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27,201 commits
| Author | SHA1 | Message | Date | |
|---|---|---|---|---|
Linus Torvalds
|
918e25291c |
slab changes for 7.3
-----BEGIN PGP SIGNATURE----- iQFPBAABCAA5FiEEe7vIQRWZI0iWSE3xu+CwddJFiJoFAmqMSHQbFIAAAAAABAAO bWFudTIsMi41KzEuMTIsMiwyAAoJELvgsHXSRYiaC8EH/ihctMRDnqbUxyc3cSIZ cuy3ocSSu8UnHzSNarylY8sVYIYflgY6owV7UvaUKmXGYHiHIDdI5NMDzpjola7X Ct7mpIuobFHpFhTQMqvYkeEQ3EytS7NPHKs3jd6t2HSOYJdY4lghjRZcxOlo7+GA 5EJa468TSHswWbT34e3NY7gpoHCXTucR6FBqoVtluLOliQWNMkWbeDQ9hEnMoyNy hEdooWDxt8vBuSqVRCZxrgJRK2nauf1P/CHZm4HcNttOQp0iwr8Q7GER7dBpW0jR 1b1zM9YPH4g6CSll5V6sWSMUNAaDx3Akx3ZyKhd3G2kyP3HkPXKSag/fS8xxCFLN hh0= =6lTR -----END PGP SIGNATURE----- Merge tag 'slab-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab Pull slab updates from Vlastimil Babka: - Add kfree_rcu_nolock() that can be used from contexts where spinning on a lock might be unsafe, such as a BPF program attached to an arbitrary function, or in NMI context. This complements the existing kfree_nolock() support (Harry Yoo) - Runtime instead of compile-time slabobj_ext sizing. Avoid wasting memory when memory allocation profiling is compiled but not enabled, with initial partial support to also avoid wasting memory for objcg pointers when those are not needed, while profiling is enabled (Vlastimil Babka) - Various non-urgent fixes, cleanups and optimizations (Hao Li, Hongling Zeng, Li RongQing, Li Xiasong, Seongjun Hong, Shengming Hu) * tag 'slab-for-7.3' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (31 commits) mm/slab, kfence, memcg: completely remove obj_ext for kfence objects mm/slab: stop allocating objcg pointers when unnecessary mm/slab: add cache_ and slab_needs_objcg() helpers mm/slab: stop exporting kvfree_rcu_barrier[_on_cache]() slub_kunit: extend the test for kfree_rcu_nolock() mm/slab: introduce kfree_rcu_nolock() mm/slab: introduce struct kvfree_rcu_head for kvfree_rcu batching mm/slab: reduce slabobj_ext memory with allocation profiling disabled mm/slab: introduce slab_obj_ext_has_codetag() mm/slab: allow kfree_rcu_sheaf() on PREEMPT_RT mm/slab: extend deferred free mechanism to handle rcu sheaves mm/slab: use call_rcu() in unknown context if irqs are enabled mm/slab: handle the !allow_spin case in kfree_rcu_sheaf() mm/slab: change struct slabobj_ext to a union mm/slab: replace slab.stride with obj_exts_in_object mm/slab: abstract slabobj_ext.ref access mm/slab: abstract slabobj_ext.objcg access mm/slab: make slab_obj_ext() determine object index mm: move struct slabobj_ext to mm/slab.h mm/slab: remove objs_per_slab() ... |
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Vlastimil Babka (SUSE)
|
564ed40708 |
Merge branch 'slab/for-7.3/kfree_rcu_nolock' into slab/for-next
Merge series "mm/slab: introduce kfree_rcu_nolock() and improve slub_kunit coverage" from Harry Yoo. From the cover letter [1]: This series improves kmalloc_nolock() and kfree_nolock() coverage in slub_kunit and introduces kfree_rcu_nolock() for unknown context as suggested by Alexei Starovoitov. Unknown context means the caller does not know whether spinning on a lock is safe (e.g., a BPF program attached to an arbitrary kernel function or in NMI context). The slab allocator already supports unknown context via kmalloc_nolock() and kfree_nolock(), but te slab allocator does not support freeing objects by RCU in unknown context. It is not ideal to have completely separate batching for unknown context because the worst scenario where spinning on a lock would lead to deadlock is very rare, and in most cases, it is safe to use the existing mechanism (kfree_rcu_sheaf()). Since most part of the slab allocator already supports unknown context and sheaves support batching kvfree_rcu() calls for slab objects, implement kfree_rcu_nolock() with minimal changes by teaching kfree_rcu_sheaf() how to support unknown context and making it a little bit harder to allocate an empty sheaf, instead of making intrusive changes to the existing kvfree_rcu batching logic. kfree_rcu_nolock() tries to free the object to the rcu sheaf if trylock succeeds. Once the rcu sheaf becomes full, it is submitted to RCU via call_rcu() if spinning is allowed or IRQs are enabled (to avoid calling call_rcu() in the middle of call_rcu()). Otherwise, call_rcu() is deferred via irq work. When there is no sheaf available, kfree_rcu_sheaf() falls back to defer_kfree_rcu(). It submits the object to kvfree_rcu batching via irq work. To do this, patch 6 converts kvfree_rcu to use kvfree_rcu_head without visible changes to the API for now. Unlike kfree_rcu(), only the 2-argument variant is supported. This is because the last resort of the 1-arg variant is synchronize_rcu(), which cannot be used in an unknown context. As suggested by Alexei Starovoitov, kfree_rcu_nolock() can be used with struct kvfree_rcu_head (8 bytes), which is smaller than struct rcu_head (16 bytes). Link: https://lore.kernel.org/all/20260729-kfree_rcu_nolock-v5-0-a28cdcda9673@kernel.org/ [1] |
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Vlastimil Babka (SUSE)
|
160dcfe7f9 |
Merge branch 'slab/for-7.3/objext_split' into slab/for-next
Merge series "mm/slab, alloc_tag: reduce obj_ext memory waste" from myself. From the cover letter [1]: It's been bothering me that the memory usage of struct slabobj_ext depend only on config options and not whether the fields are actually used. So with both CONFIG_MEMCG=y and CONFIG_MEM_ALLOC_PROFILING=y there is always objcg field and codetag_ref field. And thus: 1) Having memory allocation profiling config-enabled but not boot-enabled means wasted memory on unused codetag_refs. This makes it less suitable for a general distro config and the page allocator side doesn't suffer from this, only slab and percpu. 2) Complementary, with memory allocation profiling enabled, there are caches/slabs that don't need the objcg field, so memory is wasted on those. This series should solve the point 1) fully for slab; pcpuobj_ext handling can be perhaps improved similarly, haven't looked into that. For 2) it avoids allocating objcg fields for KMALLOC_NORMAL and KMALLOC_NO_OBJ_EXT caches where we know they are not necessary because kmalloc() with __GFP_ACCOUNT will pick a KMALLOC_CGROUP type (except with SLUB_TINY). The named kmem_caches are tricky. They can be created with SLAB_ACCOUNT and then we know objcg fields are always needed. But also they can be created without SLAB_ACCOUNT and then some allocations have __GFP_ACCOUNT and some not and we don't know that in advance. This series introduces a SLAB_MAY_ACCOUNT flag that's currently internal only and is applied to all caches (unless kmem accounting is disabled) except KMALLOC_NORMAL (unless that aliases KMALLOC_RECLAIM) and KMALLOC_NO_OBJ_EXT. As a followup we can make SLAB_MAY_ACCOUNT explicit and add it to to caches where we know __GFP_ACCOUNT is used. Then we could only honour __GFP_ACCOUNT for those, while warning for an unexpected usage elsewhere. To check for regressions, I forward-ported a microbenchmark hacked into slub_kunit that was used to evaluate sheaves. Tried 3 scenarios, MEMCG and KFENCE were always enabled: - CONFIG_MEM_ALLOC_PROFILING=n - CONFIG_MEM_ALLOC_PROFILING=y but _ENABLED_BY_DEFAULT=n - same but booted with sysctl.vm.mem_profiling=1 The results are quite noisy, but no regression was apparent, except perhaps few percents for the last case. I don't expect it will be visible in any real workloads. Link: https://lore.kernel.org/all/20260727-b4-objext_split-v3-0-c29ef0f1f257@kernel.org/ [1] |
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|
Linus Torvalds
|
83684c4e4d |
RCU updates:
Make expedited grace periods expedite normal RCU callbacks
Miscellaneous fixes:
* Improve diagnostic output with character task states.
