MM maps such a large folio
     ("exclusively mapped"), we can reliably detect it. Especially before
     fork() / after a short-lived child process quit, we will detect
     partial mappings reliably, which is the common case.

     In essence, if the average per-page mapcount in an anon THP is < 1,
     we know for sure that we have a partial mapping.

     However, as soon as multiple MMs are involved, we might miss detecting
     partial mappings: this might be relevant with long-lived child
     processes. If we have a fully-mapped anon folio before fork(), once
     our child processes and our parent all unmap (zap/COW) the same pages
     (but not the complete folio), we might not detect the partial mapping.
     However, once the child processes quit we would detect the partial
     mapping.

     How relevant this case is in practice remains to be seen.
     Swapout/migration will likely mitigate this.

     In the future, RMAP walkers could check for that for that case
     (e.g., when collecting access bits during reclaim) and simply flag
     them for deferred-splitting.

Link: https://lkml.kernel.org/r/20250303163014.1128035-21-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:48 -07:00
David Hildenbrand
6af8cb80d3 mm/rmap: basic MM owner tracking for large folios (!hugetlb)
For small folios, we traditionally use the mapcount to decide whether it
was "certainly mapped exclusively" by a single MM (mapcount == 1) or
whether it "maybe mapped shared" by multiple MMs (mapcount > 1).  For
PMD-sized folios that were PMD-mapped, we were able to use a similar
mechanism (single PMD mapping), but for PTE-mapped folios and in the
future folios that span multiple PMDs, this does not work.

So we need a different mechanism to handle large folios.  Let's add a new
mechanism to detect whether a large folio is "certainly mapped
exclusively", or whether it is "maybe mapped shared".

We'll use this information next to optimize CoW reuse for PTE-mapped
anonymous THP, and to convert folio_likely_mapped_shared() to
folio_maybe_mapped_shared(), independent of per-page mapcounts.

For each large folio, we'll have two slots, whereby a slot stores:
 (1) an MM id: unique id assigned to each MM
 (2) a per-MM mapcount

If a slot is unoccupied, it can be taken by the next MM that maps folio
page.

In addition, we'll remember the current state -- "mapped exclusively" vs. 
"maybe mapped shared" -- and use a bit spinlock to sync on updates and to
reduce the total number of atomic accesses on updates.  In the future, it
might be possible to squeeze a proper spinlock into "struct folio".  For
now, keep it simple, as we require the whole thing with THP only, that is
incompatible with RT.

As we have to squeeze this information into the "struct folio" of even
folios of order-1 (2 pages), and we generally want to reduce the required
metadata, we'll assign each MM a unique ID that can fit into an int.  In
total, we can squeeze everything into 4x int (2x long) on 64bit.

32bit support is a bit challenging, because we only have 2x long == 2x int
in order-1 folios.  But we can make it work for now, because we neither
expect many MMs nor very large folios on 32bit.

We will reliably detect folios as "mapped exclusively" vs.  "mapped
shared" as long as only two MMs map pages of a folio at one point in time
-- for example with fork() and short-lived child processes, or with apps
that hand over state from one instance to another.

As soon as three MMs are involved at the same time, we might detect "maybe
mapped shared" although the folio is "mapped exclusively".

Example 1:

(1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0
(2) App2 faults in a folio page -> Tracked as MM1
(4) App1 unmaps all folio pages

 -> We will detect "mapped exclusively".

Example 2:

(1) App1 faults in a (shmem/file-backed) folio page -> Tracked as MM0
(2) App2 faults in a folio page -> Tracked as MM1
(3) App3 faults in a folio page -> No slot available, tracked as "unknown"
(4) App1 and App2 unmap all folio pages

 -> We will detect "maybe mapped shared".

Make use of __always_inline to keep possible performance degradation when
(un)mapping large folios to a minimum.

Note: by squeezing the two flags into the "unsigned long" that stores the
MM ids, we can use non-atomic __bit_spin_unlock() and non-atomic
setting/clearing of the "maybe mapped shared" bit, effectively not adding
any new atomics on the hot path when updating the large mapcount + new
metadata, which further helps reduce the runtime overhead in
micro-benchmarks.

Link: https://lkml.kernel.org/r/20250303163014.1128035-13-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:46 -07:00
David Hildenbrand
845d2be6d4 mm: move _entire_mapcount in folio to page[2] on 32bit
Let's free up some space on 32bit in page[1] by moving the _pincount to
page[2].

Ordinary folios only use the entire mapcount with PMD mappings, so order-1
folios don't apply.  Similarly, hugetlb folios are always larger than
order-1, turning the entire mapcount essentially unused for all order-1
folios.  Moving it to order-1 folios will not change anything.

On 32bit, simply check in folio_entire_mapcount() whether we have an
order-1 folio, and return 0 in that case.

Note that THPs on 32bit are not particularly common (and we don't care too
much about performance), but we want to keep it working reliably, because
likely we want to use large folios there as well in the future,
independent of PMD leaf support.

Once we dynamically allocate "struct folio", the 32bit specifics will go
away again; even small folios could then have a pincount.

Link: https://lkml.kernel.org/r/20250303163014.1128035-7-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:44 -07:00
David Hildenbrand
31a31da8a6 mm: move _pincount in folio to page[2] on 32bit
Let's free up some space on 32bit in page[1] by moving the _pincount to
page[2].

For order-1 folios (never anon folios!) on 32bit, we will now also use the
GUP_PIN_COUNTING_BIAS approach.  A fully-mapped order-1 folio requires 2
references.  With GUP_PIN_COUNTING_BIAS being 1024, we'd detect such
folios as "maybe pinned" with 512 full mappings, instead of 1024 for
order-0.  As anon folios are out of the picture (which are the most
relevant users of checking for pinnings on *mapped* pages) and we are
talking about 32bit, this is not expected to cause any trouble.

In __dump_page(), copy one additional folio page if we detect a folio with
an order > 1, so we can dump the pincount on order > 1 folios reliably.

Note that THPs on 32bit are not particularly common (and we don't care too
much about performance), but we want to keep it working reliably, because
likely we want to use large folios there as well in the future,
independent of PMD leaf support.

Once we dynamically allocate "struct folio", fortunately the 32bit
specifics will likely go away again; even small folios could then have a
pincount and folio_has_pincount() would essentially always return "true".

Link: https://lkml.kernel.org/r/20250303163014.1128035-6-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:44 -07:00
David Hildenbrand
4996fc547f mm: let _folio_nr_pages overlay memcg_data in first tail page
Let's free up some more of the "unconditionally available on 64BIT" space
in order-1 folios by letting _folio_nr_pages overlay memcg_data in the
first tail page (second folio page).  Consequently, we have the
optimization now whenever we have CONFIG_MEMCG, independent of 64BIT.

We have to make sure that page->memcg on tail pages does not return
"surprises".  page_memcg_check() already properly refuses PageTail(). 
Let's do that earlier in print_page_owner_memcg() to avoid printing wrong
"Slab cache page" information.  No other code should touch that field on
tail pages of compound pages.

Reset the "_nr_pages" to 0 when splitting folios, or when freeing them
back to the buddy (to avoid false page->memcg_data "bad page" reports).

Note that in __split_huge_page(), folio_nr_pages() would stop working
already as soon as we start messing with the subpages.

Most kernel configs should have at least CONFIG_MEMCG enabled, even if
disabled at runtime.  64byte "struct memmap" is what we usually have on
64BIT.

While at it, rename "_folio_nr_pages" to "_nr_pages".

Hopefully memdescs / dynamically allocating "strut folio" in the future
will further clean this up, e.g., making _nr_pages available in all
configs and maybe even in small folios.  Doing that should be fairly easy
on top of this change.

[david@redhat.com: make "make htmldoc" happy]
  Link: https://lkml.kernel.org/r/a97f8a91-ec41-4796-81e3-7c9e0e491ba4@redhat.com
Link: https://lkml.kernel.org/r/20250303163014.1128035-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Andy Lutomirks^H^Hski <luto@kernel.org>
Cc: Borislav Betkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Jann Horn <jannh@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michal Koutn <mkoutny@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: tejun heo <tj@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Zefan Li <lizefan.x@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:43 -07:00
Lorenzo Stoakes
664dc4da26 mm/mremap: thread state through move page table operation
Finish refactoring the page table logic by threading the PMC state
throughout the operation, allowing us to control the operation as we go.

Additionally, update the old_addr, new_addr fields in move_page_tables()
as we progress through the process making use of the fact we have this
state object now to track this.

With these changes made, not only is the code far more readable, but we
can finally transmit state throughout the entire operation, which lays the
groundwork for sensibly making changes in future to how the mremap()
operation is performed.

Additionally take the opportunity to refactor the means of determining the
progress of the operation, abstracting this to pmc_progress() and
simplifying the logic to make it clearer what's going on.

Link: https://lkml.kernel.org/r/230dd7a2b7b01a6eef442678f284d575e800356e.1741639347.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:42 -07:00
Lorenzo Stoakes
2a4077f49c mm/mremap: refactor move_page_tables(), abstracting state
A lot of state is threaded throughout the page table moving logic within
the mremap code, including boolean values which control behaviour
specifically in regard to whether rmap locks need be held over the
operation and whether the VMA belongs to a temporary stack being moved by
move_arg_pages() (and consequently, relocate_vma_down()).

