Pull non-MM updates from Andrew Morton:
- "panic: sys_info: Refactor and fix a potential issue" (Andy Shevchenko)
fixes a build issue and does some cleanup in ib/sys_info.c
- "Implement mul_u64_u64_div_u64_roundup()" (David Laight)
enhances the 64-bit math code on behalf of a PWM driver and beefs up
the test module for these library functions
- "scripts/gdb/symbols: make BPF debug info available to GDB" (Ilya Leoshkevich)
makes BPF symbol names, sizes, and line numbers available to the GDB
debugger
- "Enable hung_task and lockup cases to dump system info on demand" (Feng Tang)
adds a sysctl which can be used to cause additional info dumping when
the hung-task and lockup detectors fire
- "lib/base64: add generic encoder/decoder, migrate users" (Kuan-Wei Chiu)
adds a general base64 encoder/decoder to lib/ and migrates several
users away from their private implementations
- "rbree: inline rb_first() and rb_last()" (Eric Dumazet)
makes TCP a little faster
- "liveupdate: Rework KHO for in-kernel users" (Pasha Tatashin)
reworks the KEXEC Handover interfaces in preparation for Live Update
Orchestrator (LUO), and possibly for other future clients
- "kho: simplify state machine and enable dynamic updates" (Pasha Tatashin)
increases the flexibility of KEXEC Handover. Also preparation for LUO
- "Live Update Orchestrator" (Pasha Tatashin)
is a major new feature targeted at cloud environments. Quoting the
cover letter:
This series introduces the Live Update Orchestrator, a kernel
subsystem designed to facilitate live kernel updates using a
kexec-based reboot. This capability is critical for cloud
environments, allowing hypervisors to be updated with minimal
downtime for running virtual machines. LUO achieves this by
preserving the state of selected resources, such as memory,
devices and their dependencies, across the kernel transition.
As a key feature, this series includes support for preserving
memfd file descriptors, which allows critical in-memory data, such
as guest RAM or any other large memory region, to be maintained in
RAM across the kexec reboot.
Mike Rappaport merits a mention here, for his extensive review and
testing work.
- "kexec: reorganize kexec and kdump sysfs" (Sourabh Jain)
moves the kexec and kdump sysfs entries from /sys/kernel/ to
/sys/kernel/kexec/ and adds back-compatibility symlinks which can
hopefully be removed one day
- "kho: fixes for vmalloc restoration" (Mike Rapoport)
fixes a BUG which was being hit during KHO restoration of vmalloc()
regions
* tag 'mm-nonmm-stable-2025-12-06-11-14' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (139 commits)
calibrate: update header inclusion
Reinstate "resource: avoid unnecessary lookups in find_next_iomem_res()"
vmcoreinfo: track and log recoverable hardware errors
kho: fix restoring of contiguous ranges of order-0 pages
kho: kho_restore_vmalloc: fix initialization of pages array
MAINTAINERS: TPM DEVICE DRIVER: update the W-tag
init: replace simple_strtoul with kstrtoul to improve lpj_setup
KHO: fix boot failure due to kmemleak access to non-PRESENT pages
Documentation/ABI: new kexec and kdump sysfs interface
Documentation/ABI: mark old kexec sysfs deprecated
kexec: move sysfs entries to /sys/kernel/kexec
test_kho: always print restore status
kho: free chunks using free_page() instead of kfree()
selftests/liveupdate: add kexec test for multiple and empty sessions
selftests/liveupdate: add simple kexec-based selftest for LUO
selftests/liveupdate: add userspace API selftests
docs: add documentation for memfd preservation via LUO
mm: memfd_luo: allow preserving memfd
liveupdate: luo_file: add private argument to store runtime state
mm: shmem: export some functions to internal.h
...
Pull printk updates from Petr Mladek:
- Allow creaing nbcon console drivers with an unsafe write_atomic()
callback that can only be called by the final nbcon_atomic_flush_unsafe().
Otherwise, the driver would rely on the kthread.
It is going to be used as the-best-effort approach for an
experimental nbcon netconsole driver, see
https://lore.kernel.org/r/20251121-nbcon-v1-2-503d17b2b4af@debian.org
Note that a safe .write_atomic() callback is supposed to work in NMI
context. But some networking drivers are not safe even in IRQ
context:
https://lore.kernel.org/r/oc46gdpmmlly5o44obvmoatfqo5bhpgv7pabpvb6sjuqioymcg@gjsma3ghoz35
In an ideal world, all networking drivers would be fixed first and
the atomic flush would be blocked only in NMI context. But it brings
the question how reliable networking drivers are when the system is
in a bad state. They might block flushing more reliable serial
consoles which are more suitable for serious debugging anyway.
- Allow to use the last 4 bytes of the printk ring buffer.
- Prevent queuing IRQ work and block printk kthreads when consoles are
suspended. Otherwise, they create non-necessary churn or even block
the suspend.
- Release console_lock() between each record in the kthread used for
legacy consoles on RT. It might significantly speed up the boot.