* Mark accesses to inform KCSAN of concurrency design.
* Move from kmalloc() to kmalloc_obj().
* Documentation updates.
* Improve handling of RCU deferred quiescent states.
* Clean up unused function arguments and structure fields.
* Reduce show_rcu_gp_kthreads() stack space.
Tasks RCU updates:
* Clean up after SRCU re-implementation of Tasks Trace RCU.
* Mark accesses to inform KCSAN of concurrency design.
* Add ->lazy_timer status to diagnostic output.
* Remove an unnecessary memory barrier.
* Fix a data race, courtesy of KCSAN.
* Documentation updates.
* Convert cond_resched_tasks_rcu_qs() from macro to static inline
function.
SRCU updates:
* Add Rust helpers for SRCU.
* Avoid losing queued work at cleanup_srcu_struct() time.
Torture-test updates:
* Preparation work for immediate RCU priority deboosting.
* Test RCU readers from real interrupt handlers (as opposed to softirq).
* Simplify code through use of cpumask_next_wrap().
* Improve diagnostic output with character task states.
* Add rcutorture.nwriters parameter to allow lightweight stall testing,
and rcutorture.stall_only to make doing so easier.
* Test an RCU Tasks Trace grace period implying an RCU grace period.
* Make RCU Tasks Trace torturing track reader batches.
* Fix a data race, courtesy of KCSAN.
* Plug a shuffle_tmp_mask memory leak on kthread spawn failure.
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Merge tag 'rcu.2026.08.18a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux
Pull RCU updates from Paul McKenney:
"Make expedited grace periods expedite normal RCU callbacks
Miscellaneous fixes:
- Improve diagnostic output with character task states
- Mark accesses to inform KCSAN of concurrency design
- Move from kmalloc() to kmalloc_obj()
- Documentation updates
- Improve handling of RCU deferred quiescent states
- Clean up unused function arguments and structure fields
- Reduce show_rcu_gp_kthreads() stack space
Tasks RCU updates:
- Clean up after SRCU re-implementation of Tasks Trace RCU
- Mark accesses to inform KCSAN of concurrency design
- Add ->lazy_timer status to diagnostic output
- Remove an unnecessary memory barrier
- Fix a data race, courtesy of KCSAN
- Documentation updates
- Convert cond_resched_tasks_rcu_qs() from macro to static inline
function
SRCU updates:
- Add Rust helpers for SRCU
- Avoid losing queued work at cleanup_srcu_struct() time
Torture-test updates:
- Preparation work for immediate RCU priority deboosting
- Test RCU readers from real interrupt handlers (as opposed to
softirq)
- Simplify code through use of cpumask_next_wrap()
- Improve diagnostic output with character task states
- Add rcutorture.nwriters parameter to allow lightweight stall
testing, and rcutorture.stall_only to make doing so easier
- Test an RCU Tasks Trace grace period implying an RCU grace period
- Make RCU Tasks Trace torturing track reader batches
- Fix a data race, courtesy of KCSAN
- Plug a shuffle_tmp_mask memory leak on kthread spawn failure"
* tag 'rcu.2026.08.18a' of git://git.kernel.org/pub/scm/linux/kernel/git/rcu/linux: (59 commits)
rcu: Add closing parenthesis in comment in rcu_read_unlock_strict()
rcutorture: Make {,s}rcu_read_delay() better handle forward-progress testing
rcutorture: Announce declining to forward-progress test
torture: Don't leak shuffle_tmp_mask when shuffler kthread fails to start
rcutorture: Use this_cpu_inc() for rcu_torture_count[] and rcu_torture_batch[]
rcutorture: Make RCU Tasks Trace track Reader Batches
rcutorture: Test RCU Tasks Trace GP implying RCU GP
rcutorture: Add a stall_only module parameter
rcutorture: Add nwriters module parameter
rcutorture: Use task_state_to_char() for task-state reporting
rcutorture: Use cpumask_next_wrap() in rcu_torture_preempt()
rcutorture: Test RCU readers from hardware interrupt handlers
rcutorture: Check for immediate deboosting at reader end
srcu: Queue sdp->work when the delay timer is successfully deleted
rcu-tasks: Convert cond_resched_tasks_rcu_qs() to static inline
rcu-tasks: Fix some comments for call_rcu_tasks() and call_rcu_tasks_rude()
rcu-tasks: Rename tasks_rcu_exit_srcu_stall_timer to tasks_rcu_exit_stall_timer
rcu: Mark interrupts-enabled accesses to rdp->cpu_no_qs.s
rcu: Reduce stack usage in show_rcu_gp_kthreads()
rcu: Mark accesses to ->rcu_urgent_qs and ->rcu_need_heavy_qs
...
|
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|
Linus Torvalds
|
91959a31a3 |
kho: make boot time huge page allocation work nicely with KHO
Today allocation of gigantic pages in HugeTLB cannot work reliably with KHO:
* HugeTLB allocates gigantic pages using memblock and autoscaling of KHO
scratch accounts for these allocations. When gigantic pages occupy half
of the memory of more, KHO fails to allocate its scratch memory.
* After kexec handover, memblock allocations exclusively use KHO scratch
that is not supposed to contain preserved memory. This essentially blocks
preservation of HugeTLB with gigantic pages.
Extend early memory pools available for KHO kernel with areas that are
guaranteed not to contain preserved memory.
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Merge tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux
Pull more liveupdate updates from Mike Rapoport:
"Make boot time huge page allocation work nicely with kexec handover.
Today allocation of gigantic pages in HugeTLB cannot work reliably
with kexec handover (KHO):
- HugeTLB allocates gigantic pages using memblock and autoscaling of
KHO scratch accounts for these allocations. When gigantic pages
occupy half of the memory of more, KHO fails to allocate its
scratch memory.
- After kexec handover, memblock allocations exclusively use KHO
scratch that is not supposed to contain preserved memory. This
essentially blocks preservation of HugeTLB with gigantic pages.
Extend early memory pools available for KHO kernel with areas that are
guaranteed not to contain preserved memory"
* tag 'liveupdate-v7.3-rc1-20260823' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (21 commits)
kho: exclude hugetlb memory from scratch size calculation
memblock: add memblock_reserved_hugetlb_size()
memblock: make HugeTLB bootmem allocation work with KHO
memblock: always include KHO headers
kho: extend scratch
mm/mm_init: don't rely on memblock to get KHO scratch migratetype
kho: initialize preserved memory map radix tree earlier
kho: initialize kho_scratch pointer earlier in boot
kho: expose kho_scratch_overlap() to kexec_handover.h
kho: add kho_radix_init_tree()
kho: allow destroying KHO radix tree
kho: allow early-boot usage of the KHO radix tree
kho: add data argument to radix walk callback
kho: add callback for table pages
kho: add a struct for radix callbacks
kho: move all memory retrieval logic to kho_mem_retrieve()
kho: store incoming radix tree in kho_in
kho: disallow wide keys in radix tree
kho: make radix max key width more obvious
kho: generalize radix tree APIs
...
|
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|
Linus Torvalds
|
8dbbc7e188 |
8 hotfixes. 5 are cc:stable. 5 are for MM.