As we already transmit state throughout this operation, it is neater and
more readable to maintain a small state object.  We do so in the form of
pagetable_move_control.

In addition, this allows us to update parameters within the state as we
manipulate things, for instance with regard to the page table realignment
logic.

In future I want to add additional functionality to the page table logic,
so this is an additional motivation for making it easier to do so.

This patch changes move_page_tables() to accept a pointer to a
pagetable_move_control struct, and performs changes at this level only.
Further page table logic will be updated in a subsequent patch.

We additionally also take the opportunity to add significant comments
describing the address realignment logic to make it abundantly clear what
is going on in this code.

Link: https://lkml.kernel.org/r/e20180add9c8746184aa3f23a61fff69a06cdaa9.1741639347.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Harry Yoo <harry.yoo@oracle.com>
Cc: Liam R. Howlett <Liam.Howlett@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:42 -07:00
Alistair Popple
38607c62b3 fs/dax: properly refcount fs dax pages
Currently fs dax pages are considered free when the refcount drops to one
and their refcounts are not increased when mapped via PTEs or decreased
when unmapped.  This requires special logic in mm paths to detect that
these pages should not be properly refcounted, and to detect when the
refcount drops to one instead of zero.

On the other hand get_user_pages(), etc.  will properly refcount fs dax
pages by taking a reference and dropping it when the page is unpinned.

Tracking this special behaviour requires extra PTE bits (eg.  pte_devmap)
and introduces rules that are potentially confusing and specific to FS DAX
pages.  To fix this, and to possibly allow removal of the special PTE bits
in future, convert the fs dax page refcounts to be zero based and instead
take a reference on the page each time it is mapped as is currently the
case for normal pages.

This may also allow a future clean-up to remove the pgmap refcounting that
is currently done in mm/gup.c.

Link: https://lkml.kernel.org/r/c7d886ad7468a20452ef6e0ddab6cfe220874e7c.1740713401.git-series.apopple@nvidia.com
Signed-off-by: Alistair Popple <apopple@nvidia.com>
Reviewed-by: Dan Williams <dan.j.williams@intel.com>
Tested-by: Alison Schofield <alison.schofield@intel.com>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Asahi Lina <lina@asahilina.net>
Cc: Balbir Singh <balbirs@nvidia.com>
Cc: Bjorn Helgaas <bhelgaas@google.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Cc: "Darrick J. Wong" <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ira Weiny <ira.weiny@intel.com>
Cc: Jan Kara <jack@suse.cz>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: linmiaohe <linmiaohe@huawei.com>
Cc: Logan Gunthorpe <logang@deltatee.com>
Cc: Matthew Wilcow (Oracle) <willy@infradead.org>
Cc: Michael "Camp Drill Sergeant" Ellerman <mpe@ellerman.id.au>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Ted Ts'o <tytso@mit.edu>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vivek Goyal <vgoyal@redhat.com>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 22:06:41 -07:00
Brendan Jackman
e47f1f56dd mm/page_alloc: clarify terminology in migratetype fallback code
Patch series "mm/page_alloc: Some clarifications for migratetype
fallback", v4.

A couple of patches to try and make the code easier to follow.


This patch (of 2):

This code is rather confusing because:

 1. "Steal" is sometimes used to refer to the general concept of
    allocating from a from a block of a fallback migratetype
    (steal_suitable_fallback()) but sometimes it refers specifically to
    converting a whole block's migratetype (can_steal_fallback()).

 2. can_steal_fallback() sounds as though it's answering the question "am
    I functionally permitted to allocate from that other type" but in
    fact it is encoding a heuristic preference.

 3. The same piece of data has different names in different places:
    can_steal vs whole_block. This reinforces point 2 because it looks
    like the different names reflect a shift in intent from "am I
    allowed to steal" to "do I want to steal", but no such shift exists.

Fix 1. by avoiding the term "steal" in ambiguous contexts. Start using
the term "claim" to refer to the special case of stealing the entire
block.

Fix 2. by using "should" instead of "can", and also rename its
parameters and add some commentary to make it more explicit what they
mean.

Fix 3. by adopting the new "claim" terminology universally for this
set of variables.

Link: https://lkml.kernel.org/r/20250228-clarify-steal-v4-0-cb2ef1a4e610@google.com
Link: https://lkml.kernel.org/r/20250228-clarify-steal-v4-1-cb2ef1a4e610@google.com
Signed-off-by: Brendan Jackman <jackmanb@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Yosry Ahmed <yosry.ahmed@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-17 00:05:35 -07:00
Frank van der Linden
85abcd0236 mm/cma: introduce interface for early reservations
It can be desirable to reserve memory in a CMA area before it is
activated, early in boot.  Such reservations would effectively be memblock
allocations, but they can be returned to the CMA area later.  This
functionality can be used to allow hugetlb bootmem allocations from a
hugetlb CMA area.

A new interface, cma_reserve_early is introduced.  This allows for
pageblock-aligned reservations.  These reservations are skipped during the
initial handoff of pages in a CMA area to the buddy allocator.  The caller
is responsible for making sure that the page structures are set up, and
that the migrate type is set correctly, as with other memblock allocations
that stick around.  If the CMA area fails to activate (because it
intersects with multiple zones), the reserved memory is not given to the
buddy allocator, the caller needs to take care of that.

Link: https://lkml.kernel.org/r/20250228182928.2645936-25-fvdl@google.com
Signed-off-by: Frank van der Linden <fvdl@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:30 -07:00
Frank van der Linden
14ed3a595f mm/hugetlb: check bootmem pages for zone intersections
Bootmem hugetlb pages are allocated using memblock, which isn't (and
mostly can't be) aware of zones.

So, they may end up crossing zone boundaries.  This would create
confusion, a hugetlb page that is part of multiple zones is bad.  Worse,
HVO might then end up stealthily re-assigning pages to a different zone
when a hugetlb page is freed, since the tail page structures beyond the
first vmemmap page would inherit the zone of the first page structures.

While the chance of this happening is low, you can definitely create a
configuration where this happens (especially using ZONE_MOVABLE).

To avoid this issue, check if bootmem hugetlb pages intersect with
multiple zones during the gather phase, and discard them, handing them to
the page allocator, if they do.  Record the number of invalid bootmem
pages per node and subtract them from the number of available pages at the
end, making it easier to do these checks in multiple places later on.

Link: https://lkml.kernel.org/r/20250228182928.2645936-14-fvdl@google.com
Signed-off-by: Frank van der Linden <fvdl@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:28 -07:00
Frank van der Linden
d69d8261a9 mm: define __init_reserved_page_zone function
Sometimes page structs must be unconditionally initialized as reserved,
regardless of DEFERRED_STRUCT_PAGE_INIT.

Define a function, __init_reserved_page_zone, containing code that already
did all of the work in init_reserved_page, and make it available for use.

Link: https://lkml.kernel.org/r/20250228182928.2645936-13-fvdl@google.com
Signed-off-by: Frank van der Linden <fvdl@google.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin (Cruise) <roman.gushchin@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-16 22:06:27 -07:00
Ma Wupeng
b81679b163 mm: memory-failure: update ttu flag inside unmap_poisoned_folio
Patch series "mm: memory_failure: unmap poisoned folio during migrate
properly", v3.

Fix two bugs during folio migration if the folio is poisoned.


This patch (of 3):

Commit 6da6b1d4a7 ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to
TTU_HWPOISON") introduce TTU_HWPOISON to replace TTU_IGNORE_HWPOISON in
order to stop send SIGBUS signal when accessing an error page after a
memory error on a clean folio.  However during page migration, anon folio
must be set with TTU_HWPOISON during unmap_*().  For pagecache we need
some policy just like the one in hwpoison_user_mappings to set this flag. 
So move this policy from hwpoison_user_mappings to unmap_poisoned_folio to
handle this warning properly.

Warning will be produced during unamp poison folio with the following log:

  ------------[ cut here ]------------
  WARNING: CPU: 1 PID: 365 at mm/rmap.c:1847 try_to_unmap_one+0x8fc/0xd3c
  Modules linked in:
  CPU: 1 UID: 0 PID: 365 Comm: bash Tainted: G        W          6.13.0-rc1-00018-gacdb4bbda7ab #42
  Tainted: [W]=WARN
  Hardware name: QEMU QEMU Virtual Machine, BIOS 0.0.0 02/06/2015
  pstate: 20400005 (nzCv daif +PAN -UAO -TCO -DIT -SSBS BTYPE=--)
  pc : try_to_unmap_one+0x8fc/0xd3c
  lr : try_to_unmap_one+0x3dc/0xd3c
  Call trace:
   try_to_unmap_one+0x8fc/0xd3c (P)
   try_to_unmap_one+0x3dc/0xd3c (L)
   rmap_walk_anon+0xdc/0x1f8
   rmap_walk+0x3c/0x58
   try_to_unmap+0x88/0x90
   unmap_poisoned_folio+0x30/0xa8
   do_migrate_range+0x4a0/0x568
   offline_pages+0x5a4/0x670
   memory_block_action+0x17c/0x374
   memory_subsys_offline+0x3c/0x78
   device_offline+0xa4/0xd0
   state_store+0x8c/0xf0
   dev_attr_store+0x18/0x2c
   sysfs_kf_write+0x44/0x54
   kernfs_fop_write_iter+0x118/0x1a8
   vfs_write+0x3a8/0x4bc
   ksys_write+0x6c/0xf8
   __arm64_sys_write+0x1c/0x28
   invoke_syscall+0x44/0x100
   el0_svc_common.constprop.0+0x40/0xe0
   do_el0_svc+0x1c/0x28
   el0_svc+0x30/0xd0
   el0t_64_sync_handler+0xc8/0xcc
   el0t_64_sync+0x198/0x19c
  ---[ end trace 0000000000000000 ]---

