Merge drm/drm-fixes into drm-misc-fixes

Updating drm-misc-fixes to the state of v6.17-rc1. Begins a new release
cycle.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>

Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
"As usual, many cleanups. The below blurbiage describes 42 patchs

Merge tag 'mm-stable-2025-07-30-15-25' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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
...

show more ...

mm/damon/stat: use damon_call() repeat mode instead of damon_callback

DAMON_STAT uses damon_callback for periodically reading DAMON internal
data. Use its alternative, damon_call() repeat mode.

Li

mm/damon/stat: use damon_call() repeat mode instead of damon_callback

DAMON_STAT uses damon_callback for periodically reading DAMON internal
data. Use its alternative, damon_call() repeat mode.

Link: https://lkml.kernel.org/r/20250712195016.151108-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

show more ...

mm/damon/stat: calculate and expose idle time percentiles

Knowing how much memory is how cold can be useful for understanding
coldness and utilization efficiency of memory. The raw form of DAMON's

mm/damon/stat: calculate and expose idle time percentiles

Knowing how much memory is how cold can be useful for understanding
coldness and utilization efficiency of memory. The raw form of DAMON's
monitoring results has the information. Convert the raw results into the
per-byte idle time distributions and expose it as percentiles metric to
users, as a read-only DAMON_STAT parameter.

In detail, the metrics are calculated as follows. First, DAMON's
per-region access frequency and age information is converted into per-byte
idle time. If access frequency of a region is higher than zero, every
byte of the region has zero idle time. If the access frequency of a
region is zero, every byte of the region has idle time as the age of the
region. Then the logic sorts the per-byte idle times and provides the
value at 0/100, 1/100, ..., 99/100 and 100/100 location of the sorted
array.

The metric can be easily aggregated and compared on large scale production
systems. For example, if an average of 75-th percentile idle time of
machines that collected on similar time is two minutes, it means the
system's 25 percent memory is not accessed at all for two minutes or more
on average. If a workload considers two minutes as unit work time, we can
conclude its working set size is only 75 percent of the memory. If the
system utilizes proactive reclamation and it supports coldness-based
thresholds like DAMON_RECLAIM, the idle time percentiles can be used to
find a more safe or aggressive coldness threshold for aimed memory saving.

Link: https://lkml.kernel.org/r/20250604183127.13968-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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mm/damon/stat: calculate and expose estimated memory bandwidth

The raw form of DAMON's monitoring results captures many details of the
information. However, not every bit of the information is alwa

mm/damon/stat: calculate and expose estimated memory bandwidth

The raw form of DAMON's monitoring results captures many details of the
information. However, not every bit of the information is always required
for understanding practical access patterns. Especially on real world
production systems of high scale time and size, the raw form is difficult
to be aggregated and compared.

Convert the raw monitoring results into a single number metric, namely
estimated memory bandwidth and expose it to users as a read-only
DAMON_STAT parameter. The metric represents access intensiveness
(hotness) of the system. It can easily be aggregated and compared for
high level understanding of the access pattern on large systems.

Link: https://lkml.kernel.org/r/20250604183127.13968-3-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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mm/damon: introduce DAMON_STAT module

Patch series "mm/damon: introduce DAMON_STAT for simple and practical
access monitoring", v2.

DAMON-based access monitoring is not simple due to required DAMON

mm/damon: introduce DAMON_STAT module

Patch series "mm/damon: introduce DAMON_STAT for simple and practical
access monitoring", v2.

DAMON-based access monitoring is not simple due to required DAMON control
and results visualizations. Introduce a static kernel module for making
it simple. The module can be enabled without manual setup and provides
access pattern metrics that easy to fetch and understand the practical
access pattern information, namely estimated memory bandwidth and memory
idle time percentiles.

