linux/Documentation/core-api
Linus Torvalds 18fbf5151d mm.git review status for linus..mm-stable
Everything:
 
 Total patches:       171
 Reviews/patch:       1.83
 Reviewed rate:       82%
 
 Excluding selftests:
 
 Total patches:       149
 Reviews/patch:       1.77
 Reviewed rate:       80%
 
 Excluding selftests and maple_tree:
 
 Total patches:       129
 Reviews/patch:       1.99
 Reviewed rate:       89%
 
 Summary of patch series in this merge:
 
 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes):
 
   Index MAP_PRIVATE file-backed folios by their anonymous page offset to
   resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.
 
   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.
 
 - "promote mapped executable folios after first usage for MGLRU" (Baolin
   Wang):
 
   Make MGLRU's protection of mapped executable file folios more
   reliable.  Follow the classical LRU's logic, promoting mapped executable
   file folios after their first usage to give executable code a better
   chance to stay in memory and improve workload performance.
 
 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong Chen):
 
   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating sc_swappiness()
   into a single function that checks proactive_swappiness regardless of
   kernel configuration.
 
 - "mm/vmscan: reduce lru_lock contention via vmstat-derived scan-balance
   cost" (Usama Arif):
 
   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.
 
   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over 60%
   without impacting scan throughput.
 
 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky):
 
   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.
 
 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan):
 
   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray node
   memory accounting.
 
 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick):
 
   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.
 
 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon):
 
   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.
 
 - "zram: fix zstd error paths and add parameter validation" (Haoqin Huang):
 
   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.
 
 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia):
 
   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in writeback_store()
   and read_block_state().
 
 - "add anon mTHP collapse test cases" (Baolin Wang):
 
   Extend selftests helper functions to support arbitrary page orders and
   add new test cases and options for mTHP collapse in khugepaged.
 
 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum):
 
   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.
 
 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia):
 
   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.
 
 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren Baghdasaryan):
 
   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.
 
   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.
 
 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig):
 
   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving faster
   swap throughput during kernel builds.
 
 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas):
 
   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.
 
 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao):
 
   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second confirming
   scan.
 
 - "swap_ops updates" (Christoph Hellwig):
 
   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead.  This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly export
   their own swap_ops.
 
 - "mm/khugepaged: several cleanups" (Nico Pache):
 
   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration.  Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.
 
 - "maple_tree: lock checking and clean ups" (Liam Howlett):
 
   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.
 
   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to GFP_KERNEL
   | GFP_NOFAIL.
 -----BEGIN PGP SIGNATURE-----
 
 iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCao9nJQAKCRDdBJ7gKXxA
 jk/9AQDlfevYJuSJmzAI8bt8ISG+/TfXMtIZC/MdbHqtQVYWPQD8Cvm3DUZsdGB/
 Gloq/HBFuMPgE8p2pwUIthdgnTPNvAc=
 =c+Nb
 -----END PGP SIGNATURE-----

Merge tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull more MM updates from Andrew Morton:

 - "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
   (Lorenzo Stoakes)

   Index MAP_PRIVATE file-backed folios by their anonymous page offset
   to resolve confusion around reverse mapping for zeroed and CoW'd
   file-backed memory.

   Use this new VMA anonymous page offset tracking to eliminate index
   conflicts and lay the foundation for scalable CoW performance
   improvements.

 - "promote mapped executable folios after first usage for MGLRU"
   (Baolin Wang)

   Make MGLRU's protection of mapped executable file folios more
   reliable. Follow the classical LRU's logic, promoting mapped
   executable file folios after their first usage to give executable
   code a better chance to stay in memory and improve workload
   performance.

 - "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
   Chen)

   Fix per-node proactive reclaim interface's ignoring the swappiness
   parameter when CONFIG_MEMCG is disabled by consolidating
   sc_swappiness() into a single function that checks
   proactive_swappiness regardless of kernel configuration.

 - "mm/vmscan: reduce lru_lock contention via vmstat-derived
   scan-balance cost" (Usama Arif)

   Reduce lru_lock contention in the reclaim path by deriving
   scan-balance costs from vmstat counters rather than lock-acquired
   producer updates.

