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

Pull MM updates from Andrew Morton:

 - "powerpc/64s: do not re-activate batched TLB flush" makes
   arch_{enter|leave}_lazy_mmu_mode() nest properly (Alexander Gordeev)

   It adds a generic enter/leave layer and switches architectures to use
   it. Various hacks were removed in the process.

 - "zram: introduce compressed data writeback" implements data
   compression for zram writeback (Richard Chang and Sergey Senozhatsky)

 - "mm: folio_zero_user: clear page ranges" adds clearing of contiguous
   page ranges for hugepages. Large improvements during demand faulting
   are demonstrated (David Hildenbrand)

 - "memcg cleanups" tidies up some memcg code (Chen Ridong)

 - "mm/damon: introduce {,max_}nr_snapshots and tracepoint for damos
   stats" improves DAMOS stat's provided information, deterministic
   control, and readability (SeongJae Park)

 - "selftests/mm: hugetlb cgroup charging: robustness fixes" fixes a few
   issues in the hugetlb cgroup charging selftests (Li Wang)

 - "Fix va_high_addr_switch.sh test failure - again" addresses several
   issues in the va_high_addr_switch test (Chunyu Hu)

 - "mm/damon/tests/core-kunit: extend existing test scenarios" improves
   the KUnit test coverage for DAMON (Shu Anzai)

 - "mm/khugepaged: fix dirty page handling for MADV_COLLAPSE" fixes a
   glitch in khugepaged which was causing madvise(MADV_COLLAPSE) to
   transiently return -EAGAIN (Shivank Garg)

 - "arch, mm: consolidate hugetlb early reservation" reworks and
   consolidates a pile of straggly code related to reservation of
   hugetlb memory from bootmem and creation of CMA areas for hugetlb
   (Mike Rapoport)

 - "mm: clean up anon_vma implementation" cleans up the anon_vma
   implementation in various ways (Lorenzo Stoakes)

 - "tweaks for __alloc_pages_slowpath()" does a little streamlining of
   the page allocator's slowpath code (Vlastimil Babka)

 - "memcg: separate private and public ID namespaces" cleans up the
   memcg ID code and prevents the internal-only private IDs from being
   exposed to userspace (Shakeel Butt)

 - "mm: hugetlb: allocate frozen gigantic folio" cleans up the
   allocation of frozen folios and avoids some atomic refcount
   operations (Kefeng Wang)

 - "mm/damon: advance DAMOS-based LRU sorting" improves DAMOS's movement
   of memory betewwn the active and inactive LRUs and adds auto-tuning
   of the ratio-based quotas and of monitoring intervals (SeongJae Park)

 - "Support page table check on PowerPC" makes
   CONFIG_PAGE_TABLE_CHECK_ENFORCED work on powerpc (Andrew Donnellan)

 - "nodemask: align nodes_and{,not} with underlying bitmap ops" makes
   nodes_and() and nodes_andnot() propagate the return values from the
   underlying bit operations, enabling some cleanup in calling code
   (Yury Norov)

 - "mm/damon: hide kdamond and kdamond_lock from API callers" cleans up
   some DAMON internal interfaces (SeongJae Park)

 - "mm/khugepaged: cleanups and scan limit fix" does some cleanup work
   in khupaged and fixes a scan limit accounting issue (Shivank Garg)

 - "mm: balloon infrastructure cleanups" goes to town on the balloon
   infrastructure and its page migration function. Mainly cleanups, also
   some locking simplification (David Hildenbrand)

 - "mm/vmscan: add tracepoint and reason for kswapd_failures reset" adds
   additional tracepoints to the page reclaim code (Jiayuan Chen)

 - "Replace wq users and add WQ_PERCPU to alloc_workqueue() users" is
   part of Marco's kernel-wide migration from the legacy workqueue APIs
   over to the preferred unbound workqueues (Marco Crivellari)

 - "Various mm kselftests improvements/fixes" provides various unrelated
   improvements/fixes for the mm kselftests (Kevin Brodsky)

 - "mm: accelerate gigantic folio allocation" greatly speeds up gigantic
   folio allocation, mainly by avoiding unnecessary work in
   pfn_range_valid_contig() (Kefeng Wang)

 - "selftests/damon: improve leak detection and wss estimation
   reliability" improves the reliability of two of the DAMON selftests
   (SeongJae Park)

 - "mm/damon: cleanup kdamond, damon_call(), damos filter and
   DAMON_MIN_REGION" does some cleanup work in the core DAMON code
   (SeongJae Park)

 - "Docs/mm/damon: update intro, modules, maintainer profile, and misc"
   performs maintenance work on the DAMON documentation (SeongJae Park)

 - "mm: add and use vma_assert_stabilised() helper" refactors and cleans
   up the core VMA code. The main aim here is to be able to use the mmap
   write lock's lockdep state to perform various assertions regarding
   the locking which the VMA code requires (Lorenzo Stoakes)