All are singletons, please see their changelogs for details. -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQTTMBEPP41GrTpTJgfdBJ7gKXxAjgUCaoaDnAAKCRDdBJ7gKXxA jqXxAP9MkqbVse1cHQ42HtupyA3XWCi+BbV//Yo9ofrqAxPugwD/WdhbdDlAbRYP sbRoAsWh92j6zL/E9i6jSMFizkzVpgY= =In+3 -----END PGP SIGNATURE----- Merge tag 'mm-hotfixes-stable-2026-08-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull hotfixes from Andrew Morton: "8 hotfixes. 5 are cc:stable. 5 are for MM. All are singletons, please see their changelogs for details" * tag 'mm-hotfixes-stable-2026-08-19-21-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: mm/pagewalk: fix stale walk->action escaping walk_pmd_range() mm, swap: don't free a hibernation slot that is in the swap cache mm: memcg-v1: fix memsw and TCP failcnt accounting mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec() mailmap: add entries for Guodong Xu MAINTAINERS, mailmap: update email address for JP Kobryn MAINTAINERS: remove git URL for Squashfs memcg: keep folio's objcg same as its node |
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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
...
|
||
|
Linus Torvalds
|
55ab7e1422 |
for-7.3/block-20260819
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Merge tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux
Pull block updates from Jens Axboe:
- NVMe updates via Keith:
- Enable Clang context analysis for the nvme host driver, adding
context annotations across core, fabrics, rdma, tcp and pci
- nvmet reservation state exposed through a new namespace-level
debugfs directory, plus ABI documentation for the host sysfs and
target configfs interfaces
- nvme-tcp host memory disclosure fixes on the read path: reject a
read that transferred too few bytes, don't accept C2HData based
on blk_rq_payload_bytes() alone, and fix the R2T case for a read
command
- Parallelize nvme-rdma I/O queue allocation and startup (Surabhi)
- Apple nvme fixes and quirks: page aligned admin queue buffers,
destroy the admin queue on removal, and various DMA/NVMMU
correctness fixes
- A large pile of nvmet and host fixes for out-of-bounds reads,
refcount/resource leaks, and NULL derefs across auth, zns,
passthru, pci-epf, rdma and configfs
- Various other fixes and cleanups
- MD updates via Yu Kuai:
- llbitmap reshape support, the large series wiring exact bitmap
mapping and reshape lifecycle through raid5 and raid10, growing
the page cache in place, and remapping checkpointed bits as
reshape progresses
- raid5 fixes for lockless max_nr_stripes and recovery_offset
accesses, a reshape deadlock with more failed devices than max
degraded, and bitmap batch counter consistency
- Atomic write handling for raid1/raid10, and removal of the
REQ_NOWAIT support from raid1/10/456
- raid5-ppl use-after-free fix in ppl_do_flush()
- A batch of smaller fixes across md core and the bitmap code
- s390/dasd ESE full-track write support and the surrounding
infrastructure, plus enabling CONTEXT_ANALYSIS for s390/block
- RWF_DONTCACHE support for block devices, built on new task-context
bio completion infrastructure, and wiring it up for the iomap and
buffer dropbehind writeback paths
- Async io_uring zone reset all, plus zone management command cleanups
allowing REQ_NOWAIT and tightening conventional zone rejection
- Block integrity refactoring: lift BIP_CHECK_FLAGS to the shared
header, handle nogenerate/noverify properly in fs-integrity, and drop
the blk-integrity.h include from bdev.c
- Split out a new blk_plug.h header
- ublk improvements: add UBLK_F_IO_DESC_SIZE, split request validation
from io_desc init, reject non-power-of-2 zone sizes in SET_PARAMS,
and a series of hardening fixes around map/unmap and auto buf reg
- null_blk cleanups and configfs serialization fixes
- nbd queue freeze removal on the setup paths, and a new
pre_defined_connections module parameter for pre-created devices
- blk-cgroup fixes for the race between policy activation and blkg
destruction, and accounting per-cpu stats over possible CPUs across
blk-stat, iolatency, iocost and kyber
- Various dio fixes: leak on metadata mapping error, validate user
space vectors during extraction, and set dma_alignment from the
backing file for loop and zloop direct I/O
- bio cleanups
- Various other fixes and cleanups all over
* tag 'for-7.3/block-20260819' of git://git.kernel.org/pub/scm/linux/kernel/git/axboe/linux: (241 commits)
nbd: add pre_defined_connections module parameter for pre-created devices
nbd: remove queue freeze for newly created nbd from netlink path
nbd: factor out a nbd_genl_foreach_sock
nbd: skip queue freeze when setting size at device startup
nbd: remove queue freeze in nbd_add_socket
nbd: clear queue limits on disconnect
nbd: disallow NBD_SET_SOCK on an active device
nbd: simplify find_fallback() by removing redundant logic
blk-mq: add missing call to srcu_barrier() in blk_mq_free_tag_set()
block: mtip32xx: synchronize ioctls with device removal
ublk: avoid teardown retry loop on xarray allocation failure
null_blk: fix UBSAN shift-out-of-bounds when zone_size is 0 or overflows
block: don't include blk-integrity.h in bdev.c
xfs: avoid double deferrals for RWF_DONTCACHE writes
loop: Fix recently introduced lock inversion
block: set QUEUE_FLAG_DYING unconditionally in blk_mark_disk_dead()
swim3: Add missing MODULE_DESCRIPTION
selftests: ublk: add SET_PARAMS validation test
selftests: ublk: add helper for SET_PARAMS
ublk: reject non-power-of-2 zone sizes in SET_PARAMS
...
|
||
|
Linus Torvalds
|
38fda1d9d2 |
memblock: updates for 7.3-rc1
Non-urgent fixes:
* Fix calculation of node_spanned_pages when running with kernelcore=mirror
* Properly handle failure to allocate per_cpu_nodestats in
free_area_init_core_hotplug()
* Fix deferred initialization of the memory map for configurations where
node's RAM end is not aligned on PAGES_PER_SECTION
Cleanups:
* Remove redundant pageblock_align() call in free_unused_memmap()
* Remove unnecessary invalid range checks in users of memblock iterators.
Some users of for_each_mem_range() and for_each_mem_pfn_range() verify
that start < end for each range. This is redundant because memblock
iterators guarantee to never return an invalid range
* Stop overlapping zones with kernelcore=mirror and align behaviour of
kernelcore=mirror with other variants of kernelcore=/movablecore=
* Remove redundant updates of numa_nodes_parsed mask in the callers of
numa_add_memblk(), the latter always updates the mask anyway
* Remove unnecessary initialization of pgdat->per_cpu_nodestats to NULL,
the variable is reset to the actual value a few lines below
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Merge tag 'memblock-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull memblock updates from Mike Rapoport:
"Non-urgent fixes:
- Fix calculation of node_spanned_pages when running
with 'kernelcore=mirror'
- Properly handle failure to allocate per_cpu_nodestats
in free_area_init_core_hotplug()
- Fix deferred initialization of the memory map for
configurations where node's RAM end is not aligned
on PAGES_PER_SECTION
Cleanups:
- Remove redundant pageblock_align() call in free_unused_memmap()
- Remove unnecessary invalid range checks in users of memblock
iterators. Some users of for_each_mem_range() and
for_each_mem_pfn_range() verify that start < end for each range.
This is redundant because memblock iterators guarantee to never
return an invalid range
- Stop overlapping zones with 'kernelcore=mirror' and align behaviour
of 'kernelcore=mirror' with other variants of kernelcore and
movablecore
- Remove redundant updates of numa_nodes_parsed mask in the callers
of numa_add_memblk(), the latter always updates the mask anyway
- Remove unnecessary initialization of pgdat->per_cpu_nodestats to
NULL, the variable is reset to the actual value a few lines below"
* tag 'memblock-v7.3-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock: (25 commits)
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
mm/mm_init: remove unnecessary initialization of pgdat->per_cpu_nodestats
mm/mm_init: remove redundant memset in free_area_init()
mm: numa_memblks: use numa_add_reserved_memblk() in numa_cleanup_meminfo()
arch_numa: remove redundant node_possible_map assignment
mm: numa_memblks: remove redundant numa_nodemask_from_meminfo()
LoongArch: remove redundant numa_nodes_parsed node_set()
arch_numa: remove redundant numa_nodes_parsed node_set()
x86/numa: remove redundant numa_nodes_parsed node_set()
of/numa: remove redundant numa_nodes_parsed node_set()
ACPI: NUMA: remove redundant numa_nodes_parsed node_set()
mm: numa_memblks: set numa_nodes_parsed in numa_add_memblk()
mm/mm_init: handle alloc_percpu failure in free_area_init_core_hotplug
mm/mm_init: drop overlap_memmap_init()
mm/mm_init: don't overlap NORMAL and MOVABLE zones with kernelcore=mirror
mm/hugetlb: remove unnecessary empty range check in hugetlb_bootmem_set_nodes()
mm: remove unnecessary empty range check in early_calculate_totalpages()
powerpc64/kasan: Remove unreachable invalid range check in kasan_init_phys_region()
ARM: remove unreachable invalid range check in kasan_init()
riscv: remove unreachable invalid range check in kasan_init()
...