- Release nbcon context between each record in the atomic flush. It
prevents stalls of the related printk kthread after it has lost the
ownership in the middle of a record
- Add support for NBCON consoles into KDB
- Add %ptsP modifier for printing struct timespec64 and use it where
possible
- Misc code clean up
* tag 'printk-for-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/printk/linux: (48 commits)
printk: Use console_is_usable on console_unblank
arch: um: kmsg_dump: Use console_is_usable
drivers: serial: kgdboc: Drop checks for CON_ENABLED and CON_BOOT
lib/vsprintf: Unify FORMAT_STATE_NUM handlers
printk: Avoid irq_work for printk_deferred() on suspend
printk: Avoid scheduling irq_work on suspend
printk: Allow printk_trigger_flush() to flush all types
tracing: Switch to use %ptSp
scsi: snic: Switch to use %ptSp
scsi: fnic: Switch to use %ptSp
s390/dasd: Switch to use %ptSp
ptp: ocp: Switch to use %ptSp
pps: Switch to use %ptSp
PCI: epf-test: Switch to use %ptSp
net: dsa: sja1105: Switch to use %ptSp
mmc: mmc_test: Switch to use %ptSp
media: av7110: Switch to use %ptSp
ipmi: Switch to use %ptSp
igb: Switch to use %ptSp
e1000e: Switch to use %ptSp
...
Paragraphs of function explanation are currently not indented following
their appropriate numbered list item, which causes only the first
paragraph and function prototype code blocks to be indented in the
numbered list in htmldocs output.
Indent the explanation.
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20251013095630.34235-3-bagasdotme@gmail.com>
Pull dma-mapping updates from Marek Szyprowski:
- Refactoring of DMA mapping API to physical addresses as the primary
interface instead of page+offset parameters
This gets much closer to Matthew Wilcox's long term wish for
struct-pageless IO to cacheable DRAM and is supporting memdesc
project which seeks to substantially transform how struct page works.
An advantage of this approach is the possibility of introducing
DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow in the
common paths, what in turn lets to use recently introduced
dma_iova_link() API to map PCI P2P MMIO without creating struct page
Developped by Leon Romanovsky and Jason Gunthorpe
- Minor clean-up by Petr Tesarik and Qianfeng Rong
* tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
kmsan: fix missed kmsan_handle_dma() signature conversion
mm/hmm: properly take MMIO path
mm/hmm: migrate to physical address-based DMA mapping API
dma-mapping: export new dma_*map_phys() interface
xen: swiotlb: Open code map_resource callback
dma-mapping: implement DMA_ATTR_MMIO for dma_(un)map_page_attrs()
kmsan: convert kmsan_handle_dma to use physical addresses
dma-mapping: convert dma_direct_*map_page to be phys_addr_t based
iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()
iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys
dma-mapping: rename trace_dma_*map_page to trace_dma_*map_phys
dma-debug: refactor to use physical addresses for page mapping
iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().
dma-mapping: introduce new DMA attribute to indicate MMIO memory
swiotlb: Remove redundant __GFP_NOWARN
dma-direct: clean up the logic in __dma_direct_alloc_pages()
Pull documentation updates from Jonathan Corbet:
"It has been a relatively busy cycle in docsland, with changes all
over:
- Bring the kernel memory-model docs into the Sphinx build in the
"literal include" mode.
- Lots of build-infrastructure work, further cleaning up long-term
kernel-doc technical debt. The sphinx-pre-install tool has been
converted to Python and updated for current systems.
- A new tool to detect when documents have been moved and generate
HTML redirects; this can be used on kernel.org (or any other site
hosting the rendered docs) to avoid breaking links.
- Automated processing of the YAML files describing the netlink
protocol.
- A significant update of the maintainer's PGP guide.
... and a seemingly endless series of typo fixes, build-problem fixes,
etc"
* tag 'docs-6.18' of git://git.lwn.net/linux: (193 commits)
Documentation/features: Update feature lists for 6.17-rc7
docs: remove cdomain.py
Documentation/process: submitting-patches: fix typo in "were do"
docs: dev-tools/lkmm: Fix typo of missing file extension
Documentation: trace: histogram: Convert ftrace docs cross-reference
Documentation: trace: histogram-design: Wrap introductory note in note:: directive
Documentation: trace: historgram-design: Separate sched_waking histogram section heading and the following diagram
Documentation: trace: histogram-design: Trim trailing vertices in diagram explanation text
Documentation: trace: histogram: Fix histogram trigger subsection number order
docs: driver-api: fix spelling of "buses".
Documentation: fbcon: Use admonition directives
Documentation: fbcon: Reindent 8th step of attach/detach/unload
Documentation: fbcon: Add boot options and attach/detach/unload section headings
docs: filesystems: sysfs: add remaining top level sysfs directory descriptions
docs: filesystems: sysfs: clarify symlink destinations in dev and bus/devices descriptions
docs: filesystems: sysfs: remove top level sysfs net directory
docs: maintainer: Fix ambiguous subheading formatting
docs: kdoc: a few more dump_typedef() tweaks
docs: kdoc: remove redundant comment stripping in dump_typedef()
docs: kdoc: remove some dead code in dump_typedef()
...
Convert the DMA debug infrastructure from page-based to physical address-based
mapping as a preparation to rely on physical address for DMA mapping routines.
The refactoring renames debug_dma_map_page() to debug_dma_map_phys() and
changes its signature to accept a phys_addr_t parameter instead of struct page
and offset. Similarly, debug_dma_unmap_page() becomes debug_dma_unmap_phys().
A new dma_debug_phy type is introduced to distinguish physical address mappings
from other debug entry types. All callers throughout the codebase are updated
to pass physical addresses directly, eliminating the need for page-to-physical
conversion in the debug layer.