Background and Problems
=======================

DAMON can be used for monitoring data access patterns of the system and
workloads. Specifically, users can start DAMON to monitor access events
on specific address space with fine controls including address ranges to
monitor and time intervals between samplings and aggregations. The
resulting access information snapshot contains access frequency
(nr_accesses) and how long the frequency was kept (age) for each byte.

The monitoring usage is not simple and practical enough for production
usage. Users should first start DAMON with a number of parameters, and
wait until DAMON's monitoring results capture a reasonable amount of the
time data (age). In production, such manual start and wait is impractical
to capture useful information from a high number of machines in a timely
manner.

The monitoring result is also too detailed to be used on production
environments. The raw results are hard to be aggregated and/or compared
for production environments having a large scale of time, space and
machines fleet.

Users have to implement and use their own automation of DAMON control and
results processing. It is repetitive and challenging since there is no
good reference or guideline for such automation.

Solution: DAMON_STAT
====================

Implement such automation in kernel space as a static kernel module,
namely DAMON_STAT. It can be enabled at build, boot, or run time via its
build configuration or module parameter. It monitors the entire physical
address space with monitoring intervals that auto-tuned for a reasonable
amount of access observations and minimum overhead. It converts the raw
monitoring results into simpler metrics that can easily be aggregated and
compared, namely estimated memory bandwidth and idle time percentiles.

Understanding of the metrics and the user interface of DAMON_STAT is
essential. Refer to the commit messages of the second and the third
patches of this patch series for more details about the metrics. For the
user interface, the standard module parameters system is used. Refer to
the fourth patch of this patch series for details of the user interface.

Discussions
===========

The module aims to be useful on production environments constructed with a
large number of machines that run a long time. The auto-tuned monitoring
intervals ensure a reasonable quality of the outputs. The auto-tuning
also ensures its overhead be reasonable and low enough to be enabled
always on the production. The simplified monitoring results metrics can
be useful for showing both coldness (idle time percentiles) and hotness
(memory bandwidth) of the system's access pattern. We expect the
information can be useful for assessing system memory utilization and
inspiring optimizations or investigations on both kernel and user space
memory management logics for large scale fleets.

We hence expect the module is good enough to be just used in most
environments. For special cases that require a custom access monitoring
automation, users will still benefit by using DAMON_STAT as a reference or
a guideline for their specialized automation.


This patch (of 4):

To use DAMON for monitoring access patterns of the system, users should
manually start DAMON via DAMON sysfs ABI with a number of parameters for
specifying the monitoring target address space, address ranges, and
monitoring intervals. After that, users should also wait until desired
amount of time data is captured into DAMON's monitoring results. It is
bothersome and take a long time to be practical for access monitoring on
large fleet level production environments.

For access-aware system operations use cases like proactive cold memory
reclamation, similar problems existed. We we solved those by introducing
dedicated static kernel modules such as DAMON_RECLAIM.

Implement such static kernel module for access monitoring, namely
DAMON_STAT. It monitors the entire physical address space with auto-tuned
monitoring intervals. The auto-tuning is set to capture 4 % of observable
access events in each snapshot while keeping the sampling intervals 5
milliseconds in minimum and 10 seconds in maximum. From a few production
environments, we confirmed this setup provides high quality monitoring
results with minimum overheads. The module therefore receives only one
user input, whether to enable or disable it. It can be set on build or
boot time via build configuration or kernel boot command line. It can
also be overridden at runtime.

Note that this commit only implements the DAMON control part of the
module. Users could get the monitoring results via damon:damon_aggregated
tracepoint, but that's of course not the recommended way. Following
commits will implement convenient and optimized ways for serving the
monitoring results to users.

[sj@kernel.org: use IS_ENABLED() for enabled initial value]
Link: https://lkml.kernel.org/r/20250604205619.18929-1-sj@kernel.org
[sj@kernel.org: reset enabled when DAMON start failed]
Link: https://lkml.kernel.org/r/20250706184750.36588-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250604183127.13968-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250604183127.13968-2-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

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