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v7.3-rc1
44 Commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
ed3b875bea |
mm.git review status for mm-hotfixes-stable..mm-stable
Everything:
Total patches: 501
Reviews/patch: 1.66
Reviewed rate: 70%
Excluding DAMON:
Total patches: 356
Reviews/patch: 2.26
Reviewed rate: 90%
Excluding DAMON and selftests:
Total patches: 329
Reviews/patch: 2.31
Reviewed rate: 92%
Excluding DAMON, selftests and maple_tree:
Total patches: 328
Reviews/patch: 2.31
Reviewed rate: 92%
Summary of patch series in this merge:
- The 2 patch series "mm: drop "sub" prefix from various places" from
Dev Jain implements some page->folio conversion and a naming cleanup.
- The 2 patch series "mm/kasan: remove redundant initialization for
kasan_flag_write_only" from Igor Putko provides some KASAN cleanup work.
- The 2 patch series "mm/filemap: reduce unnecessary xarray lookups"
from Chi Zhiling provides a small speedup in the pagecaache read code.
- The 4 patch series "mm/percpu: Fix possible NOFS/NOIO reclaim
recursion" from Kaitao Cheng improves a few things in the vmalloc code -
mainly the avoidance of GFP_KERNEL allocations when the caller asked for
GFP_NOFS or GFP_NOIO.
- The 3 patch series "mm/kmemleak: avoid soft lockup when scanning task
stacks" from Breno Leitao avoids a soft lockup watchdog trigger from the
kmemleak scanning code in extreme situations.
- The 6 patch series "mm/page_owner: misc cleanups" from Ye Liu is a
collection of unrelated cleanups to the page_owner code. For some
reason lots of people have been working on the page_owner code this
cycle.
- The 4 patch series "mm: convert to walk_page_range_vma() to eliminate
find_vma()" from Kefeng Wang simplifies and accelerates the page walking
library function.
- The 3 patch series "mm/migrate: preparatory cleanups for batch copy
and offload" from Shivank Garg implements cleanups in the migration
code.
- The 4 patch series "mm/page_owner: add per-fd filter infrastructure
for print_mode and NUMA filtering" from Zhen Ni provides per-fd
filtering to page_owner in order to reduce the sometimes vast amount of
output it can produce.
- The 19 patch series "mm: Refactor bootmem gigantic hugepage
allocation" from Muchun Song is a "set of fixes and preparatory cleanups
around bootmem HugeTLB handling, sparse initialization ordering, and
related vmemmap setup".
- The 4 patch series "mm/zsmalloc: reduce lock contention in zs_free()"
from Wenchao Hao reduces lock contention in zs_free(), which dominates
the unmap path under memory pressure on Android (LMK kills) and on x86
servers running zswap-heavy workloads. Up to 1.83x improvement in
microbenchmarking.
- The 2 patch series "move alloc_tag.c file under mm/" from Suren
Baghdasaryan does that.
- The 6 patch series "samples/damon: handle damon_{start,stop}()
failures" from SJ Park fixes improper handling of damon_start(),
damon_stop(), and damon_call() failures across DAMON sample modules to
prevent potential memory leaks, operation disruptions and use-after-free
bugs.
- The 11 patch series "mm/damon/sysfs: kobject_del() directories that
users can create/remove" from SJ Park resolves an issue where delayed
sysfs directory removal under CONFIG_DEBUG_KOBJECT_RELEASE causes
creation failures due to duplicate directory names by adding missing
kobject_del() calls before creating new directories.
- The 3 patch series "mm: cleanup clear_not_present_full_ptes()" from
David Hildenbrand cleans up the core pte handling code.
- The 3 patch series "selftests/damon: misc fixes for test bugs" from
Kunwu Chan fixes several bugs in the DAMON selftests.
- The 2 patch series "selftests/damon: fix memcg_path staging handling"
from Cheng Nie fixes a bug in _damon_sysfs.py for damos_filter
memcg_path setup, and adds a test case for it in sysfs.py.
- The 2 patch series "selftests/damon: test kdamond refresh_ms" from
Ruslan Valiyev introduces selftest coverage for DAMON's refresh_ms sysfs
feature by updating the test control module and verifying that scheme
stats update automatically without manual intervention.
- The 5 patch series "mm/damon: five misc fixups" from Akinobu Mita
contains miscellaneous DAMON fixups.
- The 2 patch series "mm/damon/core: detect internal variation above
max_nr_regions/2" from Jiayuan Chen fixes DAMON's region splitting
behavior when region counts exceed half the maximum budget by
dynamically scaling down the split fraction as the limit approaches,
preventing large regions from staying un-split, and adds corresponding
KUnit test coverage.
- The 6 patch series "mm: preparatory patches for PMD level swap
entries" from Usama Arif refactors and cleans up PMD softleaf helpers,
call sites, and architecture flags to lay the groundwork for a follow-up
series that introduces PMD page table swap entries.
- The 11 patch series "mm/damon: update, optimize, and clean up doc,
tests, and code" from SJ Park updates DAMON design and ABI
documentation, expands unit and selftest coverage, optimizes
damon_commit_target_regions(), and cleans up recently added sysfs
interface code for better readability.
- The 2 patch series "mm/vmpressure: reduce CPU, memory and code
overhead on cgroup v2" from Usama Arif optimizes vmpressure() by
skipping unnecessary work on cgroup v2 for userspace event notifications
and refactors v1-only eventfd handling into mm/memcontrol-v1.c to reduce
memory overhead and code complexity.
- The 10 patch series "selftests/mm: refactor pkey helpers and fix mmap
error handling" from Hongfu Li refactors pkeys shared tracing and
assertion helpers into a common file, unifies protection key selftests
to use consistent diagnostic logging and assertions, and enforces
standardized MAP_FAILED return checks for mmap() calls across the tests.
- The 18 patch series "mm/damon: optimize out nr_accesses_bp" from SJ
Park replaces the error-prone, continuously updated nr_accesses_bp field
in damon_region with an on-demand moving sum function
(damon_nr_accesses_mvsum()), reducing structure memory overhead and
avoiding state corruption bugs.
- The 6 patch series "Open HugeTLB allocation routine for more generic
use" from Ackerley Tng decouples HugeTLB folio allocation from VMA
dependencies by introducing hugetlb_alloc_folio(), enabling subsystems
like guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs.
- The 3 patch series "mm/damon: provide pseudo moving sum probe_hits"
from SJ Park integrates DAMON's probe_hits attribute counter into the
pseudo moving sum infrastructure, enabling real-time, online monitoring
without waiting for full aggregation intervals.
- The 18 patch series "mm: Some cleanups for page allocator APIs" from
Brendan Jackman simplifies and refactors the page allocator entry points
and flags by unifying allocation paths, adding internal alloc_flags
arguments, and eliminating redundant __ prefixed alloc_pages variants.
- The 5 patch series "Fix incorrect access of hugetlb pte entries" from
Dev Jain enforces the consistent use of huge_ptep_get() instead of
ptep_get() for HugeTLB entries and fixes an unaligned address issue in
arm64's huge_ptep_get() implementation.
- The 8 patch series "mm/damon: validate all parameters in the core"
from SJ Park consolidates parameter validation into the DAMON core
specifically within damon_start() and damon_commit_ctx() to centralize
error checking, eliminate caller-side redundant checks and to improve
maintenance efficiency.
- The 3 patch series "tools/mm/page_owner_sort: fix filtering and
cleanup issues" from Yichong Chen renames is_need() to filter_record()
for clearer return semantics, fixes per-record allocation memory leaks
and bounds output copies in search_pattern() to address an existing
buffer issue.
- The 4 patch series "memcg: bail out reclaim when memcg is dying" from
Jiayuan Chen mitigates a system-wide stall which occurs when a cgroup is
removed while one of its memory control files is doing synchronous
reclaim.
- The 5 patch series "mm/memory-failure: add panic option for
unrecoverable pages" from Breno Leitao introduces an opt-in
vm.panic_on_unrecoverable_memory_failure sysctl that immediately panics
the kernel on unrecoverable memory errors in kernel-owned pages to
preserve error context and prevent delayed, silent data corruption.
- The 11 patch series "mm/damon: refactor damon_{start,stop,commit}()
for simple error handling" from SJ Park refactors the DAMON core API
functions to guarantee that all contexts are fully stopped when
damon_start(), damon_stop(), or damon_commit() fail, eliminating the
need for complex and error-prone caller-side cleanup code.
