| Age | Commit message (Collapse) | Author |
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git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm: make VMA flag semantics explicit, eliminate VM_SPECIAL" (Lorenzo
Stoakes):
Replace VM_SPECIAL with helpers describing mapping ownership and
behavior. Enforce the mmap flag rules and convert affected drivers,
removing ambiguous tests shared by driver mappings and ordinary
memory.
- "support kselftest on nommu platform" (Hajime Tazaki):
Add opt-in mmap and mremap tests for NOMMU systems. Teach the runner
to avoid its fork-dependent timeout command and document the build
and runtime requirements.
- "mm/collapse: separate a collapse from its callers" (Kiryl
Shutsemau):
Separate huge-page collapse from caller policy. Replace khugepaged
identity checks with explicit permissions, and separate scanning from
collapse with the mmap_lock drop in one place.
- "mm: implement and use vma_has_anon_rmap(), silence KCSAN" (Lorenzo
Stoakes):
Provide a common helper for testing whether a VMA has anonymous
reverse mappings. Document the locking rules, annotate intentional
concurrent reads for KCSAN, and convert the core MM callers.
- "mm/sparse: remove SECTION_MARKED_PRESENT and further cleanups"
(David Hildenbrand):
Remove SECTION_MARKED_PRESENT in favor of the early-section flag.
Simplify sparse memory initialization, section metadata handling and
related PFN validity checks.
- "sh: remove NUMA and SPARSEMEM support" (Mike Rapoport):
Remove SuperH NUMA and SPARSEMEM support. The extra memory banks have
been unusable since the NO_BOOTMEM conversion, leaving only the code
and data overhead.
- "mm: Unify device DAX and HugeTLB vmemmap population paths" (Muchun
Song):
Unify the generic device DAX and HugeTLB vmemmap population paths and
shared tail-page handling. Remove the duplicate DAX machinery while
retaining the powerpc radix implementation.
- "kselftest: mm: fix some failure of split_huge_page_test" (Yeoreum
Yun):
Fix huge-page split tests racing with khugepaged recollapse. Use
pagemap and page flags instead of VMA-boundary assumptions which fail
when glibc has already enabled THP.
- "memcg: move memcgid refcount to objcg to unpin dying memcgs"
(Bingfang Guo):
Let dying memcgs be freed while swapped-out shmem still holds their
IDs. Move ID references to reparentable objcgs, with the necessary
swap accounting and RCU lifetime changes.
- "mm/truncate: fix data loss when truncating straddling large folios"
(Zhang Yi):
Preserve out-of-range data when truncating straddling large folios.
Fix a lookup race and split-failure handling, and handle minimum
folio orders for the forthcoming ext4 iomap buffered I/O path.
- "mm/damon: introduce damos quota goal target metric complement flag"
(SJ Park):
Let DAMOS quota goals use a metric's complement, so utilization can
also express free-memory goals without adding separate metrics. Add
the sysfs interface, documentation and tests.
- "arm64/mm: Standardize printing for pgtable entries" (Anshuman
Khandual):
Use the generic formatter for arm64 page-table entries, ready for
future wider entries. Move the safe-PTE-update check out of the
header to avoid an include cycle.
- "mm: kmsan: fix iounmap metadata teardown" (Dima Koziuk):
Fix KMSAN metadata leaks on iounmap and failed ioremap allocations.
Free backing pages before removing their mappings, and share the
teardown with partial-allocation cleanup.
- "mm/damon/core: preserve quota state when constructing schemes" (Karl
Mehltretter):
Preserve running DAMOS quota state while validating parameter
updates. Even rejected updates could reset accounting and exceed the
quota window; add tests for both accepted and rejected updates.
- "mm/vmalloc: fix vmalloc_dump_obj VA lookup" (Ye Liu):
Fix vmalloc_dump_obj() lookups for last-page addresses and
allocations spanning vmap zones. These allocations were being missed
in diagnostic output.
- "mm: various (urgent?) fixes" (David Hildenbrand):
Fix mmap charge leaks and hugetlb use-after-free, wrong-address
unmapping, stuck locks and endless faults. Also preserve reservations
on failed mremap and handle stale userfaultfd bits.
- "maple_tree: fix maple_range_64 crashes in RCU mode" (Dimitris
Charisis):
Fix pointer and metadata confusion during RCU destruction of
maple_range_64 nodes, avoiding double frees and invalid accesses. Add
a regression test; no in-tree user currently uses this combination.
- "mm: fix hugetlb NR_HUGETLB accounting on folio migration" (Hongfu
Li):
Fix hugetlb migration and preallocation accounting so /proc/vmstat
retains the correct count and memory.numa_stat follows the folio to
its new node.
- "mm/damon: fix a minor bug, clean code, and add a test" (SJ Park):
Fix 32-bit DAMON age overflow which made old regions look young.
Share hugetlb folio acquisition code and add a regression test for
the previously fixed last-region skipping bug.
- "mm/damon/core: cleanup code, reduce stack usage, and add kunit" (SJ
Park):
Reduce kdamond stack usage and remove unused enums. Add deterministic
PSI quota-goal tests which do not depend on the machine's current
memory pressure.
- "mm/damon: fix the temporal goal tuner's size quota conversion"
(Donggeun Yoo):
Bound the temporal tuner's quota conversion to prevent overflow and
zero effective quotas, which could stop schemes making progress. Add
boundary tests.
- "Don't use GFP_DMA when calling dma_alloc_coherent" (Baoquan He):
Remove redundant GFP_DMA flags from coherent DMA allocation calls.
The DMA API already selects the zone from device limits and ignores
the caller's flag.
- "kselftest: mm: fix intermittent failure khugepaged test" (Yeoreum
Yun):
Propagate child-process failures in the khugepaged tests and prevent
background collapse from racing their checks. This removes false
passes and intermittent failures.
- "MAINTAINERS: cover all hugetlb headers under HUGETLB SUBSYSTEM"
(Enze Li):
Cover all hugetlb headers in MAINTAINERS so get_maintainer.pl finds
the right maintainers. Also label the closing hugetlb_cgroup.h
include guard.
Summary of the 65 singletons in this merge:
The singletons include a few worthwhile performance fixes. Avoiding
unnecessary reverse-map tree updates gave a reported 15.9% improvement
in UnixBench's execl test on a 192-core x86 system. A reclaim retry
fix stops defrag_mode from spinning under memory.low protection; a
reported file-creation stress test ran 5.7 times faster, with far less
memory pressure. Narrower hugetlb invalidations also spare KVM guests
needless refaults: the reported Redis-in-VM P99 QPS penalty while
punching holes fell from 7.09% to 1.45%.
Several fixes prevent lost data or corrupted memory. Lazyfree
huge-page races with mremap()/munmap() could lose data or access freed
memory, and MADV_COLD could lose a concurrent write's dirty bit.
Another fix prevents stale migration entries from outliving large
folios. On filesystems with blocks smaller than a page, extending a
file by 4 GiB or more could expose bytes written past the old EOF
through mmap instead of zeroes. That is fixed, along with
use-after-free races in PAGEMAP_SCAN during process exit and in
memory-cgroup accounting on PREEMPT_RT kernels.
Other fixes stop UFFDIO_MOVE spinning forever on pinned large folios,
which could wedge other memory operations, and stop mremap() leaking
commit charges until allocations fail under strict overcommit. A
further fix keeps userfaultfd tracking intact on neighboring mappings.
NUMA binding no longer prevents long-term pins when the chosen node
has only movable memory, fixing QEMU/VFIO startup and io_uring buffer
registration failures. MGLRU also gets a fix for early-boot crashes
with memory cgroups disabled at boot, notably in small crash kernels.