   Read and decay these cost signals on the reclaim side under a
   dedicated per-lruvec lock, reducing total LRU lock wait time by over
   60% without impacting scan throughput.

 - "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)

   Fix two low-risk zram bugs which Sashiko spotted in drive-by review.

 - "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
   memcg" (Zi Yan)

   Fix xas_split_alloc() by enabling target folio memcg charging during
   splits and adding the missing __GFP_ACCOUNT flag for proper XArray
   node memory accounting.

 - "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)

   Replace hardcoded binary names in selftests/mm/.gitignore with a
   generic pattern-matching rule to automatically ignore generated test
   files and avoid manual updates when adding new tests.

 - "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)

   Make the incompatibility between FLATMEM and NUMA explicit in
   mm/Kconfig and remove the unused pgdat_page_ext_init() function.

 - "zram: fix zstd error paths and add parameter validation" (Haoqin
   Huang)

   Clean up zram compression backends by removing redundant error
   cleanup, adding parameter and dictionary validation, auto-prefixing
   algorithm error logs, and resetting parameters prior to
   reinitialization.

 - "zram: fix stale scan bounds after reinitialization" (Longlong Xia)

   Prevent out-of-bounds slot accesses during concurrent zram resets by
   moving table scan bound calculations under dev_lock in
   writeback_store() and read_block_state().

 - "add anon mTHP collapse test cases" (Baolin Wang)

   Extend selftests helper functions to support arbitrary page orders
   and add new test cases and options for mTHP collapse in khugepaged.

 - "selftests/mm: Handle unsupported and transient test conditions"
   (Muhammad Usama Anjum)

   Update MM selftests to report a SKIP status instead of a failure when
   required kernel or filesystem features are unsupported, while adding
   retry logic for transient page migration errors.

 - "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)

   Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
   and extend shrink_memcg() to support batch writeback for improved
   writeback efficiency.

 - "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
   Baghdasaryan)

   Introduce an IOCTL-based binary interface for memory allocation
   profiling that enables kernel-side filtering before per-CPU counter
   aggregation.

   This eliminates the text-parsing overhead of /proc/allocinfo and
   provides up to a 20x speedup by transferring only filtered allocation
   data to userspace.

 - "better block swap batching and a different take on swap_ops v5"
   (Christoph Hellwig)

   Refactor block swap I/O to use swap_iocb for batching instead of
   single-bio requests and rebase the swap_ops interface, achieving
   faster swap throughput during kernel builds.

 - "mm: kmemleak: reduce transient false positives by confirming leaks"
   (Catalin Marinas)

   Reduce false-positive kmemleak reports by combining two kmemleak
   enhancements that add a second confirmation scan and a configurable
   minimum unreferenced scan count module parameter.

 - "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
   (Breno Leitao)

   Auto-scanning kernels can generate false-positive memory leak reports
   on single scans, so this patch defaults min_unref_scans to 2 when
   CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
   confirming scan.

 - "swap_ops updates" (Christoph Hellwig)

   Batching I/O for synchronous swap devices causes performance
   regressions and filesystem-based swap suffers from double-indirection
   overhead. This series resolves both issues by reintroducing per-folio
   writes for synchronous swap and allowing filesystems to directly
   export their own swap_ops.

 - "mm/khugepaged: several cleanups" (Nico Pache)

   khugepaged accumulated redundant state-checking patterns and outdated
   comments following mTHP integration. Introduce dedicated helpers for
   PTE validation and event counting while refreshing the internal
   documentation.

 - "maple_tree: lock checking and clean ups" (Liam Howlett)

   Syzbot reports incorrectly blame memory management exit paths for
   locking bugs, maple tree erase operations risk allocation failures
   without gfp flags and internal documentation lacks clarity.

   Improve lock error detection, update docs, fix race and allocation
   edge cases and optimize erase allocations using a fallback to
   GFP_KERNEL | GFP_NOFAIL.

* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
  selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
  memcg: move LRU size accounting on reparenting instead of copying it
  mm/vmscan: fix comment logic in balance_pgdat
  maple_tree: add helper mas_make_walkable()
  maple_tree: avoid extra gap calculation
  maple_tree: fix argument name in header
  maple_tree: change two GFP flags in tests
  maple_tree: document erase and allocations better
  maple_tree: avoid mas_erase() and mtree_erase() failures
  maple_tree: document that erase may use GFP_KERNEL for allocations
  maple_tree: catch race in mas_alloc_cyclic()
  maple_tree: add bulk parent set helper
  maple_tree: micro optimisation of mas_wr_store_type()
  maple_tree: optimise mas_wr_node_store() when not in rcu mode
  maple_tree: use prefetched value in mas_wr_store_type()
  maple_tree: clarify comments on mas_nomem()
  maple_tree: drop MAPLE_ALLOC_SLOTS
  maple_tree: drop dead code from mas_extend_spanning_null()
  maple_tree: documentation fix
  maple_tree: add write lock checking with lockdep sequence numbers
  ...
2026-08-27 09:17:06 -07:00
..
irq Documentation: Add managed interrupts 2026-04-11 07:07:02 -06:00
kho kho: add support for linked-block serialization 2026-06-03 21:15:46 +03:00
real-time Documentation: Extend the real-time hardware bits with some firmware bits 2026-08-13 09:26:18 -06:00
wrappers docs: put atomic*.txt and memory-barriers.txt into the core-api book 2022-09-29 12:55:06 -06:00
asm-annotations.rst docs: move x86 documentation into Documentation/arch/ 2023-03-30 12:58:51 -06:00
assoc_array.rst Documentation: assoc_array: Format internal tree layout tables 2025-10-17 14:23:04 -06:00
boot-time-mm.rst docs/boot-time-mm: remove bootmem documentation 2018-10-31 08:54:16 -07:00
cachetlb.rst mm: remove ARCH_IMPLEMENTS_FLUSH_DCACHE_FOLIO 2023-08-24 16:20:19 -07:00
cgroup.rst doc/cgroup: Fix title underline length 2025-01-15 09:46:18 +01:00
circular-buffers.rst doc: Remove ".vnet" from paulmck email addresses 2019-05-28 09:02:57 -07:00
cleanup.rst cleanup: Add usage and style documentation 2024-08-05 16:54:41 +02:00
cpu_hotplug.rst Documentation: core-api/cpu_hotplug: Remove stale cpu0_hotplug docs 2026-05-15 08:44:24 -06:00
debug-objects.rst
debugging-via-ohci1394.rst Documentation: Drop or replace remaining mentions of IA64 2023-09-11 08:13:18 +00:00
dma-api-howto.rst docs: dma-api: document __dma_from_device_group_begin()/end() 2025-12-31 19:28:12 -05:00
dma-api.rst docs: dma-api: remove needless bracket 2026-07-15 10:51:28 -06:00
dma-attributes.rst dma-mapping: Add internal shared allocation attribute 2026-07-31 08:40:58 +02:00
dma-isa-lpc.rst docs: core-api: avoid using ReST :doc:foo markup 2021-06-17 13:24:37 -06:00
entry.rst entry, treewide: Make syscall_enter_from_user_mode[_work]() indicate syscall execution 2026-07-20 20:38:40 +02:00
errseq.rst errseq: add missing bracket 2026-07-15 10:51:28 -06:00
floating-point.rst arch: add ARCH_HAS_KERNEL_FPU_SUPPORT 2024-05-19 14:36:17 -07:00
folio_queue.rst docs: folio_queue: Fix minor typo in folio_queue page 2025-08-12 12:40:15 -06:00
genalloc.rst lib/genalloc.c: rename addr_in_gen_pool to gen_pool_has_addr 2019-12-04 19:44:13 -08:00
generic-radix-tree.rst generic radix trees 2019-03-12 10:04:02 -07:00
genericirq.rst treewide: Update email address 2026-01-11 06:09:11 -10:00
gfp_mask-from-fs-io.rst docs: core-api/gfp_mask-from-fs-io: indicate that vmalloc supports GFP_NOFS/GFP_NOIO 2024-11-22 10:42:37 -07:00