[mawupeng1@huawei.com: unmap_poisoned_folio(): remove shadowed local `mapping', per Miaohe]
  Link: https://lkml.kernel.org/r/20250219060653.3849083-1-mawupeng1@huawei.com
Link: https://lkml.kernel.org/r/20250217014329.3610326-1-mawupeng1@huawei.com
Link: https://lkml.kernel.org/r/20250217014329.3610326-2-mawupeng1@huawei.com
Fixes: 6da6b1d4a7 ("mm/hwpoison: convert TTU_IGNORE_HWPOISON to TTU_HWPOISON")
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ma Wupeng <mawupeng1@huawei.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-03-05 21:36:13 -08:00
Alexei Starovoitov
97769a53f1 mm, bpf: Introduce try_alloc_pages() for opportunistic page allocation
Tracing BPF programs execute from tracepoints and kprobes where
running context is unknown, but they need to request additional
memory. The prior workarounds were using pre-allocated memory and
BPF specific freelists to satisfy such allocation requests.
Instead, introduce gfpflags_allow_spinning() condition that signals
to the allocator that running context is unknown.
Then rely on percpu free list of pages to allocate a page.
try_alloc_pages() -> get_page_from_freelist() -> rmqueue() ->
rmqueue_pcplist() will spin_trylock to grab the page from percpu
free list. If it fails (due to re-entrancy or list being empty)
then rmqueue_bulk()/rmqueue_buddy() will attempt to
spin_trylock zone->lock and grab the page from there.
spin_trylock() is not safe in PREEMPT_RT when in NMI or in hard IRQ.
Bailout early in such case.

The support for gfpflags_allow_spinning() mode for free_page and memcg
comes in the next patches.

This is a first step towards supporting BPF requirements in SLUB
and getting rid of bpf_mem_alloc.
That goal was discussed at LSFMM: https://lwn.net/Articles/974138/

Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250222024427.30294-3-alexei.starovoitov@gmail.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
2025-02-27 09:32:27 -08:00
Kaixiong Yu
538d5baacd mm: vmscan: move vmscan sysctls to mm/vmscan.c
This moves vm_swappiness and zone_reclaim_mode to mm/vmscan.c,
as part of the kernel/sysctl.c cleaning, also moves some external
variable declarations and function declarations from include/linux/swap.h
into mm/internal.h.

Signed-off-by: Kaixiong Yu <yukaixiong@huawei.com>
Reviewed-by: Kees Cook <kees@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Joel Granados <joel.granados@kernel.org>
2025-02-07 16:53:04 +01:00
Jens Axboe
4a9e23159f mm/truncate: add folio_unmap_invalidate() helper
Add a folio_unmap_invalidate() helper, which unmaps and invalidates a
given folio.  The caller must already have locked the folio.  Embed the
old invalidate_complete_folio2() helper in there as well, as nobody else
calls it.

Use this new helper in invalidate_inode_pages2_range(), rather than
duplicate the code there.

In preparation for using this elsewhere as well, have it take a gfp_t mask
rather than assume GFP_KERNEL is the right choice.  This bubbles back to
invalidate_complete_folio2() as well.

Link: https://lkml.kernel.org/r/20241220154831.1086649-7-axboe@kernel.dk
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Cc: Brian Foster <bfoster@redhat.com>
Cc: Chris Mason <clm@meta.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-25 20:22:43 -08:00
Jeff Xu
b487c02430 mseal: remove can_do_mseal()
No code logic change.

can_do_mseal() is called exclusively by mseal.c, and mseal.c is compiled
only when CONFIG_64BIT flag is set in makefile.  Therefore, it is
unnecessary to have 32 bit stub function in the header file, remove this
function and merge the logic into do_mseal().

Link: https://lkml.kernel.org/r/20241206013934.2782793-1-jeffxu@google.com
Link: https://lkml.kernel.org/r/20241206194839.3030596-2-jeffxu@google.com
Signed-off-by: Jeff Xu <jeffxu@chromium.org>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Jorge Lucangeli Obes <jorgelo@chromium.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Pedro Falcato <pedro.falcato@gmail.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:51 -08:00
Qi Zheng
6375e95f38 mm: pgtable: reclaim empty PTE page in madvise(MADV_DONTNEED)
Now in order to pursue high performance, applications mostly use some
high-performance user-mode memory allocators, such as jemalloc or
tcmalloc.  These memory allocators use madvise(MADV_DONTNEED or MADV_FREE)
to release physical memory, but neither MADV_DONTNEED nor MADV_FREE will
release page table memory, which may cause huge page table memory usage.

The following are a memory usage snapshot of one process which actually
happened on our server:

        VIRT:  55t
        RES:   590g
        VmPTE: 110g

In this case, most of the page table entries are empty.  For such a PTE
page where all entries are empty, we can actually free it back to the
system for others to use.

As a first step, this commit aims to synchronously free the empty PTE
pages in madvise(MADV_DONTNEED) case.  We will detect and free empty PTE
pages in zap_pte_range(), and will add zap_details.reclaim_pt to exclude
cases other than madvise(MADV_DONTNEED).

Once an empty PTE is detected, we first try to hold the pmd lock within
the pte lock.  If successful, we clear the pmd entry directly (fast path).
Otherwise, we wait until the pte lock is released, then re-hold the pmd
and pte locks and loop PTRS_PER_PTE times to check pte_none() to re-detect
whether the PTE page is empty and free it (slow path).

For other cases such as madvise(MADV_FREE), consider scanning and freeing
empty PTE pages asynchronously in the future.

The following code snippet can show the effect of optimization:

        mmap 50G
        while (1) {
                for (; i < 1024 * 25; i++) {
                        touch 2M memory
                        madvise MADV_DONTNEED 2M
                }
        }

As we can see, the memory usage of VmPTE is reduced:

                        before                          after
VIRT                   50.0 GB                        50.0 GB
RES                     3.1 MB                         3.1 MB
VmPTE                102640 KB                         240 KB

[zhengqi.arch@bytedance.com: fix uninitialized symbol 'ptl']
  Link: https://lkml.kernel.org/r/20241206112348.51570-1-zhengqi.arch@bytedance.com
  Link: https://lore.kernel.org/linux-mm/224e6a4e-43b5-4080-bdd8-b0a6fb2f0853@stanley.mountain/
Link: https://lkml.kernel.org/r/92aba2b319a734913f18ba41e7d86a265f0b84e2.1733305182.git.zhengqi.arch@bytedance.com
Signed-off-by: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jann Horn <jannh@google.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peter Xu <peterx@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>
Cc: Zach O'Keefe <zokeefe@google.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:48 -08:00
David Hildenbrand
2202f51e92 mm/page_alloc: make __alloc_contig_migrate_range() static
The single user is in page_alloc.c.

Link: https://lkml.kernel.org/r/20241203094732.200195-4-david@redhat.com
Signed-off-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N Rao <naveen@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:44 -08:00
Matthew Wilcox (Oracle)
642975242e mm/mempolicy: add alloc_frozen_pages()
Provide an interface to allocate pages from the page allocator without
incrementing their refcount.  This saves an atomic operation on free,
which may be beneficial to some users (eg slab).

Link: https://lkml.kernel.org/r/20241125210149.2976098-15-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:33 -08:00
Matthew Wilcox (Oracle)
49249a2a5e mm/page_alloc: add __alloc_frozen_pages()
Defer the initialisation of the page refcount to the new __alloc_pages()
wrapper and turn the old __alloc_pages() into __alloc_frozen_pages().

Link: https://lkml.kernel.org/r/20241125210149.2976098-14-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:33 -08:00
Matthew Wilcox (Oracle)
8fd10a892a mm/page_alloc: move set_page_refcounted() to callers of post_alloc_hook()
In preparation for allocating frozen pages, stop initialising the page
refcount in post_alloc_hook().

Link: https://lkml.kernel.org/r/20241125210149.2976098-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Muchun Song <songmuchun@bytedance.com>
Cc: William Kucharski <william.kucharski@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:31 -08:00
Matthew Wilcox (Oracle)
520128a1d1 mm/page_alloc: export free_frozen_pages() instead of free_unref_page()
We already have the concept of "frozen pages" (eg page_ref_freeze()), so
let's not complicate things by also having the concept of "unref pages".

Link: https://lkml.kernel.org/r/20241125210149.2976098-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Reviewed-by: Miaohe Lin <linmiaohe@huawei.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Hyeonggon Yoo <42.hyeyoo@gmail.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-01-13 22:40:31 -08:00
Kairui Song
62e72d2cf7 mm, madvise: fix potential workingset node list_lru leaks
Since commit 5abc1e37af ("mm: list_lru: allocate list_lru_one only when
needed"), all list_lru users need to allocate the items using the new
infrastructure that provides list_lru info for slab allocation, ensuring
that the corresponding memcg list_lru is allocated before use.