 - "mm, swap: swap table phase II: unify swapin use" removes some old
   swap code (swap cache bypassing and swap synchronization) which
   wasn't working very well. Various other cleanups and simplifications
   were made. The end result is a 20% speedup in one benchmark (Kairui
   Song)

 - "enable PT_RECLAIM on more 64-bit architectures" makes PT_RECLAIM
   available on 64-bit alpha, loongarch, mips, parisc, and um. Various
   cleanups were performed along the way (Qi Zheng)

* tag 'mm-stable-2026-02-11-19-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (325 commits)
  mm/memory: handle non-split locks correctly in zap_empty_pte_table()
  mm: move pte table reclaim code to memory.c
  mm: make PT_RECLAIM depends on MMU_GATHER_RCU_TABLE_FREE
  mm: convert __HAVE_ARCH_TLB_REMOVE_TABLE to CONFIG_HAVE_ARCH_TLB_REMOVE_TABLE config
  um: mm: enable MMU_GATHER_RCU_TABLE_FREE
  parisc: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mips: mm: enable MMU_GATHER_RCU_TABLE_FREE
  LoongArch: mm: enable MMU_GATHER_RCU_TABLE_FREE
  alpha: mm: enable MMU_GATHER_RCU_TABLE_FREE
  mm: change mm/pt_reclaim.c to use asm/tlb.h instead of asm-generic/tlb.h
  mm/damon/stat: remove __read_mostly from memory_idle_ms_percentiles
  zsmalloc: make common caches global
  mm: add SPDX id lines to some mm source files
  mm/zswap: use %pe to print error pointers
  mm/vmscan: use %pe to print error pointers
  mm/readahead: fix typo in comment
  mm: khugepaged: fix NR_FILE_PAGES and NR_SHMEM in collapse_file()
  mm: refactor vma_map_pages to use vm_insert_pages
  mm/damon: unify address range representation with damon_addr_range
  mm/cma: replace snprintf with strscpy in cma_new_area
  ...

4 files changed, 41 insertions, 32 deletions

diff --git a/Documentation/mm/damon/design.rst b/Documentation/mm/damon/design.rst
index 2d8d8ca1e0a3..dd64f5d7f319 100644
--- a/Documentation/mm/damon/design.rst
+++ b/Documentation/mm/damon/design.rst
@@ -585,6 +585,10 @@ mechanism tries to make ``current_value`` of ``target_metric`` be same to
   specific NUMA node, in bp (1/10,000).
 - ``node_memcg_free_bp``: Specific cgroup's node unused memory ratio for a
   specific NUMA node, in bp (1/10,000).
+- ``active_mem_bp``: Active to active + inactive (LRU) memory size ratio in bp
+  (1/10,000).
+- ``inactive_mem_bp``: Inactive to active + inactive (LRU) memory size ratio in
+  bp (1/10,000).
 
 ``nid`` is optionally required for only ``node_mem_used_bp``,
 ``node_mem_free_bp``, ``node_memcg_used_bp`` and ``node_memcg_free_bp`` to
@@ -718,6 +722,9 @@ scheme's execution.
 - ``nr_applied``: Total number of regions that the scheme is applied.
 - ``sz_applied``: Total size of regions that the scheme is applied.
 - ``qt_exceeds``: Total number of times the quota of the scheme has exceeded.
+- ``nr_snapshots``: Total number of DAMON snapshots that the scheme is tried to
+  be applied.
+- ``max_nr_snapshots``: Upper limit of ``nr_snapshots``.
 
 "A scheme is tried to be applied to a region" means DAMOS core logic determined
 the region is eligible to apply the scheme's :ref:`action
@@ -739,6 +746,10 @@ to exclude anonymous pages and the region has only anonymous pages, or if the
 action is ``pageout`` while all pages of the region are unreclaimable, applying
 the action to the region will fail.
 
+Unlike normal stats, ``max_nr_snapshots`` is set by users.  If it is set as
+non-zero and ``nr_snapshots`` be same to or greater than ``nr_snapshots``, the
+scheme is deactivated.
+
 To know how user-space can read the stats via :ref:`DAMON sysfs interface
 <sysfs_interface>`, refer to :ref:s`stats <sysfs_stats>` part of the
 documentation.
@@ -798,14 +809,16 @@ The ABIs are designed to be used for user space applications development,
 rather than human beings' fingers.  Human users are recommended to use such
 user space tools.  One such Python-written user space tool is available at
 Github (https://github.com/damonitor/damo), Pypi
-(https://pypistats.org/packages/damo), and Fedora
-(https://packages.fedoraproject.org/pkgs/python-damo/damo/).
+(https://pypistats.org/packages/damo), and multiple distros
+(https://repology.org/project/damo/versions).
 
 Currently, one module for this type, namely 'DAMON sysfs interface' is
 available.  Please refer to the ABI :ref:`doc <sysfs_interface>` for details of
 the interfaces.
 
