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Kiryl Shutsemau 2db5798382 mm/page_vma_mapped: track if the page is mapped across page table boundary
Patch series "mm: Improve mlock tracking for large folios", v3.

The patchset includes several fixes and improvements related to mlock
tracking of large folios.

The main objective is to reduce the undercount of Mlocked memory in
/proc/meminfo and improve the accuracy of the statistics.

Patches 1-2:

These patches address a minor race condition in folio_referenced_one()
related to mlock_vma_folio().

Currently, mlock_vma_folio() is called on large folio without the page
table lock, which can result in a race condition with unmap (i.e. 
MADV_DONTNEED).  This can lead to partially mapped folios on the
unevictable LRU list.

While not a significant issue, I do not believe backporting is necessary.

Patch 3:

This patch adds mlocking logic similar to folio_referenced_one() to
try_to_unmap_one(), allowing for mlocking of large folios where possible.

Patch 4-5:

These patches modifies finish_fault() and faultaround to map in the entire
folio when possible, enabling efficient mlocking upon addition to the
rmap.

Patch 6:

This patch makes rmap mlock large folios if they are fully mapped,
addressing the primary source of mlock undercount for large folios.


This patch (of 6):

Add a PVMW_PGTABLE_CROSSSED flag that page_vma_mapped_walk() will set if
the page is mapped across page table boundary.  Unlike other PVMW_* flags,
this one is result of page_vma_mapped_walk() and not set by the caller.

folio_referenced_one() will use it to detect if it safe to mlock the
folio.

[akpm@linux-foundation.org: s/CROSSSED/CROSSED/]
Link: https://lkml.kernel.org/r/20250923110711.690639-1-kirill@shutemov.name
Link: https://lkml.kernel.org/r/20250923110711.690639-2-kirill@shutemov.name
Signed-off-by: Kiryl Shutsemau <kas@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-09-28 11:51:29 -07:00
arch ptdesc: remove ptdesc_to_virt() 2025-09-21 14:22:27 -07:00
block block: use largest_zero_folio in __blkdev_issue_zero_pages() 2025-09-13 16:54:54 -07:00
certs sign-file,extract-cert: use pkcs11 provider for OPENSSL MAJOR >= 3 2024-09-20 19:52:48 +03:00
crypto crypto: remove nth_page() usage within SG entry 2025-09-21 14:22:09 -07:00
Documentation Docs/admin-guide/mm/damon/start: add --target_pid to DAMOS example command 2025-09-21 14:22:37 -07:00
drivers mm: make folio page count functions return unsigned 2025-09-21 14:22:31 -07:00
fs mm/hwpoison: decouple hwpoison_filter from mm/memory-failure.c 2025-09-21 14:22:21 -07:00
include mm/page_vma_mapped: track if the page is mapped across page table boundary 2025-09-28 11:51:29 -07:00
init init/main.c: fix boot time tracing crash 2025-09-03 17:10:36 -07:00
io_uring io_uring/zcrx: remove nth_page() usage within folio 2025-09-21 14:22:05 -07:00
ipc vfs-6.17-rc1.mmap_prepare 2025-07-28 13:43:25 -07:00
kernel kho: make sure page being restored is actually from KHO 2025-09-23 14:14:17 -07:00
lib alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output 2025-09-21 14:22:36 -07:00
LICENSES LICENSES: Replace the obsolete address of the FSF in the GFDL-1.2 2025-07-24 11:15:39 +02:00
mm mm/page_vma_mapped: track if the page is mapped across page table boundary 2025-09-28 11:51:29 -07:00
net net: ipv4: fix regression in local-broadcast routes 2025-08-28 10:52:30 +02:00
rust rust: maple_tree: add MapleTreeAlloc 2025-09-21 14:22:19 -07:00
samples samples/damon/mtier: use damon_initialized() 2025-09-21 14:22:39 -07:00
scripts scripts/decode_stacktrace.sh: code: preserve alignment 2025-09-21 14:22:28 -07:00
security + Features 2025-08-04 08:17:28 -07:00
sound ALSA: hda/hdmi: Add pin fix for another HP EliteDesk 800 G4 model 2025-09-01 13:51:57 +02:00
tools selftests/mm: skip soft-dirty tests when CONFIG_MEM_SOFT_DIRTY is disabled 2025-09-23 14:14:16 -07:00
usr usr/include: openrisc: don't HDRTEST bpf_perf_event.h 2025-05-12 15:03:17 +09:00
virt Merge tag 'kvm-x86-no_assignment-6.17' of https://github.com/kvm-x86/linux into HEAD 2025-07-29 08:36:42 -04:00
.clang-format Linux 6.15-rc5 2025-05-06 16:39:25 +10:00
.clippy.toml rust: clean Rust 1.88.0's warning about clippy::disallowed_macros configuration 2025-05-07 00:11:47 +02:00
.cocciconfig
.editorconfig .editorconfig: remove trim_trailing_whitespace option 2024-06-13 16:47:52 +02:00
.get_maintainer.ignore MAINTAINERS: Retire Ralf Baechle 2024-11-12 15:48:59 +01:00
.gitattributes .gitattributes: set diff driver for Rust source code files 2023-05-31 17:48:25 +02:00
.gitignore gitignore: allow .pylintrc to be tracked 2025-07-02 17:10:04 -06:00
.mailmap .mailmap: add entry for Easwar Hariharan 2025-08-19 16:35:55 -07:00
.pylintrc docs: add a .pylintrc file with sys path for docs scripts 2025-04-09 12:10:33 -06:00
.rustfmt.toml rust: add .rustfmt.toml 2022-09-28 09:02:20 +02:00
COPYING
CREDITS MAINTAINERS: retire Boris from TLS maintainers 2025-08-26 17:36:01 -07:00
Kbuild drm: ensure drm headers are self-contained and pass kernel-doc 2025-02-12 10:44:43 +02:00
Kconfig io_uring: Rename KConfig to Kconfig 2025-02-19 14:53:27 -07:00
MAINTAINERS MAINTAINERS: rename DAMON section 2025-09-21 14:22:37 -07:00
Makefile Linux 6.17-rc4 2025-08-31 15:33:07 -07:00
README README: Fix spelling 2024-03-18 03:36:32 -06:00

Linux kernel
============

There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.

In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``.  The formatted documentation can also be read online at:

    https://www.kernel.org/doc/html/latest/

There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.

Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.