- The 5 patch series "Keep tail page private zero at free and folio
split" from Zi Yan adds checks to ensure tail_page->private is zero when
freeing compound or high-order pages and when promoting tail pages
during large folio splits. By validating these fields at free and split
time, it allows the removal of redundant private field clearing inside
prep_compound_tail().
- The 4 patch series "mm: drop redundant lru_add_drain in anon folio
reuse paths" from Barry Song eliminates redundant lru_add_drain() calls
in wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead.
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads.
- The 3 patch series "mm: clean up folio LRU and swap declarations" from
Jianyue Wu reorganizes folio LRU and swap code by relocating
page-cluster state to mm/swap_state.c, renaming mm/swap.c to mm/folio.c,
and moving MM-internal reclaim declarations into mm/internal.h.
- The 15 patch series "userfaultfd: working set tracking for VM guest
memory" from Kiryl Shutsemau adds userfaultfd support for tracking the
working set of VM guest memory, so a VMM can identify hot pages and
reclaim cold ones to tiered or remote storage.
- The 10 patch series "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part
2)" from David Hildenbrand removes the remaining pieces of
CONFIG_HAVE_BOOTMEM_INFO_NODE, performing some smaller cleanups around
freeing of reserved vmemmap pages on the way.
- The 7 patch series "mm/damon: update probe hits for runtime parameter
commits" from SJ Park ensures that DAMON's probe_hits attribute counter
is properly updated when monitoring intervals are changed at runtime,
matching the behavior of nr_accesses. To achieve this, it refactors and
renames existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- The 3 patch series "KSM: performance optimizations for rmap_walk_ksm"
from xu xin resolves a severe KSM reverse-mapping performance bottleneck
where thousands of split VMAs sharing a single anon_vma cause extended
lock contention. By adding an interval-filtering check during the rmap
walk, it reduces worst-case anon_vma lock hold times from over 500ms
down to under 2ms, preventing application freezes and latency spikes
under memory pressure.
- The 3 patch series "mm: split a couple of headers from internal.h"
from Mike Rapoport splits declarations related to mm_init, memblock,
vmalloc and sparse into new headers.
- The 2 patch series "KSM: use linear_page_index in collect_procs_ksm()"
from xu xin applies the interval tree optimization from rmap_walk_ksm()
to collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling. It hoists loop-invariant address
initialization and restricts the anon_vma_interval_tree_foreach walk to
a targeted page offset range, reducing redundant checks and improving
lookup efficiency.
- The 3 patch series "selftests/mm: avoid false failures in hugetlb and
KSM tests" from Sayali Patil fixes issues in the hugetlb and KSM MM
selftest categories that can report failures when the prerequisites for
the tests are not satisfied.
- The 19 patch series "mm/damon: introduce data attributes only
monitoring" from SJ Park introduces attribute-weighted region management
in DAMON, allowing users to prioritize specific data attributes (such as
page sizes or cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely disable
access tracking and adjust monitoring regions based on weighted
probe-hit counters to optimize monitoring quality for attribute-focused
workloads.
- The 8 patch series "mm/hmm: Add mmap lock-drop support for
userfaultfd-backed mappings" from Stanislav Kinsburskii extends
hmm_range_fault() to support userfaultfd-backed regions by allowing the
mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd regions
while preserving backward compatibility for existing callers.
- The 33 patch series "mm: make VMA page offset handling more
consistent" from Lorenzo Stoakes cleans up and standardizes how
vma->vm_pgoff is accessed and manipulated across file-backed and
anonymous mappings in the kernel.
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while renaming
rmap interval tree helpers to better reflect their functionality.
These changes establish a cleaner foundation for future work that will
unify virtual page offset indexing for all anonymous and CoW'd folios.
- The 3 patch series "mm: handle device-private PMDs in walk callbacks"
from Usama Arif addresses kernel panics and state corruption caused by
MM walk callbacks reaching non-present device-private PMD swap entries
created during HMM migrations.
It ensures that functions which acquire pmd_trans_huge_lock() properly
recognize device-private PMDs instead of assuming a present THP or a
standard migration entry.
- The 5 patch series "mm/rmap: Refactor try_to_unmap_one" from Dev Jain
refactors try_to_unmap_one by modularizing Hugetlb, anonymous-lazyfree,
and anonymous-swapbacked logic into dedicated functions, laying the
structural groundwork for batched anonymous large folio unmapping.
- The 4 patch series "Docs/ABI/damon: sysfs ABI document fixes and
additions" from Song Hu fixes typos and fills in missing entries in the
DAMON sysfs ABI document.
- The 10 patch series "dax/kmem: atomic whole-device hotplug via sysfs"
from Gregory Price introduces an atomic sysfs state attribute and
supporting DAX/MM infrastructure to prevent userland races when
offlining and removing entire memory regions.
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- The 13 patch series "mm: convert more vm_flags_t users to vma_flags_t"
from Lorenzo Stoakes continues transitioning the kernel from the
deprecated vm_flags_t type to vma_flags_t across core memory management
infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- The 2 patch series "Two small patches to clean up mm/mm_slot.h" from
xu xin refactors mm_slot.h by introducing mm_slot_remove() to unify
duplicate slot deletion sequences in khugepaged and KSM. It also adds
code documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- The 10 patch series "mm/damon/core: hide core-private struct fields"
from SJ Park cleans up DAMON core structures by consistently marking
internal-only fields with private: comment tags to prevent improper
direct access from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- The 6 patch series "mm/damon: unurgent fixes for infinite loop, NULL
de-ref and races" from SJ Park addresses potential infinite loops, NULL
dereferences, and race conditions identified in DAMON.
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- The 2 patch series "mm/page_alloc: fixes for free_pages_nolock() on
RT/UP" from Brendan Jackman fixes an NMI safety flaw in
__free_frozen_pages() where freeing pages on non-SMP or PREEMPT_RT
kernels can bypass can_spin_trylock() checks via non-PCP or isolated
migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- The 4 patch series "mm/page_alloc: couple of followups for recent
cleanups" from Brendan Jackman cleans up and updates page allocator
nomenclature, documentation, and debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete VM_BUG_ON()
assertions in allocation paths.
- The 3 patch series "mm/mseal: further cleanups" from Lorenzo Stoakes
refactors and simplifies the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO, eliminates
mm_struct parameters to enforce that sealing applies only to
current->mm, and streamlines overall logic and comments with no
functional changes intended.
- The 4 patch series "mm/vmscan: fix swappiness=max and clean up
per-node proactive reclaim" from Ridong Chen resolves reclaim behavior
bugs and cleans up function parameters across memory reclaim paths.
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead of
collapsing all failures into -EAGAIN, and removes the obsolete gfp_mask
parameter from __node_reclaim().
- The 6 patch series "mm: mincore: misc cleanups" from Kefeng Wang
cleans up and simplifies the mincore code. Most importantly, it removes
the historical special behavior that always reports VM_PFNMAP pages as
non-resident.
- The 2 patch series "mm/huge_memory: drop dead split helper variants"
from Kiryl Shutsemau implements two trivial cleanups in the folio split
API.
- The 7 patch series "mm/damon: fix uninitialized DAMOS field and kunit
exec expectation bugs" from SJ Park resolves minor operational and
testing bugs in DAMON identified by Sashiko. It initializes the
damos->last_applied field to prevent occasional efficiency degradation
and fixes invalid memory accesses in DAMON KUnit tests during test
failure handling.
- The 3 patch series "cleanup for stable_page_flags()" from Jinjiang Tu
cleans up and refactors stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- The 3 patch series "Batch unmap of uffd-wp file folios" from Dev Jain
extends batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching capabilities
to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- The 3 patch series "mm/early_ioremap: clarify and clean up
early_ioremap_reset()" from Sang-Heon Jeon clarifies and cleans up the
architecture-specific usage of __late_set_fixmap() and
__late_clear_fixmap() after early_ioremap_reset().
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset calls
in the RISC-V and ARM64 architectures.
- The 4 patch series "mm: fix reclaim storms in defrag_mode" from
Johannes Weiner addresses severe performance regressions, swap storms,
and spurious OOMs caused by vm.defrag_mode=1 under high memory pressure
in Meta production.
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- The 2 patch series "zram: lockmap tweaks" from Sebastian Siewior
optimizes and fixes lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolating lock classes across multiple instances.
It reduces memory overhead by replacing per-entry lockdep_map instances
with a single map per struct zram, and assigns a dynamic lock_class_key
to each instance to prevent false deadlock reports when different zram
devices are backed by distinct filesystems.