|
||
|
Linus Torvalds
|
ab5ed08f2d |
vfs-7.3-rc1.lookup
Please consider pulling these changes from the signed vfs-7.3-rc1.lookup tag. Thanks! Christian -----BEGIN PGP SIGNATURE----- iHUEABYKAB0WIQRAhzRXHqcMeLMyaSiRxhvAZXjcogUCan7RJQAKCRCRxhvAZXjc ouj6AQCnBHstCt5RRimywLYU+eTmdKe203zRQYxXpwlYOAzm7wEAm1mIC7/Of6bD jkiJilcPDcyYcJsqwBw/Vcz5HR+v8wo= =TX6K -----END PGP SIGNATURE----- Merge tag 'vfs-7.3-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs Pull vfs lookup updates from Christian Brauner: "This refactors lookup_open() and adds vfs_lookup_open() for nfsd. mnt_want_write() and parent locking are moved into lookup_open() itself. audit_inode_child() is also now called in lookup_open() on failure. That is the calling convention in vfs_create() and vfs_mkdir(), but lookup_open() made no such call when atomic_open() should have created a file and did not. And neither did the regular ->create() path fwiw. This also contains work to remove the unneeded excl argument from the ->create() inode op" * tag 'vfs-7.3-rc1.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: fs/namei.c: fix coding style in atomic_open() and lookup_open() fs/namei.c: fix kerneldoc of atomic_open() and vfs_lookup_open() fs/namei.c: update stale comments in lookup_open() Remove excl arg to ->create inode_operation fs/namei.c: update kerneldoc of atomic_open() vfs: call audit_inode_child() in lookup_open() on failure vfs: move create error && negative dentry case in lookup_open() up VFS: add vfs_lookup_open() for nfsd VFS: move delegated_inode retry loop into lookup_open() VFS: move mnt_want_write() and locking into lookup_open() |
||
Hyunwoo Kim
|
aedf2efd18 |
mm/pagewalk: fix stale walk->action escaping walk_pmd_range()
If ->pmd_entry() sets walk->action = ACTION_AGAIN, the pmd_none() check is retried. The PMD entry may be cleared at the point of retry. In this case, if walk->ops->install_pte is not specified, the code continues to the next PMD entry in the range without resetting walk->action to ACTION_SUBTREE. This leaves walk->action erroneously set to ACTION_AGAIN, which is incorrect. This was incorrect but not problematic up until commit |
||
Youngjun Park
|
10d9012e83 |
mm, swap: don't free a hibernation slot that is in the swap cache
A slot with a folio in the swap cache is freed when the folio leaves the
cache, not when its count drops. swap_put_entries_cluster() follows that
rule. swap_free_hibernation_slot() does not, it calls
__swap_cluster_free_entries() whether or not a folio sits on the slot.
Cluster readahead can put one there. It walks a raw page_cluster sized
window of offsets around the faulting entry, and a hibernation slot passes
__swap_cache_add_check() because it is not a folio and its count is not
zero. Freeing the slot then clears the entry under that folio.
The folio is now unreachable from the swap table, and the offset goes back
to the allocator. The folio is still on the LRU though, so reclaim can
pick it up later. It then takes the old offset out of folio->swap and
overwrites the table entry there, which by then may belong to someone
else.
This bug can trigger silent memory corruption, process crashes, or data
instability across completely unrelated userspace applications - typically
occurring when uswsusp is preparing the hibernation image.
I found this while working on giving hibernation slots their own marker in
the swap table, which I had discussed with Kairui.
(https://lore.kernel.org/linux-mm/abp7aDgYLrxF3Me8@KASONG-MC4/) As far as
I know there are no reports, so there is no Reported-by/Closes to add.
Check for a cached folio before freeing. The slot is then left in the
ordinary state where only the swap cache holds it, and it is freed when
the folio leaves the cache, either through the reclaim below or through
normal reclaim later.
Link: https://lore.kernel.org/20260811132209.2862708-2-youngjun.park@lge.com
Fixes:
|
||
Guopeng Zhang
|
92192e9c5e |
mm: memcg-v1: fix memsw and TCP failcnt accounting
Commit |
||
Breno Leitao
|
25f52e8121 |
mm/vmscan: report RCU-tasks quiescent states in shrink_lruvec()
I am seeing some rcu_tasks stalls in the Meta fleet during reclaim. INFO: rcu_tasks detected stalls on tasks: 0000000088620d09: .. nvcsw: 6735/6735 holdout: 1 idle_cpu: -1/8 task:GlobalCPUThread state:R running task pid:2552016 tgid:2524552 Call Trace: shrink_lruvec mem_cgroup_iter shrink_node do_try_to_free_pages try_to_free_pages __alloc_frozen_pages_noprof alloc_pages_noprof pte_alloc_one __pte_alloc handle_mm_fault Nothing promises direct reclaim returns in bounded time, and the scan loop in shrink_lruvec() only calls cond_resched(), which is a no-op on PREEMPTION kernels. Involuntary preemption is not a Tasks-RCU quiescent state, so the reclaiming task never reports one and becomes a holdout. Upgrade it to cond_resched_tasks_rcu_qs(), which reports a quiescent state even when cond_resched() does nothing. PS: This has been discussed in [1] Link: https://lore.kernel.org/20260810-rcu_task_shrink_lruvec-v1-1-4d9f7d5251cb@debian.org Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Shakeel Butt <shakeel.butt@linux.dev> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@kernel.org> Cc: Kairui Song <kasong@tencent.com> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Shakeel Butt
|
bf4ade7dbd |
memcg: keep folio's objcg same as its node
memcg_reparent_objcgs() has an inherent assumption that a folio's objcg is
the objcg of the folio's node. Folio migration across nodes breaks that
assumption: the new folio simply inherits the old folio's objcg while
living on a different node.
Once the assumption is broken, the reparenting of the folio's objcg and
the reparenting of the folio's LRU list are no longer atomic.
memcg_reparent_objcgs() handles one node per iteration and drops all the
locks in between, so the objcg gets reparented in the iteration for the
objcg's node while the LRU list gets spliced in the iteration for the
folio's node. Any LRU operation on that folio in between resolves its
lruvec through the objcg, and thus takes the lru_lock of the wrong memcg,
not the lru_lock of the list the folio is actually on.
Fix this by selecting the objcg by folio_nid() at charge time, and by
re-deriving it for the destination node in mem_cgroup_migrate() and
mem_cgroup_replace_folio().
Link: https://lore.kernel.org/20260807142406.443516-1-shakeel.butt@linux.dev
Fixes:
|
||
Mike Rapoport (Microsoft)
|
b3c1ec1a9a | Merge branch 'misc' into for-next | ||
|
Mike Rapoport (Microsoft)
|
d606ff2083 | Merge branch 'range-checks' into for-next | ||
|
Mike Rapoport (Microsoft)
|
6abae98a05 | Merge branch 'numa_memblks-redundant-work' into for-next | ||
|
Mike Rapoport (Microsoft)
|
51a1af5c72 | Merge branch 'kernelcore-mirror' into for-next | ||
Alexander Graf
|
97090500d7 |
mm/mm_init: deferred_grow_zone(): fix out-of-range first_deferred_pfn
With CONFIG_DEFERRED_STRUCT_PAGE_INIT enabled, deferred_grow_zone()
initializes struct pages early in boot to satisfy an allocation.
With a large CMA reservation in place, the ranges deferred_init_memmap()
finds may not add up to the allocation it was asked for, and the function
ends up initializing the memory map of the entire zone and still falls
short.
That is fine in itself: the function accounts for it and leaves the
caller to decide whether it now has enough memory.