For workingset shadow nodes (which are xa_node), users are converted to
use the new infrastructure by commit 9bbdc0f324 ("xarray: use
kmem_cache_alloc_lru to allocate xa_node").  The xas->xa_lru will be set
correctly for filemap users.  However, there is a missing case: xa_node
allocations caused by madvise(..., MADV_COLLAPSE).

madvise(..., MADV_COLLAPSE) will also read in the absent parts of file
map, and there will be xa_nodes allocated for the caller's memcg (assuming
it's not rootcg).  However, these allocations won't trigger memcg list_lru
allocation because the proper xas info was not set.

If nothing else has allocated other xa_nodes for that memcg to trigger
list_lru creation, and memory pressure starts to evict file pages,
workingset_update_node will try to add these xa_nodes to their
corresponding memcg list_lru, and it does not exist (NULL).  So they will
be added to rootcg's list_lru instead.

This shouldn't be a significant issue in practice, but it is indeed
unexpected behavior, and these xa_nodes will not be reclaimed effectively.
And may lead to incorrect counting of the list_lru->nr_items counter.

This problem wasn't exposed until recent commit 28e98022b3
("mm/list_lru: simplify reparenting and initial allocation") added a
sanity check: only dying memcg could have a NULL list_lru when
list_lru_{add,del} is called.  This problem triggered this WARNING.

So make madvise(..., MADV_COLLAPSE) also call xas_set_lru() to pass the
list_lru which we may want to insert xa_node into later.  And move
mapping_set_update to mm/internal.h, and turn into a macro to avoid
including extra headers in mm/internal.h.

Link: https://lkml.kernel.org/r/20241222122936.67501-1-ryncsn@gmail.com
Fixes: 9bbdc0f324 ("xarray: use kmem_cache_alloc_lru to allocate xa_node")
Reported-by: syzbot+38a0cbd267eff2d286ff@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/lkml/675d01e9.050a0220.37aaf.00be.GAE@google.com/
Signed-off-by: Kairui Song <kasong@tencent.com>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Qi Zheng <zhengqi.arch@bytedance.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sasha Levin <sashal@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-30 17:59:11 -08:00
Zi Yan
c51a4f11e6 mm: use clear_user_(high)page() for arch with special user folio handling
Some architectures have special handling after clearing user folios:
architectures, which set cpu_dcache_is_aliasing() to true, require
flushing dcache; arc, which sets cpu_icache_is_aliasing() to true, changes
folio->flags to make icache coherent to dcache.  So __GFP_ZERO using only
clear_page() is not enough to zero user folios and clear_user_(high)page()
must be used.  Otherwise, user data will be corrupted.

Fix it by always clearing user folios with clear_user_(high)page() when
cpu_dcache_is_aliasing() is true or cpu_icache_is_aliasing() is true. 
Rename alloc_zeroed() to user_alloc_needs_zeroing() and invert the logic
to clarify its intend.

Link: https://lkml.kernel.org/r/20241209182326.2955963-2-ziy@nvidia.com
Fixes: 5708d96da2 ("mm: avoid zeroing user movable page twice with init_on_alloc=1")
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reported-by: Geert Uytterhoeven <geert+renesas@glider.be>
Closes: https://lore.kernel.org/linux-mm/CAMuHMdV1hRp_NtR5YnJo=HsfgKQeH91J537Gh4gKk3PFZhSkbA@mail.gmail.com/
Tested-by: Geert Uytterhoeven <geert+renesas@glider.be>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Alexander Potapenko <glider@google.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-12-18 19:04:43 -08:00
Linus Torvalds
6a34dfa15d Kbuild updates for v6.13
- Add generic support for built-in boot DTB files
 
  - Enable TAB cycling for dialog buttons in nconfig
 
  - Fix issues in streamline_config.pl
 
  - Refactor Kconfig
 
  - Add support for Clang's AutoFDO (Automatic Feedback-Directed
    Optimization)
 
  - Add support for Clang's Propeller, a profile-guided optimization.
 
  - Change the working directory to the external module directory for M=
    builds
 
  - Support building external modules in a separate output directory
 
  - Enable objtool for *.mod.o and additional kernel objects
 
  - Use lz4 instead of deprecated lz4c
 
  - Work around a performance issue with "git describe"
 
  - Refactor modpost
 -----BEGIN PGP SIGNATURE-----
 
 iQJJBAABCgAzFiEEbmPs18K1szRHjPqEPYsBB53g2wYFAmdKGgEVHG1hc2FoaXJv
 eUBrZXJuZWwub3JnAAoJED2LAQed4NsGrFoQAIgioJPRG+HC6bGmjy4tL4bq1RAm
 78nbD12grrAa+NvQGRZYRs264rWxBGwrNfGGS9BDvlWJZ3fmKEuPlfCIxC0nkKk8
 LVLNxSVvgpHE47RQ+E4V+yYhrlZKb4aWZjH3ZICn7vxRgbQ5Veq61aatluVHyn9c
 I8g+APYN/S1A4JkFzaLe8GV7v5OM3+zGSn3M9n7/DxVkoiNrMOXJm5hRdRgYfEv/
 kMppheY2PPshZsaL+yLAdrJccY5au5vYE/v8wHkMtvM/LF6YwjgqPVDRFQ30BuLM
 sAMMd6AUoopiDZQOpqmXYukU0b0MQPswg3jmB+PWUBrlsuydRa8kkyPwUaFrDd+w
 9d0jZRc8/O/lxUdD1AefRkNcA/dIJ4lTPr+2NpxwHuj2UFo0gLQmtjBggMFHaWvs
 0NQRBPlxfOE4+Htl09gyg230kHuWq+rh7xqbyJCX+hBOaZ6kI2lryl6QkgpAoS+x
 KDOcUKnsgGMGARQRrvCOAXnQs+rjkW8fEm6t7eSBFPuWJMK85k4LmxOog8GVYEdM
 JcwCnCHt9TtcHlSxLRnVXj2aqGTFNLJXE1aLyCp9u8MxZ7qcx01xOuCmwp6FRzNq
 ghal7ngA58Y/S4K/oJ+CW2KupOb6CFne8mpyotpYeWI7MR64t0YWs4voZkuK46E2
 CEBfA4PDehA4BxQe
 =GDKD
 -----END PGP SIGNATURE-----

Merge tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild

Pull Kbuild updates from Masahiro Yamada:

 - Add generic support for built-in boot DTB files

 - Enable TAB cycling for dialog buttons in nconfig

 - Fix issues in streamline_config.pl

 - Refactor Kconfig

 - Add support for Clang's AutoFDO (Automatic Feedback-Directed
   Optimization)

 - Add support for Clang's Propeller, a profile-guided optimization.

 - Change the working directory to the external module directory for M=
   builds

 - Support building external modules in a separate output directory

 - Enable objtool for *.mod.o and additional kernel objects

 - Use lz4 instead of deprecated lz4c

 - Work around a performance issue with "git describe"

 - Refactor modpost

* tag 'kbuild-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (85 commits)
  kbuild: rename .tmp_vmlinux.kallsyms0.syms to .tmp_vmlinux0.syms
  gitignore: Don't ignore 'tags' directory
  kbuild: add dependency from vmlinux to resolve_btfids
  modpost: replace tdb_hash() with hash_str()
  kbuild: deb-pkg: add python3:native to build dependency
  genksyms: reduce indentation in export_symbol()
  modpost: improve error messages in device_id_check()
  modpost: rename alias symbol for MODULE_DEVICE_TABLE()
  modpost: rename variables in handle_moddevtable()
  modpost: move strstarts() to modpost.h
  modpost: convert do_usb_table() to a generic handler
  modpost: convert do_of_table() to a generic handler
  modpost: convert do_pnp_device_entry() to a generic handler
  modpost: convert do_pnp_card_entries() to a generic handler
  modpost: call module_alias_printf() from all do_*_entry() functions
  modpost: pass (struct module *) to do_*_entry() functions
  modpost: remove DEF_FIELD_ADDR_VAR() macro
  modpost: deduplicate MODULE_ALIAS() for all drivers
  modpost: introduce module_alias_printf() helper
  modpost: remove unnecessary check in do_acpi_entry()
  ...
2024-11-30 13:41:50 -08:00
Masahiro Yamada
dbefa1f31a Rename .data.once to .data..once to fix resetting WARN*_ONCE
Commit b1fca27d38 ("kernel debug: support resetting WARN*_ONCE")
added support for clearing the state of once warnings. However,
it is not functional when CONFIG_LD_DEAD_CODE_DATA_ELIMINATION or
CONFIG_LTO_CLANG is enabled, because .data.once matches the
.data.[0-9a-zA-Z_]* pattern in the DATA_MAIN macro.

Commit cb87481ee8 ("kbuild: linker script do not match C names unless
LD_DEAD_CODE_DATA_ELIMINATION is configured") was introduced to suppress
the issue for the default CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=n case,
providing a minimal fix for stable backporting. We were aware this did
not address the issue for CONFIG_LD_DEAD_CODE_DATA_ELIMINATION=y. The
plan was to apply correct fixes and then revert cb87481ee8. [1]

Seven years have passed since then, yet the #ifdef workaround remains in
place. Meanwhile, commit b1fca27d38 introduced the .data.once section,
and commit dc5723b02e ("kbuild: add support for Clang LTO") extended
the #ifdef.

Using a ".." separator in the section name fixes the issue for
CONFIG_LD_DEAD_CODE_DATA_ELIMINATION and CONFIG_LTO_CLANG.