* tag 'mm-stable-2026-10-25-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (213 commits)
mm: multi-gen LRU: fix NULL lruvec->pgdat deref with memcg disabled on cmdline
mm/page_counter: use WRITE_ONCE() for emin/elow when parent is the root
mm/memcontrol: publish null pointer before dropping css reference
test_maple_tree: test maple_range_64 node in RCU mode
maple_tree: fix maple_range_64 crashes in RCU mode
mm/vma: avoid broken uffd merge on mremap
tools/testing/shared: catch a failed posix_memalign()
mm/damon/core: remove unreachable damos charge_{target,addr}_from
mm/shrinker: allocate shrinker_info_unit from a dedicated kmem_cache
riscv: mm: exclude invalid THP PMDs from page table check
mm/damon/core: filter out damos address filter-split failed region
fs/proc/task_mmu: pin mm_users in do_pagemap_scan()
mm/mempolicy: apply bind policies against the scoped allocation zone
mm/vmscan: reclaim every zone in per-node proactive reclaim
mm/mremap: correctly uncharge accountable VMAs in error path
mm/mremap: populate calculated fields in vrm state correctly
MAINTAINERS: add an entry for MEMORY MANAGEMENT - MEMORY MAP
mm: bdi: reset min_ratio after the sysfs attributes are gone
mm/page_vma_mapped: continue past nonmatching huge PMDs
selftests/mm: skip hugetlb cgroup v2 tests without the needed controllers
...
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So far the assumption has been that mm->mm_lock_seq overflow is benign,
resulting only in readers spuriously falling back to the mmap lock, however
it turns out that this was an unsafe assumption.
If a VMA can be spuriously considered write locked that means read lock
exclusion does not take place, and thus a VMA can end up write-locked with
concurrent readers.
Since overflow only occurs every 2^31 write lock/unlock cycles, resolve the
issue by resetting every VMA's vma->vm_lock_seq each time such an overflow
occurs.
This is done in vma_end_write_all(), which is called when the mmap write
lock is released, i.e. in mmap_write_unlock() and mmap_write_downgrade().
Care must be taken, as resetting the sequence count at overflow means
changing the seqcount of VMAs which are already attached and observable.
The mm's seqcount is guaranteed to be odd when a write lock is held, and
thus any write locked VMA will have an odd seqcount assigned.
Therefore resetting to an even value prevents spurious write locks, since
these can only occur with the mmap write lock held, at which point the mmap
seqcount will be odd.
However, vma_start_read() also checks vma->vm_lock_seq == mm->mm_lock_seq,
bailing if so (indicating a write lock).
This would cause any even reset value chosen to prevent VMA read locks from
being taken - avoid this by also checking whether the VMA seqcount is odd
before bailing on the read lock.
So far, vma->vm_lock_seq has defaulted to UINT_MAX, but this has been
unnecessary since commit e5e7fb278e59 ("mm: convert mm_lock_seq to a proper
seqcount"), since this is assigned when the VMA is still detached, and
cannot be observed.
Therefore perform both reset and initialisation of vma->vm_lock_seq by
simply setting vma->vm_lock_seq to zero.
The reset, performed in __mm_reset_vma_seqcounts(), only needs to
WRITE_ONCE() the value.
However the read of vma->vm_lock_seq in vma_start_read() needs to have
acquire semantics to pair with the smp_wmb() in do_raw_write_seqcount_end()
so a reader reading a reset value also observes VMA modifications made
under the write lock.
Since all VMA write locks were just released and the mmap write lock is
still held, there are no concurrent VMA writers.
Concurrent VMA readers are unaffected. New VMA readers observe either zero,
never a write lock, or the prior seqcount, behaving as before the reset.
Since this only occurs every 2^31 write lock/unlock cycles, the time taken
to update all VMAs is considered to be acceptable.
Also update comments, documentation and VMA userland tests to reflect the
change.
User facing effects are - dangerous races that could cause memory
corruption or NULL pointer derefences (especially on page table traversal)
are avoided.
Link: https://lore.kernel.org/20261016-fix-vma-lock-overflow-v2-1-9eb778b79b58@kernel.org
Fixes: 5e31275cc997 ("mm: add per-VMA lock and helper functions to control it")
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Daehyeon Ko <4ncienth@gmail.com>
Closes: https://lore.kernel.org/all/20261015143735.1630957-1-4ncienth@gmail.com/
Reviewed-by: Jose A. Perez de Azpillaga <azpijr@gmail.com>
Tested-by: Jose A. Perez de Azpillaga <azpijr@gmail.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jann Horn <jannh@google.com>
Cc: Pedro Falcato <pfalcato@suse.de>
Cc: <stable@vger.kernel.org> # 7.3.x
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Update DAMON design document for the newly added damos quota goal metric
value complement flag.
Link: https://lore.kernel.org/20260929080113.41708-7-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/mm/core
Pull core memory management updates from David Hildenbrand:
"This includes updates to:
- MEMHP (Memory Hotplug)
- GUP (Get User Pages)
The main change is:
- Reduce zone contiguity checking overhead during memory hot(un)plug
(Yuan Liu)
Other changes include smaller fixes along with various cleanups"
* tag 'mm-core-7.4-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mm/core:
mm/memory_hotplug: fix missing rollback in __add_pages()
mm/memory_hotplug: optimize zone contiguous check when changing pfn range
mm/memory_hotplug: make shrink_zone_span() more robust
mm/gup: honour FOLL_PIN in NOMMU __get_user_pages_locked()
mm/gup_test: report actual pinned bytes
mm/gup_test: safely calculate GUP batch size
mm: gup: cleanup the gup_fast_*() call chain
mm: gup: move pmd_protnone() into gup_fast_pmd_leaf()
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The set_memory() and set_direct_map() APIs change permissions of existing
kernel mappings, but their semantics are only described by the code, and
that code differs from architecture to architecture.
Add Documentation/mm/kernel-page-tables.rst that briefly describes what
the kernel page tables consist of, defines the semantics both APIs have in
common, including the parts that are easy to get wrong, and lists the
differences between the architecture implementations.
Add kernel-doc comments for the generic set_memory() and set_direct_map()
stubs and link them into Documentation/core-api/mm-api.rst.
[rppt@kernel.org: fix phrasing, per Kevin]
Link: https://lore.kernel.org/arJNn2QD_pY6e14R@kernel.org
Link: https://lore.kernel.org/20260919-set-memory-docs-v2-1-a2a4b3657690@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Kevin Brodsky <kevin.brodsky@arm.com>
Assisted-by: copilot:claude-opus
Cc: "David Hildenbrand (arm)" <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: "Vlastimil Babka (SUSE)" <vbabka@kernel.org>
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DAMON design document uses "bp" for "basis point" in multiple places.
Because it is not clearly mentioned, it is difficult to understand what
"bp" stands for. Add the clarification.
Link: https://lore.kernel.org/20260917142210.90829-11-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Closes: https://lore.kernel.org/107dc6ba-697e-4b25-ba3e-8ce2499cac9a@infradead.org
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@davidgow.net>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
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Update DAMON design document for the newly added hugepage_size data
attribute probe filter type.
Link: https://lore.kernel.org/20260915143359.91472-7-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
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Correct incorrect references of "quota" to "goal" in the temporal
auto-tuning algorithm description and fix the square bracket formatting.
Link: https://lore.kernel.org/20260914141952.91465-7-sj@kernel.org
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@davidgow.net>
Cc: David Hildenbrand <david@kernel.org>
Cc: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kunwu Chan <kunwu.chan@gmail.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lian Wang <lianux.mm@gmail.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: "Zenghui Yu (Huawei)" <zenghui.yu@linux.dev>
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qt_exceeds counts how many times a scheme's quota has been exceeded.