This refactoring eliminates the need to convert between page pointers and
physical addresses in the debug layer, making the code more efficient and
consistent with the DMA mapping API's physical address focus.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
[mszyprow: added a fixup]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/56d1a6769b68dfcbf8b26a75a7329aeb8e3c3b6a.1757423202.git.leonro@nvidia.com
Link: https://lore.kernel.org/all/20250910052618.GH341237@unreal/
This patch introduces the DMA_ATTR_MMIO attribute to mark DMA buffers
that reside in memory-mapped I/O (MMIO) regions, such as device BARs
exposed through the host bridge, which are accessible for peer-to-peer
(P2P) DMA.
This attribute is especially useful for exporting device memory to other
devices for DMA without CPU involvement, and avoids unnecessary or
potentially detrimental CPU cache maintenance calls.
DMA_ATTR_MMIO is supposed to provide dma_map_resource() functionality
without need to call to special function and perform branching when
processing generic containers like bio_vec by the callers.
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/6f058ec395c5348014860dbc2eed348c17975843.1757423202.git.leonro@nvidia.com
The documents explain the design concepts behind PREEMPT_RT and highlight key
differences necessary to achieve it.
It also include a list of requirements that must be fulfilled to support
PREEMPT_RT on a given architecture.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
[jc: tweaked "how they differ" section head]
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250815093858.930751-4-bigeasy@linutronix.de
Pull more MM updates from Andrew Morton:
"Significant patch series in this pull request:
- "mseal cleanups" (Lorenzo Stoakes)
Some mseal cleaning with no intended functional change.
- "Optimizations for khugepaged" (David Hildenbrand)
Improve khugepaged throughput by batching PTE operations for large
folios. This gain is mainly for arm64.
- "x86: enable EXECMEM_ROX_CACHE for ftrace and kprobes" (Mike Rapoport)
A bugfix, additional debug code and cleanups to the execmem code.
- "mm/shmem, swap: bugfix and improvement of mTHP swap in" (Kairui Song)
Bugfixes, cleanups and performance improvememnts to the mTHP swapin
code"
* tag 'mm-stable-2025-08-03-12-35' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (38 commits)
mm: mempool: fix crash in mempool_free() for zero-minimum pools
mm: correct type for vmalloc vm_flags fields
mm/shmem, swap: fix major fault counting
mm/shmem, swap: rework swap entry and index calculation for large swapin
mm/shmem, swap: simplify swapin path and result handling
mm/shmem, swap: never use swap cache and readahead for SWP_SYNCHRONOUS_IO
mm/shmem, swap: tidy up swap entry splitting
mm/shmem, swap: tidy up THP swapin checks
mm/shmem, swap: avoid redundant Xarray lookup during swapin
x86/ftrace: enable EXECMEM_ROX_CACHE for ftrace allocations
x86/kprobes: enable EXECMEM_ROX_CACHE for kprobes allocations
execmem: drop writable parameter from execmem_fill_trapping_insns()
execmem: add fallback for failures in vmalloc(VM_ALLOW_HUGE_VMAP)
execmem: move execmem_force_rw() and execmem_restore_rox() before use
execmem: rework execmem_cache_free()
execmem: introduce execmem_alloc_rw()
execmem: drop unused execmem_update_copy()
mm: fix a UAF when vma->mm is freed after vma->vm_refcnt got dropped
mm/rmap: add anon_vma lifetime debug check
mm: remove mm/io-mapping.c
...
Pull workqueue updates from Tejun Heo:
- Prepare for defaulting to unbound workqueue. A separate branch was
created to ease pulling in from other trees but none of the
conversions have landed yet
- Memory allocation profiling support added
- Misc changes
* tag 'wq-for-6.17' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/wq:
workqueue: Use atomic_try_cmpxchg_relaxed() in tryinc_node_nr_active()
workqueue: Remove unused work_on_cpu_safe
workqueue: Add new WQ_PERCPU flag
workqueue: Add system_percpu_wq and system_dfl_wq
workqueue: Basic memory allocation profiling support
workqueue: fix opencoded cpumask_next_and_wrap() in wq_select_unbound_cpu()
Pull MM updates from Andrew Morton:
"As usual, many cleanups. The below blurbiage describes 42 patchsets.
21 of those are partially or fully cleanup work. "cleans up",
"cleanup", "maintainability", "rationalizes", etc.
I never knew the MM code was so dirty.
"mm: ksm: prevent KSM from breaking merging of new VMAs" (Lorenzo Stoakes)
addresses an issue with KSM's PR_SET_MEMORY_MERGE mode: newly
mapped VMAs were not eligible for merging with existing adjacent
VMAs.
"mm/damon: introduce DAMON_STAT for simple and practical access monitoring" (SeongJae Park)
adds a new kernel module which simplifies the setup and usage of
DAMON in production environments.
"stop passing a writeback_control to swap/shmem writeout" (Christoph Hellwig)
is a cleanup to the writeback code which removes a couple of
pointers from struct writeback_control.
"drivers/base/node.c: optimization and cleanups" (Donet Tom)
contains largely uncorrelated cleanups to the NUMA node setup and
management code.
"mm: userfaultfd: assorted fixes and cleanups" (Tal Zussman)
does some maintenance work on the userfaultfd code.
"Readahead tweaks for larger folios" (Ryan Roberts)
implements some tuneups for pagecache readahead when it is reading
into order>0 folios.
"selftests/mm: Tweaks to the cow test" (Mark Brown)
provides some cleanups and consistency improvements to the
selftests code.