[1]: https://lore.kernel.org/linux-kbuild/CAK7LNASck6BfdLnESxXUeECYL26yUDm0cwRZuM4gmaWUkxjL5g@mail.gmail.com/

Fixes: b1fca27d38 ("kernel debug: support resetting WARN*_ONCE")
Fixes: dc5723b02e ("kbuild: add support for Clang LTO")
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
2024-11-27 09:38:27 +09:00
Maíra Canal
1c8d484975 mm: move `get_order_from_str()` to internal.h
In order to implement a kernel parameter similar to ``thp_anon=`` for
shmem, we'll need the function ``get_order_from_str()``.

Instead of duplicating the function, move the function to a shared
header, in which both mm/shmem.c and mm/huge_memory.c will be able to
use it.

Link: https://lkml.kernel.org/r/20241101165719.1074234-5-mcanal@igalia.com
Signed-off-by: Maíra Canal <mcanal@igalia.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: David Hildenbrand <david@redhat.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lance Yang <ioworker0@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-11 13:09:43 -08:00
Lorenzo Stoakes
5f6170a469 mm: pagewalk: add the ability to install PTEs
Patch series "implement lightweight guard pages", v4.

Userland library functions such as allocators and threading
implementations often require regions of memory to act as 'guard pages' -
mappings which, when accessed, result in a fatal signal being sent to the
accessing process.

The current means by which these are implemented is via a PROT_NONE mmap()
mapping, which provides the required semantics however incur an overhead
of a VMA for each such region.

With a great many processes and threads, this can rapidly add up and incur
a significant memory penalty.  It also has the added problem of preventing
merges that might otherwise be permitted.

This series takes a different approach - an idea suggested by Vlastimil
Babka (and before him David Hildenbrand and Jann Horn - perhaps more - the
provenance becomes a little tricky to ascertain after this - please
forgive any omissions!) - rather than locating the guard pages at the VMA
layer, instead placing them in page tables mapping the required ranges.

Early testing of the prototype version of this code suggests a 5 times
speed up in memory mapping invocations (in conjunction with use of
process_madvise()) and a 13% reduction in VMAs on an entirely idle android
system and unoptimised code.

We expect with optimisation and a loaded system with a larger number of
guard pages this could significantly increase, but in any case these
numbers are encouraging.

This way, rather than having separate VMAs specifying which parts of a
range are guard pages, instead we have a VMA spanning the entire range of
memory a user is permitted to access and including ranges which are to be
'guarded'.

After mapping this, a user can specify which parts of the range should
result in a fatal signal when accessed.

By restricting the ability to specify guard pages to memory mapped by
existing VMAs, we can rely on the mappings being torn down when the
mappings are ultimately unmapped and everything works simply as if the
memory were not faulted in, from the point of view of the containing VMAs.

This mechanism in effect poisons memory ranges similar to hardware memory
poisoning, only it is an entirely software-controlled form of poisoning.

The mechanism is implemented via madvise() behaviour - MADV_GUARD_INSTALL
which installs page table-level guard page markers - and MADV_GUARD_REMOVE
- which clears them.

Guard markers can be installed across multiple VMAs and any existing
mappings will be cleared, that is zapped, before installing the guard page
markers in the page tables.

There is no concept of 'nested' guard markers, multiple attempts to
install guard markers in a range will, after the first attempt, have no
effect.

Importantly, removing guard markers over a range that contains both guard
markers and ordinary backed memory has no effect on anything but the guard
markers (including leaving huge pages un-split), so a user can safely
remove guard markers over a range of memory leaving the rest intact.

The actual mechanism by which the page table entries are specified makes
use of existing logic - PTE markers, which are used for the userfaultfd
UFFDIO_POISON mechanism.

Unfortunately PTE_MARKER_POISONED is not suited for the guard page
mechanism as it results in VM_FAULT_HWPOISON semantics in the fault
handler, so we add our own specific PTE_MARKER_GUARD and adapt existing
logic to handle it.

We also extend the generic page walk mechanism to allow for installation
of PTEs (carefully restricted to memory management logic only to prevent
unwanted abuse).

We ensure that zapping performed by MADV_DONTNEED and MADV_FREE do not
remove guard markers, nor does forking (except when VM_WIPEONFORK is
specified for a VMA which implies a total removal of memory
characteristics).

It's important to note that the guard page implementation is emphatically
NOT a security feature, so a user can remove the markers if they wish.  We
simply implement it in such a way as to provide the least surprising
behaviour.

An extensive set of self-tests are provided which ensure behaviour is as
expected and additionally self-documents expected behaviour of guard
ranges.


This patch (of 5):

The existing generic pagewalk logic permits the walking of page tables,
invoking callbacks at individual page table levels via user-provided
mm_walk_ops callbacks.

This is useful for traversing existing page table entries, but precludes
the ability to establish new ones.

Existing mechanism for performing a walk which also installs page table
entries if necessary are heavily duplicated throughout the kernel, each
with semantic differences from one another and largely unavailable for use
elsewhere.

Rather than add yet another implementation, we extend the generic pagewalk
logic to enable the installation of page table entries by adding a new
install_pte() callback in mm_walk_ops.  If this is specified, then upon
encountering a missing page table entry, we allocate and install a new one
and continue the traversal.

If a THP huge page is encountered at either the PMD or PUD level we split
it only if there are ops->pte_entry() (or ops->pmd_entry at PUD level),
otherwise if there is only an ops->install_pte(), we avoid the unnecessary
split.

We do not support hugetlb at this stage.

If this function returns an error, or an allocation fails during the
operation, we abort the operation altogether.  It is up to the caller to
deal appropriately with partially populated page table ranges.

If install_pte() is defined, the semantics of pte_entry() change - this
callback is then only invoked if the entry already exists.  This is a
useful property, as it allows a caller to handle existing PTEs while
installing new ones where necessary in the specified range.

If install_pte() is not defined, then there is no functional difference to
this patch, so all existing logic will work precisely as it did before.

As we only permit the installation of PTEs where a mapping does not
already exist there is no need for TLB management, however we do invoke
update_mmu_cache() for architectures which require manual maintenance of
mappings for other CPUs.

We explicitly do not allow the existing page walk API to expose this
feature as it is dangerous and intended for internal mm use only. 
Therefore we provide a new walk_page_range_mm() function exposed only to
mm/internal.h.

We take the opportunity to additionally clean up the page walker logic to
be a little easier to follow.

Link: https://lkml.kernel.org/r/cover.1730123433.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/51b432ebef013e3fdf9f92101533435de1bffadf.1730123433.git.lorenzo.stoakes@oracle.com
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Jann Horn <jannh@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Vlastimil Babka <vbabka@suse.cz>
Suggested-by: Jann Horn <jannh@google.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Arnd Bergmann <arnd@kernel.org>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Chris Zankel <chris@zankel.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jeff Xu <jeffxu@chromium.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Sidhartha Kumar <sidhartha.kumar@oracle.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Vlastimil Babka <vbabkba@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-11 00:26:44 -08:00
Matthew Wilcox (Oracle)
68158bfa3d mm: mass constification of folio/page pointers
Now that page_pgoff() takes const pointers, we can constify the pointers
to a lot of functions.

Link: https://lkml.kernel.org/r/20241005200121.3231142-5-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:38:07 -08:00
Matthew Wilcox (Oracle)
713da0b33b mm: renovate page_address_in_vma()
This function doesn't modify any of its arguments, so if we make a few
other functions take const pointers, we can make page_address_in_vma()
take const pointers too.  All of its callers have the containing folio
already, so pass that in as an argument instead of recalculating it.  Also
add kernel-doc

Link: https://lkml.kernel.org/r/20241005200121.3231142-4-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:38:07 -08:00
Suren Baghdasaryan
0f9b685626 alloc_tag: populate memory for module tags as needed
The memory reserved for module tags does not need to be backed by physical
pages until there are tags to store there.  Change the way we reserve this
memory to allocate only virtual area for the tags and populate it with
physical pages as needed when we load a module.

[surenb@google.com: avoid execmem_vmap() when !MMU]
  Link: https://lkml.kernel.org/r/20241031233611.3833002-1-surenb@google.com
Link: https://lkml.kernel.org/r/20241023170759.999909-5-surenb@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Pasha Tatashin <pasha.tatashin@soleen.com>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Daniel Gomez <da.gomez@samsung.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: David Rientjes <rientjes@google.com>
Cc: Dennis Zhou <dennis@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Luis Chamberlain <mcgrof@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Minchan Kim <minchan@google.com>
Cc: Paul E. McKenney <paulmck@kernel.org>
Cc: Petr Pavlu <petr.pavlu@suse.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Sami Tolvanen <samitolvanen@google.com>
Cc: Sourav Panda <souravpanda@google.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Thomas Huth <thuth@redhat.com>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Xiongwei Song <xiongwei.song@windriver.com>
Cc: Yu Zhao <yuzhao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:16 -08:00
Mike Rapoport (Microsoft)
2e45474ab1 execmem: add support for cache of large ROX pages
Using large pages to map text areas reduces iTLB pressure and improves
performance.

Extend execmem_alloc() with an ability to use huge pages with ROX
permissions as a cache for smaller allocations.

To populate the cache, a writable large page is allocated from vmalloc
with VM_ALLOW_HUGE_VMAP, filled with invalid instructions and then
remapped as ROX.