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Merge tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm: drop "sub" prefix from various places" (Dev Jain)
page->folio conversion and a naming cleanup
- "mm/kasan: remove redundant initialization for kasan_flag_write_only"
(Igor Putko)
KASAN cleanup work
- "mm/filemap: reduce unnecessary xarray lookups" (Chi Zhiling)
Small speedup in the pagecaache read code
- "mm/percpu: Fix possible NOFS/NOIO reclaim recursion" (Kaitao Cheng)
Improve the vmalloc code - mainly the avoidance of GFP_KERNEL
allocations when the caller asked for GFP_NOFS or GFP_NOIO
- "mm/kmemleak: avoid soft lockup when scanning task stacks" (Breno
Leitao)
Avoid a soft lockup watchdog trigger from the kmemleak scanning code
in extreme situations
- "mm/page_owner: misc cleanups" (Ye Liu)
Cleanups to the page_owner code. For some reason lots of people have
been working on the page_owner code this cycle.
- "mm: convert to walk_page_range_vma() to eliminate find_vma()"
(Kefeng Wang)
Simplify and accelerate the page walking library function
- "mm/migrate: preparatory cleanups for batch copy and offload"
(Shivank Garg)
Cleanups in the migration code
- "mm/page_owner: add per-fd filter infrastructure for print_mode and
NUMA filtering" (Zhen Ni)
Per-fd filtering to page_owner in order to reduce the sometimes vast
amount of output it can produce
- "mm: Refactor bootmem gigantic hugepage allocation" (Muchun Song)
Fixes and preparatory cleanups around bootmem HugeTLB handling,
sparse initialization ordering, and related vmemmap setup
- "mm/zsmalloc: reduce lock contention in zs_free()" (Wenchao Hao)
Reduce lock contention in zs_free(), which dominates the unmap path
under memory pressure on Android (LMK kills) and on x86 servers
running zswap-heavy workloads.
Up to 1.83x improvement in microbenchmarking.
- "move alloc_tag.c file under mm/" (Suren Baghdasaryan)
- "samples/damon: handle damon_{start,stop}() failures" (SJ Park)
Fix improper handling of damon_start(), damon_stop(), and
damon_call() failures across DAMON sample modules to prevent
potential memory leaks, operation disruptions and use-after-free
bugs
- "mm/damon/sysfs: kobject_del() directories that users can
create/remove" (SJ Park)
Fix delayed sysfs directory removal under DEBUG_KOBJECT_RELEASE
causeing creation failures due to duplicate directory names by adding
missing kobject_del() calls before creating new directories
- "mm: cleanup clear_not_present_full_ptes()" (David Hildenbrand)
Clean up the core pte handling code
- "selftests/damon: misc fixes for test bugs" (Kunwu Chan)
Fix several bugs in the DAMON selftests
- "selftests/damon: fix memcg_path staging handling" (Cheng Nie)
Fix a bug in _damon_sysfs.py for damos_filter memcg_path setup, and
add a test case for it in sysfs.py.
- "selftests/damon: test kdamond refresh_ms" (Ruslan Valiyev)
Selftest coverage for DAMON's refresh_ms sysfs feature by updating
the test control module and verifying that scheme stats update
automatically without manual intervention
- "mm/damon: five misc fixups" (Akinobu Mita)
Miscellaneous DAMON fixups.
- "mm/damon/core: detect internal variation above max_nr_regions/2"
(Jiayuan Chen)
Fix DAMON's region splitting behavior when region counts exceed half
the maximum budget by dynamically scaling down the split fraction as
the limit approaches, preventing large regions from staying un-split,
and add corresponding KUnit test coverage
- "mm: preparatory patches for PMD level swap entries" (Usama Arif)
Refactor and clean up PMD softleaf helpers, call sites, and
architecture flags to lay the groundwork for a follow-up series that
introduces PMD page table swap entries
- "mm/damon: update, optimize, and clean up doc, tests, and code" (SJ
Park)
Update DAMON design and ABI documentation, expands unit and selftest
coverage, optimize damon_commit_target_regions(), and clean up
recently added sysfs interface code for better readability
- "mm/vmpressure: reduce CPU, memory and code overhead on cgroup v2"
(Usama Arif)
Optimize vmpressure() by skipping unnecessary work on cgroup v2 for
userspace event notifications and refactor v1-only eventfd handling
into mm/memcontrol-v1.c to reduce memory overhead and code complexity
- "selftests/mm: refactor pkey helpers and fix mmap error handling"
(Hongfu Li)
Refactor pkeys shared tracing and assertion helpers into a common
file, unify protection key selftests to use consistent diagnostic
logging and assertions, and enforce standardized MAP_FAILED return
checks for mmap() calls across the tests
- "mm/damon: optimize out nr_accesses_bp" (SJ Park)
Replace the error-prone, continuously updated nr_accesses_bp field in
damon_region with an on-demand moving sum function, reducing
structure memory overhead and avoiding state corruption bugs
- "Open HugeTLB allocation routine for more generic use" (Ackerley Tng)
Decouple HugeTLB folio allocation from VMA dependencies by
introducing hugetlb_alloc_folio(), enabling subsystems like
guest_memfd to allocate HugeTLB folios without standard VMA
reservations or pseudo-VMAs
- "mm/damon: provide pseudo moving sum probe_hits" (SJ Park)
Integrate DAMON's probe_hits attribute counter into the pseudo moving
sum infrastructure, enabling real-time, online monitoring without
waiting for full aggregation intervals
- "mm: Some cleanups for page allocator APIs" (Brendan Jackman)
Simplify and refactor the page allocator entry points and flags by
unifying allocation paths, adding internal alloc_flags arguments, and
eliminating redundant __ prefixed alloc_pages variants.
- "Fix incorrect access of hugetlb pte entries" (Dev Jain)
Enforce the consistent use of huge_ptep_get() instead of ptep_get()
for HugeTLB entries and fixes an unaligned address issue in arm64's
huge_ptep_get() implementation
- "mm/damon: validate all parameters in the core" (SJ Park)
Consolidate parameter validation into the DAMON core specifically
within damon_start() and damon_commit_ctx() to centralize error
checking, eliminate caller-side redundant checks and to improve
maintenance efficiency
- "tools/mm/page_owner_sort: fix filtering and cleanup issues" (Yichong
Chen)
Rename is_need() to filter_record() for clearer return semantics, fix
per-record allocation memory leaks and bound output copies in
search_pattern() to address an existing buffer issue
- "memcg: bail out reclaim when memcg is dying" (Jiayuan Chen)
Mitigate a system-wide stall which occurs when a cgroup is removed
while one of its memory control files is doing synchronous reclaim
- "mm/memory-failure: add panic option for unrecoverable pages" (Breno
Leitao)
Introduce an opt-in vm.panic_on_unrecoverable_memory_failure sysctl
that immediately panics the kernel on unrecoverable memory errors in
kernel-owned pages to preserve error context and prevent delayed,
silent data corruption
- "mm/damon: refactor damon_{start,stop,commit}() for simple error
handling" (SJ Park)
Refactor the DAMON core API functions to guarantee that all contexts
are fully stopped when damon_start(), damon_stop(), or damon_commit()
fail, eliminating the need for complex and error-prone caller-side
cleanup code
- "Keep tail page private zero at free and folio split" (Zi Yan)
Add checks to ensure tail_page->private is zero when freeing compound
or high-order pages and when promoting tail pages during large folio
splits. By validating these fields at free and split time, it allows
the removal of redundant private field clearing inside
prep_compound_tail()
- "mm: drop redundant lru_add_drain in anon folio reuse paths" (Barry
Song)
Eliminate redundant lru_add_drain() calls in
wp_can_reuse_anon_folio() and do_swap_page() to reduce LRU lock
contention and system overhead
By validating folio refcounts against the LRU cache before draining
and removing unnecessary drains in the swap path, it achieves up to a
30.5% reduction in drain calls during heavy swap workloads
- "mm: clean up folio LRU and swap declarations" (Jianyue Wu)
Reorganize folio LRU and swap code by relocating page-cluster state
to mm/swap_state.c, renaming mm/swap.c to mm/folio.c, and moving
MM-internal reclaim declarations into mm/internal.h.