When using the temporal auto-tuning algorithm, the effective size quota
becomes zero once the goal is [over-]achieved. In this case, the quotas
are still set, so qt_exceeds keeps increasing once per quota reset
interval while the goal stays achieved.
Clarify this behavior in the design document.
Link: https://lore.kernel.org/20260914141952.91465-6-sj@kernel.org
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@davidgow.net>
Cc: David Hildenbrand <david@kernel.org>
Cc: Eva Kurchatova <eva.kurchatova@virtuozzo.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kunwu Chan <kunwu.chan@gmail.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lian Wang <lianux.mm@gmail.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: "Zenghui Yu (Huawei)" <zenghui.yu@linux.dev>
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Update DAMON design document for the newly added probe hits weighted sum
based DAMOS core filter type.
Link: https://lore.kernel.org/20260911135510.96914-7-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
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Device DAX now uses the common per-zone shared tail page for vmemmap
deduplication. The old documentation still described a DAX-specific
layout with a separately populated tail vmemmap page and half the HugeTLB
savings.
Update the generic and powerpc documentation to describe the shared
layout. In the powerpc document, keep the radix and 64K-specific details,
drop the duplicated 4K PUD arithmetic, and replace the repeated device-dax
diagrams with a single parameterized PMD/PUD diagram.
Link: https://lore.kernel.org/20260930140627.57431-13-songmuchun@bytedance.com
Signed-off-by: Muchun Song <muchun.song@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Qi Zheng <qi.zheng@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Christophe Leroy <chleroy@kernel.org>
Cc: Ritesh Harjani (IBM) <ritesh.list@gmail.com>
Cc: Shrikanth Hegde <sshegde@linux.ibm.com>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Lance Yang <lance.yang@linux.dev>
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Update DAMON design document for the newly added pgidle_set probe filter
type.
Link: https://lore.kernel.org/20260910142234.171562-6-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
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Now that page tables are freed after an RCU grace period, it is safe for
read-only page table walkers to walk page table ranges that are being
concurrently torn down, provided the mm is kept alive via mmgrab().
It is however unsafe for writers to do so, as they must obtain an
appropriate lock to do so safely.
Update the pte_offset_map_lock()'s comment block to reflect this.
Similarly update the process addresses documentation.
Link: https://lore.kernel.org/20260925-rcu-pagetable-freeing-v5-12-31e91065fea4@kernel.org
Signed-off-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Kiryl Shutsemau (Meta) <kas@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Cc: Zi Yan <ziy@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Nico Pache <nico.pache@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Usama Arif <usama.arif@linux.dev>
Cc: Guo Ren <guoren@kernel.org>
Cc: Brian Cain <bcain@kernel.org>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Dinh Nguyen <dinguyen@kernel.org>
Cc: Simon Schuster <schuster.simon@siemens-energy.com>
Cc: Jonas Bonn <jonas@southpole.se>
Cc: Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Rich Felker <dalias@libc.org>
Cc: John Paul Adrian Glaubitz <glaubitz@physik.fu-berlin.de>
Cc: Paul Walmsley <pjw@kernel.org>
Cc: Palmer Dabbelt <palmer@dabbelt.com>
Cc: Albert Ou <aou@eecs.berkeley.edu>
Cc: Alexandre Ghiti <alex@ghiti.fr>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Vineet Gupta <vgupta@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Chris Zankel <chris@zankel.net>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Will Deacon <will@kernel.org>
Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org>
Cc: Nicholas Piggin <npiggin@gmail.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: David S. Miller <davem@davemloft.net>
Cc: Andreas Larsson <andreas@gaisler.com>
Cc: Richard Henderson <richard.henderson@linaro.org>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Magnus Lindholm <linmag7@gmail.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Huacai Chen <chenhuacai@kernel.org>
Cc: WANG Xuerui <kernel@xen0n.name>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: James Bottomley <james.bottomley@hansenpartnership.com>
Cc: Helge Deller <deller@gmx.de>
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Christophe Leroy <chleroy@kernel.org>
Cc: Heiko Carstens <hca@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Alexander Gordeev <agordeev@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@linux.ibm.com>
Cc: Sven Schnelle <svens@linux.ibm.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Anton Ivanov <anton.ivanov@cambridgegreys.com>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: Thomas Gleixner <tglx@kernel.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jason Gunthorpe <jgg@ziepe.ca>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Qi Zheng <qi.zheng@linux.dev>
|
|
The Statistics section refers readers to the DAMON sysfs interface
documentation for how to read the statistics, using a ':ref:' role.
However, the role name has a superfluous 's' appended (':ref:s' instead of
':ref:'). Moreover, its target label 'sysfs_stats' does not exist; the
correct label is 'sysfs_schemes_stats'. Fix both.
Also fix a typo, 'frequenceis' -> 'frequencies', in the Adaptive Regions
Adjustment section.
Link: https://lore.kernel.org/20260908135257.97523-1-sj@kernel.org
Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
The Reference section of ksm.rst asks mm/ksm.c for mm_slot, stable_node
and rmap_item. Commit 21fbd59136e0 ("ksm: add the ksm prefix to the names
of the ksm private structures") renamed them to ksm_mm_slot,
ksm_stable_node and ksm_rmap_item. Since then only ksm_scan is rendered
and the three structures are missing from the generated documentation.
Use the current names.
Link: https://lore.kernel.org/20260905084034.39521-1-kmehltretter@gmail.com
Fixes: 21fbd59136e0 ("ksm: add the ksm prefix to the names of the ksm private structures")
Signed-off-by: Karl Mehltretter <kmehltretter@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Assisted-by: LLM
|
|
In the past, sharing Sashiko review results was tedious. Also it was
suggested to minimize the recipients on the sharing mails. Hence the AI
review section of DAMON maintainer profile document was updated to give
guidance about available tools for making the sharing easier, and how the
recipients list should be managed.
Now DAMON is onboarded [1] to Sashiko's automatic review replies feature.
Sashiko directly sends its reviews as replies to the patch mail thread.
It also reduces the recipients list to deliver the reporting to only the
author and the mailing list.
Remove the old guidance that is no more necessary but only confusing.
Link: https://lore.kernel.org/20260902054747.99370-12-sj@kernel.org
Link: https://github.com/sashiko-dev/sashiko/commit/b554c7b6e733 [1]
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Gow <davidgow@davidgow.net>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Kunwu Chan <kunwu.chan@gmail.com>
|
|
Update DAMON design document for the newly added DAMON probe preps
feature.
Link: https://lore.kernel.org/20260901132506.99243-16-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Update DAMON design document for the newly added pgidle_unset probe filter
type. Also use a list for the types, as it becomes not very easy to read
the whole types in a simple sentence.
Link: https://lore.kernel.org/20260901132506.99243-5-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Document hugepage_mem_bp metric exposed by sysfs.
Link: https://lore.kernel.org/20260831144732.80910-4-sj@kernel.org
Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Fix a typo (nr_snapshots -> max_nr_snapshots) and corrects a grammar
error.
Link: https://lore.kernel.org/20260831150227.83416-4-sj@kernel.org
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Explain the difference between nr_snapshots reaches max_nr_snapshots and
watermarks.
Link: https://lore.kernel.org/20260831150227.83416-3-sj@kernel.org
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Patch series "docs/mm/damon/design: add explanation of nr_snapshots", v3.
Add an explanation of nr_snapshots to avoid misunderstandings.