However, the update of pgdat->first_deferred_pfn that tracks where
uninitialized memory map starts could overflow.
If the node's RAM end is not aligned on PAGES_PER_SECTION boundaries and
some deferred struct pages were initialized, pgdat->first_deferred_pfn
would point past the end of the node's memory.
deferred_init_memmap() later picks up from pgdat->first_deferred_pfn and
hits a BUG_ON(), because it expects a pfn within its node.
For example, when running a kernel with CONFIG_DEFERRED_STRUCT_PAGE_INIT=y
and CONFIG_CMA=y using the following qemu command line
qemu-system-x86_64 -enable-kvm -m 8032M -kernel bzImage \
-append "nokaslr cma=4768M@0x100000000"
the kernel panics:
kernel BUG at mm/mm_init.c:2131!
CPU: 3 UID: 0 PID: 36 Comm: pgdatinit0 Not tainted 7.2.0-rc6 #1
RIP: 0010:deferred_init_memmap+0x1b8/0x1c0
RAX: 0000000000236000 R13: 0000000000238000
Call Trace:
kthread+0xdf/0x120
ret_from_fork+0x187/0x250
Make sure that the update of pgdta->first_deferred_pfn does not overflow
when the entire zone's (and therefore node's) memory map is initialized.
Fixes:
|
||
|
Linus Torvalds
|
f9a2394a23 |
17 hotfixes. 15 are cc:stable. 16 are for MM.
There's a 3 patch series from Lorenzo "mm: fix UAF caused by race between
ptdump and vmap pgtable freeing" which addresses a quite old bug in the
ptdump code.
And a 2 patch series also from Lorenzo which fixes a four year old bug in
the huge_zero_folio handling.
A 3 patch series from SJ fixes a few possible divide-by-zero issues which
Sashiko sniffed out. And a 2 patch series which fixes handling of the
commit_inputs parameters.
The remainder are singletons, please see their changelogs for details.
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Merge tag 'mm-hotfixes-stable-2026-08-06-18-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM fixes from Andrew Morton:
"17 hotfixes. 15 are cc:stable. 16 are for MM.
There's a patch series from Lorenzo "mm: fix UAF caused by race
between ptdump and vmap pgtable freeing" which addresses a quite old
bug in the ptdump code.
And another series also from Lorenzo which fixes a four year old bug
in the huge_zero_folio handling.
A series from SJ fixes a few possible divide-by-zero issues which
Sashiko sniffed out. And a series which fixes handling of the
commit_inputs parameters.
The remainder are singletons, please see their changelogs for details"
* tag 'mm-hotfixes-stable-2026-08-06-18-44' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/damon: adjust isolated pages stat for DAMOS_MIGRATE_{HOT,COLD}
mm/damon/ops-common: putback folios on invalid migrate nid
mm/huge_memory: initialise workingset state before folio split
mm/page_table_check: skip special zero mappings
mm/damon/lru_sort: skip damon_call() if ctx has not started
mm/damon/reclaim: skip damon_call() if ctx has not started
mm/damon/lru_sort: error out for >10000 active_mem_bp
samples/damon/mtier: error out for zero quota goal target values
mailmap: map old addresses to Danila Tikhonov
mm/huge_memory: separate out CONFIG_PERSISTENT_HUGE_ZERO_FOLIO logic
mm/huge_memory: fix huge_zero_pfn race
MAINTAINERS: update address for Brendan Jackman
mm/filemap: __filemap_add_folio() restore index before retrying
microblaze: restore the page alignment of swapper_pg_dir
arm64: remove redundant concurrent ptdump UAF mitigation
mm/ptdump: always stabilise against page table freeing using init_mm
mm/vmalloc: acquire init_mm lock on huge vmap to avoid ptdump UAF
|
||
Jiacheng Yu
|
1d3897b024 |
mm/shmem: downgrade final i_blocks check in shmem_evict_inode() to pr_warn()
shmem_evict_inode() ends with WARN_ON(inode->i_blocks) as a final consistency check of shmem's block accounting. When it fires, the inode-local counters die with the inode; what may linger is a small residue in accounting kept outside the inode, such as per-mount or per-user charges. No data is lost, and no corruption follows. On kernels running with panic_on_warn=1, this accounting inconsistency escalates to a full machine panic, which is disproportionate to the impact. Downgrade the WARN_ON() to a pr_warn() that reports the inode together with its accounting counters (i_blocks, alloced, swapped, nrpages), keeping the inconsistency visible in the logs. The accounting bugs this check has caught over the years -- the swapout race described in commit |
||
Jakov Novak
|
0ec282155c |
mm/khugepaged: replace mutex_lock/mutex_unlock usage with guard macro
Currently, khugepaged locks the khugepaged_mutex in two functions: start_stop_khugepaged and khugepaged_min_free_kbytes_update. Remove mutex_lock/mutex_unlock usage in these functions and replace it with the guard macro. This makes the code more readable (removing a goto statement) and makes it harder to introduce bugs in the future. No functional changes introduced. Link: https://lore.kernel.org/20260730204724.16912-1-jakovnovak30@gmail.com Signed-off-by: Jakov Novak <jakovnovak30@gmail.com> Reviewed-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org> Reviewed-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Zi Yan <ziy@nvidia.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Lance Yang <lance.yang@linux.dev> Cc: Liam R. Howlett <liam@infradead.org> Cc: Nico Pache <npache@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Richard Chang
|
f276408a81 |
mm/zsmalloc: fix release order of locks in zs_page_migrate()
In zs_page_migrate(), locks are acquired in the following order: 1. write_lock(&pool->lock) 2. spin_lock(&class->lock) 3. zspage_write_trylock(zspage) However, upon successful page migration, they were being released in forward acquisition (FIFO) order: 1. write_unlock(&pool->lock) 2. spin_unlock(&class->lock) 3. zspage_write_unlock(zspage) Fix the unlocking order to release locks in strict reverse (LIFO) order of acquisition: 3. zspage_write_unlock(zspage) 2. spin_unlock(&class->lock) 1. write_unlock(&pool->lock) Releasing locks in reverse order of acquisition adheres to standard kernel locking hygiene, prevents potential lock ordering and lockdep inconsistencies. Link: https://lore.kernel.org/20260728055333.421080-1-richardycc@google.com Signed-off-by: Richard Chang <richardycc@google.com> Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org> Tested-by: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: Martin Liu <liumartin@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Wang Wensheng
|
6be12ddb52 |
ksm: stop iterating VMAs when ksm_test_exit returns true
In scan_get_next_rmap_item() the break statement only exits the inner while loop, leaving remaining VMAs to be iterated even if ksm_test_exit() returns true. Replace it with a goto statement to avoid the unnecessary work. Link: https://lore.kernel.org/20260726133501.504048-1-wsw9603@163.com Signed-off-by: Wang Wensheng <wsw9603@163.com> Reviewed-by: Xu Xin <xu.xin16@zte.com.cn> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Chengming Zhou <chengming.zhou@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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|
Breno Leitao
|
efe8f86c09 |
mm/migrate: report RCU-tasks quiescent states in migrate_pages_batch()
migrate_pages_batch() unmaps each folio before moving it, and every unmap runs the mmu_notifier invalidate callbacks. On KVM hosts try_to_migrate() ends up in kvm_mmu_notifier_invalidate_range_start() -> tdp_mmu_zap_leafs(), which is expensive, so unmapping a large batch keeps the CPU busy for a long time. The loop already calls cond_resched(), but on PREEMPTION kernels that is a no-op, and involuntary preemption is not a Tasks-RCU quiescent state. A long batch therefore never reports a quiescent state, and the migrating task (e.g. kcompactd) becomes a Tasks-RCU holdout, stalling the Tasks-RCU grace period for minutes, which is common at Meta fleet: INFO: rcu_tasks detected stalls on tasks: 0000000055349ecc: .. nvcsw: 1157401/1157401 holdout: 1 idle_cpu: -1/56 task:kcompactd0 state:R running task Call Trace: tdp_mmu_zap_leafs tdp_mmu_next_root gfn_to_pfn_cache_invalidate_start kvm_mmu_notifier_invalidate_range_start __mmu_notifier_invalidate_range_start try_to_migrate_one try_to_migrate migrate_pages_batch migrate_pages compact_zone compact_node kcompactd kthread Use cond_resched_tasks_rcu_qs() so a quiescent state is reported even when cond_resched() does nothing. This has also been discussed at [1] Link: https://lore.kernel.org/20260727-kcompact-v1-1-bdfefddd6874@debian.org Link: https://lore.kernel.org/all/amdWVTs0WKOxguxP@gmail.com/ [1] Signed-off-by: Breno Leitao <leitao@debian.org> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Gregory Price <gourry@gourry.net> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Alistair Popple <apopple@nvidia.com> Cc: Byungchul Park <byungchul@sk.com> Cc: "Huang, Ying" <ying.huang@linux.alibaba.com> Cc: Joshua Hahn <joshua.hahnjy@gmail.com> Cc: Matthew Brost <matthew.brost@intel.com> Cc: Rakie Kim <rakie.kim@sk.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Johannes Weiner
|
7e8756d7ad |
mm: page_alloc: fix non-movable reclaim storm in defrag_mode
As we deployed defrag_mode into Meta production, pressure spikes and
excessive swapping were observed on some workloads. Tracing confirmed
that this is unmovable/reclaimable requests spinning in the allocator and
direct reclaim, causing excessive amounts of swap.