- "userfaultfd: working set tracking for VM guest memory" (Kiryl
Shutsemau)
Add userfaultfd support for tracking the working set of VM guest
memory, so a VMM can identify hot pages and reclaim cold ones to
tiered or remote storage
- "mm: remove CONFIG_HAVE_BOOTMEM_INFO_NODE (Part 2)" (David
Hildenbrand)
Remove the remaining pieces of CONFIG_HAVE_BOOTMEM_INFO_NODE,
performing some smaller cleanups around freeing of reserved vmemmap
pages on the way.
- "mm/damon: update probe hits for runtime parameter commits" (SJ Park)
Ensure that DAMON's probe_hits attribute counter is properly updated
when monitoring intervals are changed at runtime, matching the
behavior of nr_accesses. To achieve this, it refactors and renames
existing helper functions for shared use, applies the updates to
probe_hits, and handles edge cases in damon_probe_hits_mvsum() to
maintain measurement accuracy.
- "KSM: performance optimizations for rmap_walk_ksm" (xu xin)
Resolve a severe KSM reverse-mapping performance bottleneck where
thousands of split VMAs sharing a single anon_vma cause extended lock
contention.
By adding an interval-filtering check during the rmap walk, it
reduces worst-case anon_vma lock hold times from over 500ms down to
under 2ms, preventing application freezes and latency spikes under
memory pressure.
- "mm: split a couple of headers from internal.h" (Mike Rapoport)
Split declarations related to mm_init, memblock, vmalloc and sparse
into new headers
- "KSM: use linear_page_index in collect_procs_ksm()" (xu xin)
Apply the interval tree optimization from rmap_walk_ksm() to
collect_procs_ksm() to avoid iterating over non-matching VMAs during
KSM memory error handling.
It hoists loop-invariant address initialization and restricts the
anon_vma_interval_tree_foreach walk to a targeted page offset range,
reducing redundant checks and improving lookup efficiency.
- "selftests/mm: avoid false failures in hugetlb and KSM tests" (Sayali
Patil)
Fix issues in the hugetlb and KSM MM selftest categories that can
report failures when the prerequisites for the tests are not
satisfied
- "mm/damon: introduce data attributes only monitoring" (SJ Park)
Introduce attribute-weighted region management in DAMON, allowing
users to prioritize specific data attributes (such as page sizes or
cgroups) over or instead of access monitoring.
By assigning weights to attribute probes, DAMON can completely
disable access tracking and adjust monitoring regions based on
weighted probe-hit counters to optimize monitoring quality for
attribute-focused workloads.
- "mm/hmm: Add mmap lock-drop support for userfaultfd-backed mappings"
(Stanislav Kinsburskii)
Extend hmm_range_fault() to support userfaultfd-backed regions by
allowing the mmap lock to be dropped during fault handling via a new
hmm_range_fault_locked() helper.
By accepting a locked pointer and signaling retry status when lock
release occurs, it enables page fault resolution in userfaultfd
regions while preserving backward compatibility for existing callers.
- "mm: make VMA page offset handling more consistent" (Lorenzo Stoakes)
Clean up and standardize how vma->vm_pgoff is accessed and
manipulated across file-backed and anonymous mappings in the kernel
It introduces dedicated helper functions such as vma_start_pgoff(),
vma_end_pgoff(), vma_set_pgoff() and linear_page_delta() while
renaming rmap interval tree helpers to better reflect their
functionality.
These changes establish a cleaner foundation for future work that
will unify virtual page offset indexing for all anonymous and CoW'd
folios.
- "mm: handle device-private PMDs in walk callbacks" (Usama Arif)
Address kernel panics and state corruption caused by MM walk
callbacks reaching non-present device-private PMD swap entries
created during HMM migrations
It ensures that functions which acquire pmd_trans_huge_lock()
properly recognize device-private PMDs instead of assuming a present
THP or a standard migration entry.
- "mm/rmap: Refactor try_to_unmap_one" (Dev Jain)
Refactor try_to_unmap_one by modularizing Hugetlb,
anonymous-lazyfree, and anonymous-swapbacked logic into dedicated
functions, laying the structural groundwork for batched anonymous
large folio unmapping.
- "Docs/ABI/damon: sysfs ABI document fixes and additions" (Song Hu)
Fix typos and fills in missing entries in the DAMON sysfs ABI
document
- "dax/kmem: atomic whole-device hotplug via sysfs" (Gregory Price)
Introduce an atomic sysfs state attribute and supporting DAX/MM
infrastructure to prevent userland races when offlining and removing
entire memory regions
By adding an unplugged state alongside standard online modes, it
enables whole-device atomic hotplug control while preserving backward
compatibility.
- "mm: convert more vm_flags_t users to vma_flags_t" (Lorenzo Stoakes)
Continue transitioning the kernel from the deprecated vm_flags_t type
to vma_flags_t across core memory management infrastructure.
It replaces legacy type usage in core functions such as do_mmap(),
unmapped area allocation, mm->def_vma_flags, and VMA operations like
mlock, mprotect, and mremap.
- "Two small patches to clean up mm/mm_slot.h" (xu xin)
Refactor mm_slot.h by introducing mm_slot_remove() to unify duplicate
slot deletion sequences in khugepaged and KSM. It also adds code
documentation explaining why mm_slot_lookup and mm_slot_insert must
remain as preprocessor macros rather than static inline functions.
- "mm/damon/core: hide core-private struct fields" (SJ Park)
Clean up DAMON core structures by consistently marking internal-only
fields with private: comment tags to prevent improper direct access
from outer layers.
It enforces encapsulation across core structures including
damon_region, damon_target, and damon_ctx and updates DAMON_SYSFS to
interact through approved access APIs instead of exposing raw struct
members.
- "mm/damon: unurgent fixes for infinite loop, NULL de-ref and races"
(SJ Park)
Address potential infinite loops, NULL dereferences, and race
conditions identified in DAMON
It fixes an infinite loop triggered by extreme user configurations, a
NULL pointer dereference within unit tests and minor monitoring
accuracy degradation caused by subtle runtime races.
- "mm/page_alloc: fixes for free_pages_nolock() on RT/UP" (Brendan
Jackman)
Fix an NMI safety flaw in __free_frozen_pages() where freeing pages
on non-SMP or PREEMPT_RT kernels can bypass can_spin_trylock() checks
via non-PCP or isolated migration paths.
It also resolves potential kernel crashes and privilege escalation
risks triggered when BPF tracing runs in NMI context alongside memory
hotplug or large allocation frees.
- "mm/page_alloc: couple of followups for recent cleanups" (Brendan
Jackman)
Clean up and update page allocator nomenclature, documentation, and
debug assertions.
It aligns internal FPI_ flags with the public "nolock" naming
convention, removes outdated internal implementation details from
high-level page allocator comments, and eliminates obsolete
VM_BUG_ON() assertions in allocation paths.
- "mm/mseal: further cleanups" (Lorenzo Stoakes)
Refactor and simplify the mseal implementation by clarifying API
boundaries and removing unnecessary code complexity.
It replaces generic do_mseal() usage outside the syscall with a
dedicated mseal_mmap_page_zero() helper for MMAP_PAGE_ZERO,
eliminates mm_struct parameters to enforce that sealing applies only
to current->mm, and streamlines overall logic and comments with no
functional changes intended.
- "mm/vmscan: fix swappiness=max and clean up per-node proactive
reclaim" (Ridong Chen)
Resolve reclaim behavior bugs and clean up function parameters across
memory reclaim paths
It fixes swappiness=max in both standard reclaim and MGLRU so
unswappable anonymous memory no longer falls back to evicting page
cache, ensures reclaim_store() returns accurate error codes instead
of collapsing all failures into -EAGAIN, and removes the obsolete
gfp_mask parameter from __node_reclaim().
- "mm: mincore: misc cleanups" (Kefeng Wang)
Clean up and simplifies the mincore code. Most importantly, it
removes the historical special behavior that always reports VM_PFNMAP
pages as non-resident.
- "mm/huge_memory: drop dead split helper variants" (Kiryl Shutsemau)
Two trivial cleanups in the folio split API
- "mm/damon: fix uninitialized DAMOS field and kunit exec expectation
bugs" (SJ Park)
Resolve minor operational and testing bugs in DAMON identified by
Sashiko. It initializes the damos->last_applied field to prevent
occasional efficiency degradation and fixes invalid memory accesses
in DAMON KUnit tests during test failure handling.
- "cleanup for stable_page_flags()" (Jinjiang Tu)
Clean up and refactor stable_page_flags() used by /proc/kpageflags
without altering functionality.