This patch (of 3):
Change "tried to be applied" -> "completely tried to be applied" to
maintain consistency between the documentation and the code.
Link: https://lore.kernel.org/20260831150227.83416-1-sj@kernel.org
Link: https://lore.kernel.org/20260831150227.83416-2-sj@kernel.org
Signed-off-by: Liew Rui Yan <aethernet65535@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
|
|
Page owner stack traces already contain kernel module names in the
"[module]" format produced by %pS, but page_owner_sort has no way to sort,
cull, or filter by module.
Extract the first module name from each record's stack trace using the
regex \[([a-zA-Z0-9_]+)\]. Records whose stack traces contain no module
frames are assigned "vmlinux".
New options:
-M Sort by module name
--sort=mod Sort by module name (supports +/- prefix)
--cull=mod Cull (aggregate) by module name
--module <modlist> Filter to records matching the given module(s)
The module field is also printed in cull output when relevant.
Link: https://lore.kernel.org/20260819021611.2910835-3-ye.liu@linux.dev
Signed-off-by: Ye Liu <liuye@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Cc: David Hildenbrand (Arm) <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Liu Jing <liujing@cmss.chinamobile.com>
Cc: Yichong Chen <chenyichong@uniontech.com>
|
|
When move_pfn_range_to_zone() or remove_pfn_range_from_zone() updates a
zone, set_zone_contiguous() rescans the entire zone pageblock-by-pageblock
to rebuild zone->contiguous. For large zones this is a significant cost
during memory hotplug and hot-unplug.
Add a new zone member, pages_with_online_memmap, that tracks the
number of pages within the zone span that have an online memory map,
including present pages and memory holes whose memory map has been
initialized and for which pfn_to_online_page() succeeds.
For early boot memory, pages_with_online_memmap is calculated in
memmap_init_zone_range(). PFNs initialized by memmap_init_range() are
included in pages_with_online_memmap, and hole PFNs for which
pfn_to_online_page() succeeds are also counted in
init_unavailable_range(). For hotplugged memory,
pages_with_online_memmap is updated through adjust_present_page_count(),
which is called during memory online and offline operations. When
spanned_pages == pages_with_online_memmap, every PFN in the zone span
has a valid memmap entry, so pfn_to_page() can be called for any PFN
within the zone span without an additional pfn_valid() check.
Note: this counter may temporarily undercount when pages with an
online memory map exist outside the current zone span. Such pages
are only created during boot, when initializing the memory map of
pages that do not fall into any zone span. The undercount itself
can only happen after boot, during memory hotplug, when growing
the zone to cover such pages and later shrinking it back, which
may result in a "too small" value. This is safe: it merely
prevents detecting a contiguous zone.
Here is an example (page numbers are just for illustration purposes):
after boot:
[ zone span ]
[ zone pages ]
spanned=10, initialized=15, online=10
online == spanned -> contiguous
growing after hotplug (hotplug 5):
[ zone span ]
[ zone pages ] [ zone pages ]
spanned=30, initialized=20, online=15
online != spanned -> not contiguous
shrinking after hotunplug (hotunplug 5 again):
[ zone span ]
[ zone pages ]
spanned=15, initialized=15, online=10
online != spanned -> not contiguous although contiguous
The contiguity check using pages_with_online_memmap is stricter than
the old pageblock-by-pageblock scan. The old set_zone_contiguous()
iterated at pageblock granularity via pageblock_pfn_to_page(), so a
zone could be marked contiguous even if a subsection-sized hole
existed within a pageblock. The new check requires
spanned_pages == pages_with_online_memmap, meaning every PFN in the
zone span must satisfy pfn_to_online_page().
The following test cases of memory hotplug for a VM [1], tested in the
environment [2], show that this optimization can significantly reduce the
memory hotplug time [3].
+----------------+------+---------------+--------------+----------------+
| | Size | Time (before) | Time (after) | Time Reduction |
| +------+---------------+--------------+----------------+
| Plug Memory | 256G | 10s | 3s | 70% |
| +------+---------------+--------------+----------------+
| | 512G | 36s | 7s | 81% |
+----------------+------+---------------+--------------+----------------+
+----------------+------+---------------+--------------+----------------+
| | Size | Time (before) | Time (after) | Time Reduction |
| +------+---------------+--------------+----------------+
| Unplug Memory | 256G | 11s | 4s | 64% |
| +------+---------------+--------------+----------------+
| | 512G | 36s | 9s | 75% |
+----------------+------+---------------+--------------+----------------+
[1] Qemu commands to hotplug 256G/512G memory for a VM:
object_add memory-backend-ram,id=hotmem0,size=256G/512G,share=on
device_add virtio-mem-pci,id=vmem1,memdev=hotmem0,bus=port1
qom-set vmem1 requested-size 256G/512G (Plug Memory)
qom-set vmem1 requested-size 0G (Unplug Memory)
[2] Hardware : Intel Icelake server
Guest Kernel : v7.3-rc3
Qemu : v9.0.0
Launch VM :
qemu-system-x86_64 -accel kvm -cpu host \
-drive file=./Centos10_cloud.qcow2,format=qcow2,if=virtio \
-drive file=./seed.img,format=raw,if=virtio \
-smp 3,cores=3,threads=1,sockets=1,maxcpus=3 \
-m 2G,slots=10,maxmem=2052472M \
-device pcie-root-port,id=port1,bus=pcie.0,slot=1,multifunction=on \
-device pcie-root-port,id=port2,bus=pcie.0,slot=2 \
-nographic -machine q35 \
-nic user,hostfwd=tcp::3000-:22
Guest kernel auto-onlines newly added memory blocks:
echo online > /sys/devices/system/memory/auto_online_blocks
[3] The time from typing the QEMU commands in [1] to when the output of
'grep MemTotal /proc/meminfo' on Guest reflects that all hotplugged
memory is recognized.
Reported-by: Nanhai Zou <nanhai.zou@intel.com>
Reported-by: Chen Zhang <zhangchen.kidd@jd.com>
Tested-by: Yuan Liu <yuan1.liu@intel.com>
Reviewed-by: Jason Zeng <jason.zeng@intel.com>
Reviewed-by: Chen Yu <yu.c.chen@intel.com>
Reviewed-by: Pan Deng <pan.deng@intel.com>
Co-developed-by: Tianyou Li <tianyou.li@intel.com>
Signed-off-by: Tianyou Li <tianyou.li@intel.com>
Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Link: https://patch.msgid.link/20260920084946.3266279-3-yuan1.liu@intel.com
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
- "mm/rmap: index MAP_PRIVATE file-backed folios by anonymous pgoff"
(Lorenzo Stoakes)
Index MAP_PRIVATE file-backed folios by their anonymous page offset
to resolve confusion around reverse mapping for zeroed and CoW'd
file-backed memory.
Use this new VMA anonymous page offset tracking to eliminate index
conflicts and lay the foundation for scalable CoW performance
improvements.
- "promote mapped executable folios after first usage for MGLRU"
(Baolin Wang)
Make MGLRU's protection of mapped executable file folios more
reliable. Follow the classical LRU's logic, promoting mapped
executable file folios after their first usage to give executable
code a better chance to stay in memory and improve workload
performance.
- "mm: vmscan: fix node reclaim ignoring swappiness parameter" (Ridong
Chen)
Fix per-node proactive reclaim interface's ignoring the swappiness
parameter when CONFIG_MEMCG is disabled by consolidating
sc_swappiness() into a single function that checks
proactive_swappiness regardless of kernel configuration.