The initial plan for defrag_mode was to rely on kswapd/kcompactd to
produce blocks, and if those are overwhelmed under high pressure, let the
allocator fall back (__rmqueue_steal()) after its retry loops. However,
that retrying results in more reclaim on some of these workloads than we'd
hoped, sometimes excessively so, spurred on by the !costly order
conditions in should_reclaim_retry().
The storms are dependent on the request type. Reclaim will inevitably
make room in existing movable blocks, since that's where the LRU pages
live. So if movable requests retry on reclaim, they make progress.
When non-movable requests spin in reclaim that isn't productive. They
cannot use the individually freed pages, and the process is unlikely to
accidentally free whole blocks to meet the ALLOC_NOFRAGMENT bar. They
spin and overreclaim excessively, which tanks performance and triggers
userspace guards like swap exhaustion or pressure based OOM.
To fix this, send non-movable requests, regardless of order, into
pageblock reclaim/compaction. This way, they help move things along to
meet the ALLOC_NOFRAGMENT bar. After this patch, the reclaim storms and
excess OOM rates are no longer observed in production.
The longer-term plan is still to have all requests, including the movable
ones, help make blocks to spread the cost of defragmenting more evenly and
fairly; combined with proper watermarking to reduce allocation latencies
in the common case. However, doing this naively unearths scaling and
concurrency limitations in compaction that need to be addressed first.
Promoting just non-movables for now is the minimally viable bug fix for
the above issue.
[brendan.jackman@linux.dev: fix try_to_compact_pages() kerneldoc]
Link: https://lore.kernel.org/DK7NM9RPUJOD.11PNJJ5N2OBED@linux.dev
Link: https://lore.kernel.org/20260722150006.3848560-5-hannes@cmpxchg.org
Fixes:
|
||
|
Vlastimil Babka (SUSE)
|
aee220f565 |
mm: page_alloc: move capture_control to the page allocator
The compaction capturing code assumes the allocation request order and
compaction target order are the same. That won't be true once defrag_mode
promotes sub-block allocations to pageblock-order compaction: compaction
targets the larger order, while capture should remain at the original
allocation order.
Move the capture_control to the page allocator and give it its own copies
of what the page freeing path matches against - zone, migratetype and the
allocation order - rather than reaching into compaction's live
compact_control. __alloc_pages_direct_compact() fills in migratetype and
order, and installs and hides current->capture_control around the whole
compaction call; try_to_compact_pages() aims capc->zone at each zone while
it is being compacted. compact_zone_order() no longer deals with capture
at all.
Pass the capture_control through try_to_compact_pages() /
compact_zone_order() in place of the bare struct page **.
No functional change.
Link: https://lore.kernel.org/20260722150006.3848560-4-hannes@cmpxchg.org
Fixes:
|
||
|
Johannes Weiner
|
1b4b697a57 |
mm: compaction: support non-movable compaction for pageblock requests
While trying to fix a reclaim storm in defrag_mode, I noticed that
non-movable direct compaction is extremely inefficient.
When searching for space to evacuate, compaction only allows blocks of the
same type as the incoming request. This is to prevent migratetype
pollution, where a small non-movable request frees space in a movable
block and provokes the allocator to fall back and pollute it.
This protection is reasonable on one hand, but the downside is that it
makes non-movable direct compaction nearly useless: if we get the type
annotations right, by definition there aren't any movable pages inside the
non-movable blocks it is allowed to scan.
With defrag_mode, the goal is the production of whole blocks, which are
essentially type neutral: __rmqueue_claim() will convert them wholesale on
alloc. This makes type mixing and pollution a non-issue.
Fix the pollution gates to take the requested order into account, and
allow whole-block requests to scan blocks of other types.
The only exception is CMA blocks. That type is sticky and these blocks
cannot be claimed to other types. Continue to be strict with them, and
allow only explicit ALLOC_CMA requests and kcompactd to evacuate them.
Link: https://lore.kernel.org/20260722150006.3848560-3-hannes@cmpxchg.org
Fixes:
|
||
|
Johannes Weiner
|
37864d0bf5 |
mm: page_alloc: __GFP_FS lockdep annotation for direct compaction
Patch series "mm: fix reclaim storms in defrag_mode", v2.
As we deployed vm.defrag_mode=1 in Meta production, some workloads
regressed with recurring pressure spikes and swap storms (which in turn
triggered userspace OOM rules on pressure and swap utilization levels).
Tracing pinned this to non-movable requests spinning and reclaiming
unproductively when kswapd/kcompactd are overwhelmed. Direct reclaim
predominantly frees up pages in movable blocks, but those requests cannot
use that space under defrag_mode rules; and it is unlikely to free up
whole blocks incidentally for __rmqueue_claim() to work.
This series fixes it by making non-movable requests participate in
pageblock production in the allocator slowpath - meaning, they will invoke
direct reclaim and direct compaction with pageblock_order.
That requires some small-ish adjustments up front in the allocator and the
compaction code: three prep patches and the fix last.
The series has been in production against one of the affected workloads
for several weeks and restores the OOM kill rate to !defrag_mode baseline.
This patch (of 4):
A subsequent patch will have some order-0 allocations participate in
compaction under defrag_mode, to stave off extfrag events.
Since this is a sprawling expansion of entry points, and compaction can
enter filesystem paths, add lockdep annotations that catches __GFP_FS
passing errors.
Direct reclaim has had this annotation for a while, and since reclaim and
compaction are usually used in conjunction, this is unlikely to unearth
old bugs. It's more about future proofing and peace of mind.
Link: https://lore.kernel.org/20260722150006.3848560-1-hannes@cmpxchg.org
Link: https://lore.kernel.org/20260722150006.3848560-2-hannes@cmpxchg.org
Fixes:
|
||
Yichong Chen
|
47f3cecd72 |
hugetlb: evaluate subpool free state while locked
unlock_or_release_subpool() drops spool->lock before calling subpool_is_free(). However, subpool_is_free() reads fields that are updated under spool->lock, including count, used_hpages and rsv_hpages. Keep the free-state evaluation under the same lock that protects those fields. The reservation accounting and kfree() calls still happen after dropping spool->lock. Link: https://lore.kernel.org/20260721035207.1437935-1-chenyichong@uniontech.com Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Reviewed-by: Joshua Hahn <joshua.hahnjy@gmail.com> Reviewed-by: Jane Chu <jane.chu@oracle.com> Cc: David Hildenbrand <david@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Xuewen Wang
|
64a853c9a6 |
mm/damon: remove trailing semicolons after function definitions
Three function definitions terminate with '};' instead of '}', which is unnecessary and inconsistent with kernel coding style: - damon_pa_initcall() in paddr.c - damon_va_initcall() in vaddr.c - damos_get_some_mem_psi_total() in core.c No functional change intended. Link: https://lore.kernel.org/20260721135333.241106-1-sj@kernel.org Signed-off-by: Xuewen Wang <wangxuewen@kylinos.cn> Reviewed-by: SJ Park <sj@kernel.org> Signed-off-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
Jiahui Zhang
|
613c2d5552 |
mm/damon/ops-common: prevent migration fallback to non-target nodes
DAMOS_MIGRATE_{HOT,COLD} passes a target NUMA node to migrate_pages().