It uses BIT_ULL() to prevent shift-overflow warnings on 64-bit flag
bits, converts folio-specific flag checks to standard folio_test_*()
helpers, and removes redundant CONFIG_PAGE_IDLE_FLAG handling.
- "Batch unmap of uffd-wp file folios" (Dev Jain)
Extend batched folio unmapping support to file folios within
userfaultfd write-protect (uffd-wp) VMAs by adding batching
capabilities to pte_install_uffd_wp_if_needed().
This removes special-case restrictions on uffd-wp VMAs in
try_to_unmap_one(), significantly simplifying the function's control
flow and complexity.
- "mm/early_ioremap: clarify and clean up early_ioremap_reset()"
(Sang-Heon Jeon)
Clarify and clean up the architecture-specific usage of
__late_set_fixmap() and __late_clear_fixmap() after
early_ioremap_reset()
It adds explicit documentation regarding when early_ioremap_reset()
must be called and removes redundant macro definitions and reset
calls in the RISC-V and ARM64 architectures.
- "mm: fix reclaim storms in defrag_mode" (Johannes Weiner)
Address severe performance regressions, swap storms, and spurious
OOMs caused by vm.defrag_mode=1 under high memory pressure in Meta
production
It updates the page allocator slowpath so non-movable allocation
requests actively trigger direct reclaim and direct compaction at
pageblock_order scale, allowing them to claim whole pageblocks rather
than spinning unproductively.
- "zram: lockmap tweaks" (Sebastian Siewior)
Optimize and fix lockdep tracking for zram devices by consolidating
per-entry lockmaps and isolate lock classes across multiple instances
This reduces memory overhead by replacing per-entry lockdep_map
instances with a single map per struct zram, and assigns a dynamic
lock_class_key to each instance to prevent false deadlock reports
when different zram devices are backed by distinct filesystems.
* tag 'mm-stable-2026-08-18-18-39' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (501 commits)
selftests/mm: thuge-gen: fix test_shmget() for PAGE_SIZE check
selftests/mm: unpoison pages in memory-failure teardown
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
mm/zsmalloc: fix release order of locks in zs_page_migrate()
Documentation: zram: remove sections numbering
ksm: stop iterating VMAs when ksm_test_exit returns true
mm: fold userfaultfd_rwp() to false without CONFIG_ARCH_HAS_PTE_PROTNONE
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
zram: use a custom key for each zram object
zram: move lockmap to be per-zram instead per table
selftests/mm: fix gup_longterm EINVAL error message
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
mm: page_alloc: move capture_control to the page allocator
mm: compaction: support non-movable compaction for pageblock requests
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
hugetlb: evaluate subpool free state while locked
mm/damon: remove trailing semicolons after function definitions
mm/damon/ops-common: prevent migration fallback to non-target nodes
mm/damon: update outdated comment about DAMOS filter handling
...
|
||
|
SJ Park
|
a16fd3ad9d |
samples/damon/mtier: error out for zero quota goal target values
Patch series "mm/damon: avoid division by zero from damos_quota_score()".
DAMON_SAMPLE_MTIER and DAMON_LRU_SORT allow the user to trigger division
by zero in damos_quota_score(). Avoid it by adding parameters validation
checks.
This patch (of 2):
damos_quota_score() can trigger division by zero if the target_value is
zero. DAMON_SAMPLE_MTIER lets users set the target_value via
node0_mem_{used,free}_bp parameters. It doesn't guard zero value case,
though. As a result, users can trigger division by zero. Fix the issue
by returning an error when the user tries to start DAMON with zero
node0_mem_{used,free}_bp parameter values.
DAMON_SAMPLE_MTIER is just a sample module, but the consequence is quite
bad. Also the zero node0_mem_free_bp parameter might look like a
reasonable setup to some users. Hence, the issue might really happen in
the real world.
One reliable way to reproduce the issue is like below:
# cd /sys/module/damon_sample_mtier/parameters
# echo 4096 > node0_start_addr
# echo 8192 > node0_end_addr
# echo 8192 > node1_start_addr
# echo 81920 > node1_end_addr
# echo 0 > node0_mem_free_bp
# echo Y > enabled
# dmesg -w
[...]
[18792.235916] Oops: divide error: 0000 [#1] SMP NOPTI
[...]
[18792.242787] RIP: 0010:damos_quota_score+0x6f/0x480
[...]
This issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260803134034.15217-1-sj@kernel.org
Link: https://lore.kernel.org/20260803134034.15217-2-sj@kernel.org
Link: https://lore.kernel.org/20260801202657.117135-1-sj@kernel.org [1]
Fixes:
|
||
|
SJ Park
|
b1cc60c13b |
samples/damon/prcl: do not stop DAMON for damon_call() failure
damon_call() failure was causing the context to be stopped, but asynchronously by the kdamond thread. To handle the race, the caller had to stop the context. damon_call() is updated to do the stop on its own. Remove the damon_stop() call from the damon_call() error handling. Link: https://lore.kernel.org/20260706140628.87414-12-sj@kernel.org Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SJ Park
|
cfd843b299 |
samples/damon/wsse: do not stop ctx for damon_call() failure
damon_call() failure was causing the context to be stopped, but asynchronously by the kdamond thread. To handle the race, the caller had to stop the context. damon_call() is updated to do the stop on its own. Remove the damon_stop() call from the damon_call() error handling. Link: https://lore.kernel.org/20260706140628.87414-11-sj@kernel.org Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SJ Park
|
3e734a0514 |
samples/damon/mtier: stop all contexts with single damon_stop() call
damon_stop() was theoretically able to return failure while keeping the second context for mtier running. mtier stops its contexts one by one with two damon_stop() call for the reason. damon_stop() is refactored to always successfully stop all requested DAMON contexts. The two calls are unnecessary. Use only single damon_stop() call for all contexts. Link: https://lore.kernel.org/20260706140628.87414-9-sj@kernel.org Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SJ Park
|
5c5df7aa64 |
samples/damon/mtier: do not stop first context for damon_start() failure
damon_start() was able to fail while keeping the first context running. mtier hence stops the first context in the case. damon_start() is refactored to avoid that. The error handling is no longer necessary. Remove it. Link: https://lore.kernel.org/20260706140628.87414-3-sj@kernel.org Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Asier Gutierrez
|
2ab5ed1c2b |
samples/damon: fix typos in Kconfig help text
Fix a couple of typos in samples/damon/Kconfig help text. Change "Thps" to "This", and "tierign" to "tiering". Link: https://lore.kernel.org/20260629145538.134832-5-sj@kernel.org Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com> Signed-off-by: SJ Park <sj@kernel.org> Reviewed-by: SJ Park <sj@kernel.org> Cc: Akinobu Mita <akinobu.mita@gmail.com> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: David Hildenbrand <david@kernel.org> Cc: Doehyun Baek <doehyunbaek@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: "Liam R. Howlett" <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Philippe Laferriere <plafer@proton.me> Cc: Sailesh Nandanavanam <saileshnandanavanam@gmail.com> Cc: Shuah Khan <skhan@linuxfoundation.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SJ Park
|
a73fa45d3f |
samples/damon/prcl: stop and free damon ctx when damon_call() fails
damon_sample_prcl_start() calls damon_call() right after damon_start() is
succeeded. The kdamond that has started by the damon_start() could be
terminated by itself before or in the middle of the damon_call()
execution. There could be multiple reasons for such a stop including
monitoring target process termination and kdamond_fn() internal memory
allocation failures. In the case, damon_call() will fail and return an
error without cleaning up the DAMON context object. The
damon_sample_prcl_start() caller assumes it would clean up the object,
though. When the user requests to start DAMON again,
damon_sample_prcl_start() is called again, allocates a new DAMON context
object and overwrites the pointer for the previous object. As a result,
the previous context object is leaked.
Safely stop the kdamond and deallocate the context object when the failure
is returned. Note that the kdamond should be stopped first, because
damon_call() failure means not complete termination of the kdamond but
only the fact that the termination process has started.
The user impact shouldn't be that significant because the race is not easy
to happen, and only up to one DAMON context object can be leaked per race.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-7-sj@kernel.org
Link: https://lore.kernel.org/20260610035214.4850-1-sj@kernel.org [1]
Fixes:
|
||
|
SJ Park
|
a2c6fa6c23 |
samples/damon/wsse: stop and free damon ctx when damon_call() fails
damon_sample_wsse_start() calls damon_call() right after damon_start() is
succeeded. The kdamond that has started by the damon_start() could be
terminated by itself before or in the middle of the damon_call()
execution. There could be multiple reasons for such a stop including
monitoring target process termination and kdamond_fn() internal memory
allocation failures. In the case, damon_call() will fail and return an
error without cleaning up the DAMON context object. The
damon_sample_wsse_start() caller assumes it would clean up the object,
though. When the user requests to start DAMON again,
damon_sample_wsse_start() is called again, allocates a new DAMON context
object and overwrites the pointer for the previous object. As a result,
the previous context object is leaked.