- "mm/vmscan: reduce lru_lock contention via vmstat-derived
scan-balance cost" (Usama Arif)
Reduce lru_lock contention in the reclaim path by deriving
scan-balance costs from vmstat counters rather than lock-acquired
producer updates.
Read and decay these cost signals on the reclaim side under a
dedicated per-lruvec lock, reducing total LRU lock wait time by over
60% without impacting scan throughput.
- "zram: fix zram issues reported by sashiko" (Sergey Senozhatsky)
Fix two low-risk zram bugs which Sashiko spotted in drive-by review.
- "Honor XA_FLAGS_ACCOUNT in xas_split_alloc() and charge to folio's
memcg" (Zi Yan)
Fix xas_split_alloc() by enabling target folio memcg charging during
splits and adding the missing __GFP_ACCOUNT flag for proper XArray
node memory accounting.
- "selftests/mm: use pattern matching in .gitignore" (Pratyush Mallick)
Replace hardcoded binary names in selftests/mm/.gitignore with a
generic pattern-matching rule to automatically ignore generated test
files and avoid manual updates when adding new tests.
- "mm/page_ext: remove pgdat_page_ext_init()" (Sang-Heon Jeon)
Make the incompatibility between FLATMEM and NUMA explicit in
mm/Kconfig and remove the unused pgdat_page_ext_init() function.
- "zram: fix zstd error paths and add parameter validation" (Haoqin
Huang)
Clean up zram compression backends by removing redundant error
cleanup, adding parameter and dictionary validation, auto-prefixing
algorithm error logs, and resetting parameters prior to
reinitialization.
- "zram: fix stale scan bounds after reinitialization" (Longlong Xia)
Prevent out-of-bounds slot accesses during concurrent zram resets by
moving table scan bound calculations under dev_lock in
writeback_store() and read_block_state().
- "add anon mTHP collapse test cases" (Baolin Wang)
Extend selftests helper functions to support arbitrary page orders
and add new test cases and options for mTHP collapse in khugepaged.
- "selftests/mm: Handle unsupported and transient test conditions"
(Muhammad Usama Anjum)
Update MM selftests to report a SKIP status instead of a failure when
required kernel or filesystem features are unsupported, while adding
retry logic for transient page migration errors.
- "mm/zswap: Fixes and improves the zswap shrink" (Hao Jia)
Fix the missing zswap global shrinker when CONFIG_MEMCG is disabled
and extend shrink_memcg() to support batch writeback for improved
writeback efficiency.
- "alloc_tag: introduce IOCTL-based filtering for MAP" (Suren
Baghdasaryan)
Introduce an IOCTL-based binary interface for memory allocation
profiling that enables kernel-side filtering before per-CPU counter
aggregation.
This eliminates the text-parsing overhead of /proc/allocinfo and
provides up to a 20x speedup by transferring only filtered allocation
data to userspace.
- "better block swap batching and a different take on swap_ops v5"
(Christoph Hellwig)
Refactor block swap I/O to use swap_iocb for batching instead of
single-bio requests and rebase the swap_ops interface, achieving
faster swap throughput during kernel builds.
- "mm: kmemleak: reduce transient false positives by confirming leaks"
(Catalin Marinas)
Reduce false-positive kmemleak reports by combining two kmemleak
enhancements that add a second confirmation scan and a configurable
minimum unreferenced scan count module parameter.
- "mm: kmemleak: default min_unref_scans to 2 for verbose kernels"
(Breno Leitao)
Auto-scanning kernels can generate false-positive memory leak reports
on single scans, so this patch defaults min_unref_scans to 2 when
CONFIG_DEBUG_KMEMLEAK_VERBOSE is enabled to require a second
confirming scan.
- "swap_ops updates" (Christoph Hellwig)
Batching I/O for synchronous swap devices causes performance
regressions and filesystem-based swap suffers from double-indirection
overhead. This series resolves both issues by reintroducing per-folio
writes for synchronous swap and allowing filesystems to directly
export their own swap_ops.
- "mm/khugepaged: several cleanups" (Nico Pache)
khugepaged accumulated redundant state-checking patterns and outdated
comments following mTHP integration. Introduce dedicated helpers for
PTE validation and event counting while refreshing the internal
documentation.
- "maple_tree: lock checking and clean ups" (Liam Howlett)
Syzbot reports incorrectly blame memory management exit paths for
locking bugs, maple tree erase operations risk allocation failures
without gfp flags and internal documentation lacks clarity.
Improve lock error detection, update docs, fix race and allocation
edge cases and optimize erase allocations using a fallback to
GFP_KERNEL | GFP_NOFAIL.
* tag 'mm-stable-2026-08-26-15-22' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (172 commits)
selftests/proc: make proc-maps-race work with READ_IMPLIES_EXEC
memcg: move LRU size accounting on reparenting instead of copying it
mm/vmscan: fix comment logic in balance_pgdat
maple_tree: add helper mas_make_walkable()
maple_tree: avoid extra gap calculation
maple_tree: fix argument name in header
maple_tree: change two GFP flags in tests
maple_tree: document erase and allocations better
maple_tree: avoid mas_erase() and mtree_erase() failures
maple_tree: document that erase may use GFP_KERNEL for allocations
maple_tree: catch race in mas_alloc_cyclic()
maple_tree: add bulk parent set helper
maple_tree: micro optimisation of mas_wr_store_type()
maple_tree: optimise mas_wr_node_store() when not in rcu mode
maple_tree: use prefetched value in mas_wr_store_type()
maple_tree: clarify comments on mas_nomem()
maple_tree: drop MAPLE_ALLOC_SLOTS
maple_tree: drop dead code from mas_extend_spanning_null()
maple_tree: documentation fix
maple_tree: add write lock checking with lockdep sequence numbers
...
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Steps 7 and 9 of the migration description still say "radix tree", unlike
steps 5 and 11 which already use "i_pages lock". The page cache moved to
the XArray at mapping->i_pages long ago. Use "page cache tree" for the
two remaining references.
Link: https://lore.kernel.org/20260812075739.325441-1-husong@kylinos.cn
Signed-off-by: Song Hu <husong@kylinos.cn>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Patch series "alloc_tag: introduce IOCTL-based filtering for MAP", v8.
Currently, memory allocation profiling data is primarily exposed through
/proc/allocinfo. While useful for manual inspection, this text-based
interface poses challenges for production monitoring and large-scale
analysis:
1. Userspace must parse large amounts of text to extract specific
fields.
2. To find specific tags, userspace must read the entire dataset,
requiring many context switches and high data copying.
3. The kernel currently aggregates per-CPU counters for every allocation
size, even those the user intends to filter out immediately.
This series introduces a new IOCTL-based binary interface for allocinfo
that supports kernel-side filtering. By allowing the user to specify a
filter mask, we significantly reduce the work performed in-kernel and the
amount of data transferred to userspace. The IOCTL mechanism was chosen
for allocinfo to address the per-CPU counter aggregation bottleneck. A
traditional read() operation must report the total allocation count and
sizes for every code tag in the system. Doing so requires iterating
across all CPUs to sum their per-CPU counters for thousands of tags, which
introduces substantial runtime overhead.
The IOCTL interface allows userspace to push selective filtering criteria
directly into the kernel before the per-CPU counter aggregation. The
kernel aggregates per-CPU counters only for a small subset of tags that
match the filter. This results in significant performance improvement.
Beyond fast filtered retrieval, the IOCTL foundation allows introducing a
context capture mechanism in the future to capture the context for
specific allocations.
Performance measurements were conducted on an Intel Xeon Platinum 8481C
(224 CPUs) with caches dropped before each run.