But alloc_migration_target() only treats mtc->nid as a preferred node
unless __GFP_THISNODE is set. Hence target allocation can fall back to
another node, and migrate_pages() can report success without placing the
folio on the requested target node.
Consider a two-node tiered system where node 0 is a fast tier and node 1
is a CPU-less slow tier such as CXL memory, and the user wants to promote
hot regions from node 1 to node 0 with a command like:
sudo damo start --ops vaddr --target_pid ${workload_pid} \
--damos_action migrate_hot 0 \
--damos_access_rate 70% max
Without the __GFP_THISNODE flag, when the memory allocator finds that node
0 is nearly full, it can fall back to node 1 without waking up kswapd.
Then the pages allocated for migrate_pages() are still on node 1, and the
regions that are expected to be promoted to node 0 are only moved to
different physical pages on node 1.
Meanwhile, both the mm_migrate_pages tracepoint and DAMOS's own sz_applied
statistics (reported via the damos_stat_after_apply_interval tracepoint)
show the migrations as successful, which makes the failure practically
invisible and hard to investigate.
Running a demotion-purpose DAMOS scheme alongside the promotion scheme
does not fully avoid this either. If demotion cannot keep up with the
promotion rate, allocation can still fall back to node 1 during promotion,
and the same misleading statistics show up.
Make DAMON's migration target allocation strict by setting __GFP_THISNODE,
so that a failed allocation on the target node is reported as a failure
instead of silently landing on a different node. This is consistent with
alloc_misplaced_dst_folio(), alloc_demote_folio(), and with
do_move_pages_to_node(), which all use __GFP_THISNODE for migrations to an
explicit destination node.
Link: https://lore.kernel.org/20260721135607.251869-1-sj@kernel.org
Signed-off-by: Jiahui Zhang <jiahuitry@outlook.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Honggyu Kim <honggyu.kim@sk.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
Sang-Heon Jeon
|
6fa0d03840 |
mm/early_ioremap: clarify early_ioremap_reset() semantics
Patch series "mm/early_ioremap: clarify and clean up
early_ioremap_reset()".
__late_set_fixmap() and __late_clear_fixmap() are only used after
early_ioremap_reset() has been called, but the comment above them does not
say anything about that. So arm64, riscv and powerpc, whose
__set_fixmap() works before and after paging_init(), describe the same
situation in three different ways:
calls reset defines the macros
arm64 yes yes
riscv no yes
powerpc no no
Patch 1 documents when early_ioremap_reset() needs to be called and that
only architectures calling it need to define the macros.
Patches 2 and 3 remove the unneeded riscv macros, which are unreachable,
and the arm64 reset call and macros, which change nothing.
No functional change.
This patch (of 3):
__late_set_fixmap() and __late_clear_fixmap() are only used after
early_ioremap_reset() has been called.
arm64, riscv and powerpc all have a __set_fixmap() that works before and
after paging_init(), so they do not need to call early_ioremap_reset() or
define the macros, but they describe the same situation in three different
ways:
calls reset defines the macros
arm64 yes yes
riscv no yes
powerpc no no
The existing comment is vague and allows all three. Replace it with
comments that make it clear when the reset and the macros are needed.
No functional change.
Link: https://lore.kernel.org/20260708170647.362562-1-ekffu200098@gmail.com
Link: https://lore.kernel.org/20260708170647.362562-2-ekffu200098@gmail.com
Signed-off-by: Sang-Heon Jeon <ekffu200098@gmail.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: David Hildenbrand <david@kernel.org>
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: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Will Deacon <will@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
||
Dev Jain
|
4fe4ea4cbe |
mm/rmap: batch unmap file folios belonging to uffd-wp VMAs
Commit
|
||
|
Dev Jain
|
4259767463 |
mm/memory: batch set uffd-wp markers during zapping
Enable batch setting of uffd-wp PTE markers. The code paths passing nr > 1 to zap_install_uffd_wp_if_needed() produce that nr through either folio_pte_batch() or swap_pte_batch(), therefore batching is correct: 1) All PTEs belong to the same type of VMA: anonymous or non-anonymous, wp-armed or non-wp-armed. 2) All PTEs are either marked with uffd-wp or not marked with uffd-wp; the same applies to the pte_swp_uffd_any() check. 3) uffd_supports_wp_marker() is independent of the function parameters. Use set_pte_at() in a loop instead of set_ptes(), because set_ptes() cannot handle nonpresent to nonpresent conversion for nr_pages > 1. Rename the helper to cond_install_uffd_wp_ptes(). Link: https://lore.kernel.org/20260720065508.2695106-3-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: Harry Yoo <harry@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Lance Yang <lance.yang@linux.dev> 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: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Dev Jain
|
5d72b5d76d |
mm/memory: move pte_install_uffd_wp_if_needed() into memory.c
Patch series "Batch unmap of uffd-wp file folios", v2. Currently, batched unmapping is supported if: 1) folio is a file folio, not belonging to uffd-wp VMA 2) folio is anonymous and not swapbacked (lazyfree), not belonging to uffd-wp VMA So the cases which are not supported are 1) folio belonging to uffd-wp VMA 2) folio is anonymous and swapbacked It is easy to see that this adds a lot of cognitive load while reading try_to_unmap_one - we need to remember throughout whether nr_pages == 1 or > 1. The uffd-wp handling in try_to_unmap_one is regarding preserving the uffd-wp state for file folios via pte_install_uffd_wp_if_needed (for anon folio, we handle that while constructing the swap pte). Stop special casing on uffd-wp VMAs by simply adding batching support to pte_install_uffd_wp_if_needed. This patch (of 3): pte_install_uffd_wp_if_needed() has grown too large for mm_inline.h. Move it to memory.c. This helper is only used inside mm/, so declare it in mm/internal.h instead of a public header. While at it, convert the comment to kerneldoc and rename the local arguments from pte/pteval to ptep/pte so the pointer and PTE value are easier to distinguish. Link: https://lore.kernel.org/20260720065508.2695106-1-dev.jain@arm.com Link: https://lore.kernel.org/20260720065508.2695106-2-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Barry Song <baohua@kernel.org> Cc: Harry Yoo <harry@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: Lance Yang <lance.yang@linux.dev> 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: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Wei Xu <weixugc@google.com> Cc: Yuanchu Xie <yuanchu@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
||
|
Yichong Chen
|
60191388ca |
hugetlb: make hugepage_put_subpool() tolerate NULL
Both callers of hugepage_put_subpool() check whether the subpool pointer is NULL before calling it. Move the NULL check into hugepage_put_subpool() so callers can use the helper unconditionally. This is a follow-up cleanup after using hugepage_put_subpool() from the hugetlbfs_fill_super() failure path. Link: https://lore.kernel.org/20260720073841.1389354-1-chenyichong@uniontech.com Signed-off-by: Yichong Chen <chenyichong@uniontech.com> Reviewed-by: Muchun Song <muchun.song@linux.dev> Cc: David Hildenbrand <david@kernel.org> Cc: Oscar Salvador <osalvador@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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SJ Park
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c608748607 |
mm/damon/core: handle region split failure in apply_min_nr_regions()
damon_apply_min_nr_regions() repeatedly split each region until its size
becomes small enough to meet the user-defined low limit of the number of
regions. The loop assumes the split operation (damon_split_region_at())
will always succeed and create the new region. But the operation could
silently fail for memory allocation failures, for example.
If such failure happens and the region was the last region, the linked
list-based next region fetching returns invalid pointer. As a result,
invalid memory dereference and corruption could happen. Even if the
corner case is handled, it imposes stress to the allocator by trying split
regions for other targets. Fix the issue by breaking all the loops for
any region split failure.