"Optimize mremap() for large folios" (Dev Jain)
does that. A 37% reduction in execution time was measured in a
memset+mremap+munmap microbenchmark.
"Remove zero_user()" (Matthew Wilcox)
expunges zero_user() in favor of the more modern memzero_page().
"mm/huge_memory: vmf_insert_folio_*() and vmf_insert_pfn_pud() fixes" (David Hildenbrand)
addresses some warts which David noticed in the huge page code.
These were not known to be causing any issues at this time.
"mm/damon: use alloc_migrate_target() for DAMOS_MIGRATE_{HOT,COLD" (SeongJae Park)
provides some cleanup and consolidation work in DAMON.
"use vm_flags_t consistently" (Lorenzo Stoakes)
uses vm_flags_t in places where we were inappropriately using other
types.
"mm/memfd: Reserve hugetlb folios before allocation" (Vivek Kasireddy)
increases the reliability of large page allocation in the memfd
code.
"mm: Remove pXX_devmap page table bit and pfn_t type" (Alistair Popple)
removes several now-unneeded PFN_* flags.
"mm/damon: decouple sysfs from core" (SeongJae Park)
implememnts some cleanup and maintainability work in the DAMON
sysfs layer.
"madvise cleanup" (Lorenzo Stoakes)
does quite a lot of cleanup/maintenance work in the madvise() code.
"madvise anon_name cleanups" (Vlastimil Babka)
provides additional cleanups on top or Lorenzo's effort.
"Implement numa node notifier" (Oscar Salvador)
creates a standalone notifier for NUMA node memory state changes.
Previously these were lumped under the more general memory
on/offline notifier.
"Make MIGRATE_ISOLATE a standalone bit" (Zi Yan)
cleans up the pageblock isolation code and fixes a potential issue
which doesn't seem to cause any problems in practice.
"selftests/damon: add python and drgn based DAMON sysfs functionality tests" (SeongJae Park)
adds additional drgn- and python-based DAMON selftests which are
more comprehensive than the existing selftest suite.
"Misc rework on hugetlb faulting path" (Oscar Salvador)
fixes a rather obscure deadlock in the hugetlb fault code and
follows that fix with a series of cleanups.
"cma: factor out allocation logic from __cma_declare_contiguous_nid" (Mike Rapoport)
rationalizes and cleans up the highmem-specific code in the CMA
allocator.
"mm/migration: rework movable_ops page migration (part 1)" (David Hildenbrand)
provides cleanups and future-preparedness to the migration code.
"mm/damon: add trace events for auto-tuned monitoring intervals and DAMOS quota" (SeongJae Park)
adds some tracepoints to some DAMON auto-tuning code.
"mm/damon: fix misc bugs in DAMON modules" (SeongJae Park)
does that.
"mm/damon: misc cleanups" (SeongJae Park)
also does what it claims.
"mm: folio_pte_batch() improvements" (David Hildenbrand)
cleans up the large folio PTE batching code.
"mm/damon/vaddr: Allow interleaving in migrate_{hot,cold} actions" (SeongJae Park)
facilitates dynamic alteration of DAMON's inter-node allocation
policy.
"Remove unmap_and_put_page()" (Vishal Moola)
provides a couple of page->folio conversions.
"mm: per-node proactive reclaim" (Davidlohr Bueso)
implements a per-node control of proactive reclaim - beyond the
current memcg-based implementation.
"mm/damon: remove damon_callback" (SeongJae Park)
replaces the damon_callback interface with a more general and
powerful damon_call()+damos_walk() interface.
"mm/mremap: permit mremap() move of multiple VMAs" (Lorenzo Stoakes)
implements a number of mremap cleanups (of course) in preparation
for adding new mremap() functionality: newly permit the remapping
of multiple VMAs when the user is specifying MREMAP_FIXED. It still
excludes some specialized situations where this cannot be performed
reliably.
"drop hugetlb_free_pgd_range()" (Anthony Yznaga)
switches some sparc hugetlb code over to the generic version and
removes the thus-unneeded hugetlb_free_pgd_range().
"mm/damon/sysfs: support periodic and automated stats update" (SeongJae Park)
augments the present userspace-requested update of DAMON sysfs
monitoring files. Automatic update is now provided, along with a
tunable to control the update interval.
"Some randome fixes and cleanups to swapfile" (Kemeng Shi)
does what is claims.
"mm: introduce snapshot_page" (Luiz Capitulino and David Hildenbrand)
provides (and uses) a means by which debug-style functions can grab
a copy of a pageframe and inspect it locklessly without tripping
over the races inherent in operating on the live pageframe
directly.
"use per-vma locks for /proc/pid/maps reads" (Suren Baghdasaryan)
addresses the large contention issues which can be triggered by
reads from that procfs file. Latencies are reduced by more than
half in some situations. The series also introduces several new
selftests for the /proc/pid/maps interface.
"__folio_split() clean up" (Zi Yan)
cleans up __folio_split()!
"Optimize mprotect() for large folios" (Dev Jain)
provides some quite large (>3x) speedups to mprotect() when dealing
with large folios.
"selftests/mm: reuse FORCE_READ to replace "asm volatile("" : "+r" (XXX));" and some cleanup" (wang lian)
does some cleanup work in the selftests code.