The direct map alias of that large page is exculded from the direct map.

Portions of that large page are handed out to execmem_alloc() callers
without any changes to the permissions.

When the memory is freed with execmem_free() it is invalidated again so
that it won't contain stale instructions.

An architecture has to implement execmem_fill_trapping_insns() callback
and select ARCH_HAS_EXECMEM_ROX configuration option to be able to use the
ROX cache.

The cache is enabled on per-range basis when an architecture sets
EXECMEM_ROX_CACHE flag in definition of an execmem_range.

Link: https://lkml.kernel.org/r/20241023162711.2579610-8-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Luis Chamberlain <mcgrof@kernel.org>
Tested-by: kdevops <kdevops@lists.linux.dev>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Brian Cain <bcain@quicinc.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Guo Ren <guoren@kernel.org>
Cc: Helge Deller <deller@gmx.de>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Liam R. Howlett <Liam.Howlett@Oracle.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Richard Weinberger <richard@nod.at>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Song Liu <song@kernel.org>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Steven Rostedt (Google) <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Uladzislau Rezki (Sony) <urezki@gmail.com>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-07 14:25:16 -08:00
Zi Yan
5708d96da2 mm: avoid zeroing user movable page twice with init_on_alloc=1
Commit 6471384af2 ("mm: security: introduce init_on_alloc=1 and
init_on_free=1 boot options") forces allocated page to be zeroed in
post_alloc_hook() when init_on_alloc=1.

For order-0 folios, if arch does not define
vma_alloc_zeroed_movable_folio(), the default implementation again zeros
the page return from the buddy allocator.  So the page is zeroed twice. 
Fix it by passing __GFP_ZERO instead to avoid double page zeroing.  At the
moment, s390,arm64,x86,alpha,m68k are not impacted since they define their
own vma_alloc_zeroed_movable_folio().

For >0 order folios (mTHP and PMD THP), folio_zero_user() is called to
zero the folio again.  Fix it by calling folio_zero_user() only if
init_on_alloc is set.  All arch are impacted.

Add alloc_zeroed() helper to encapsulate the init_on_alloc check.

[ziy@nvidia.com: comment fixes, per David]
  Link: https://lkml.kernel.org/r/97DB52E1-C594-49B5-9736-89AC302FAB01@nvidia.com
Link: https://lkml.kernel.org/r/20241011150304.709590-1-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: "Huang, Ying" <ying.huang@intel.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:13 -08:00
Matthew Wilcox (Oracle)
b9a256352f mm: remove PageKsm()
All callers have been converted to use folio_test_ksm() or
PageAnonNotKsm(), so we can remove this wrapper.

Link: https://lkml.kernel.org/r/20241002152533.1350629-6-willy@infradead.org
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Alex Shi <alexs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-06 20:11:08 -08:00
Lorenzo Stoakes
4080ef1579 mm: unconditionally close VMAs on error
Incorrect invocation of VMA callbacks when the VMA is no longer in a
consistent state is bug prone and risky to perform.

With regards to the important vm_ops->close() callback We have gone to
great lengths to try to track whether or not we ought to close VMAs.

Rather than doing so and risking making a mistake somewhere, instead
unconditionally close and reset vma->vm_ops to an empty dummy operations
set with a NULL .close operator.

We introduce a new function to do so - vma_close() - and simplify existing
vms logic which tracked whether we needed to close or not.

This simplifies the logic, avoids incorrect double-calling of the .close()
callback and allows us to update error paths to simply call vma_close()
unconditionally - making VMA closure idempotent.

Link: https://lkml.kernel.org/r/28e89dda96f68c505cb6f8e9fc9b57c3e9f74b42.1730224667.git.lorenzo.stoakes@oracle.com
Fixes: deb0f65628 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:49:55 -08:00
Lorenzo Stoakes
3dd6ed34ce mm: avoid unsafe VMA hook invocation when error arises on mmap hook
Patch series "fix error handling in mmap_region() and refactor
(hotfixes)", v4.

mmap_region() is somewhat terrifying, with spaghetti-like control flow and
numerous means by which issues can arise and incomplete state, memory
leaks and other unpleasantness can occur.

A large amount of the complexity arises from trying to handle errors late
in the process of mapping a VMA, which forms the basis of recently
observed issues with resource leaks and observable inconsistent state.

This series goes to great lengths to simplify how mmap_region() works and
to avoid unwinding errors late on in the process of setting up the VMA for
the new mapping, and equally avoids such operations occurring while the
VMA is in an inconsistent state.

The patches in this series comprise the minimal changes required to
resolve existing issues in mmap_region() error handling, in order that
they can be hotfixed and backported.  There is additionally a follow up
series which goes further, separated out from the v1 series and sent and
updated separately.


This patch (of 5):

After an attempted mmap() fails, we are no longer in a situation where we
can safely interact with VMA hooks.  This is currently not enforced,
meaning that we need complicated handling to ensure we do not incorrectly
call these hooks.

We can avoid the whole issue by treating the VMA as suspect the moment
that the file->f_ops->mmap() function reports an error by replacing
whatever VMA operations were installed with a dummy empty set of VMA
operations.

We do so through a new helper function internal to mm - mmap_file() -
which is both more logically named than the existing call_mmap() function
and correctly isolates handling of the vm_op reassignment to mm.

All the existing invocations of call_mmap() outside of mm are ultimately
nested within the call_mmap() from mm, which we now replace.

It is therefore safe to leave call_mmap() in place as a convenience
function (and to avoid churn).  The invokers are:

     ovl_file_operations -> mmap -> ovl_mmap() -> backing_file_mmap()
    coda_file_operations -> mmap -> coda_file_mmap()
     shm_file_operations -> shm_mmap()
shm_file_operations_huge -> shm_mmap()
            dma_buf_fops -> dma_buf_mmap_internal -> i915_dmabuf_ops
	                    -> i915_gem_dmabuf_mmap()

None of these callers interact with vm_ops or mappings in a problematic
way on error, quickly exiting out.

Link: https://lkml.kernel.org/r/cover.1730224667.git.lorenzo.stoakes@oracle.com
Link: https://lkml.kernel.org/r/d41fd763496fd0048a962f3fd9407dc72dd4fd86.1730224667.git.lorenzo.stoakes@oracle.com
Fixes: deb0f65628 ("mm/mmap: undo ->mmap() when arch_validate_flags() fails")
Signed-off-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reported-by: Jann Horn <jannh@google.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Jann Horn <jannh@google.com>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Helge Deller <deller@gmx.de>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mark Brown <broonie@kernel.org>
Cc: Peter Xu <peterx@redhat.com>
Cc: Will Deacon <will@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:49:54 -08:00
Hugh Dickins
f8f931bba0 mm/thp: fix deferred split unqueue naming and locking
Recent changes are putting more pressure on THP deferred split queues:
under load revealing long-standing races, causing list_del corruptions,
"Bad page state"s and worse (I keep BUGs in both of those, so usually
don't get to see how badly they end up without).  The relevant recent
changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin,
improved swap allocation, and underused THP splitting.

Before fixing locking: rename misleading folio_undo_large_rmappable(),
which does not undo large_rmappable, to folio_unqueue_deferred_split(),
which is what it does.  But that and its out-of-line __callee are mm
internals of very limited usability: add comment and WARN_ON_ONCEs to
check usage; and return a bool to say if a deferred split was unqueued,
which can then be used in WARN_ON_ONCEs around safety checks (sparing
callers the arcane conditionals in __folio_unqueue_deferred_split()).

Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all
of whose callers now call it beforehand (and if any forget then bad_page()
will tell) - except for its caller put_pages_list(), which itself no
longer has any callers (and will be deleted separately).

Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0
without checking and unqueueing a THP folio from deferred split list;
which is unfortunate, since the split_queue_lock depends on the memcg
(when memcg is enabled); so swapout has been unqueueing such THPs later,
when freeing the folio, using the pgdat's lock instead: potentially
corrupting the memcg's list.  __remove_mapping() has frozen refcount to 0
here, so no problem with calling folio_unqueue_deferred_split() before
resetting memcg_data.

That goes back to 5.4 commit 87eaceb3fa ("mm: thp: make deferred split
shrinker memcg aware"): which included a check on swapcache before adding
to deferred queue, but no check on deferred queue before adding THP to
swapcache.  That worked fine with the usual sequence of events in reclaim
(though there were a couple of rare ways in which a THP on deferred queue
could have been swapped out), but 6.12 commit dafff3f4c8 ("mm: split
underused THPs") avoids splitting underused THPs in reclaim, which makes
swapcache THPs on deferred queue commonplace.

Keep the check on swapcache before adding to deferred queue?  Yes: it is
no longer essential, but preserves the existing behaviour, and is likely
to be a worthwhile optimization (vmstat showed much more traffic on the
queue under swapping load if the check was removed); update its comment.

Memcg-v1 move (deprecated): mem_cgroup_move_account() has been changing
folio->memcg_data without checking and unqueueing a THP folio from the
deferred list, sometimes corrupting "from" memcg's list, like swapout. 
Refcount is non-zero here, so folio_unqueue_deferred_split() can only be
used in a WARN_ON_ONCE to validate the fix, which must be done earlier:
mem_cgroup_move_charge_pte_range() first try to split the THP (splitting
of course unqueues), or skip it if that fails.  Not ideal, but moving
charge has been requested, and khugepaged should repair the THP later:
nobody wants new custom unqueueing code just for this deprecated case.