 
+.. _damon_modules_special_purpose:
+
 Special-Purpose Access-aware Kernel Modules
 -------------------------------------------
 
@@ -823,5 +836,18 @@ To support such cases, yet more DAMON API user kernel modules that provide more
 simple and optimized user space interfaces are available.  Currently, two
 modules for proactive reclamation and LRU lists manipulation are provided.  For
 more detail, please read the usage documents for those
-(:doc:`/admin-guide/mm/damon/reclaim` and
+(:doc:`/admin-guide/mm/damon/stat`, :doc:`/admin-guide/mm/damon/reclaim` and
 :doc:`/admin-guide/mm/damon/lru_sort`).
+
+
+Sample DAMON Modules
+--------------------
+
+DAMON modules that provides example DAMON kernel API usages.
+
+kernel programmers can build their own special or general purpose DAMON modules
+using DAMON kernel API.  To help them easily understand how DAMON kernel API
+can be used, a few sample modules are provided under ``samples/damon/`` of the
+linux source tree.  Please note that these modules are not developed for being
+used on real products, but only for showing how DAMON kernel API can be used in
+simple ways.
diff --git a/Documentation/mm/damon/index.rst b/Documentation/mm/damon/index.rst
index 31c1fa955b3d..82f6c5eea49a 100644
--- a/Documentation/mm/damon/index.rst
+++ b/Documentation/mm/damon/index.rst
@@ -4,28 +4,15 @@
 DAMON: Data Access MONitoring and Access-aware System Operations
 ================================================================
 
-DAMON is a Linux kernel subsystem that provides a framework for data access
-monitoring and the monitoring results based system operations.  The core
-monitoring :ref:`mechanisms <damon_design_monitoring>` of DAMON make it
-
- - *accurate* (the monitoring output is useful enough for DRAM level memory
-   management; It might not appropriate for CPU Cache levels, though),
- - *light-weight* (the monitoring overhead is low enough to be applied online),
-   and
- - *scalable* (the upper-bound of the overhead is in constant range regardless
-   of the size of target workloads).
-
-Using this framework, therefore, the kernel can operate system in an
-access-aware fashion.  Because the features are also exposed to the :doc:`user
-space </admin-guide/mm/damon/index>`, users who have special information about
-their workloads can write personalized applications for better understanding
-and optimizations of their workloads and systems.
-
-For easier development of such systems, DAMON provides a feature called
-:ref:`DAMOS <damon_design_damos>` (DAMon-based Operation Schemes) in addition
-to the monitoring.  Using the feature, DAMON users in both kernel and :doc:`user
-spaces </admin-guide/mm/damon/index>` can do access-aware system operations
-with no code but simple configurations.
+DAMON is a Linux kernel subsystem for efficient :ref:`data access monitoring
+<damon_design_monitoring>` and :ref:`access-aware system operations
+<damon_design_damos>`.  It is designed for being
+
+ - *accurate* (for DRAM level memory management),
+ - *light-weight* (for production online usages),
+ - *scalable* (in terms of memory size),
+ - *tunable* (for flexible usages), and
+ - *autoamted* (for production operation without manual tunings).
 
 .. toctree::
    :maxdepth: 2
diff --git a/Documentation/mm/damon/maintainer-profile.rst b/Documentation/mm/damon/maintainer-profile.rst
index e761edada1e9..41b1d73b9bd7 100644
--- a/Documentation/mm/damon/maintainer-profile.rst
+++ b/Documentation/mm/damon/maintainer-profile.rst
@@ -3,8 +3,8 @@
 DAMON Maintainer Entry Profile
 ==============================
 
-The DAMON subsystem covers the files that are listed in 'DATA ACCESS MONITOR'
-section of 'MAINTAINERS' file.
+The DAMON subsystem covers the files that are listed in 'DAMON' section of
+'MAINTAINERS' file.
 
 The mailing lists for the subsystem are damon@lists.linux.dev and
 linux-mm@kvack.org.  Patches should be made against the `mm-new tree
@@ -48,8 +48,7 @@ Further doing below and putting the results will be helpful.
 - Run `damon-tests/corr
   <https://github.com/damonitor/damon-tests/tree/master/corr>`_ for normal
   changes.
-- Run `damon-tests/perf
-  <https://github.com/damonitor/damon-tests/tree/master/perf>`_ for performance
+- Measure impacts on benchmarks or real world workloads for performance
   changes.
 
 Key cycle dates
diff --git a/Documentation/mm/memory-model.rst b/Documentation/mm/memory-model.rst
index 7957122039e8..199b11328f4f 100644
--- a/Documentation/mm/memory-model.rst
+++ b/Documentation/mm/memory-model.rst
@@ -97,9 +97,6 @@ sections:
   `mem_section` objects and the number of rows is calculated to fit
   all the memory sections.
 
-The architecture setup code should call sparse_init() to
-initialize the memory sections and the memory maps.
-
 With SPARSEMEM there are two possible ways to convert a PFN to the
 corresponding `struct page` - a "classic sparse" and "sparse
 vmemmap". The selection is made at build time and it is determined by