The IOCTL mechanism shows a ~20x performance improvement for
filtered queries. The kernel avoids the expensive per-CPU counter
aggregation (alloc_tag_read) for any tags that fail the initial string
or location filters.
Scenario 1: Specific File Filtering (arch/x86/events/rapl.c)
1. Traditional (cat /proc/allocinfo | grep): 22ms (sys)
2. IOCTL Interface: 1ms (sys)
Scenario 2: Compound Filtering (Filename + Size)
1. Traditional: (cat ... | grep | awk): 21ms (sys)
2. IOCTL Interface: 1ms (sys)
Scenario 3: Size-Based Filtering (min_size = 1MB)
1. Traditional: (cat ... | awk): 21ms (sys)
2. IOCTL Interface: 14ms (sys)
This patch (of 6):
Add the following ioctl commands for /proc/allocinfo file:
ALLOCINFO_IOC_CONTENT_ID - gets content identifier which can be used to
check whether the file content has changed specifically due to module
load/unload. Every time a module is loaded / unloaded, the returned value
will be different. By comparing the identifier value at the beginning and
at the end of the content retrieval operation, users can validate
retrieved information for consistency.
ALLOCINFO_IOC_GET_AT - gets the record at the specified position. This is
the position of a record in /proc/allocinfo.
ALLOCINFO_IOC_GET_NEXT - gets the record next to the last retrieved one.
If no records were previously retrieved, returns the first record.
Note, function file and module names often have the same prefixes,
therefore when filtering for them, we compare the last 64 characters to
minimize the chances of name collisions.
[akpm@linux-foundation.org: include compat.h, per Suren]
Closes: https://lore.kernel.org/oe-kbuild-all/202607091820.qbjlGhKK-lkp@intel.com/
Link: https://lore.kernel.org/cover.1783532853.git.abhishekbapat@google.com
Link: https://lore.kernel.org/15596de2607ef13e7c77c6d74763f4ae992ec475.1783532853.git.abhishekbapat@google.com
Signed-off-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Abhishek Bapat <abhishekbapat@google.com>
Acked-by: Hao Ge <hao.ge@linux.dev>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Kent Overstreet <kent.overstreet@linux.dev>
Cc: Sourav Panda <souravpanda@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Currently, userspace has limited visibility into the exact active runtime
state of memory allocation profiling and its page extension compression
('sysctl.vm.mem_profiling={0|1|never}[,compressed]').
While reading the sysctl provides basic on/off status, it is currently
impossible for userspace to natively determine whether page-tag
compression was successfully enabled without scraping dmesg boot logs.
Add a new read-only sysctl representing how compression was configured
at boot time.
Link: https://lore.kernel.org/c795f8089f82841e8a6e00d7ca286da2b23aeb7b.1785950530.git.abhishekbapat@google.com
Signed-off-by: Abhishek Bapat <abhishekbapat@google.com>
Acked-by: Suren Baghdasaryan <surenb@google.com>
Cc: Hao Ge <hao.ge@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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The KSM code already stores and checks the stable node key via
folio->mapping, but the comment in ksm_get_folio() and the reverse mapping
documentation in ksm.rst still refer to page->mapping.
This is a pure wording update to match the folio-based implementation. No
functional change is intended.
Link: https://lore.kernel.org/20260805105927.41987-1-hongfu.li@linux.dev
Signed-off-by: Hongfu Li <lihongfu@kylinos.cn>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Xu Xin <xu.xin16@zte.com.cn>
Reviewed-by: Dongliang Mu <dzm91@hust.edu.cn>
Cc: Alex Shi <alexs@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Yanteng Si <si.yanteng@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
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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deferred_split_queue was removed from struct pglist_data {} in commit
fafaeceb89a5 ("mm: switch deferred split shrinker to list_lru"). Remove
its description in doc as well.
Link: https://lore.kernel.org/20260721111919.22923-1-zenghui.yu@linux.dev
Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Correct typos in mm documentation by balancing parentheses.
Link: https://lore.kernel.org/20260629161156.90213-2-manuelebner@mailbox.org
Signed-off-by: Manuel Ebner <manuelebner@mailbox.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Vishal Moola <vishal.moola@gmail.com>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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hmm_range_fault() requires the caller to hold the mmap read lock for the
duration of the call. This is incompatible with mappings whose fault
handler may release the mmap lock, notably userfaultfd-managed regions,
where handle_mm_fault() can return VM_FAULT_RETRY or VM_FAULT_COMPLETED
after dropping the lock. Drivers that need to populate device page tables
for such mappings have no way to do so today.
Add hmm_range_fault_unlocked_timeout() for callers that do not need to
hold mmap_lock across any work outside the HMM fault itself. The helper
takes mmap_read_lock_killable() internally, calls the common HMM fault
implementation, and releases the lock before returning if it is still
held. The timeout is specified in jiffies; passing 0 retries
indefinitely, while a non-zero timeout makes the helper return -EBUSY when
the retry budget expires. The retry deadline is set before refreshing the
notifier sequence and acquiring mmap_lock, so contended mmap_lock
acquisition is included in the retry budget. After acquiring mmap_lock,
the helper also rejects unstable address spaces before walking page
tables.
When handle_mm_fault() drops mmap_lock, or when the range is invalidated,
hmm_range_fault_unlocked_timeout() refreshes range->notifier_seq and
retries the walk internally. If the lock was dropped, the retry deadline
is also restarted because a lock-dropping fault handler made progress.
Ordinary -EBUSY retries keep the existing deadline, preserving the
caller's timeout policy for repeated mmu-notifier invalidations.
The caller only needs to perform the usual post-success
mmu_interval_read_retry() check while holding its update lock before
consuming the pfns. If mmap_lock acquisition is interrupted or a fatal
signal is pending during retry handling, -EINTR is returned instead.
The common implementation conditionally sets FAULT_FLAG_ALLOW_RETRY and
FAULT_FLAG_KILLABLE only for hmm_range_fault_unlocked_timeout(). The
existing hmm_range_fault() path still passes no locked state, does not
allow handle_mm_fault() to drop mmap_lock, and remains a thin wrapper
preserving the existing API contract for current callers.
The previous refactor that moved page fault handling out of the page-table
walk callbacks is what makes this change small. Faults now run after
walk_page_range() has unwound, with only mmap_lock held, so dropping it
does not interact with the walker's pte spinlock or hugetlb_vma_lock.
Hugetlb regions therefore participate in the unlocked path uniformly with
PTE- and PMD-level mappings; no special case is required.
Documentation/mm/hmm.rst is updated with a description of the new API and
the recommended caller pattern.
Link: https://lore.kernel.org/20260723-hmm-v10-v11-2-c55b003a4b61@gmail.com
Signed-off-by: Stanislav Kinsburskii <skinsburskii@gmail.com>
Cc: Danilo Krummrich <dakr@kernel.org>
Cc: Dave Airlie <airlied@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Jason Gunthorpe <jgg@nvidia.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: K. Y. Srinivasan <kys@microsoft.com>
Cc: Leon Romanovsky <leon@kernel.org>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lizhi Hou <lizhi.hou@amd.com>
Cc: Long Li <longli@microsoft.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Lyude <lyude@redhat.com>
Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Oded Gabbay <ogabbay@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Thomas Zimemrmann <tzimmermann@suse.de>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Update DAMON usage document for newly added probe weight file.
Link: https://lore.kernel.org/20260710134651.18084-19-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Update DAMON design document for the attributes only monitoring mode.
Link: https://lore.kernel.org/20260710134651.18084-18-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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struct kfence_metadata only contains struct slabobj_ext with
CONFIG_MEMCG, which is then used for the "fake" slab's obj_exts field.