This means there could be a min_nr_regions violation. It will only rarely
happen since the allocation is arguably too small to fail. Even if it
happens, it is only temporal. damon_apply_min_nr_regions() will be called
again after the aggregation interval.
The user impact of the issue should be minor, since the allocation is
arguably too small to fail. But, it could still theoretically happen, and
the consequence is very bad.
This issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260719155442.88794-1-sj@kernel.org
Link: https://lore.kernel.org/20260717011834.120715-1-sj@kernel.org [1]
Fixes:
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SJ Park
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6c25083f7a |
mm/damon/ops-common: use nr_accesses moving sum for quota score
Since commit |
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Enze Li
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a43ea999c5 |
mm/damon/ops-common: remove redundant local variable in damon_migrate_folio_list()
In damon_migrate_folio_list(), we're redeclaring folio inside the first while loop, but it just shadows the outer one. Since the second loop uses the outer folio anyway, the inner declaration is pointless. Remove it to consistently reuse the same variable throughout the function and improve readability. Link: https://lore.kernel.org/20260718002125.637104-1-lienze@kylinos.cn Signed-off-by: Enze Li <lienze@kylinos.cn> Reviewed-by: SJ Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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SJ Park
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488cf81c49 |
mm/damon/core-kunit: skip wrong region walk in commit_target_regions()
damon_test_commit_target_regions_for() traverses expected values array
after damon_commit_target_regions() call. It assumes
damon_commit_target_regions() made expected number of regions. It might
not. Because the traversal is made based on the region count, it could do
out of bounds access to the expectation value array.
The consequent user impact (out-of-bound access) is quite bad. The
realistic user impact would be limited, though. It would affect only test
run setups.
Fix it by testing if the number of regions was also changed as expected
and exit early for the failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-8-sj@kernel.org
Link: https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org [1]
Fixes:
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SJ Park
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867bbe6dbd |
mm/damon/core-kunit: skip wrong quota goal walk in commit_quota_goals()
damos_test_commit_quota_goals_for() traverses damos quota goals after
damos_commit_quota_goals() call. It assumes damos_commit_quota_goals()
made expected numbers of goals. It might not. Because the traversal is
made based on destination struct length, it could do out of bounds access
for source expectation value array.
The consequent user impact (out-of-bound access ) is quite bad. The
realistic user impact would be limited though. It would affect only test
run setups.
Fix it by testing if the number of goals was also changed as expected and
exit early for the failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-7-sj@kernel.org
Link: https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org [1]
Fixes:
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SJ Park
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7e2f2c41b2 |
mm/damon/core-kunit: skip wrong dest walk in commit_dests_for()
damos_test_commit_dests_for() traverse damos action destinations after
damos_commit_dests(). It assumes damos_commit_dests() made expected
numbers of destinations for source and destination structures. It might
not. Because the traversal is made based on destination struct length, it
could do out of bounds access for source value expectation.
The consequent user impact (out-of-bound access ) is quite bad. The
realistic user impact would be limited, though. It would affect only test
run setups.
Fix it by exiting early for the number of regions test failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-6-sj@kernel.org
Link: https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org [1]
Fixes:
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SJ Park
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3423fe7039 |
mm/damon/core-kunit: handle region split failure in filter_out()
damos_test_filter_out() test checks if damos_filter_match() of an address
filter splits the region as expected under a given condition. But, the
test continued regardless of the split successes. As a result, the later
part of the test could dereference invalid pointers that returned from
damon_next_region(). Further, it could corrupt memory from
damon_destroy_region().
The consequent user impact (memory corruption) is quite bad. The
realistic user impact would be limited, though. It would affect only test
run setups.
Fix it by exiting early for the number of regions test failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-5-sj@kernel.org
Link: https://lore.kernel.org/20260714142352.100478-1-sj@kernel.org [1]
Fixes:
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SJ Park
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5fea07e460 |
mm/damon/vaddr-kunit: check region count in three_regions test
damon_do_test_apply_three_regions() iterates regions after
damon_set_regions() call assuming the function would succeed at setting
the number of regions the same to the expected one. It might have failed.
In this case, __nth_region_of() in the iteration could return NULL and
NULL dereference can happen in the test.
The consequent user impact (NULL dereference) is quite bad. The realistic
user impact would be limited, though. It would affect only test run
setups.
Fix it by testing if the number of regions was also changed as expected
and exit early for the failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-4-sj@kernel.org
Link: https://lore.kernel.org/20260713144757.39740-1-sj@kernel.org [1]
Fixes:
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SJ Park
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9b18ef3c3a |
mm/damon/core-kunit: check region count before testing in split_at()
damon_test_split_at() test next region that is assumed to be created by
damon_split_region_at() invocation. But the split might fail. In this
case, the succeeding test may dereference invalid pointers returned by
damon_next_region().
The invalid pointer may not cause a really bad user impact, because of the
implementation detail. It would only read wrong contents in the belonging
damon_target struct. Depending on the future change of the offset from
the link header to the accessing field, this could also be really
dangerous, though. Still, the realistic user impact would be limited. It
would affect only test run setups.
Fix it by testing if the number of regions was also changed as expected
and exit early for the failure.
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-3-sj@kernel.org
Link: https://lore.kernel.org/20260714142352.100478-1-sj@kernel.org [1]
Fixes:
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SJ Park
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af5f76aeb9 |
mm/damon/core: initialize damos->last_applied
Patch series "mm/damon: fix uninitialized DAMOS field and kunit exec
expectation bugs".
Fix a few Sashiko-found unurgent bugs. Patch 1 fixes use of uninitialized
damos->last_applied field. Patches 2-7 fix DAMON kunit tests that do
invalid memory access under test failures.
The bugs are better to be fixed and eventually merged into stable@ kernel.
That said, the fixes are arguably not urgent. Patch 1 only introduces
negligible DAMOS efficiency degradation in occasional cases. Kunit fixes
could introduce quite bad consequences but those are test code that affect
only test run setups.
This patch (of 7):
Multiple DAMON regions could exist across a folio. If they fulfill the
condition to apply a DAMOS scheme, the scheme could be applied multiple
times to the folio. To avoid this, each DAMOS scheme stores the folio
that the scheme was applied to last time in the damos->last_applied field
and skips repeatedly applying the same scheme to the same folio.
The field is being used without initialization, though. Hence, the
mechanism could wrongly skip applying a scheme to a folio at the very
first time of DAMOS run.
The user impact is trivial. DAMON might unexpectedly skip applying DAMOS
action for one folio for the first time per scheme. In the DAMON's
best-effort world, this is never a real problem. No critical consequences
such as kernel panic or memory corruption happen.
It is a clear bug, though, and the fix is straightforward. Fix the issue
by initializing the field in DAMOS scheme creation function,
damon_new_scheme().
The issue was discovered [1] by Sashiko.
Link: https://lore.kernel.org/20260718001442.87129-1-sj@kernel.org
Link: https://lore.kernel.org/20260718001442.87129-2-sj@kernel.org
Link: https://lore.kernel.org/20260714055436.120034-1-sj@kernel.org [1]
Fixes:
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Kefeng Wang
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557f842e25 |
mm: mincore: refactor mincore_page()
Use early returns to reduce indentation and improve readability. Link: https://lore.kernel.org/20260717091347.1144789-7-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Pedro Falcato <pfalcato@suse.de> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |
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Kefeng Wang
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751a1f061a |
mm: mincore: improve mincore_hugetlb()
walk_hugetlb_range() always passes a non-NULL pte, so remove the dead NULL check. Replace the per-page iteration loop with memset() for better performance. [wangkefeng.wang@huawei.com: fixup improve mincore_hugetlb()] Link: https://lore.kernel.org/20260720124252.1483984-1-wangkefeng.wang@huawei.com Link: https://lore.kernel.org/20260717091347.1144789-6-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Acked-by: David Hildenbrand (Arm) <david@kernel.org> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <liam@infradead.org> Cc: Lorenzo Stoakes <ljs@kernel.org> Cc: Vlastimil Babka <vbabka@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> |