Safely stop the kdamond and deallocate the context object when the failure
is returned. Note that the kdamond should be stopped first, because
damon_call() failure means not complete termination of the kdamond but
only the fact that the termination process has started.
The user impact shouldn't be that significant because the race is not easy
to happen, and only up to one DAMON context object can be leaked per race.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-6-sj@kernel.org
Link: https://lore.kernel.org/20260610034828.4632-1-sj@kernel.org [1]
Fixes:
|
||
|
SJ Park
|
9dc5b6d66f |
samples/damon/mtier: handle damon_stop() failure
damon_sample_mtier_stop() assumes its damon_stop() call will always
successfully stops the two DAMON contexts. Hence it deallocates the two
DAMON contexts after the damon_stop() call. However, if a given context
is already stopped, damon_stop() fails and returns an error while letting
the DAMON contexts that have not yet stopped keep running. This kind of
unexpected early DAMON context stops could happen due to memory allocation
failures in kdamond_fn(). Because damon_sample_mtier_stop() just
deallocates all DAMON contexts with damon_target and damon_region objects
that are linked to the contexts, the execution of the unstopped DAMON
context (kdamond) ends up using the memory that freed (use-after-free).
Fix the issue by separating the damon_stop() to be invoked per context.
Note that DAMON_SYSFS also allows multiple DAMON contexts execution. But,
it calls damon_stop() for each context one by one. Hence this issue is
only in mtier.
For the long term, it would be better to refactor damon_stop() to always
ensure stopping all contexts regardless of the failures in the middle.
Make this fix in the current way, though, to keep it simple and easy to
backport. I will do the refactoring later.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-5-sj@kernel.org
Link: https://lore.kernel.org/20260609014219.3013-1-sj@kernel.org [1]
Fixes:
|
||
|
SJ Park
|
c7230d08ee |
samples/damon/mtier: handle damon_start() failure
damon_sample_mtier_start() callers assume it will clean up resources when
it fails. And the function does the cleanup for context buildup failures.
However, it is not doing the cleanup for damon_start() failure.
As a result, when damon_start() fails, it could leak the memory for DAMON
context. Also, if damon_start() fails for only the second context, the
first context will indefinitely run, and avoid starting other DAMON
contexts since it is running in the exclusive mode. Stop possibly started
DAMON context and free the contexts in case of the failure to fix the
issues.
Note that the issue can reliably be reproduced because the module calls
damon_start() in the exclusive mode. For example,
$ sudo damo start
$ echo Y | sudo tee /sys/module/damon_sample_mtier/parameters/enabled
$ sudo cat /proc/allocinfo | grep damon_new_ctx
Because the first command is running another DAMON instance, the second
command fails the damon_start() call because the new DAMON instance cannot
exclusively run. And without this fix, by repeating the second and the
third commands above, we can show the memory consumption is only
increasing due to the leaks. It requires the sudo permission though.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-4-sj@kernel.org
Link: https://lore.kernel.org/20260608112455.274231F00893@smtp.kernel.org [1]
Fixes:
|
||
|
SJ Park
|
8b72434922 |
samples/damon/prcl: handle damon_start() failure
damon_sample_prcl_start() callers assume it will clean up resources when
it fails. And the function does the cleanup for context buildup failures.
However, it is not doing the cleanup for damon_start() failure. As a
result, when damon_start() fails, it leaks the memory for DAMON context.
Free the context in case of the failure to fix the issues.
Note that the issue can reliably be reproduced because the module calls
damon_start() in the exclusive mode. For example,
$ sudo damo start
$ echo $$ | sudo tee /sys/module/damon_sample_prcl/parameters/target_pid
$ echo Y | sudo tee /sys/module/damon_sample_prcl/parameters/enabled
$ sudo cat /proc/allocinfo | grep damon_new_ctx
Because the first command is running another DAMON instance, the third
command fails the damon_start() call because the new DAMON instance cannot
exclusively run. And without this fix, by repeating the third and the
fourth commands above, we can show the memory consumption is only
increasing due to the leaks. It requires the sudo permission though.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-3-sj@kernel.org
Link: https://lore.kernel.org/20260609145814.70163-1-sj@kernel.org [1]
Fixes:
|
||
|
SJ Park
|
e4742be45e |
samples/damon/wsse: handle damon_start() failure
Patch series "samples/damon: handle damon_{start,stop}() failures".
All DAMON sample modules are not correctly handling failures from
damon_start(). Among those, mtier also has an additional problem for
handling of damon_stop() failures. wsse and prcl also have a problem in
their damon_call() failure handling. As a result, memory leaks, next
DAMON operation disruptions, and use-after-free can happen. Fix those.
Note that only the damon_start() failure caused issues can reliably be
reproduced. Reproducing those issues require the admin permission,
though.
This patch (of 6):
damon_sample_wsse_start() callers assume it will clean up resources when
it fails. And the function does the cleanup for context buildup failures.
However, it is not doing the cleanup for damon_start() failure. As a
result, when damon_start() fails, it leaks the memory for DAMON context.
Free the context in case of the failure to fix the issues.
Note that the issue can reliably be reproduced because the module calls
damon_start() in the exclusive mode. For example,
$ sudo damo start
$ echo $$ | sudo tee /sys/module/damon_sample_wsse/parameters/target_pid
$ echo Y | sudo tee /sys/module/damon_sample_wsse/parameters/enabled
$ sudo cat /proc/allocinfo | grep damon_new_ctx
Because the first command is running another DAMON instance, the third
command fails the damon_start() call because the new DAMON instance cannot
exclusively run. And without this fix, by repeating the third and the
fourth commands above, we can show the memory consumption is only
increasing due to the leaks. It requires the sudo permission though.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260628215447.96166-2-sj@kernel.org
Link: https://lore.kernel.org/20260609145814.70163-1-sj@kernel.org [1]
Fixes:
|
||
|
Zenghui Yu
|
7746d72c64 |
samples/damon/mtier: fail early if address range parameters are invalid
The comment on top of `struct damon_region` clearly says that
For any use case, @ar should be non-zero positive size.
which is now verified in damon_verify_new_region() if the kernel is built
with DAMON_DEBUG_SANITY.
The WARN_ONCE() can be triggered if the mtier sample module is enabled
before node{0,1}_{start,end}_addr have been properly initialized, which is
obviously not good.
------------[ cut here ]------------
start 0 >= end 0
WARNING: mm/damon/core.c:217 at damon_new_region+0xf4/0x118, CPU#59: bash/341468
Call trace:
damon_new_region+0xf4/0x118 (P)
damon_set_regions+0xfc/0x3c0
damon_sample_mtier_build_ctx+0xe8/0x3a8
damon_sample_mtier_start+0x1c/0x90
damon_sample_mtier_enable_store+0x98/0xb0
param_attr_store+0xb4/0x128
module_attr_store+0x2c/0x50
sysfs_kf_write+0x58/0x90
kernfs_fop_write_iter+0x16c/0x238
vfs_write+0x2c0/0x370
ksys_write+0x74/0x118
__arm64_sys_write+0x24/0x38
invoke_syscall+0xa8/0x118
el0_svc_common.constprop.0+0x48/0xf0
do_el0_svc+0x24/0x38
el0_svc+0x54/0x370
el0t_64_sync_handler+0xa0/0xe8
el0t_64_sync+0x1ac/0x1b0
---[ end trace 0000000000000000 ]---
Note that the same issue can happen if detect_node_addresses is true, and
node 0 or 1 is memoryless. Fix it together by checking the validity of
parameters right before damon_new_region() and fail early if they're
invalid.