If CONFIG_MEMCG is enabled, the struct can also end up used for memory
allocation profiling. If CONFIG_MEMCG is disabled but profiling is
enabled, it will end up allocating its obj_exts via
prepare_slab_obj_exts_hook() and assigning them to the fake struct slab.
These will probably then never be freed.
So things sorta work, but not always in the intended and optimal way.
The upcoming changes to slabobj_ext layout would additionally need a
proper refactoring to keep working.
However, there's little benefit in accounting KFENCE objects. KFENCE
allocations are rare and there can be only CONFIG_KFENCE_NUM_OBJECTS
(default to 255) outstanding ones at any time. For any callsite
prominent enough in the memory allocation profiling stats, allocations
served from KFENCE will be lost in the noise.
Thus let's not complicate things and simply stop accounting KFENCE
objects in allocation profiling and skip them in the related slab hooks.
We also need to skip kfence objects in mark_obj_codetag_empty() in case
a sheaf is allocated from kfence, per earlier sashiko review.
Link: https://patch.msgid.link/20260727-b4-objext_split-v3-1-c29ef0f1f257@kernel.org
Reviewed-by: Hao Li <hao.li@linux.dev>
Signed-off-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
|
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Patch series "mm/damon: update, optimize, and clean up doc, tests, and
code".
Patches 1 and 2 update the design and ABI documents for recently added
DAMON features. Patches 3-7 add or update more unit and self tests for
DAMON to cover recently changed or added functions and sysfs files. Patch
8 optimizes damon_commit_target_regions() to skip unnecessary adjacent
ranges setup. Patches 9-11 clean and fix up recently added DAMON sysfs
interface code for readability.
This patch (of 11):
Commit 9138e27a3bc3 ("mm/damon: add node_eligible_mem_bp goal metric")
introduced DAMOS_QUOTA_NODE_ELIGIBLE_MEM_BP but forgot updating the DAMON
design document for that. Update.
Link: https://lore.kernel.org/20260630141726.92246-1-sj@kernel.org
Link: https://lore.kernel.org/20260630141726.92246-2-sj@kernel.org
Signed-off-by: SJ Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: SeongJae Park <sj@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Fix minor DAMON documentation issues. Correct the sysfs scheme file name
apply_interval_us, the DAMON_STAT module count, a malformed reference, a
misplaced label indentation, and a few typos.
Link: https://lore.kernel.org/20260629145538.134832-4-sj@kernel.org
Signed-off-by: Doehyun Baek <doehyunbaek@gmail.com>
Signed-off-by: SJ Park <sj@kernel.org>
Reviewed-by: SJ Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Liam R. Howlett" <liam@infradead.org>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Akinobu Mita <akinobu.mita@gmail.com>
Cc: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: Philippe Laferriere <plafer@proton.me>
Cc: Sailesh Nandanavanam <saileshnandanavanam@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
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Add documentation for the page_owner_filter userspace tool and
kernel-level filtering features.
[rdunlap@infradead.org: avoid docs build warning]
Link: https://lore.kernel.org/20260708213548.469155-1-rdunlap@infradead.org
Link: https://lore.kernel.org/20260707115411.1714314-5-zhen.ni@easystack.cn
Signed-off-by: Zhen Ni <zhen.ni@easystack.cn>
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
|
|
git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux
Pull more documentation updates from Jonathan Corbet:
"A handful of late-arriving docs fixes, along with one document update
that fell through the cracks before"
* tag 'docs-7.2-2' of git://git.kernel.org/pub/scm/linux/kernel/git/docs/linux:
docs: tools: Fix typo 'ackward' to 'awkward' in unittest.rst
kdoc: xforms: ignore special static/inline macros
kdoc: xforms_lists: handle DECLARE_PER_CPU() in kernel-doc
MAINTAINERS: Fix regex for kdoc
docs: kgdb: Fix path of driver options
Documentation: tracing: fix typo in events documentation
Docs/driver-api/uio-howto: document mmap_prepare callback
docs/mm: clarify that we are not looking for LLM generated content
kernel-doc: xforms: support __SYSFS_FUNCTION_ALTERNATIVE()
|
|
Let's make it clear that we are not looking for LLM generated content
from contributors not familiar with the details of MM, as it shifts the
real work onto reviewers.
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
Acked-by: Dev Jain <dev.jain@arm.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Acked-by: Harry Yoo (Oracle) <harry@kernel.org>
Acked-by: SeongJae Park <sj@kernel.org>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Message-ID: <20260420-llmdoc-v1-1-47d2091177c4@kernel.org>
|
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git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux
Pull liveupdate updates from Mike Rapoport:
"Kexec Handover (KHO):
- make memory preservation compatible with deferred initialization
of the memory map
Live Update Orchestrator (LUO):
- add LIVEUPDATE_SESSION_GET_NAME ioctl and parameter verification
for LIVEUPDATE_IOCTL_CREATE_SESSION ioctl
- documentation updates for liveupdate=on command line option,
systemd support and the current compatibility status
- remove the fixed limits on the number of files that can be
preserved within a single session, and the total number of
sessions managed by the LUO
Misc fixes:
- reference count incoming File-Lifecycle-Bound (FLB) data so
it cannot be freed while a subsystem is still using it
- fixes for a TOCTOU race in luo_session_retrieve(), a use-
after-free in the file finish and unpreserve paths, concurrent
session mutations during reboot and serialization on
preserve_context kexec
- make sure ioctls for incoming LUO sessions are blocked for
outgoing sessions and vice versa
- make sure KHO scratch size is always aligned by
CMA_MIN_ALIGNMENT_BYTES
- fix memblock tests build issue introduced by KHO changes"
* tag 'liveupdate-v7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/liveupdate/linux: (36 commits)
liveupdate: Document that retrieve failure is permanent
docs: memfd_preservation: fix rendering of ABI documentation
selftests/liveupdate: Add stress-files kexec test
selftests/liveupdate: Add stress-sessions kexec test
selftests/liveupdate: Test session and file limit removal
liveupdate: Remove limit on the number of files per session
liveupdate: Remove limit on the number of sessions
liveupdate: defer session block allocation and physical address setting
kho: add support for linked-block serialization
liveupdate: Extract luo_session_deserialize_one helper
liveupdate: Extract luo_file_deserialize_one helper
liveupdate: register luo_ser as KHO subtree
liveupdate: centralize state management into struct luo_ser
liveupdate: avoid mixing cleanup guards with goto in luo_session_retrieve_fd
liveupdate: change file_set->count type to u64 for type safety
liveupdate: Remove unused ser field from struct luo_session
liveupdate: fix u-a-f in luo_file_unpreserve_files() and luo_file_finish()
liveupdate: block session mutations during reboot
liveupdate: fix TOCTOU race in luo_session_retrieve()
liveupdate: skip serialization for context-preserving kexec
...
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The "memfd Live Update ABI" section in include/linux/kho/abi/memfd.h
currently does not render in the exported documentation. This is because
it should not include the "DOC:" in its reference. Drop it to ensure
correct rendering. Tested by running make htmldocs.
Fixes: 15fc11bb2cb6 ("docs: add documentation for memfd preservation via LUO")
Signed-off-by: Pratyush Yadav (Google) <pratyush@kernel.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260605160645.3650271-1-pratyush@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
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L140: "unsinged" -> "unsigned"
L371: "sampleing" -> "sampling"
L387: "multipled" -> "multiplied"
Link: https://lore.kernel.org/20260520012104.93602-3-sj@kernel.org
Signed-off-by: Sakurai Shun <ssh1326@icloud.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: Lorenzo Stoakes <ljs@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: niecheng <niecheng1@uniontech.com>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Zenghui Yu <zenghui.yu@linux.dev>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Update DAMON design document for the newly added belonging memory cgroup
attribute monitoring feature.