The 87eaceb3fa commit did have the code to move from one deferred list
to another (but was not conscious of its unsafety while refcount non-0);
but that was removed by 5.6 commit fac0516b55 ("mm: thp: don't need care
deferred split queue in memcg charge move path"), which argued that the
existence of a PMD mapping guarantees that the THP cannot be on a deferred
list.  As above, false in rare cases, and now commonly false.

Backport to 6.11 should be straightforward.  Earlier backports must take
care that other _deferred_list fixes and dependencies are included.  There
is not a strong case for backports, but they can fix cornercases.

Link: https://lkml.kernel.org/r/8dc111ae-f6db-2da7-b25c-7a20b1effe3b@google.com
Fixes: 87eaceb3fa ("mm: thp: make deferred split shrinker memcg aware")
Fixes: dafff3f4c8 ("mm: split underused THPs")
Signed-off-by: Hugh Dickins <hughd@google.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Yang Shi <shy828301@gmail.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kefeng Wang <wangkefeng.wang@huawei.com>
Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Wei Yang <richard.weiyang@gmail.com>
Cc: Zi Yan <ziy@nvidia.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-11-05 16:49:54 -08:00
Linus Torvalds
617a814f14 ALong with the usual shower of singleton patches, notable patch series in
this pull request are:
 
 "Align kvrealloc() with krealloc()" from Danilo Krummrich.  Adds
 consistency to the APIs and behaviour of these two core allocation
 functions.  This also simplifies/enables Rustification.
 
 "Some cleanups for shmem" from Baolin Wang.  No functional changes - mode
 code reuse, better function naming, logic simplifications.
 
 "mm: some small page fault cleanups" from Josef Bacik.  No functional
 changes - code cleanups only.
 
 "Various memory tiering fixes" from Zi Yan.  A small fix and a little
 cleanup.
 
 "mm/swap: remove boilerplate" from Yu Zhao.  Code cleanups and
 simplifications and .text shrinkage.
 
 "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt.  This
 is a feature, it adds new feilds to /proc/vmstat such as
 
     $ grep kstack /proc/vmstat
     kstack_1k 3
     kstack_2k 188
     kstack_4k 11391
     kstack_8k 243
     kstack_16k 0
 
 which tells us that 11391 processes used 4k of stack while none at all
 used 16k.  Useful for some system tuning things, but partivularly useful
 for "the dynamic kernel stack project".
 
 "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov.
 Teaches kmemleak to detect leaksage of percpu memory.
 
 "mm: memcg: page counters optimizations" from Roman Gushchin.  "3
 independent small optimizations of page counters".
 
 "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David
 Hildenbrand.  Improves PTE/PMD splitlock detection, makes powerpc/8xx work
 correctly by design rather than by accident.
 
 "mm: remove arch_make_page_accessible()" from David Hildenbrand.  Some
 folio conversions which make arch_make_page_accessible() unneeded.
 
 "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel.
 Cleans up and fixes our handling of the resetting of the cgroup/process
 peak-memory-use detector.
 
 "Make core VMA operations internal and testable" from Lorenzo Stoakes.
 Rationalizaion and encapsulation of the VMA manipulation APIs.  With a
 view to better enable testing of the VMA functions, even from a
 userspace-only harness.
 
 "mm: zswap: fixes for global shrinker" from Takero Funaki.  Fix issues in
 the zswap global shrinker, resulting in improved performance.
 
 "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao.  Fill in
 some missing info in /proc/zoneinfo.
 
 "mm: replace follow_page() by folio_walk" from David Hildenbrand.  Code
 cleanups and rationalizations (conversion to folio_walk()) resulting in
 the removal of follow_page().
 
 "improving dynamic zswap shrinker protection scheme" from Nhat Pham.  Some
 tuning to improve zswap's dynamic shrinker.  Significant reductions in
 swapin and improvements in performance are shown.
 
 "mm: Fix several issues with unaccepted memory" from Kirill Shutemov.
 Improvements to the new unaccepted memory feature,
 
 "mm/mprotect: Fix dax puds" from Peter Xu.  Implements mprotect on DAX
 PUDs.  This was missing, although nobody seems to have notied yet.
 
 "Introduce a store type enum for the Maple tree" from Sidhartha Kumar.
 Cleanups and modest performance improvements for the maple tree library
 code.
 
 "memcg: further decouple v1 code from v2" from Shakeel Butt.  Move more
 cgroup v1 remnants away from the v2 memcg code.
 
 "memcg: initiate deprecation of v1 features" from Shakeel Butt.  Adds
 various warnings telling users that memcg v1 features are deprecated.
 
 "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li.
 Greatly improves the success rate of the mTHP swap allocation.
 
 "mm: introduce numa_memblks" from Mike Rapoport.  Moves various disparate
 per-arch implementations of numa_memblk code into generic code.
 
 "mm: batch free swaps for zap_pte_range()" from Barry Song.  Greatly
 improves the performance of munmap() of swap-filled ptes.
 
 "support large folio swap-out and swap-in for shmem" from Baolin Wang.
 With this series we no longer split shmem large folios into simgle-page
 folios when swapping out shmem.
 
 "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao.  Nice performance
 improvements and code reductions for gigantic folios.
 
 "support shmem mTHP collapse" from Baolin Wang.  Adds support for
 khugepaged's collapsing of shmem mTHP folios.
 
 "mm: Optimize mseal checks" from Pedro Falcato.  Fixes an mprotect()
 performance regression due to the addition of mseal().
 
 "Increase the number of bits available in page_type" from Matthew Wilcox.
 Increases the number of bits available in page_type!
 
 "Simplify the page flags a little" from Matthew Wilcox.  Many legacy page
 flags are now folio flags, so the page-based flags and their
 accessors/mutators can be removed.
 
 "mm: store zero pages to be swapped out in a bitmap" from Usama Arif.  An
 optimization which permits us to avoid writing/reading zero-filled zswap
 pages to backing store.
 
 "Avoid MAP_FIXED gap exposure" from Liam Howlett.  Fixes a race window
 which occurs when a MAP_FIXED operqtion is occurring during an unrelated
 vma tree walk.
 
 "mm: remove vma_merge()" from Lorenzo Stoakes.  Major rotorooting of the
 vma_merge() functionality, making ot cleaner, more testable and better
 tested.
 
 "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.  Minor
 fixups of DAMON selftests and kunit tests.
 
 "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.  Code
 cleanups and folio conversions.
 
 "Shmem mTHP controls and stats improvements" from Ryan Roberts.  Cleanups
 for shmem controls and stats.
 
 "mm: count the number of anonymous THPs per size" from Barry Song.  Expose
 additional anon THP stats to userspace for improved tuning.
 
 "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio
 conversions and removal of now-unused page-based APIs.
 
 "replace per-quota region priorities histogram buffer with per-context
 one" from SeongJae Park.  DAMON histogram rationalization.
 
 "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae
 Park.  DAMON documentation updates.
 
 "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve
 related doc and warn" from Jason Wang: fixes usage of page allocator
 __GFP_NOFAIL and GFP_ATOMIC flags.
 
 "mm: split underused THPs" from Yu Zhao.  Improve THP=always policy - this
 was overprovisioning THPs in sparsely accessed memory areas.
 
 "zram: introduce custom comp backends API" frm Sergey Senozhatsky.  Add
 support for zram run-time compression algorithm tuning.
 
 "mm: Care about shadow stack guard gap when getting an unmapped area" from
 Mark Brown.  Fix up the various arch_get_unmapped_area() implementations
 to better respect guard areas.
 
 "Improve mem_cgroup_iter()" from Kinsey Ho.  Improve the reliability of
 mem_cgroup_iter() and various code cleanups.
 
 "mm: Support huge pfnmaps" from Peter Xu.  Extends the usage of huge
 pfnmap support.
 
 "resource: Fix region_intersects() vs add_memory_driver_managed()" from
 Huang Ying.  Fix a bug in region_intersects() for systems with CXL memory.
 
 "mm: hwpoison: two more poison recovery" from Kefeng Wang.  Teaches a
 couple more code paths to correctly recover from the encountering of
 poisoned memry.
 
 "mm: enable large folios swap-in support" from Barry Song.  Support the
 swapin of mTHP memory into appropriately-sized folios, rather than into
 single-page folios.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYIAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCZu1BBwAKCRDdBJ7gKXxA
 jlWNAQDYlqQLun7bgsAN4sSvi27VUuWv1q70jlMXTfmjJAvQqwD/fBFVR6IOOiw7
 AkDbKWP2k0hWPiNJBGwoqxdHHx09Xgo=
 =s0T+
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Along with the usual shower of singleton patches, notable patch series
  in this pull request are:

   - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds
     consistency to the APIs and behaviour of these two core allocation
     functions. This also simplifies/enables Rustification.

   - "Some cleanups for shmem" from Baolin Wang. No functional changes -
     mode code reuse, better function naming, logic simplifications.

   - "mm: some small page fault cleanups" from Josef Bacik. No
     functional changes - code cleanups only.

   - "Various memory tiering fixes" from Zi Yan. A small fix and a
     little cleanup.

   - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and
     simplifications and .text shrinkage.

   - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel
     Butt. This is a feature, it adds new feilds to /proc/vmstat such as

       $ grep kstack /proc/vmstat
       kstack_1k 3
       kstack_2k 188
       kstack_4k 11391
       kstack_8k 243
       kstack_16k 0

     which tells us that 11391 processes used 4k of stack while none at
     all used 16k. Useful for some system tuning things, but
     partivularly useful for "the dynamic kernel stack project".

   - "kmemleak: support for percpu memory leak detect" from Pavel
     Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory.

   - "mm: memcg: page counters optimizations" from Roman Gushchin. "3
     independent small optimizations of page counters".

   - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from
     David Hildenbrand. Improves PTE/PMD splitlock detection, makes
     powerpc/8xx work correctly by design rather than by accident.

   - "mm: remove arch_make_page_accessible()" from David Hildenbrand.
     Some folio conversions which make arch_make_page_accessible()
     unneeded.

   - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David
     Finkel. Cleans up and fixes our handling of the resetting of the
     cgroup/process peak-memory-use detector.

   - "Make core VMA operations internal and testable" from Lorenzo
     Stoakes. Rationalizaion and encapsulation of the VMA manipulation
     APIs. With a view to better enable testing of the VMA functions,
     even from a userspace-only harness.

   - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix
     issues in the zswap global shrinker, resulting in improved
     performance.

   - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill
     in some missing info in /proc/zoneinfo.

   - "mm: replace follow_page() by folio_walk" from David Hildenbrand.
     Code cleanups and rationalizations (conversion to folio_walk())
     resulting in the removal of follow_page().

   - "improving dynamic zswap shrinker protection scheme" from Nhat
     Pham. Some tuning to improve zswap's dynamic shrinker. Significant
     reductions in swapin and improvements in performance are shown.

   - "mm: Fix several issues with unaccepted memory" from Kirill
     Shutemov. Improvements to the new unaccepted memory feature,

   - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on
     DAX PUDs. This was missing, although nobody seems to have notied
     yet.

   - "Introduce a store type enum for the Maple tree" from Sidhartha
     Kumar. Cleanups and modest performance improvements for the maple
     tree library code.

   - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move
     more cgroup v1 remnants away from the v2 memcg code.

   - "memcg: initiate deprecation of v1 features" from Shakeel Butt.
     Adds various warnings telling users that memcg v1 features are
     deprecated.

   - "mm: swap: mTHP swap allocator base on swap cluster order" from
     Chris Li. Greatly improves the success rate of the mTHP swap
     allocation.

   - "mm: introduce numa_memblks" from Mike Rapoport. Moves various
     disparate per-arch implementations of numa_memblk code into generic
     code.

   - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly
     improves the performance of munmap() of swap-filled ptes.

   - "support large folio swap-out and swap-in for shmem" from Baolin
     Wang. With this series we no longer split shmem large folios into
     simgle-page folios when swapping out shmem.

   - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice
     performance improvements and code reductions for gigantic folios.

   - "support shmem mTHP collapse" from Baolin Wang. Adds support for
     khugepaged's collapsing of shmem mTHP folios.

   - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect()
     performance regression due to the addition of mseal().

   - "Increase the number of bits available in page_type" from Matthew
     Wilcox. Increases the number of bits available in page_type!

   - "Simplify the page flags a little" from Matthew Wilcox. Many legacy
     page flags are now folio flags, so the page-based flags and their
     accessors/mutators can be removed.

   - "mm: store zero pages to be swapped out in a bitmap" from Usama
     Arif. An optimization which permits us to avoid writing/reading
     zero-filled zswap pages to backing store.

   - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race
     window which occurs when a MAP_FIXED operqtion is occurring during
     an unrelated vma tree walk.

   - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of
     the vma_merge() functionality, making ot cleaner, more testable and
     better tested.

   - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park.
     Minor fixups of DAMON selftests and kunit tests.

   - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang.
     Code cleanups and folio conversions.

   - "Shmem mTHP controls and stats improvements" from Ryan Roberts.
     Cleanups for shmem controls and stats.

   - "mm: count the number of anonymous THPs per size" from Barry Song.
     Expose additional anon THP stats to userspace for improved tuning.

   - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more
     folio conversions and removal of now-unused page-based APIs.

   - "replace per-quota region priorities histogram buffer with
     per-context one" from SeongJae Park. DAMON histogram
     rationalization.

   - "Docs/damon: update GitHub repo URLs and maintainer-profile" from
     SeongJae Park. DAMON documentation updates.

   - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and
     improve related doc and warn" from Jason Wang: fixes usage of page
     allocator __GFP_NOFAIL and GFP_ATOMIC flags.

   - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy.
     This was overprovisioning THPs in sparsely accessed memory areas.

   - "zram: introduce custom comp backends API" frm Sergey Senozhatsky.
     Add support for zram run-time compression algorithm tuning.

   - "mm: Care about shadow stack guard gap when getting an unmapped
     area" from Mark Brown. Fix up the various arch_get_unmapped_area()
     implementations to better respect guard areas.

   - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability
     of mem_cgroup_iter() and various code cleanups.

   - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge
     pfnmap support.

   - "resource: Fix region_intersects() vs add_memory_driver_managed()"
     from Huang Ying. Fix a bug in region_intersects() for systems with
     CXL memory.

   - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches
     a couple more code paths to correctly recover from the encountering
     of poisoned memry.

   - "mm: enable large folios swap-in support" from Barry Song. Support
     the swapin of mTHP memory into appropriately-sized folios, rather
     than into single-page folios"

* tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits)
  zram: free secondary algorithms names
  uprobes: turn xol_area->pages[2] into xol_area->page
  uprobes: introduce the global struct vm_special_mapping xol_mapping
  Revert "uprobes: use vm_special_mapping close() functionality"
  mm: support large folios swap-in for sync io devices
  mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios
  mm: fix swap_read_folio_zeromap() for large folios with partial zeromap
  mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries
  set_memory: add __must_check to generic stubs
  mm/vma: return the exact errno in vms_gather_munmap_vmas()
  memcg: cleanup with !CONFIG_MEMCG_V1
  mm/show_mem.c: report alloc tags in human readable units
  mm: support poison recovery from copy_present_page()
  mm: support poison recovery from do_cow_fault()
  resource, kunit: add test case for region_intersects()
  resource: make alloc_free_mem_region() works for iomem_resource
  mm: z3fold: deprecate CONFIG_Z3FOLD
  vfio/pci: implement huge_fault support
  mm/arm64: support large pfn mappings
  mm/x86: support large pfn mappings
  ...
2024-09-21 07:29:05 -07:00
Vishal Moola (Oracle)
2a058ab328 mm: change vmf_anon_prepare() to __vmf_anon_prepare()
Some callers of vmf_anon_prepare() may not want us to release the per-VMA
lock ourselves.  Rename vmf_anon_prepare() to __vmf_anon_prepare() and let
the callers drop the lock when desired.

Also, make vmf_anon_prepare() a wrapper that releases the per-VMA lock
itself for any callers that don't care.

This is in preparation to fix this bug reported by syzbot:
https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/

Link: https://lkml.kernel.org/r/20240914194243.245-1-vishal.moola@gmail.com
Fixes: 9acad7ba3e ("hugetlb: use vmf_anon_prepare() instead of anon_vma_prepare()")
Reported-by: syzbot+2dab93857ee95f2eeb08@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-mm/00000000000067c20b06219fbc26@google.com/
Signed-off-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-17 00:58:04 -07:00
Kefeng Wang
24f937796c mm: remove putback_lru_page()
There are no more callers of putback_lru_page(), remove it.

Link: https://lkml.kernel.org/r/20240826065814.1336616-7-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:38:59 -07:00
Kefeng Wang
775d28fd45 mm: remove isolate_lru_page()
There are no more callers of isolate_lru_page(), remove it.

[wangkefeng.wang@huawei.com: convert page to folio in comment and document, per Matthew]
  Link: https://lkml.kernel.org/r/20240826144114.1928071-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-6-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:38:59 -07:00
Kefeng Wang
5c8525a37b mm: migrate_device: convert to migrate_device_coherent_folio()
Patch series "mm: finish isolate/putback_lru_page()".

Convert to use more folios in migrate_device.c, then we could remove
isolate_lru_page() and putback_lru_page().  


This patch (of 6):

Save a few calls to compound_head() and use folio throughout.

Link: https://lkml.kernel.org/r/20240826065814.1336616-1-wangkefeng.wang@huawei.com
Link: https://lkml.kernel.org/r/20240826065814.1336616-2-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Vishal Moola (Oracle) <vishal.moola@gmail.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Zi Yan <ziy@nvidia.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-09 16:38:58 -07:00
Kefeng Wang
16038c4fff mm: memory-failure: add unmap_poisoned_folio()
Add unmap_poisoned_folio() helper which will be reused by
do_migrate_range() from memory hotplug soon.

[akpm@linux-foundation.org: whitespace tweak, per Miaohe Lin]
  Link: https://lkml.kernel.org/r/1f80c7e3-c30d-1ac1-6a36-d1a5f5907f7c@huawei.com
Link: https://lkml.kernel.org/r/20240827114728.3212578-3-wangkefeng.wang@huawei.com
Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Jonathan Cameron <Jonathan.Cameron@huawei.com>
Cc: Naoya Horiguchi <nao.horiguchi@gmail.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2024-09-03 21:15:59 -07:00