housekeeping.rst docs: housekeeping: Fix struct member access in code example 2026-05-15 08:25:16 -06:00
idr.rst IDR: Note that the IDR API is deprecated 2022-07-10 21:17:30 -04:00
index.rst Docs: SMP: add an SMP docbook chapter 2026-07-15 10:51:27 -06:00
kernel-api.rst block: Include bvec.h kernel-doc in the htmldocs 2026-05-29 05:34:25 -06:00
kobject.rst docs: Update documentation to avoid mentioning of kernel.h 2025-12-22 14:59:18 -07:00
kref.rst Documentation: adopt new coding style of type-aware kmalloc-family 2026-05-03 08:54:21 -06:00
librs.rst treewide: Update email address 2026-01-11 06:09:11 -10:00
list.rst Docs: list: Fix bracket 2026-07-15 10:51:27 -06:00
liveupdate.rst liveupdate: luo_flb: introduce File-Lifecycle-Bound global state 2026-02-08 00:13:33 -08:00
local_ops.rst timers: Update the documentation to reflect on the new timer_shutdown() API 2022-11-24 15:09:12 +01:00
maple_tree.rst maple_tree: document erase and allocations better 2026-08-24 18:43:31 -07:00
memory-allocation.rst docs/core-api: memory-allocation: GFP_NOWAIT doesn't need __GFP_NOWARN 2024-07-29 15:10:25 -06:00
memory-hotplug.rst docs: memory-hotplug: fix typo 'fo' -> 'for' in NODE_ADDED_FIRST_MEMORY description 2026-03-17 08:42:05 -06:00
min_heap.rst Documentation/core-api: min_heap: remove documented but unimplemented min_heap_empty() 2026-07-22 10:24:49 -06:00
mm-api.rst mm: rename swap.c to folio.c 2026-08-04 19:18:35 -07:00
netlink.rst doc/netlink: Update genetlink-legacy documentation 2023-08-27 17:17:09 -07:00
packing.rst docs: packing: fix brackets 2026-07-15 10:51:27 -06:00
padata.rst Documentation: core-api: padata: correct spelling 2023-02-16 16:58:01 -07:00
parser.rst Documentation: core-api: add generic parser docbook 2024-12-11 09:07:40 -07:00
pin_user_pages.rst mm: remove page_mkclean() 2024-07-03 19:30:17 -07:00
printk-basics.rst Documentation: printk: Add section about avoiding lockups 2026-03-17 08:37:49 -06:00
printk-formats.rst vsprintf: Add upper case flavour to %p[mM] 2026-06-12 14:20:25 +02:00
printk-index.rst docs:core-api: fixed typos and grammar in printk-index page 2024-05-07 08:01:11 -06:00
protection-keys.rst Documentation/protection-keys: add AArch64 to documentation 2024-10-14 17:27:48 +01:00
rbtree.rst Docs/core-api: fix typos in rbtree.rst 2026-02-14 10:11:43 -07:00
refcount-vs-atomic.rst refcount: provide ops for cases when object's memory can be reused 2025-03-16 22:06:19 -07:00
SMP.rst Docs: SMP: add an SMP docbook chapter 2026-07-15 10:51:27 -06:00
swiotlb.rst dma/swiotlb: introduce Kconfig option for compile-time default pool size 2026-07-17 09:15:38 +02:00
symbol-namespaces.rst docs: symbol-namespaces: mention sysfs attribute 2026-03-19 22:49:37 +00:00
this_cpu_ops.rst docs: Improve discussion of this_cpu_ptr(), add raw_cpu_ptr() 2025-02-04 21:50:06 -08:00
timekeeping.rst timekeeping: Introduce fast accessor to clock tai 2022-04-14 16:19:30 +02:00
tracepoint.rst
unaligned-memory-access.rst move asm/unaligned.h to linux/unaligned.h 2024-10-02 17:23:23 -04:00
union_find.rst Documentation: Fix the compilation errors in union_find.rst 2024-08-02 08:58:16 -10:00
watch_queue.rst Documentation: move watch_queue to core-api 2022-04-22 09:47:25 -06:00
workqueue.rst docs: workqueue: Fix bracket 2026-07-09 10:55:59 -10:00
xarray.rst xarray: add xas_try_split() to split a multi-index entry 2025-03-17 22:06:59 -07:00