Link: https://lore.kernel.org/20260518234119.97569-28-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Update DAMON usage document for the newly added data attributes monitoring
feature.
Link: https://lore.kernel.org/20260518234119.97569-22-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Update DAMON design document for newly added data attributes monitoring
feature.
Link: https://lore.kernel.org/20260518234119.97569-21-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Replace "presense" with "presence"
Link: https://lore.kernel.org/20260517103640.45444-1-ssh1326@icloud.com
Signed-off-by: Sakurai Shun <ssh1326@icloud.com>
Reviewed-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Update DAMON design document for the context execution pause/resume
feature.
Link: https://lore.kernel.org/20260427151231.113429-4-sj@kernel.org
Signed-off-by: SeongJae Park <sj@kernel.org>
Cc: Brendan Higgins <brendan.higgins@linux.dev>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <shuah@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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This patch set introces a new action: DAMOS_COLLAPSE.
For DAMOS_HUGEPAGE and DAMOS_NOHUGEPAGE to work, khugepaged should be
working, since it relies on hugepage_madvise to add a new slot. This slot
should be picked up by khugepaged and eventually collapse (or not, if we
are using DAMOS_NOHUGEPAGE) the pages. If THP is not enabled, khugepaged
will not be working, and therefore no collapse will happen.
DAMOS_COLLAPSE eventually calls madvise_collapse, which will collapse the
address range synchronously. In cases where there is a large VMA
(databases, for example), DAMOS_COLLAPSE allows us to collapse only the
hot region, and not the entire VMA.
This new action may be required to support autotuning with hugepage
as a goal[1].
=========
Benchmarks:
=========
MySQL
=====
Tests were performed in an ARM physical server with MariaDB 10.5 and
sysbench. Read only benchmark was perform with gaussian row hitting,
which follows a normal distribution.
T n, D h: THP set to never, DAMON action set to hugepage
T m, D h: THP set to madvise, DAMON action set to hugepage
T n, D c: THP set to never, DAMON action set to collapse
Memory consumption. Lower is better.
+------------------+----------+----------+----------+
| | T n, D h | T m, D h | T n, D c |
+------------------+----------+----------+----------+
| Total memory use | 2.13 | 2.20 | 2.20 |
| Huge pages | 0 | 1.3 | 1.27 |
+------------------+----------+----------+----------+
Performance in TPS (Transactions Per Second). Higher is better.
T n, D h: 18225.58
T m, D h 18252.93
T n, D c: 18270.21
Performance counter
I got the number of L1 D/I TLB accesses and the number a D/I TLB
accesses that triggered a page walk. I divided the second by the
first to get the percentage of page walkes per TLB access. The
lower the better.
+---------------+--------------+--------------+--------------+
| | T n, D h | T m, D h | T n, D c |
+---------------+--------------+--------------+--------------+
| L1 DTLB | 127248242753 | 125431020479 | 125327001821 |
| L1 ITLB | 80332558619 | 79346759071 | 79298139590 |
| DTLB walk | 75011087 | 52800418 | 55895794 |
| ITLB walk | 71577076 | 71505137 | 67262140 |
| DTLB % misses | 0.058948623 | 0.042095183 | 0.044599961 |
| ITLB % misses | 0.089100954 | 0.090117275 | 0.084821839 |
+---------------+--------------+--------------+--------------+
Masim
=====
I used masim with the "demo" configuration, but changing the times
to 100 seconds for the initial phase and 50 seconds for the rest of
the phases.
Memory consumption:
+------------------+----------+----------+----------+
| | T n, D h | T m, D h | T n, D c |
+------------------+----------+----------+----------+
| Total memory use | 2.38 GB | 2.36 GB | 2.37 GB |
| Huge pages | 0 | 190 MB | 188 MB |
+------------------+----------+----------+----------+
Performance:
THP never, DAMOS_HUGEPAGE
initial phase: 40,491 accesses/msec, 100001 msecs run
low phase 0: 39,658 accesses/msec, 50002 msecs run
high phase 0: 41,678 accesses/msec, 50000 msecs run
low phase 1: 39,625 accesses/msec, 50003 msecs run
high phase 1: 41,658 accesses/msec, 50002 msecs run
low phase 2: 39,642 accesses/msec, 50002 msecs run
high phase 2: 41,640 accesses/msec, 50001 msecs run
THP madvise, DAMOS_HUGEPAGE
initial phase: 51,977 accesses/msec, 100000 msecs run
low phase 0: 86,953 accesses/msec, 50000 msecs run
high phase 0: 94,812 accesses/msec, 50000 msecs run
low phase 1: 101,017 accesses/msec, 50000 msecs run
high phase 1: 94,841 accesses/msec, 50000 msecs run
low phase 2: 100,993 accesses/msec, 50000 msecs run
high phase 2: 94,791 accesses/msec, 50001 msecs run
THP never, DAMOS_COLLAPSE
initial phase: 93,678 accesses/msec, 100001 msecs run
low phase 0: 101,475 accesses/msec, 50000 msecs run
high phase 0: 98,589 accesses/msec, 50000 msecs run
low phase 1: 101,531 accesses/msec, 50001 msecs run
high phase 1: 98,506 accesses/msec, 50001 msecs run
low phase 2: 101,458 accesses/msec, 50001 msecs run
high phase 2: 98,555 accesses/msec, 50000 msecs run
Memory consumption dynamic (how quickly collapses occur):
It shows in seconds how many huge pages are allocated.
+----+----------+----------+
| | T m, D h | T n, D c |
+----+----------+----------+
| 5 | 32 | 188 |
| 10 | 48 | 188 |
| 15 | 64 | 188 |
| 20 | 96 | 188 |
| 30 | 112 | 188 |
| 35 | 144 | 188 |
| 40 | 160 | 188 |
| 45 | 190 | 188 |
| 50 | 190 | 188 |
| 55 | 190 | 188 |
| 60 | 190 | 188 |
+----+----------+----------+
=========
- We can see that DAMOS "hugepage" action works only when THP is set
to madvise. "collapse" action works even when THP is set to never.
- Performance for "collapse" action is slightly lower than "hugepage"
action and THP madvise. This is due to the fact that collapases
occur synchronously. With "hugepage" they may occur during page
faults.
- Memory consumption is slighly lower for "collapse" than "hugepage"
with THP madvise. This is due to the khugepage collapses all VMAs,
while "collapse" action only collapses the VMAs in the hot region.
- There is an improvement in TLB utilization when collapse through
"hugepage" or "collapse" actions are triggered. The amount of
TLB misses is lower.
- "collapse" action is performance synchronously, which means that
page collapses happen earlier and more rapidly. This can be
useful or not, depending on the scenario.
- "hugepage" action may trigger a VMA split in some scenarios, since
it needs to change the flag of the VMA to THP enabled. This may
lead to additional overhead.
Collapse action just adds a new option to chose the correct system
balance.
Link: https://lore.kernel.org/20260426231619.107231-5-sj@kernel.org
Link: https://lore.kernel.org/damon/20260313000816.79933-1-sj@kernel.org/ [1]
Signed-off-by: Asier Gutierrez <gutierrez.asier@huawei-partners.com>
Signed-off-by: SeongJae Park <sj@kernel.org>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Cheng-Han Wu <hank20010209@gmail.com>
Cc: David Hildenbrand <david@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Liew Rui Yan <aethernet65535@gmail.com>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Shuah Khan <skhan@linuxfoundation.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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