"tools/testing: expand mremap testing" (Lorenzo Stoakes)
extends the mremap() selftest in several ways, including adding
more checking of Lorenzo's recently added "permit mremap() move of
multiple VMAs" feature.
"selftests/damon/sysfs.py: test all parameters" (SeongJae Park)
extends the DAMON sysfs interface selftest so that it tests all
possible user-requested parameters. Rather than the present minimal
subset"
* tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (370 commits)
MAINTAINERS: add missing headers to mempory policy & migration section
MAINTAINERS: add missing file to cgroup section
MAINTAINERS: add MM MISC section, add missing files to MISC and CORE
MAINTAINERS: add missing zsmalloc file
MAINTAINERS: add missing files to page alloc section
MAINTAINERS: add missing shrinker files
MAINTAINERS: move memremap.[ch] to hotplug section
MAINTAINERS: add missing mm_slot.h file THP section
MAINTAINERS: add missing interval_tree.c to memory mapping section
MAINTAINERS: add missing percpu-internal.h file to per-cpu section
mm/page_alloc: remove trace_mm_alloc_contig_migrate_range_info()
selftests/damon: introduce _common.sh to host shared function
selftests/damon/sysfs.py: test runtime reduction of DAMON parameters
selftests/damon/sysfs.py: test non-default parameters runtime commit
selftests/damon/sysfs.py: generalize DAMON context commit assertion
selftests/damon/sysfs.py: generalize monitoring attributes commit assertion
selftests/damon/sysfs.py: generalize DAMOS schemes commit assertion
selftests/damon/sysfs.py: test DAMOS filters commitment
selftests/damon/sysfs.py: generalize DAMOS scheme commit assertion
selftests/damon/sysfs.py: test DAMOS destinations commitment
...
Pull documentation updates from Jonathan Corbet:
"It has been a relatively busy cycle for docs, especially the build
system:
- The Perl kernel-doc script was added to 2.3.52pre1 just after the
turn of the millennium. Over the following 25 years, it accumulated
a vast amount of cruft, all in a language few people want to deal
with anymore. Mauro's Python replacement in 6.16 faithfully
reproduced all of the cruft in the hope of avoiding regressions.
Now that we have a more reasonable code base, though, we can work
on cleaning it up; many of the changes this time around are toward
that end.
- A reorganization of the ext4 docs into the usual TOC format.
- Various Chinese translations and updates.
- A new script from Mauro to help with docs-build testing.
- A new document for linked lists
- A sweep through MAINTAINERS fixing broken GitHub git:// repository
links.
...and lots of fixes and updates"
* tag 'docs-6.17' of git://git.lwn.net/linux: (147 commits)
scripts: add origin commit identification based on specific patterns
sphinx: kernel_abi: fix performance regression with O=<dir>
Documentation: core-api: entry: Replace deprecated KVM entry/exit functions
docs: fault-injection: drop reference to md-faulty
docs: document linked lists
scripts: kdoc: make it backward-compatible with Python 3.7
docs: kernel-doc: emit warnings for ancient versions of Python
Documentation/rtla: Describe exit status
Documentation/rtla: Add include common_appendix.rst
docs: kernel: Clarify printk_ratelimit_burst reset behavior
Documentation: ioctl-number: Don't repeat macro names
Documentation: ioctl-number: Shorten macros table
Documentation: ioctl-number: Correct full path to papr-physical-attestation.h
Documentation: ioctl-number: Extend "Include File" column width
Documentation: ioctl-number: Fix linuxppc-dev mailto link
overlayfs.rst: fix typos
docs: kdoc: emit a warning for ancient versions of Python
docs: kdoc: clean up check_sections()
docs: kdoc: directly access the always-there KdocItem fields
docs: kdoc: straighten up dump_declaration()
...
Add an introductory paragraph to Part Id - Streaming DMA mappings and move
the explanation of address constraints there, because it applies to all map
functions.
Clarify that streaming DMA can be used with memory which does not meet the
addressing constraints of a device, but it may fail in that case.
Make a note about SWIOTLB and link to the detailed description of it.
Do not mention platform-dependent allocation flags. The note may mislead
device driver authors into thinking that they should poke into and try to
second-guess the DMA API implementation. They definitely shouldn't.
Remove the claim that platforms with an IOMMU may not require physically
contiguous buffers. The current implementation explicitly rejects vmalloc
addresses, regardless of IOMMU.
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250627101015.1600042-8-ptesarik@suse.com
The wording sometimes suggests there are multiple functions for an
operation. This was in fact the case before PCI DMA API was removed, but
since there is only one API now, the documentation has become confusing.
To improve readability:
* Remove implicit references to the PCI DMA API (plurals, use of "both",
etc.)
* Where possible, refer to an actual function rather than a more generic
description of the operation.
Signed-off-by: Petr Tesarik <ptesarik@suse.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Link: https://lore.kernel.org/r/20250627101015.1600042-4-ptesarik@suse.com
Document these widely used functions.
Update kernel-api.rst to point to the correct place, instead of to
crc32-main.c which no longer contains kerneldoc comments.
Simplify the documentation in crc32poly.h to just point to the
corresponding functions, now that they are properly documented. Change
the value of CRC32C_POLY_LE to lower case, for consistency.
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20250619183414.100082-2-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Rework how lib/crc/ supports arch-optimized code. First, instead of the
arch-optimized CRC code being in arch/$(SRCARCH)/lib/, it will now be in
lib/crc/$(SRCARCH)/. Second, the API functions (e.g. crc32c()),
arch-optimized functions (e.g. crc32c_arch()), and generic functions
(e.g. crc32c_base()) will now be part of a single module for each CRC
type, allowing better inlining and dead code elimination. The second
change is made possible by the first.