Link: https://lore.kernel.org/20260629144432.133962-1-sj@kernel.org
Fixes:
|
||
|
SeongJae Park
|
cd036cc8c3 |
samples/damon/mtier: replace damon_add_region() with damon_set_regions()
mtier DAMON sample module and DAMON virtual address operation set (vaddr) unit tests are using damon_add_region() for setup of DAMON monitoring target region boundaries setup. But, damon_set_regions() is designed for exactly the purpose. All other DAMON API callers use the function for the purpose. Replace damon_add_region() usage in mtier sample module with damon_set_regions(), for unifying the use case and reducing the maintenance cost. Link: https://lore.kernel.org/20260522154026.80546-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Brendan Higgins <brendan.higgins@linux.dev> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
d93871f473 |
samples/damon/mtier: use damon_initialized()
damon_sample_mtier is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
20c0ed5035 |
samples/damon/prcl: use damon_initialized()
damon_sample_prcl is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
1f70367f7b |
samples/damon/wsse: use damon_initialized()
damon_sample_wsse is assuming DAMON is ready to use in module_init time, and uses its own hack to see if it is the time. Use damon_initialized(), which is a way for seeing if DAMON is ready to be used that is more reliable and better to maintain instead of the hack. Link: https://lkml.kernel.org/r/20250916033511.116366-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
c62cff4048 |
samples/damon/mtier: avoid starting DAMON before initialization
Commit |
||
|
SeongJae Park
|
e6b733ca2f |
samples/damon/prcl: avoid starting DAMON before initialization
Commit |
||
|
SeongJae Park
|
f826edeb88 |
samples/damon/wsse: avoid starting DAMON before initialization
Patch series "samples/damon: fix boot time enable handling fixup merge mistakes". First three patches of the patch series "mm/damon: fix misc bugs in DAMON modules" [1] were trying to fix boot time DAMON sample modules enabling issues. The issues are the modules can crash if those are enabled before DAMON is enabled, like using boot time parameter options. The three patches were fixing the issues by avoiding starting DAMON before the module initialization phase. However, probably by a mistake during a merge, only half of the change is merged, and the part for avoiding the starting of DAMON before the module initialized is missed. So the problem is not solved and thus the modules can still crash if enabled before DAMON is initialized. Fix those by applying the unmerged parts again. Note that the broken commits are merged into 6.17-rc1, but also backported to relevant stable kernels. So this series also needs to be merged into the stable kernels. Hence Cc-ing stable@. This patch (of 3): Commit |
||
|
SeongJae Park
|
ff01aba6e4 |
mm/damon/vaddr: put pid in cleanup_target()
Implement cleanup_target() callback for [f]vaddr, which calls put_pid() for each target that will be destroyed. Also remove redundant put_pid() calls in core, sysfs and sample modules, which were required to be done redundantly due to the lack of such self cleanup in vaddr. Link: https://lkml.kernel.org/r/20250712195016.151108-11-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
cc9c1b8c20 |
samples/damon/wsse: use damon_call() repeat mode instead of damon_callback
wsse uses damon_callback for periodically reading DAMON internal data. Use its alternative, damon_call() repeat mode. Link: https://lkml.kernel.org/r/20250712195016.151108-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
a6c33f1054 |
samples/damon/prcl: use damon_call() repeat mode instead of damon_callback
prcl uses damon_callback for periodically reading DAMON internal data. Use its alternative, damon_call() repeat mode. Link: https://lkml.kernel.org/r/20250712195016.151108-7-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Yunjeong Mun
|
749cc6533b |
samples/damon: support automatic node address detection
This patch adds a new knob `detect_node_addresses`, which determines whether the physical address range is set manually using the existing knobs or automatically by the mtier module. When `detect_node_addresses` set to 'Y', mtier automatically converts node0 and node1 to their physical addresses. If set to 'N', it uses the existing 'node#_start_addr' and 'node#_end_addr' to define regions as before. Link: https://lkml.kernel.org/r/20250707235919.513-1-yunjeong.mun@sk.com Signed-off-by: Yunjeong Mun <yunjeong.mun@sk.com> Suggested-by: Honggyu Kim <honggyu.kim@sk.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Honggyu Kim
|
793020545c |
samples/damon: change enable parameters to enabled
The damon_{lru_sort,reclaim,stat} kernel modules use "enabled" parameter
knobs as follows.
/sys/module/damon_lru_sort/parameters/enabled
/sys/module/damon_reclaim/parameters/enabled
/sys/module/damon_stat/parameters/enabled
However, other sample modules of damon use "enable" parameter knobs so
it'd be better to rename them from "enable" to "enabled" to keep the
consistency with other damon modules.
Before:
/sys/module/damon_sample_wsse/parameters/enable
/sys/module/damon_sample_prcl/parameters/enable
/sys/module/damon_sample_mtier/parameters/enable
After:
/sys/module/damon_sample_wsse/parameters/enabled
/sys/module/damon_sample_prcl/parameters/enabled
/sys/module/damon_sample_mtier/parameters/enabled
There is no functional changes in this patch.
Link: https://lkml.kernel.org/r/20250707024548.1964-1-honggyu.kim@sk.com
Signed-off-by: Honggyu Kim <honggyu.kim@sk.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
|
SeongJae Park
|
775c96714d |
samples/damon/mtier: rename to have damon_sample_ prefix
DAMON sample module, mtier has its name 'mtier'. It could conflict with future modules, and not very easy to identify it by name. Use a prefix, "damon_sample_" for the name. Note that this could break users if they depend on the old name. But it is just a sample, so no such usage is expected, or known. Even if such usage exists, updating it for the new name should be straightforward. Link: https://lkml.kernel.org/r/20250705175000.56259-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
6a52ac0b60 |
samples/damon/prcl: rename to have damon_sample_ prefix
DAMON sample module, prcl has its name 'prcl'. It could conflict with future modules, and not very easy to identify it by name. Use a prefix, "damon_sample_" for the name. Note that this could break users if they depend on the old name. But it is just a sample, so no such usage is expected, or known. Even if such usage exists, updating it for the new name should be straightforward. Link: https://lkml.kernel.org/r/20250705175000.56259-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
c1db0cb157 |
samples/damon/wsse: rename to have damon_sample_ prefix
Patch series "mm/damon: misc cleanups". Yet another round of miscellaneous DAMON cleanups. This patch (of 6): DAMON sample module, wsse has its name 'wsse'. It could conflict with future modules, and not very easy to identify it by name. Use a prefix, "damon_sample_" for the name. Note that this could break users if they depend on the old name. But it is just a sample, so no such usage is expected, or known. Even if such usage exists, updating it for the new name should be straightforward. Link: https://lkml.kernel.org/r/20250705175000.56259-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250705175000.56259-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
964314344e |
samples/damon/mtier: support boot time enable setup
If 'enable' parameter of the 'mtier' DAMON sample module is set at boot
time via the kernel command line, memory allocation is tried before the
slab is initialized. As a result kernel NULL pointer dereference BUG can
happen. Fix it by checking the initialization status.
Link: https://lkml.kernel.org/r/20250706193207.39810-4-sj@kernel.org
Fixes:
|
||
|
SeongJae Park
|
2780505ec2 |
samples/damon/prcl: fix boot time enable crash
If 'enable' parameter of the 'prcl' DAMON sample module is set at boot
time via the kernel command line, memory allocation is tried before the
slab is initialized. As a result kernel NULL pointer dereference BUG can
happen. Fix it by checking the initialization status.
Link: https://lkml.kernel.org/r/20250706193207.39810-3-sj@kernel.org
Fixes:
|
||
|
SeongJae Park
|
0ed1165c37 |
samples/damon/wsse: fix boot time enable handling
Patch series "mm/damon: fix misc bugs in DAMON modules".
From manual code review, I found below bugs in DAMON modules.
DAMON sample modules crash if those are enabled at boot time, via kernel
command line. A similar issue was found and fixed on DAMON non-sample
modules in the past, but we didn't check that for sample modules.
DAMON non-sample modules are not setting 'enabled' parameters accordingly
when real enabling is failed. Honggyu found and fixed[1] this type of
bugs in DAMON sample modules, and my inspection was motivated by the great
work. Kudos to Honggyu.
Finally, DAMON_RECLIAM is mistakenly losing scheme internal status due to
misuse of damon_commit_ctx(). DAMON_LRU_SORT has a similar misuse, but
fortunately it is not causing real status loss.
Fix the bugs. Since these are similar patterns of bugs that were found in
the past, it would be better to add tests or refactor the code, in future.
This patch (of 6):
If 'enable' parameter of the 'wsse' DAMON sample module is set at boot
time via the kernel command line, memory allocation is tried before the
slab is initialized. As a result kernel NULL pointer dereference BUG can
happen. Fix it by checking the initialization status.