As an example, consider CONFIG_CRC32=m on x86. We'll now have just
crc32.ko instead of both crc32-x86.ko and crc32.ko. The two modules
were already coupled together and always both got loaded together via
direct symbol dependency, so the separation provided no benefit.
Note: later I'd like to apply the same design to lib/crypto/ too, where
often the API functions are out-of-line so this will work even better.
In those cases, for each algorithm we currently have 3 modules all
coupled together, e.g. libsha256.ko, libsha256-generic.ko, and
sha256-x86.ko. We should have just one, inline things properly, and
rely on the compiler's dead code elimination to decide the inclusion of
the generic code instead of manually setting it via kconfig.
Having arch-specific code outside arch/ was somewhat controversial when
Zinc proposed it back in 2018. But I don't think the concerns are
warranted. It's better from a technical perspective, as it enables the
improvements mentioned above. This model is already successfully used
in other places in the kernel such as lib/raid6/. The community of each
architecture still remains free to work on the code, even if it's not in
arch/. At the time there was also a desire to put the library code in
the same files as the old-school crypto API, but that was a mistake; now
that the library is separate, that's no longer a constraint either.
Reviewed-by: "Martin K. Petersen" <martin.petersen@oracle.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: "Jason A. Donenfeld" <Jason@zx2c4.com>
Link: https://lore.kernel.org/r/20250607200454.73587-3-ebiggers@kernel.org
Link: https://lore.kernel.org/r/20250612054514.142728-1-ebiggers@kernel.org
Link: https://lore.kernel.org/r/20250621012221.4351-1-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
Currently if a user enqueue a work item using schedule_delayed_work() the
used wq is "system_wq" (per-cpu wq) while queue_delayed_work() use
WORK_CPU_UNBOUND (used when a cpu is not specified). The same applies to
schedule_work() that is using system_wq and queue_work(), that makes use
again of WORK_CPU_UNBOUND.
This lack of consistentcy cannot be addressed without refactoring the API.
This patch adds a new WQ_PERCPU flag to explicitly request the use of
the per-CPU behavior. Both flags coexist for one release cycle to allow
callers to transition their calls.
Once migration is complete, WQ_UNBOUND can be removed and unbound will
become the implicit default.
tj: Merged doc patch.
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Marco Crivellari <marco.crivellari@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Pull Kbuild updates from Masahiro Yamada:
- Add support for the EXPORT_SYMBOL_GPL_FOR_MODULES() macro, which
exports a symbol only to specified modules
- Improve ABI handling in gendwarfksyms
- Forcibly link lib-y objects to vmlinux even if CONFIG_MODULES=n
- Add checkers for redundant or missing <linux/export.h> inclusion
- Deprecate the extra-y syntax
- Fix a genksyms bug when including enum constants from *.symref files
* tag 'kbuild-v6.16' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (28 commits)
genksyms: Fix enum consts from a reference affecting new values
arch: use always-$(KBUILD_BUILTIN) for vmlinux.lds
kbuild: set y instead of 1 to KBUILD_{BUILTIN,MODULES}
efi/libstub: use 'targets' instead of extra-y in Makefile
module: make __mod_device_table__* symbols static
scripts/misc-check: check unnecessary #include <linux/export.h> when W=1
scripts/misc-check: check missing #include <linux/export.h> when W=1
scripts/misc-check: add double-quotes to satisfy shellcheck
kbuild: move W=1 check for scripts/misc-check to top-level Makefile
scripts/tags.sh: allow to use alternative ctags implementation
kconfig: introduce menu type enum
docs: symbol-namespaces: fix reST warning with literal block
kbuild: link lib-y objects to vmlinux forcibly even when CONFIG_MODULES=n
tinyconfig: enable CONFIG_LD_DEAD_CODE_DATA_ELIMINATION
docs/core-api/symbol-namespaces: drop table of contents and section numbering
modpost: check forbidden MODULE_IMPORT_NS("module:") at compile time
kbuild: move kbuild syntax processing to scripts/Makefile.build
Makefile: remove dependency on archscripts for header installation
Documentation/kbuild: Add new gendwarfksyms kABI rules
Documentation/kbuild: Drop section numbers
...
Use a literal block for the EXPORT_SYMBOL_GPL_FOR_MODULES() example to
avoid a Docutils warning about unmatched '*'. This ensures correct rendering
and keeps the source readable.
Warning:
Documentation/core-api/symbol-namespaces.rst:90: WARNING: Inline emphasis start-string without end-string. [docutils]
Signed-off-by: Khaled Elnaggar <khaledelnaggarlinux@gmail.com>
Reviewed-by: Bagas Sanjaya <bagasdotme@gmail.com>
Signed-off-by: Masahiro Yamada <masahiroy@kernel.org>
Pull netfs updates from Christian Brauner:
- The main API document has been extensively updated/rewritten
- Fix an oops in write-retry due to mis-resetting the I/O iterator
- Fix the recording of transferred bytes for short DIO reads
- Fix a request's work item to not require a reference, thereby
avoiding the need to get rid of it in BH/IRQ context
- Fix waiting and waking to be consistent about the waitqueue used
- Remove NETFS_SREQ_SEEK_DATA_READ, NETFS_INVALID_WRITE,
NETFS_ICTX_WRITETHROUGH, NETFS_READ_HOLE_CLEAR,
NETFS_RREQ_DONT_UNLOCK_FOLIOS, and NETFS_RREQ_BLOCKED
- Reorder structs to eliminate holes
- Remove netfs_io_request::ractl
- Only provide proc_link field if CONFIG_PROC_FS=y
- Remove folio_queue::marks3
- Fix undifferentiation of DIO reads from unbuffered reads
* tag 'vfs-6.16-rc1.netfs' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
netfs: Fix undifferentiation of DIO reads from unbuffered reads
netfs: Fix wait/wake to be consistent about the waitqueue used
netfs: Fix the request's work item to not require a ref
netfs: Fix setting of transferred bytes with short DIO reads
netfs: Fix oops in write-retry from mis-resetting the subreq iterator
fs/netfs: remove unused flag NETFS_RREQ_BLOCKED
fs/netfs: remove unused flag NETFS_RREQ_DONT_UNLOCK_FOLIOS
folio_queue: remove unused field `marks3`
fs/netfs: declare field `proc_link` only if CONFIG_PROC_FS=y
fs/netfs: remove `netfs_io_request.ractl`
fs/netfs: reorder struct fields to eliminate holes
fs/netfs: remove unused enum choice NETFS_READ_HOLE_CLEAR
fs/netfs: remove unused flag NETFS_ICTX_WRITETHROUGH
fs/netfs: remove unused source NETFS_INVALID_WRITE
fs/netfs: remove unused flag NETFS_SREQ_SEEK_DATA_READ
Pull MM updates from Andrew Morton:
- "Add folio_mk_pte()" from Matthew Wilcox simplifies the act of
creating a pte which addresses the first page in a folio and reduces
the amount of plumbing which architecture must implement to provide
this.
- "Misc folio patches for 6.16" from Matthew Wilcox is a shower of
largely unrelated folio infrastructure changes which clean things up
and better prepare us for future work.
- "memory,x86,acpi: hotplug memory alignment advisement" from Gregory
Price adds early-init code to prevent x86 from leaving physical
memory unused when physical address regions are not aligned to memory
block size.
- "mm/compaction: allow more aggressive proactive compaction" from
Michal Clapinski provides some tuning of the (sadly, hard-coded (more
sadly, not auto-tuned)) thresholds for our invokation of proactive
compaction. In a simple test case, the reduction of a guest VM's
memory consumption was dramatic.
- "Minor cleanups and improvements to swap freeing code" from Kemeng
Shi provides some code cleaups and a small efficiency improvement to
this part of our swap handling code.
- "ptrace: introduce PTRACE_SET_SYSCALL_INFO API" from Dmitry Levin
adds the ability for a ptracer to modify syscalls arguments. At this
time we can alter only "system call information that are used by
strace system call tampering, namely, syscall number, syscall
arguments, and syscall return value.
This series should have been incorporated into mm.git's "non-MM"
branch, but I goofed.
- "fs/proc: extend the PAGEMAP_SCAN ioctl to report guard regions" from
Andrei Vagin extends the info returned by the PAGEMAP_SCAN ioctl
against /proc/pid/pagemap. This permits CRIU to more efficiently get
at the info about guard regions.
- "Fix parameter passed to page_mapcount_is_type()" from Gavin Shan
implements that fix. No runtime effect is expected because
validate_page_before_insert() happens to fix up this error.
- "kernel/events/uprobes: uprobe_write_opcode() rewrite" from David
Hildenbrand basically brings uprobe text poking into the current
decade. Remove a bunch of hand-rolled implementation in favor of
using more current facilities.
- "mm/ptdump: Drop assumption that pxd_val() is u64" from Anshuman
Khandual provides enhancements and generalizations to the pte dumping
code. This might be needed when 128-bit Page Table Descriptors are
enabled for ARM.
- "Always call constructor for kernel page tables" from Kevin Brodsky
ensures that the ctor/dtor is always called for kernel pgtables, as
it already is for user pgtables.
This permits the addition of more functionality such as "insert hooks
to protect page tables". This change does result in various
architectures performing unnecesary work, but this is fixed up where
it is anticipated to occur.
- "Rust support for mm_struct, vm_area_struct, and mmap" from Alice
Ryhl adds plumbing to permit Rust access to core MM structures.
- "fix incorrectly disallowed anonymous VMA merges" from Lorenzo
Stoakes takes advantage of some VMA merging opportunities which we've
been missing for 15 years.
- "mm/madvise: batch tlb flushes for MADV_DONTNEED and MADV_FREE" from
SeongJae Park optimizes process_madvise()'s TLB flushing.
Instead of flushing each address range in the provided iovec, we
batch the flushing across all the iovec entries. The syscall's cost
was approximately halved with a microbenchmark which was designed to
load this particular operation.
- "Track node vacancy to reduce worst case allocation counts" from
Sidhartha Kumar makes the maple tree smarter about its node
preallocation.
stress-ng mmap performance increased by single-digit percentages and
the amount of unnecessarily preallocated memory was dramaticelly
reduced.
- "mm/gup: Minor fix, cleanup and improvements" from Baoquan He removes
a few unnecessary things which Baoquan noted when reading the code.
- ""Enhance sysfs handling for memory hotplug in weighted interleave"
from Rakie Kim "enhances the weighted interleave policy in the memory
management subsystem by improving sysfs handling, fixing memory
leaks, and introducing dynamic sysfs updates for memory hotplug
support". Fixes things on error paths which we are unlikely to hit.
- "mm/damon: auto-tune DAMOS for NUMA setups including tiered memory"
from SeongJae Park introduces new DAMOS quota goal metrics which
eliminate the manual tuning which is required when utilizing DAMON
for memory tiering.
- "mm/vmalloc.c: code cleanup and improvements" from Baoquan He
provides cleanups and small efficiency improvements which Baoquan
found via code inspection.
- "vmscan: enforce mems_effective during demotion" from Gregory Price
changes reclaim to respect cpuset.mems_effective during demotion when
possible. because presently, reclaim explicitly ignores
cpuset.mems_effective when demoting, which may cause the cpuset
settings to violated.
This is useful for isolating workloads on a multi-tenant system from
certain classes of memory more consistently.
- "Clean up split_huge_pmd_locked() and remove unnecessary folio
pointers" from Gavin Guo provides minor cleanups and efficiency gains
in in the huge page splitting and migrating code.
- "Use kmem_cache for memcg alloc" from Huan Yang creates a slab cache
for `struct mem_cgroup', yielding improved memory utilization.
- "add max arg to swappiness in memory.reclaim and lru_gen" from
Zhongkun He adds a new "max" argument to the "swappiness=" argument
for memory.reclaim MGLRU's lru_gen.
This directs proactive reclaim to reclaim from only anon folios
rather than file-backed folios.
- "kexec: introduce Kexec HandOver (KHO)" from Mike Rapoport is the
first step on the path to permitting the kernel to maintain existing
VMs while replacing the host kernel via file-based kexec. At this
time only memblock's reserve_mem is preserved.
- "mm: Introduce for_each_valid_pfn()" from David Woodhouse provides
and uses a smarter way of looping over a pfn range. By skipping
ranges of invalid pfns.
- "sched/numa: Skip VMA scanning on memory pinned to one NUMA node via
cpuset.mems" from Libo Chen removes a lot of pointless VMA scanning
when a task is pinned a single NUMA mode.
Dramatic performance benefits were seen in some real world cases.
- "JFS: Implement migrate_folio for jfs_metapage_aops" from Shivank
Garg addresses a warning which occurs during memory compaction when
using JFS.
- "move all VMA allocation, freeing and duplication logic to mm" from
Lorenzo Stoakes moves some VMA code from kernel/fork.c into the more
appropriate mm/vma.c.
- "mm, swap: clean up swap cache mapping helper" from Kairui Song
provides code consolidation and cleanups related to the folio_index()
function.
- "mm/gup: Cleanup memfd_pin_folios()" from Vishal Moola does that.
- "memcg: Fix test_memcg_min/low test failures" from Waiman Long
addresses some bogus failures which are being reported by the
test_memcontrol selftest.
- "eliminate mmap() retry merge, add .mmap_prepare hook" from Lorenzo
Stoakes commences the deprecation of file_operations.mmap() in favor
of the new file_operations.mmap_prepare().
The latter is more restrictive and prevents drivers from messing with
things in ways which, amongst other problems, may defeat VMA merging.
- "memcg: decouple memcg and objcg stocks"" from Shakeel Butt decouples
the per-cpu memcg charge cache from the objcg's one.
This is a step along the way to making memcg and objcg charging
NMI-safe, which is a BPF requirement.
- "mm/damon: minor fixups and improvements for code, tests, and
documents" from SeongJae Park is yet another batch of miscellaneous
DAMON changes. Fix and improve minor problems in code, tests and
documents.
- "memcg: make memcg stats irq safe" from Shakeel Butt converts memcg
stats to be irq safe. Another step along the way to making memcg
charging and stats updates NMI-safe, a BPF requirement.
- "Let unmap_hugepage_range() and several related functions take folio
instead of page" from Fan Ni provides folio conversions in the
hugetlb code.
* tag 'mm-stable-2025-05-31-14-50' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (285 commits)
mm: pcp: increase pcp->free_count threshold to trigger free_high
mm/hugetlb: convert use of struct page to folio in __unmap_hugepage_range()
mm/hugetlb: refactor __unmap_hugepage_range() to take folio instead of page
mm/hugetlb: refactor unmap_hugepage_range() to take folio instead of page
mm/hugetlb: pass folio instead of page to unmap_ref_private()
memcg: objcg stock trylock without irq disabling
memcg: no stock lock for cpu hot-unplug
memcg: make __mod_memcg_lruvec_state re-entrant safe against irqs
memcg: make count_memcg_events re-entrant safe against irqs
memcg: make mod_memcg_state re-entrant safe against irqs
memcg: move preempt disable to callers of memcg_rstat_updated
memcg: memcg_rstat_updated re-entrant safe against irqs
mm: khugepaged: decouple SHMEM and file folios' collapse
selftests/eventfd: correct test name and improve messages
alloc_tag: check mem_profiling_support in alloc_tag_init
Docs/damon: update titles and brief introductions to explain DAMOS
selftests/damon/_damon_sysfs: read tried regions directories in order
mm/damon/tests/core-kunit: add a test for damos_set_filters_default_reject()
mm/damon/paddr: remove unused variable, folio_list, in damon_pa_stat()
mm/damon/sysfs-schemes: fix wrong comment on damons_sysfs_quota_goal_metric_strs
...