Link: https://lkml.kernel.org/r/20250706193207.39810-1-sj@kernel.org
Link: https://lkml.kernel.org/r/20250706193207.39810-2-sj@kernel.org
Link: https://lore.kernel.org/20250702000205.1921-1-honggyu.kim@sk.com [1]
Fixes:
|
||
|
Yunjeong Mun
|
c5e67d40a1 |
samples/damon/mtier: add parameters for node0 memory usage
Change the hard-coded quota goal metric values into sysfs knobs: `node0_mem_used_bp` and `node0_mem_free_bp`. These knobs represent the used and free memory ratio of node0 in basis points (bp, where 1 bp = 0.01%). As mentioned in [1], this patch is developed under the assumption that node0 is always the fast-tier in a two-tiers memory setup. [1] https://lore.kernel.org/linux-mm/20250420194030.75838-8-sj@kernel.org/ Link: https://lkml.kernel.org/r/20250627163329.50997-1-sj@kernel.org Link: https://patch.msgid.link/20250619050313.1535-1-yunjeong.mun@sk.com Signed-off-by: Yunjeong Mun <yunjeong.mun@sk.com> Signed-off-by: SeongJae Park <sj@kernel.org> Suggested-by: Honggyu Kim <honggyu.kim@sk.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Honggyu Kim
|
ddba1b6cf4 |
samples/damon: fix damon sample mtier for start failure
The damon_sample_mtier_start() can fail so we must reset the "enable"
parameter to "false" again for proper rollback.
In such cases, setting Y to "enable" then N triggers the similar crash
with mtier because damon sample start failed but the "enable" stays as Y.
Link: https://lkml.kernel.org/r/20250702000205.1921-4-honggyu.kim@sk.com
Fixes:
|
||
|
Honggyu Kim
|
f1221c8442 |
samples/damon: fix damon sample wsse for start failure
The damon_sample_wsse_start() can fail so we must reset the "enable"
parameter to "false" again for proper rollback.
In such cases, setting Y to "enable" then N triggers the similar crash
with wsse because damon sample start failed but the "enable" stays as Y.
Link: https://lkml.kernel.org/r/20250702000205.1921-3-honggyu.kim@sk.com
Fixes:
|
||
|
Honggyu Kim
|
d9e01c62b7 |
samples/damon: fix damon sample prcl for start failure
Patch series "mm/damon: fix divide by zero and its samples", v3.
This series includes fixes against damon and its samples to make it safer
when damon sample starting fails.
It includes the following changes.
- fix unexpected divide by zero crash for zero size regions
- fix bugs for damon samples in case of start failures
This patch (of 4):
The damon_sample_prcl_start() can fail so we must reset the "enable"
parameter to "false" again for proper rollback.
In such cases, setting Y to "enable" then N triggers the following crash
because damon sample start failed but the "enable" stays as Y.
[ 2441.419649] damon_sample_prcl: start
[ 2454.146817] damon_sample_prcl: stop
[ 2454.146862] ------------[ cut here ]------------
[ 2454.146865] kernel BUG at mm/slub.c:546!
[ 2454.148183] Oops: invalid opcode: 0000 [#1] SMP NOPTI
...
[ 2454.167555] Call Trace:
[ 2454.167822] <TASK>
[ 2454.168061] damon_destroy_ctx+0x78/0x140
[ 2454.168454] damon_sample_prcl_enable_store+0x8d/0xd0
[ 2454.168932] param_attr_store+0xa1/0x120
[ 2454.169315] module_attr_store+0x20/0x50
[ 2454.169695] sysfs_kf_write+0x72/0x90
[ 2454.170065] kernfs_fop_write_iter+0x150/0x1e0
[ 2454.170491] vfs_write+0x315/0x440
[ 2454.170833] ksys_write+0x69/0xf0
[ 2454.171162] __x64_sys_write+0x19/0x30
[ 2454.171525] x64_sys_call+0x18b2/0x2700
[ 2454.171900] do_syscall_64+0x7f/0x680
[ 2454.172258] ? exit_to_user_mode_loop+0xf6/0x180
[ 2454.172694] ? clear_bhb_loop+0x30/0x80
[ 2454.173067] ? clear_bhb_loop+0x30/0x80
[ 2454.173439] entry_SYSCALL_64_after_hwframe+0x76/0x7e
Link: https://lkml.kernel.org/r/20250702000205.1921-1-honggyu.kim@sk.com
Link: https://lkml.kernel.org/r/20250702000205.1921-2-honggyu.kim@sk.com
Fixes:
|
||
|
SeongJae Park
|
82a08bde3c |
samples/damon: implement a DAMON module for memory tiering
Implement a sample DAMON module that shows how self-tuned DAMON-based memory tiering can be written. It is a sample since the purpose is to give an idea about how it can be implemented and perform, rather than be used on general production setups. Especially, it supports only two tiers memory setup having only one CPU-attached NUMA node. [sj@kernel.org: fix wrong DAMON attrs setting] Link: https://lkml.kernel.org/r/20250510220932.47722-1-sj@kernel.org [sj@kernel.org: trigger build even if only mtier is enabled] Link: https://lkml.kernel.org/r/20250426184054.11437-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250420194030.75838-8-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Yunjeong Mun <yunjeong.mun@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Enze Li
|
1477b8cd26 |
samples/damon/prcl: fix a comment typo
This patch just fixes a typo in the comment. Link: https://lkml.kernel.org/r/20250411073800.1444481-1-lienze@kylinos.cn Signed-off-by: Enze Li <lienze@kylinos.cn> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Seongjun Kim
|
a58f3dcf20 |
samples/damon: a typo in the kconfig - sameple
There is a typo in the Kconfig file of the damon sample module. Correct it: s/sameple/sample/ Link: https://lkml.kernel.org/r/20250226184204.29370-1-sj@kernel.org Signed-off-by: Seongjun Kim <bus710@gmail.com> Signed-off-by: SeongJae Park <sj@kernel.org> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
15e01f3912 |
samples/damon/prcl: implement schemes setup
Implement a proactive cold memory regions reclaiming logic of prcl sample module using DAMOS. The logic treats memory regions that not accessed at all for five or more seconds as cold, and reclaim those as soon as found. Link: https://lkml.kernel.org/r/20241210215030.85675-6-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
2aca254620 |
samples/damon: introduce a skeleton of a smaple DAMON module for proactive reclamation
DAMON is not only for monitoring of access patterns, but also for access-aware system operations. For the system operations, DAMON provides a feature called DAMOS (Data Access Monitoring-based Operation Schemes). There is no sample API usage of DAMOS, though. Copy the working set size estimation sample modules with changed names of the module and symbols, to use it as a skeleton for a sample module showing the DAMOS API usage. The following commit will make it proactively reclaim cold memory of the given process, using DAMOS. Link: https://lkml.kernel.org/r/20241210215030.85675-5-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
65cc56d02d |
samples/damon/wsse: implement working set size estimation and logging
Implement the DAMON-based working set size estimation logic. The logic iterates memory regions in DAMON-generated access pattern snapshot for every aggregation interval and get the total sum of the size of any region having one or higher 'nr_accesses' count. That is, it assumes any region having one or higher 'nr_accesses' to be a part of the working set. The estimated value is reported to the user by printing it to the kernel log. Link: https://lkml.kernel.org/r/20241210215030.85675-4-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
b757c6cfc6 |
samples/damon/wsse: start and stop DAMON as the user requests
Start running DAMON to monitor accesses of a process that the user specified via 'target_pid' parameter, when 'y' is passed to 'enable' parameter. Stop running DAMON when 'n' is passed to 'enable' parameter. Estimating the working set size from DAMON's monitoring results and reporting it to the user will be implemented by the following commit. Link: https://lkml.kernel.org/r/20241210215030.85675-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
SeongJae Park
|
19d7c3adfd |
samples: add a skeleton of a sample DAMON module for working set size estimation
Patch series "mm/damon: add sample modules". Implement a proactive cold memory regions reclaiming logic of prcl sample module using DAMOS. The logic treats memory regions that not accessed at all for five or more seconds as cold, and reclaim those as soon as found. This patch (of 5): Add a skeleton for a sample DAMON static module that can be used for estimating working set size of a given process. Note that it is a static module since DAMON is not exporting symbols to loadable modules for now. It exposes two module parameters, namely 'pid' and 'enable'. 'pid' will specify the process that the module will estimate the working set size of. 'enable' will receive whether to start or stop the estimation. Because this is just a skeleton, the parameters do nothing, though. The functionalities will be implemented by following commits. Link: https://lkml.kernel.org/r/20241210215030.85675-1-sj@kernel.org Link: https://lkml.kernel.org/r/20241210215030.85675-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |