If obj_exts allocation failed, slab->obj_exts is set to OBJEXTS_ALLOC_FAIL,
But we do not clear it when freeing the slab. Since OBJEXTS_ALLOC_FAIL and
MEMCG_DATA_OBJEXTS currently share the same bit position, during the
release of the associated folio, a VM_BUG_ON_FOLIO() check in
folio_memcg_kmem() is triggered because the OBJEXTS_ALLOC_FAIL flag was
not cleared, causing it to be interpreted as a kmem folio (non-slab)
with MEMCG_OBJEXTS_DATA flag set, which is invalid because
MEMCG_OBJEXTS_DATA is supposed to be set only on slabs.
Another problem that predates sharing the OBJEXTS_ALLOC_FAIL and
MEMCG_DATA_OBJEXTS bits is that on configurations with
is_check_pages_enabled(), the non-cleared bit in page->memcg_data will
trigger a free_page_is_bad() failure "page still charged to cgroup"
When freeing a slab, we clear slab->obj_exts if the obj_ext array has
been successfully allocated. So let's clear it also when the allocation
has failed.
Fixes: 09c46563ff ("codetag: debug: introduce OBJEXTS_ALLOC_FAIL to mark failed slab_ext allocations")
Fixes: 7612833192 ("slab: Reuse first bit for OBJEXTS_ALLOC_FAIL")
Link: https://lore.kernel.org/all/20251015141642.700170-1-hao.ge@linux.dev/
Cc: <stable@vger.kernel.org>
Signed-off-by: Hao Ge <gehao@kylinos.cn>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
defer_free() links pending objects using the slab's freelist offset
which is fine as they are not free yet. free_deferred_objects() then
clears this pointer to avoid confusing the debugging consistency checks
that may be enabled for the cache.
However, with CONFIG_SLAB_FREELIST_HARDENED, even the NULL pointer needs
to be encoded appropriately using set_freepointer(), otherwise it's
decoded as something else and triggers the consistency checks, as found
by the kernel test robot.
Use set_freepointer() to prevent the issue.
Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Reported-and-tested-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202510101652.7921fdc6-lkp@intel.com
Acked-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
preserve vmalloc allocations across handover.
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Merge tag 'mm-nonmm-stable-2025-10-10-15-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more updates from Andrew Morton:
"Just one series here - Mike Rappoport has taught KEXEC handover to
preserve vmalloc allocations across handover"
* tag 'mm-nonmm-stable-2025-10-10-15-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
lib/test_kho: use kho_preserve_vmalloc instead of storing addresses in fdt
kho: add support for preserving vmalloc allocations
kho: replace kho_preserve_phys() with kho_preserve_pages()
kho: check if kho is finalized in __kho_preserve_order()
MAINTAINERS, .mailmap: update Umang's email address
All singletons, please see the changelogs for details.
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Merge tag 'mm-hotfixes-stable-2025-10-10-15-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull misc fixes from Andrew Morton:
"7 hotfixes. All 7 are cc:stable and all 7 are for MM.
All singletons, please see the changelogs for details"
* tag 'mm-hotfixes-stable-2025-10-10-15-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm: hugetlb: avoid soft lockup when mprotect to large memory area
fsnotify: pass correct offset to fsnotify_mmap_perm()
mm/ksm: fix flag-dropping behavior in ksm_madvise
mm/damon/vaddr: do not repeat pte_offset_map_lock() until success
mm/rmap: fix soft-dirty and uffd-wp bit loss when remapping zero-filled mTHP subpage to shared zeropage
mm/thp: fix MTE tag mismatch when replacing zero-filled subpages
memcg: skip cgroup_file_notify if spinning is not allowed
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Merge tag 'slab-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab fixes from Vlastimil Babka:
- Fixes for several corner cases in error paths and debugging options,
related to the new kmalloc_nolock() functionality (Kuniyuki Iwashima,
Ran Xiaokai)
* tag 'slab-for-6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab:
slub: Don't call lockdep_unregister_key() for immature kmem_cache.
slab: Fix using this_cpu_ptr() in preemptible context
slab: Add allow_spin check to eliminate kmemleak warnings
fsnotify_mmap_perm() requires a byte offset for the file about to be
mmap'ed. But it is called from vm_mmap_pgoff(), which has a page offset.
Previously the conversion was done incorrectly so let's fix it, being
careful not to overflow on 32-bit platforms.
Discovered during code review.
Link: https://lkml.kernel.org/r/20251003155238.2147410-1-ryan.roberts@arm.com
Fixes: 066e053fe2 ("fsnotify: add pre-content hooks on mmap()")
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
Reviewed-by: Kiryl Shutsemau <kas@kernel.org>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: David Hildenbrand <david@redhat.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
DAMON's virtual address space operation set implementation (vaddr) calls
pte_offset_map_lock() inside the page table walk callback function. This
is for reading and writing page table accessed bits. If
pte_offset_map_lock() fails, it retries by returning the page table walk
callback function with ACTION_AGAIN.
pte_offset_map_lock() can continuously fail if the target is a pmd
migration entry, though. Hence it could cause an infinite page table walk
if the migration cannot be done until the page table walk is finished.
This indeed caused a soft lockup when CPU hotplugging and DAMON were
running in parallel.
Avoid the infinite loop by simply not retrying the page table walk. DAMON
is promising only a best-effort accuracy, so missing access to such pages
is no problem.
Link: https://lkml.kernel.org/r/20250930004410.55228-1-sj@kernel.org
Fixes: 7780d04046 ("mm/pagewalkers: ACTION_AGAIN if pte_offset_map_lock() fails")
Signed-off-by: SeongJae Park <sj@kernel.org>
Reported-by: Xinyu Zheng <zhengxinyu6@huawei.com>
Closes: https://lore.kernel.org/20250918030029.2652607-1-zhengxinyu6@huawei.com
Acked-by: Hugh Dickins <hughd@google.com>
Cc: <stable@vger.kernel.org> [6.5+]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When splitting an mTHP and replacing a zero-filled subpage with the shared
zeropage, try_to_map_unused_to_zeropage() currently drops several
important PTE bits.
For userspace tools like CRIU, which rely on the soft-dirty mechanism for
incremental snapshots, losing the soft-dirty bit means modified pages are
missed, leading to inconsistent memory state after restore.
As pointed out by David, the more critical uffd-wp bit is also dropped.
This breaks the userfaultfd write-protection mechanism, causing writes to
be silently missed by monitoring applications, which can lead to data
corruption.
Preserve both the soft-dirty and uffd-wp bits from the old PTE when
creating the new zeropage mapping to ensure they are correctly tracked.
Link: https://lkml.kernel.org/r/20250930081040.80926-1-lance.yang@linux.dev
Fixes: b1f202060a ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Suggested-by: David Hildenbrand <david@redhat.com>
Suggested-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Jann Horn <jannh@google.com>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Peter Xu <peterx@redhat.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Usama Arif <usamaarif642@gmail.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When both THP and MTE are enabled, splitting a THP and replacing its
zero-filled subpages with the shared zeropage can cause MTE tag mismatch
faults in userspace.
Remapping zero-filled subpages to the shared zeropage is unsafe, as the
zeropage has a fixed tag of zero, which may not match the tag expected by
the userspace pointer.
KSM already avoids this problem by using memcmp_pages(), which on arm64
intentionally reports MTE-tagged pages as non-identical to prevent unsafe
merging.
As suggested by David[1], this patch adopts the same pattern, replacing the
memchr_inv() byte-level check with a call to pages_identical(). This
leverages existing architecture-specific logic to determine if a page is
truly identical to the shared zeropage.
Having both the THP shrinker and KSM rely on pages_identical() makes the
design more future-proof, IMO. Instead of handling quirks in generic code,
we just let the architecture decide what makes two pages identical.
[1] https://lore.kernel.org/all/ca2106a3-4bb2-4457-81af-301fd99fbef4@redhat.com
Link: https://lkml.kernel.org/r/20250922021458.68123-1-lance.yang@linux.dev
Fixes: b1f202060a ("mm: remap unused subpages to shared zeropage when splitting isolated thp")
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Reported-by: Qun-wei Lin <Qun-wei.Lin@mediatek.com>
Closes: https://lore.kernel.org/all/a7944523fcc3634607691c35311a5d59d1a3f8d4.camel@mediatek.com
Suggested-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Usama Arif <usamaarif642@gmail.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Alistair Popple <apopple@nvidia.com>
Cc: andrew.yang <andrew.yang@mediatek.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Byungchul Park <byungchul@sk.com>
Cc: Charlie Jenkins <charlie@rivosinc.com>
Cc: Chinwen Chang <chinwen.chang@mediatek.com>
Cc: Dev Jain <dev.jain@arm.com>
Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com>
Cc: Gregory Price <gourry@gourry.net>
Cc: "Huang, Ying" <ying.huang@linux.alibaba.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Joshua Hahn <joshua.hahnjy@gmail.com>
Cc: Kairui Song <ryncsn@gmail.com>
Cc: Kalesh Singh <kaleshsingh@google.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Mathew Brost <matthew.brost@intel.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Palmer Dabbelt <palmer@rivosinc.com>
Cc: Rakie Kim <rakie.kim@sk.com>
Cc: Rik van Riel <riel@surriel.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Samuel Holland <samuel.holland@sifive.com>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Yu Zhao <yuzhao@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Generally memcg charging is allowed from all the contexts including NMI
where even spinning on spinlock can cause locking issues. However one
call chain was missed during the addition of memcg charging from any
context support. That is try_charge_memcg() -> memcg_memory_event() ->
cgroup_file_notify().
The possible function call tree under cgroup_file_notify() can acquire
many different spin locks in spinning mode. Some of them are
cgroup_file_kn_lock, kernfs_notify_lock, pool_workqeue's lock. So, let's
just skip cgroup_file_notify() from memcg charging if the context does not
allow spinning.
Alternative approach was also explored where instead of skipping
cgroup_file_notify(), we defer the memcg event processing to irq_work [1].
However it adds complexity and it was decided to keep things simple until
we need more memcg events with !allow_spinning requirement.
Link: https://lore.kernel.org/all/5qi2llyzf7gklncflo6gxoozljbm4h3tpnuv4u4ej4ztysvi6f@x44v7nz2wdzd/ [1]
Link: https://lkml.kernel.org/r/20250922220203.261714-1-shakeel.butt@linux.dev
Fixes: 3ac4638a73 ("memcg: make memcg_rstat_updated nmi safe")
Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev>
Acked-by: Michal Hocko <mhocko@suse.com>
Closes: https://lore.kernel.org/all/20250905061919.439648-1-yepeilin@google.com/
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kumar Kartikeya Dwivedi <memxor@gmail.com>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Peilin Ye <yepeilin@google.com>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Tejun Heo <tj@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
to make it clear that KHO operates on pages rather than on a random
physical address.
The kho_preserve_pages() will be also used in upcoming support for vmalloc
preservation.
Link: https://lkml.kernel.org/r/20250921054458.4043761-3-rppt@kernel.org
Signed-off-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Reviewed-by: Pratyush Yadav <pratyush@kernel.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Cc: Alexander Graf <graf@amazon.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Changyuan Lyu <changyuanl@google.com>
Cc: Chris Li <chrisl@kernel.org>
Cc: Pasha Tatashin <pasha.tatashin@soleen.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
- two small fixes for the recently performed code refactoring (Shigeru
Yoshida) and missing handling of direction parameter in DMA debug code
(Petr Tesarik)
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Merge tag 'dma-mapping-6.18-2025-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping fixes from Marek Szyprowski:
"Two small fixes for the recently performed code refactoring (Shigeru
Yoshida) and missing handling of direction parameter in DMA debug code
(Petr Tesarik)"
* tag 'dma-mapping-6.18-2025-10-07' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
dma-mapping: fix direction in dma_alloc direction traces
kmsan: fix kmsan_handle_dma() to avoid false positives
- The 3 patch series "mm/memory_hotplug: fixup crash during uevent
handling" from Hannes Reinecke which fixes a race which was causing udev
to trigger a crash in the memory hotplug code.
- The 2 patch series "mm_slot: following fixup for usage of
mm_slot_entry()" from Wei Yang adds some touchups to the just-merged
mm_slot changes.
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Merge tag 'mm-stable-2025-10-03-16-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull more MM updates from Andrew Morton:
"Only two patch series in this pull request:
- "mm/memory_hotplug: fixup crash during uevent handling" from Hannes
Reinecke fixes a race that was causing udev to trigger a crash in
the memory hotplug code
- "mm_slot: following fixup for usage of mm_slot_entry()" from Wei
Yang adds some touchups to the just-merged mm_slot changes"
* tag 'mm-stable-2025-10-03-16-49' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm:
mm/khugepaged: use KMEM_CACHE()
mm/ksm: cleanup mm_slot_entry() invocation
Documentation/mm: drop pxx_mkdevmap() descriptions from page table helpers
mm: clean up is_guard_pte_marker()
drivers/base: move memory_block_add_nid() into the caller
mm/memory_hotplug: activate node before adding new memory blocks
drivers/base/memory: add node id parameter to add_memory_block()
Refactor and simplify deferred initialization of the memory map.
Beside the negative diffstat it gives 3ms (55ms vs 58ms) reduction in the
initialization of deferred pages on single node system with 64GiB of RAM.
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Merge tag 'memblock-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock
Pull mm-init update from Mike Rapoport:
"Simplify deferred initialization of struct pages
Refactor and simplify deferred initialization of the memory map.
Beside the negative diffstat it gives 3ms (55ms vs 58ms) reduction in
the initialization of deferred pages on single node system with 64GiB
of RAM"
* tag 'memblock-v6.18-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rppt/memblock:
memblock: drop for_each_free_mem_pfn_range_in_zone_from()
mm/mm_init: drop deferred_init_maxorder()
mm/mm_init: deferred_init_memmap: use a job per zone
mm/mm_init: use deferred_init_memmap_chunk() in deferred_grow_zone()
- refactoring of DMA mapping API to physical addresses as the primary
interface instead of page+offset parameters; this gets much closer to
Matthew Wilcox's long term wish for struct-pageless IO to cacheable DRAM and is
supporting memdesc project which seeks to substantially transform how
struct page works; an advantage of this approach is the possibility of
introducing DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow
in the common paths, what in turn lets to use recently introduced
dma_iova_link() API to map PCI P2P MMIO without creating struct page;
developped by Leon Romanovsky and Jason Gunthorpe
- minor clean-up by Petr Tesarik and Qianfeng Rong
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Merge tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux
Pull dma-mapping updates from Marek Szyprowski:
- Refactoring of DMA mapping API to physical addresses as the primary
interface instead of page+offset parameters
This gets much closer to Matthew Wilcox's long term wish for
struct-pageless IO to cacheable DRAM and is supporting memdesc
project which seeks to substantially transform how struct page works.
An advantage of this approach is the possibility of introducing
DMA_ATTR_MMIO, which covers existing 'dma_map_resource' flow in the
common paths, what in turn lets to use recently introduced
dma_iova_link() API to map PCI P2P MMIO without creating struct page
Developped by Leon Romanovsky and Jason Gunthorpe
- Minor clean-up by Petr Tesarik and Qianfeng Rong
* tag 'dma-mapping-6.18-2025-09-30' of git://git.kernel.org/pub/scm/linux/kernel/git/mszyprowski/linux:
kmsan: fix missed kmsan_handle_dma() signature conversion
mm/hmm: properly take MMIO path
mm/hmm: migrate to physical address-based DMA mapping API
dma-mapping: export new dma_*map_phys() interface
xen: swiotlb: Open code map_resource callback
dma-mapping: implement DMA_ATTR_MMIO for dma_(un)map_page_attrs()
kmsan: convert kmsan_handle_dma to use physical addresses
dma-mapping: convert dma_direct_*map_page to be phys_addr_t based
iommu/dma: implement DMA_ATTR_MMIO for iommu_dma_(un)map_phys()
iommu/dma: rename iommu_dma_*map_page to iommu_dma_*map_phys
dma-mapping: rename trace_dma_*map_page to trace_dma_*map_phys
dma-debug: refactor to use physical addresses for page mapping
iommu/dma: implement DMA_ATTR_MMIO for dma_iova_link().
dma-mapping: introduce new DMA attribute to indicate MMIO memory
swiotlb: Remove redundant __GFP_NOWARN
dma-direct: clean up the logic in __dma_direct_alloc_pages()
We got some late review commits during review of commit b4c9ffb54b
("mm/khugepaged: remove definition of struct khugepaged_mm_slot"). No
need to keep the old cache name "khugepaged_mm_slot", let's simply use
KMEM_CACHE().
Link: https://lkml.kernel.org/r/20251001091900.20041-3-richard.weiyang@gmail.com
Fixes: b4c9ffb54b ("mm/khugepaged: remove definition of struct khugepaged_mm_slot")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Acked-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Kiryl Shutsemau <kirill@shutemov.name>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: SeongJae Park <sj@kernel.org>
Cc: Nico Pache <npache@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Kiryl Shutsemau <kas@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Patch series "mm_slot: following fixup for usage of mm_slot_entry()", v2.
We got some late review commits during review of "mm_slot: fix the usage of
mm_slot_entry()" in [1].
This patch (of 2):
We got some late review commits during review of commit 08498be43e
("mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL"). Let's
reduce the indentation level and make the code easier to follow by using
gotos to a new label.
Link: https://lkml.kernel.org/r/20251001091900.20041-1-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20251001091900.20041-2-richard.weiyang@gmail.com
Link: https://lkml.kernel.org/r/20250927004539.19308-1-richard.weiyang@gmail.com [1]
Fixes: 08498be43e ("mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL")
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Kiryl Shutsemau <kas@kernel.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: xu xin <xu.xin16@zte.com.cn>
Cc: Dan Carpenter <dan.carpenter@linaro.org>
Cc: Chengming Zhou <chengming.zhou@linux.dev>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Raghavendra K T <raghavendra.kt@amd.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Cc: Kiryl Shutsemau <kirill@shutemov.name>
Cc: SeongJae Park <sj@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Let's simplify the implementation. The current code is redundant as it
effectively expands to:
is_swap_pte(pte) &&
is_pte_marker_entry(...) && // from is_pte_marker()
is_pte_marker_entry(...) // from is_guard_swp_entry()
While a modern compiler could likely optimize this away, let's have clean
code and not rely on it.
Link: https://lkml.kernel.org/r/20250924045830.3817-1-lance.yang@linux.dev
Signed-off-by: Lance Yang <lance.yang@linux.dev>
Reviewed-by: Wei Yang <richard.weiyang@gmail.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Hugh Dickins <hughd@google.com>
Cc: Kairui Song <kasong@tencent.com>
Cc: "Kirill A. Shutemov" <kirill@shutemov.name>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Mika Penttilä <mpenttil@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
The sysfs attributes for memory blocks require the node ID to be set and
initialized, so move the node activation before adding new memory blocks.
This also has the nice side effect that the BUG_ON() can be converted into
a WARN_ON() as we now can handle registration errors.
Link: https://lkml.kernel.org/r/20250729064637.51662-3-hare@kernel.org
Fixes: b9ff036082 ("mm/memory_hotplug.c: make add_memory_resource use __try_online_node")
Signed-off-by: Hannes Reinecke <hare@kernel.org>
Acked-by: David Hildenbrand <david@redhat.com>
Acked-by: Oscar Salvador <osalvador@suse.de>
Reviewed-by: Donet Tom <donettom@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
New Features:
* Add a Kconfig option to redirect dfprintk() to the trace buffer
* Enable use of the RWF_DONTCACHE flag on the NFS client
* Add striped layout handling to pNFS flexfiles
* Add proper localio handling for READ and WRITE O_DIRECT
Bugfixes:
* Handle NFS4ERR_GRACE errors during delegation recall
* Fix NFSv4.1 backchannel max_resp_sz verification check
* Fix mount hang after CREATE_SESSION failure
* Fix d_parent->d_inode locking in nfs4_setup_readdir()
Other Cleanups and Improvements:
* Improvements to write handling tracepoints
* Fix a few trivial spelling mistakes
* Cleanups to the rpcbind cleanup call sites
* Convert the SUNRPC xdr_buf to use a scratch folio instead of scratch page
* Remove unused NFS_WBACK_BUSY() macro
* Remove __GFP_NOWARN flags
* Unexport rpc_malloc() and rpc_free()
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Merge tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs
Pull NFS client updates from Anna Schumaker:
"New Features:
- Add a Kconfig option to redirect dfprintk() to the trace buffer
- Enable use of the RWF_DONTCACHE flag on the NFS client
- Add striped layout handling to pNFS flexfiles
- Add proper localio handling for READ and WRITE O_DIRECT
Bugfixes:
- Handle NFS4ERR_GRACE errors during delegation recall
- Fix NFSv4.1 backchannel max_resp_sz verification check
- Fix mount hang after CREATE_SESSION failure
- Fix d_parent->d_inode locking in nfs4_setup_readdir()
Other Cleanups and Improvements:
- Improvements to write handling tracepoints
- Fix a few trivial spelling mistakes
- Cleanups to the rpcbind cleanup call sites
- Convert the SUNRPC xdr_buf to use a scratch folio instead of
scratch page
- Remove unused NFS_WBACK_BUSY() macro
- Remove __GFP_NOWARN flags
- Unexport rpc_malloc() and rpc_free()"
* tag 'nfs-for-6.18-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (46 commits)
NFS: add basic STATX_DIOALIGN and STATX_DIO_READ_ALIGN support
nfs/localio: add tracepoints for misaligned DIO READ and WRITE support
nfs/localio: add proper O_DIRECT support for READ and WRITE
nfs/localio: refactor iocb initialization
nfs/localio: refactor iocb and iov_iter_bvec initialization
nfs/localio: avoid issuing misaligned IO using O_DIRECT
nfs/localio: make trace_nfs_local_open_fh more useful
NFSD: filecache: add STATX_DIOALIGN and STATX_DIO_READ_ALIGN support
sunrpc: unexport rpc_malloc() and rpc_free()
NFSv4/flexfiles: Add support for striped layouts
NFSv4/flexfiles: Update layout stats & error paths for striped layouts
NFSv4/flexfiles: Write path updates for striped layouts
NFSv4/flexfiles: Commit path updates for striped layouts
NFSv4/flexfiles: Read path updates for striped layouts
NFSv4/flexfiles: Update low level helper functions to be DS stripe aware.
NFSv4/flexfiles: Add data structure support for striped layouts
NFSv4/flexfiles: Use ds_commit_idx when marking a write commit
NFSv4/flexfiles: Remove cred local variable dependency
nfs4_setup_readdir(): insufficient locking for ->d_parent->d_inode dereferencing
NFS: Enable use of the RWF_DONTCACHE flag on the NFS client
...
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Merge tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:
- Extend copy_file_range interface to be fully 64bit capable (Miklos)
- Add selftest for fusectl (Chen Linxuan)
- Move fuse docs into a separate directory (Bagas Sanjaya)
- Allow fuse to enter freezable state in some cases (Sergey
Senozhatsky)
- Clean up writeback accounting after removing tmp page copies (Joanne)
- Optimize virtiofs request handling (Li RongQing)
- Add synchronous FUSE_INIT support (Miklos)
- Allow server to request prune of unused inodes (Miklos)
- Fix deadlock with AIO/sync release (Darrick)
- Add some prep patches for block/iomap support (Darrick)
- Misc fixes and cleanups
* tag 'fuse-update-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: (26 commits)
fuse: move CREATE_TRACE_POINTS to a separate file
fuse: move the backing file idr and code into a new source file
fuse: enable FUSE_SYNCFS for all fuseblk servers
fuse: capture the unique id of fuse commands being sent
fuse: fix livelock in synchronous file put from fuseblk workers
mm: fix lockdep issues in writeback handling
fuse: add prune notification
fuse: remove redundant calls to fuse_copy_finish() in fuse_notify()
fuse: fix possibly missing fuse_copy_finish() call in fuse_notify()
fuse: remove FUSE_NOTIFY_CODE_MAX from <uapi/linux/fuse.h>
fuse: remove fuse_readpages_end() null mapping check
fuse: fix references to fuse.rst -> fuse/fuse.rst
fuse: allow synchronous FUSE_INIT
fuse: zero initialize inode private data
fuse: remove unused 'inode' parameter in fuse_passthrough_open
virtio_fs: fix the hash table using in virtio_fs_enqueue_req()
mm: remove BDI_CAP_WRITEBACK_ACCT
fuse: use default writeback accounting
virtio_fs: Remove redundant spinlock in virtio_fs_request_complete()
fuse: remove unneeded offset assignment when filling write pages
...
In slab_post_alloc_hook(), kmemleak check is skipped when
gfpflags_allow_spinning() returns false since commit af92793e52
("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Therefore, unconditionally calling kmemleak_not_leak() in
alloc_slab_obj_exts() would trigger the following warning:
kmemleak: Trying to color unknown object at 0xffff8881057f5000 as Grey
Call Trace:
alloc_slab_obj_exts+0x1b5/0x370
__alloc_tagging_slab_alloc_hook+0x9f/0x2d0
__kmalloc_cache_noprof+0x1c4/0x5c0
__set_page_owner+0x10d/0x1c0
post_alloc_hook+0x84/0xf0
get_page_from_freelist+0x73b/0x1380
__alloc_frozen_pages_noprof+0x110/0x2c0
alloc_pages_mpol+0x44/0x140
alloc_slab_page+0xac/0x150
allocate_slab+0x78/0x3a0
___slab_alloc+0x76b/0xed0
__slab_alloc.constprop.0+0x5a/0xb0
Add the allow_spin check in alloc_slab_obj_exts() to eliminate the above
warning.
Fixes: af92793e52 ("slab: Introduce kmalloc_nolock() and kfree_nolock().")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/r/20250930063831.782815-1-ranxiaokai627@163.com
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
KMSAN reports an uninitialized value issue in dma_map_phys()[1]. This
is a false positive caused by the way the virtual address is handled
in kmsan_handle_dma(). Fix it by translating the physical address to
a virtual address using phys_to_virt().
[1]
BUG: KMSAN: uninit-value in dma_map_phys+0xdc5/0x1060
dma_map_phys+0xdc5/0x1060
dma_map_page_attrs+0xcf/0x130
e1000_xmit_frame+0x3c51/0x78f0
dev_hard_start_xmit+0x22f/0xa30
sch_direct_xmit+0x3b2/0xcf0
__dev_queue_xmit+0x3588/0x5e60
neigh_resolve_output+0x9c5/0xaf0
ip6_finish_output2+0x24e0/0x2d30
ip6_finish_output+0x903/0x10d0
ip6_output+0x331/0x600
mld_sendpack+0xb4a/0x1770
mld_ifc_work+0x1328/0x19b0
process_scheduled_works+0xb91/0x1d80
worker_thread+0xedf/0x1590
kthread+0xd5c/0xf00
ret_from_fork+0x1f5/0x4c0
ret_from_fork_asm+0x1a/0x30
Uninit was created at:
__kmalloc_cache_noprof+0x8f5/0x16b0
syslog_print+0x9a/0xef0
do_syslog+0x849/0xfe0
__x64_sys_syslog+0x97/0x100
x64_sys_call+0x3cf8/0x3e30
do_syscall_64+0xd9/0xfa0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Bytes 0-89 of 90 are uninitialized
Memory access of size 90 starts at ffff8880367ed000
CPU: 1 UID: 0 PID: 1552 Comm: kworker/1:2 Not tainted 6.17.0-next-20250929 #26 PREEMPT(none)
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.17.0-5.fc42 04/01/2014
Workqueue: mld mld_ifc_work
Fixes: 6eb1e769b2 ("kmsan: convert kmsan_handle_dma to use physical addresses")
Signed-off-by: Shigeru Yoshida <syoshida@redhat.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20251002051024.3096061-1-syoshida@redhat.com
- The 3 patch series "mm, swap: improve cluster scan strategy" from
Kairui Song improves performance and reduces the failure rate of swap
cluster allocation.
- The 4 patch series "support large align and nid in Rust allocators"
from Vitaly Wool permits Rust allocators to set NUMA node and large
alignment when perforning slub and vmalloc reallocs.
- The 2 patch series "mm/damon/vaddr: support stat-purpose DAMOS" from
Yueyang Pan extend DAMOS_STAT's handling of the DAMON operations sets
for virtual address spaces for ops-level DAMOS filters.
- The 3 patch series "execute PROCMAP_QUERY ioctl under per-vma lock"
from Suren Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps.
- The 2 patch series "mm/mincore: minor clean up for swap cache
checking" from Kairui Song performs some cleanup in the swap code.
- The 11 patch series "mm: vm_normal_page*() improvements" from David
Hildenbrand provides code cleanup in the pagemap code.
- The 5 patch series "add persistent huge zero folio support" from
Pankaj Raghav provides a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero.
- The 3 patch series "kho: fixes and cleanups" from Mike Rapoport adds a
few touchups to the recently added Kexec Handover feature.
- The 10 patch series "mm: make mm->flags a bitmap and 64-bit on all
arches" from Lorenzo Stoakes turns mm_struct.flags into a bitmap. To
end the constant struggle with space shortage on 32-bit conflicting with
64-bit's needs.
- The 2 patch series "mm/swapfile.c and swap.h cleanup" from Chris Li
cleans up some swap code.
- The 7 patch series "selftests/mm: Fix false positives and skip
unsupported tests" from Donet Tom fixes a few things in our selftests
code.
- The 7 patch series "prctl: extend PR_SET_THP_DISABLE to only provide
THPs when advised" from David Hildenbrand "allows individual processes
to opt-out of THP=always into THP=madvise, without affecting other
workloads on the system".
It's a long story - the [1/N] changelog spells out the considerations.
- The 11 patch series "Add and use memdesc_flags_t" from Matthew Wilcox
gets us started on the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc.
- The 3 patch series "Tiny optimization for large read operations" from
Chi Zhiling improves the efficiency of the pagecache read path.
- The 5 patch series "Better split_huge_page_test result check" from Zi
Yan improves our folio splitting selftest code.
- The 2 patch series "test that rmap behaves as expected" from Wei Yang
adds some rmap selftests.
- The 3 patch series "remove write_cache_pages()" from Christoph Hellwig
removes that function and converts its two remaining callers.
- The 2 patch series "selftests/mm: uffd-stress fixes" from Dev Jain
fixes some UFFD selftests issues.
- The 3 patch series "introduce kernel file mapped folios" from Boris
Burkov introduces the concept of "kernel file pages". Using these
permits btrfs to account its metadata pages to the root cgroup, rather
than to the cgroups of random inappropriate tasks.
- The 2 patch series "mm/pageblock: improve readability of some
pageblock handling" from Wei Yang provides some readability improvements
to the page allocator code.
- The 11 patch series "mm/damon: support ARM32 with LPAE" from SeongJae
Park teaches DAMON to understand arm32 highmem.
- The 4 patch series "tools: testing: Use existing atomic.h for
vma/maple tests" from Brendan Jackman performs some code cleanups and
deduplication under tools/testing/.
- The 2 patch series "maple_tree: Fix testing for 32bit compiles" from
Liam Howlett fixes a couple of 32-bit issues in
tools/testing/radix-tree.c.
- The 2 patch series "kasan: unify kasan_enabled() and remove
arch-specific implementations" from Sabyrzhan Tasbolatov moves KASAN
arch-specific initialization code into a common arch-neutral
implementation.
- The 3 patch series "mm: remove zpool" from Johannes Weiner removes
zspool - an indirection layer which now only redirects to a single thing
(zsmalloc).
- The 2 patch series "mm: task_stack: Stack handling cleanups" from
Pasha Tatashin makes a couple of cleanups in the fork code.
- The 37 patch series "mm: remove nth_page()" from David Hildenbrand
makes rather a lot of adjustments at various nth_page() callsites,
eventually permitting the removal of that undesirable helper function.
- The 2 patch series "introduce kasan.write_only option in hw-tags" from
Yeoreum Yun creates a KASAN read-only mode for ARM, using that
architecture's memory tagging feature. It is felt that a read-only mode
KASAN is suitable for use in production systems rather than debug-only.
- The 3 patch series "mm: hugetlb: cleanup hugetlb folio allocation"
from Kefeng Wang does some tidying in the hugetlb folio allocation code.
- The 12 patch series "mm: establish const-correctness for pointer
parameters" from Max Kellermann makes quite a number of the MM API
functions more accurate about the constness of their arguments. This
was getting in the way of subsystems (in this case CEPH) when they
attempt to improving their own const/non-const accuracy.
- The 7 patch series "Cleanup free_pages() misuse" from Vishal Moola
fixes a number of code sites which were confused over when to use
free_pages() vs __free_pages().
- The 3 patch series "Add Rust abstraction for Maple Trees" from Alice
Ryhl makes the mapletree code accessible to Rust. Required by nouveau
and by its forthcoming successor: the new Rust Nova driver.
- The 2 patch series "selftests/mm: split_huge_page_test:
split_pte_mapped_thp improvements" from David Hildenbrand adds a fix and
some cleanups to the thp selftesting code.
- The 14 patch series "mm, swap: introduce swap table as swap cache
(phase I)" from Chris Li and Kairui Song is the first step along the
path to implementing "swap tables" - a new approach to swap allocation
and state tracking which is expected to yield speed and space
improvements. This patchset itself yields a 5-20% performance benefit
in some situations.
- The 3 patch series "Some ptdesc cleanups" from Matthew Wilcox utilizes
the new memdesc layer to clean up the ptdesc code a little.
- The 3 patch series "Fix va_high_addr_switch.sh test failure" from
Chunyu Hu fixes some issues in our 5-level pagetable selftesting code.
- The 2 patch series "Minor fixes for memory allocation profiling" from
Suren Baghdasaryan addresses a couple of minor issues in relatively new
memory allocation profiling feature.
- The 3 patch series "Small cleanups" from Matthew Wilcox has a few
cleanups in preparation for more memdesc work.
- The 2 patch series "mm/damon: add addr_unit for DAMON_LRU_SORT and
DAMON_RECLAIM" from Quanmin Yan makes some changes to DAMON in
furtherance of supporting arm highmem.
- The 2 patch series "selftests/mm: Add -Wunreachable-code and fix
warnings" from Muhammad Anjum adds that compiler check to selftests code
and fixes the fallout, by removing dead code.
- The 10 patch series "Improvements to Victim Process Thawing and OOM
Reaper Traversal Order" from zhongjinji makes a number of improvements
in the OOM killer: mainly thawing a more appropriate group of victim
threads so they can release resources.
- The 5 patch series "mm/damon: misc fixups and improvements for 6.18"
from SeongJae Park is a bunch of small and unrelated fixups for DAMON.
- The 7 patch series "mm/damon: define and use DAMON initialization
check function" from SeongJae Park implement reliability and
maintainability improvements to a recently-added bug fix.
- The 2 patch series "mm/damon/stat: expose auto-tuned intervals and
non-idle ages" from SeongJae Park provides additional transparency to
userspace clients of the DAMON_STAT information.
- The 2 patch series "Expand scope of khugepaged anonymous collapse"
from Dev Jain removes some constraints on khubepaged's collapsing of
anon VMAs. It also increases the success rate of MADV_COLLAPSE against
an anon vma.
- The 2 patch series "mm: do not assume file == vma->vm_file in
compat_vma_mmap_prepare()" from Lorenzo Stoakes moves us further towards
removal of file_operations.mmap(). This patchset concentrates upon
clearing up the treatment of stacked filesystems.
- The 6 patch series "mm: Improve mlock tracking for large folios" from
Kiryl Shutsemau provides some fixes and improvements to mlock's tracking
of large folios. /proc/meminfo's "Mlocked" field became more accurate.
- The 2 patch series "mm/ksm: Fix incorrect accounting of KSM counters
during fork" from Donet Tom fixes several user-visible KSM stats
inaccuracies across forks and adds selftest code to verify these
counters.
- The 2 patch series "mm_slot: fix the usage of mm_slot_entry" from Wei
Yang addresses some potential but presently benign issues in KSM's
mm_slot handling.
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Merge tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
Pull MM updates from Andrew Morton:
- "mm, swap: improve cluster scan strategy" from Kairui Song improves
performance and reduces the failure rate of swap cluster allocation
- "support large align and nid in Rust allocators" from Vitaly Wool
permits Rust allocators to set NUMA node and large alignment when
perforning slub and vmalloc reallocs
- "mm/damon/vaddr: support stat-purpose DAMOS" from Yueyang Pan extend
DAMOS_STAT's handling of the DAMON operations sets for virtual
address spaces for ops-level DAMOS filters
- "execute PROCMAP_QUERY ioctl under per-vma lock" from Suren
Baghdasaryan reduces mmap_lock contention during reads of
/proc/pid/maps
- "mm/mincore: minor clean up for swap cache checking" from Kairui Song
performs some cleanup in the swap code
- "mm: vm_normal_page*() improvements" from David Hildenbrand provides
code cleanup in the pagemap code
- "add persistent huge zero folio support" from Pankaj Raghav provides
a block layer speedup by optionalls making the
huge_zero_pagepersistent, instead of releasing it when its refcount
falls to zero
- "kho: fixes and cleanups" from Mike Rapoport adds a few touchups to
the recently added Kexec Handover feature
- "mm: make mm->flags a bitmap and 64-bit on all arches" from Lorenzo
Stoakes turns mm_struct.flags into a bitmap. To end the constant
struggle with space shortage on 32-bit conflicting with 64-bit's
needs
- "mm/swapfile.c and swap.h cleanup" from Chris Li cleans up some swap
code
- "selftests/mm: Fix false positives and skip unsupported tests" from
Donet Tom fixes a few things in our selftests code
- "prctl: extend PR_SET_THP_DISABLE to only provide THPs when advised"
from David Hildenbrand "allows individual processes to opt-out of
THP=always into THP=madvise, without affecting other workloads on the
system".
It's a long story - the [1/N] changelog spells out the considerations
- "Add and use memdesc_flags_t" from Matthew Wilcox gets us started on
the memdesc project. Please see
https://kernelnewbies.org/MatthewWilcox/Memdescs and
https://blogs.oracle.com/linux/post/introducing-memdesc
- "Tiny optimization for large read operations" from Chi Zhiling
improves the efficiency of the pagecache read path
- "Better split_huge_page_test result check" from Zi Yan improves our
folio splitting selftest code
- "test that rmap behaves as expected" from Wei Yang adds some rmap
selftests
- "remove write_cache_pages()" from Christoph Hellwig removes that
function and converts its two remaining callers
- "selftests/mm: uffd-stress fixes" from Dev Jain fixes some UFFD
selftests issues
- "introduce kernel file mapped folios" from Boris Burkov introduces
the concept of "kernel file pages". Using these permits btrfs to
account its metadata pages to the root cgroup, rather than to the
cgroups of random inappropriate tasks
- "mm/pageblock: improve readability of some pageblock handling" from
Wei Yang provides some readability improvements to the page allocator
code
- "mm/damon: support ARM32 with LPAE" from SeongJae Park teaches DAMON
to understand arm32 highmem
- "tools: testing: Use existing atomic.h for vma/maple tests" from
Brendan Jackman performs some code cleanups and deduplication under
tools/testing/
- "maple_tree: Fix testing for 32bit compiles" from Liam Howlett fixes
a couple of 32-bit issues in tools/testing/radix-tree.c
- "kasan: unify kasan_enabled() and remove arch-specific
implementations" from Sabyrzhan Tasbolatov moves KASAN arch-specific
initialization code into a common arch-neutral implementation
- "mm: remove zpool" from Johannes Weiner removes zspool - an
indirection layer which now only redirects to a single thing
(zsmalloc)
- "mm: task_stack: Stack handling cleanups" from Pasha Tatashin makes a
couple of cleanups in the fork code
- "mm: remove nth_page()" from David Hildenbrand makes rather a lot of
adjustments at various nth_page() callsites, eventually permitting
the removal of that undesirable helper function
- "introduce kasan.write_only option in hw-tags" from Yeoreum Yun
creates a KASAN read-only mode for ARM, using that architecture's
memory tagging feature. It is felt that a read-only mode KASAN is
suitable for use in production systems rather than debug-only
- "mm: hugetlb: cleanup hugetlb folio allocation" from Kefeng Wang does
some tidying in the hugetlb folio allocation code
- "mm: establish const-correctness for pointer parameters" from Max
Kellermann makes quite a number of the MM API functions more accurate
about the constness of their arguments. This was getting in the way
of subsystems (in this case CEPH) when they attempt to improving
their own const/non-const accuracy
- "Cleanup free_pages() misuse" from Vishal Moola fixes a number of
code sites which were confused over when to use free_pages() vs
__free_pages()
- "Add Rust abstraction for Maple Trees" from Alice Ryhl makes the
mapletree code accessible to Rust. Required by nouveau and by its
forthcoming successor: the new Rust Nova driver
- "selftests/mm: split_huge_page_test: split_pte_mapped_thp
improvements" from David Hildenbrand adds a fix and some cleanups to
the thp selftesting code
- "mm, swap: introduce swap table as swap cache (phase I)" from Chris
Li and Kairui Song is the first step along the path to implementing
"swap tables" - a new approach to swap allocation and state tracking
which is expected to yield speed and space improvements. This
patchset itself yields a 5-20% performance benefit in some situations
- "Some ptdesc cleanups" from Matthew Wilcox utilizes the new memdesc
layer to clean up the ptdesc code a little
- "Fix va_high_addr_switch.sh test failure" from Chunyu Hu fixes some
issues in our 5-level pagetable selftesting code
- "Minor fixes for memory allocation profiling" from Suren Baghdasaryan
addresses a couple of minor issues in relatively new memory
allocation profiling feature
- "Small cleanups" from Matthew Wilcox has a few cleanups in
preparation for more memdesc work
- "mm/damon: add addr_unit for DAMON_LRU_SORT and DAMON_RECLAIM" from
Quanmin Yan makes some changes to DAMON in furtherance of supporting
arm highmem
- "selftests/mm: Add -Wunreachable-code and fix warnings" from Muhammad
Anjum adds that compiler check to selftests code and fixes the
fallout, by removing dead code
- "Improvements to Victim Process Thawing and OOM Reaper Traversal
Order" from zhongjinji makes a number of improvements in the OOM
killer: mainly thawing a more appropriate group of victim threads so
they can release resources
- "mm/damon: misc fixups and improvements for 6.18" from SeongJae Park
is a bunch of small and unrelated fixups for DAMON
- "mm/damon: define and use DAMON initialization check function" from
SeongJae Park implement reliability and maintainability improvements
to a recently-added bug fix
- "mm/damon/stat: expose auto-tuned intervals and non-idle ages" from
SeongJae Park provides additional transparency to userspace clients
of the DAMON_STAT information
- "Expand scope of khugepaged anonymous collapse" from Dev Jain removes
some constraints on khubepaged's collapsing of anon VMAs. It also
increases the success rate of MADV_COLLAPSE against an anon vma
- "mm: do not assume file == vma->vm_file in compat_vma_mmap_prepare()"
from Lorenzo Stoakes moves us further towards removal of
file_operations.mmap(). This patchset concentrates upon clearing up
the treatment of stacked filesystems
- "mm: Improve mlock tracking for large folios" from Kiryl Shutsemau
provides some fixes and improvements to mlock's tracking of large
folios. /proc/meminfo's "Mlocked" field became more accurate
- "mm/ksm: Fix incorrect accounting of KSM counters during fork" from
Donet Tom fixes several user-visible KSM stats inaccuracies across
forks and adds selftest code to verify these counters
- "mm_slot: fix the usage of mm_slot_entry" from Wei Yang addresses
some potential but presently benign issues in KSM's mm_slot handling
* tag 'mm-stable-2025-10-01-19-00' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (372 commits)
mm: swap: check for stable address space before operating on the VMA
mm: convert folio_page() back to a macro
mm/khugepaged: use start_addr/addr for improved readability
hugetlbfs: skip VMAs without shareable locks in hugetlb_vmdelete_list
alloc_tag: fix boot failure due to NULL pointer dereference
mm: silence data-race in update_hiwater_rss
mm/memory-failure: don't select MEMORY_ISOLATION
mm/khugepaged: remove definition of struct khugepaged_mm_slot
mm/ksm: get mm_slot by mm_slot_entry() when slot is !NULL
hugetlb: increase number of reserving hugepages via cmdline
selftests/mm: add fork inheritance test for ksm_merging_pages counter
mm/ksm: fix incorrect KSM counter handling in mm_struct during fork
drivers/base/node: fix double free in register_one_node()
mm: remove PMD alignment constraint in execmem_vmalloc()
mm/memory_hotplug: fix typo 'esecially' -> 'especially'
mm/rmap: improve mlock tracking for large folios
mm/filemap: map entire large folio faultaround
mm/fault: try to map the entire file folio in finish_fault()
mm/rmap: mlock large folios in try_to_unmap_one()
mm/rmap: fix a mlock race condition in folio_referenced_one()
...
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Merge tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab
Pull slab updates from Vlastimil Babka:
- A new layer for caching objects for allocation and free via percpu
arrays called sheaves.
The aim is to combine the good parts of SLAB (lower-overhead and
simpler percpu caching, compared to SLUB) without the past issues
with arrays for freeing remote NUMA node objects and their flushing.
It also allows more efficient kfree_rcu(), and cheaper object
preallocations for cases where the exact number of objects is
unknown, but an upper bound is.
Currently VMAs and maple nodes are using this new caching, with a
plan to enable it for all caches and remove the complex SLUB fastpath
based on cpu (partial) slabs and this_cpu_cmpxchg_double().
(Vlastimil Babka, with Liam Howlett and Pedro Falcato for the maple
tree changes)
- Re-entrant kmalloc_nolock(), which allows opportunistic allocations
from NMI and tracing/kprobe contexts.
Building on prior page allocator and memcg changes, it will result in
removing BPF-specific caches on top of slab (Alexei Starovoitov)
- Various fixes and cleanups. (Kuan-Wei Chiu, Matthew Wilcox, Suren
Baghdasaryan, Ye Liu)
* tag 'slab-for-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/vbabka/slab: (40 commits)
slab: Introduce kmalloc_nolock() and kfree_nolock().
slab: Reuse first bit for OBJEXTS_ALLOC_FAIL
slab: Make slub local_(try)lock more precise for LOCKDEP
mm: Introduce alloc_frozen_pages_nolock()
mm: Allow GFP_ACCOUNT to be used in alloc_pages_nolock().
locking/local_lock: Introduce local_lock_is_locked().
maple_tree: Convert forking to use the sheaf interface
maple_tree: Add single node allocation support to maple state
maple_tree: Prefilled sheaf conversion and testing
tools/testing: Add support for prefilled slab sheafs
maple_tree: Replace mt_free_one() with kfree()
maple_tree: Use kfree_rcu in ma_free_rcu
testing/radix-tree/maple: Hack around kfree_rcu not existing
tools/testing: include maple-shim.c in maple.c
maple_tree: use percpu sheaves for maple_node_cache
mm, vma: use percpu sheaves for vm_area_struct cache
tools/testing: Add support for changes to slab for sheaves
slab: allow NUMA restricted allocations to use percpu sheaves
tools/testing/vma: Implement vm_refcnt reset
slab: skip percpu sheaves for remote object freeing
...
Core & protocols
----------------
- Improve drop account scalability on NUMA hosts for RAW and UDP sockets
and the backlog, almost doubling the Pps capacity under DoS.
- Optimize the UDP RX performance under stress, reducing contention,
revisiting the binary layout of the involved data structs and
implementing NUMA-aware locking. This improves UDP RX performance by
an additional 50%, even more under extreme conditions.
- Add support for PSP encryption of TCP connections; this mechanism has
some similarities with IPsec and TLS, but offers superior HW offloads
capabilities.
- Ongoing work to support Accurate ECN for TCP. AccECN allows more than
one congestion notification signal per RTT and is a building block for
Low Latency, Low Loss, and Scalable Throughput (L4S).
- Reorganize the TCP socket binary layout for data locality, reducing
the number of touched cachelines in the fastpath.
- Refactor skb deferral free to better scale on large multi-NUMA hosts,
this improves TCP and UDP RX performances significantly on such HW.
- Increase the default socket memory buffer limits from 256K to 4M to
better fit modern link speeds.
- Improve handling of setups with a large number of nexthop, making dump
operating scaling linearly and avoiding unneeded synchronize_rcu() on
delete.
- Improve bridge handling of VLAN FDB, storing a single entry per bridge
instead of one entry per port; this makes the dump order of magnitude
faster on large switches.
- Restore IP ID correctly for encapsulated packets at GSO segmentation
time, allowing GRO to merge packets in more scenarios.
- Improve netfilter matching performance on large sets.
- Improve MPTCP receive path performance by leveraging recently
introduced core infrastructure (skb deferral free) and adopting recent
TCP autotuning changes.
- Allow bridges to redirect to a backup port when the bridge port is
administratively down.
- Introduce MPTCP 'laminar' endpoint that con be used only once per
connection and simplify common MPTCP setups.
- Add RCU safety to dst->dev, closing a lot of possible races.
- A significant crypto library API for SCTP, MPTCP and IPv6 SR, reducing
code duplication.
- Supports pulling data from an skb frag into the linear area of an XDP
buffer.
Things we sprinkled into general kernel code
--------------------------------------------
- Generate netlink documentation from YAML using an integrated
YAML parser.
Driver API
----------
- Support using IPv6 Flow Label in Rx hash computation and RSS queue
selection.
- Introduce API for fetching the DMA device for a given queue, allowing
TCP zerocopy RX on more H/W setups.
- Make XDP helpers compatible with unreadable memory, allowing more
easily building DevMem-enabled drivers with a unified XDP/skbs
datapath.
- Add a new dedicated ethtool callback enabling drivers to provide the
number of RX rings directly, improving efficiency and clarity in RX
ring queries and RSS configuration.
- Introduce a burst period for the health reporter, allowing better
handling of multiple errors due to the same root cause.
- Support for DPLL phase offset exponential moving average, controlling
the average smoothing factor.
Device drivers
--------------
- Add a new Huawei driver for 3rd gen NIC (hinic3).
- Add a new SpacemiT driver for K1 ethernet MAC.
- Add a generic abstraction for shared memory communication devices
(dibps)
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- Use multiple per-queue doorbell, to avoid MMIO contention issues
- support adjacent functions, allowing them to delegate their
SR-IOV VFs to sibling PFs
- support RSS for IPSec offload
- support exposing raw cycle counters in PTP and mlx5
- support for disabling host PFs.
- Intel (100G, ice, idpf):
- ice: support for SRIOV VFs over an Active-Active link aggregate
- ice: support for firmware logging via debugfs
- ice: support for Earliest TxTime First (ETF) hardware offload
- idpf: support basic XDP functionalities and XSk
- Broadcom (bnxt):
- support Hyper-V VF ID
- dynamic SRIOV resource allocations for RoCE
- Meta (fbnic):
- support queue API, zero-copy Rx and Tx
- support basic XDP functionalities
- devlink health support for FW crashes and OTP mem corruptions
- expand hardware stats coverage to FEC, PHY, and Pause
- Wangxun:
- support ethtool coalesce options
- support for multiple RSS contexts
- Ethernet virtual:
- Macsec:
- replace custom netlink attribute checks with policy-level checks
- Bonding:
- support aggregator selection based on port priority
- Microsoft vNIC:
- use page pool fragments for RX buffers instead of full pages to
improve memory efficiency
- Ethernet NICs consumer, and embedded:
- Qualcomm: support Ethernet function for IPQ9574 SoC
- Airoha: implement wlan offloading via NPU
- Freescale
- enetc: add NETC timer PTP driver and add PTP support
- fec: enable the Jumbo frame support for i.MX8QM
- Renesas (R-Car S4): support HW offloading for layer 2 switching
- support for RZ/{T2H, N2H} SoCs
- Cadence (macb): support TAPRIO traffic scheduling
- TI:
- support for Gigabit ICSS ethernet SoC (icssm-prueth)
- Synopsys (stmmac): a lot of cleanups
- Ethernet PHYs:
- Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS
driver
- Support bcm63268 GPHY power control
- Support for Micrel lan8842 PHY and PTP
- Support for Aquantia AQR412 and AQR115
- CAN:
- a large CAN-XL preparation work
- reorganize raw_sock and uniqframe struct to minimize memory usage
- rcar_canfd: update the CAN-FD handling
- WiFi:
- extended Neighbor Awareness Networking (NAN) support
- S1G channel representation cleanup
- improve S1G support
- WiFi drivers:
- Intel (iwlwifi):
- major refactor and cleanup
- Broadcom (brcm80211):
- support for AP isolation
- RealTek (rtw88/89) rtw88/89:
- preparation work for RTL8922DE support
- MediaTek (mt76):
- HW restart improvements
- MLO support
- Qualcomm/Atheros (ath10k_
- GTK rekey fixes
- Bluetooth drivers:
- btusb: support for several new IDs for MT7925
- btintel: support for BlazarIW core
- btintel_pcie: support for _suspend() / _resume()
- btintel_pcie: support for Scorpious, Panther Lake-H484 IDs
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Merge tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next
Pull networking updates from Paolo Abeni:
"Core & protocols:
- Improve drop account scalability on NUMA hosts for RAW and UDP
sockets and the backlog, almost doubling the Pps capacity under DoS
- Optimize the UDP RX performance under stress, reducing contention,
revisiting the binary layout of the involved data structs and
implementing NUMA-aware locking. This improves UDP RX performance
by an additional 50%, even more under extreme conditions
- Add support for PSP encryption of TCP connections; this mechanism
has some similarities with IPsec and TLS, but offers superior HW
offloads capabilities
- Ongoing work to support Accurate ECN for TCP. AccECN allows more
than one congestion notification signal per RTT and is a building
block for Low Latency, Low Loss, and Scalable Throughput (L4S)
- Reorganize the TCP socket binary layout for data locality, reducing
the number of touched cachelines in the fastpath
- Refactor skb deferral free to better scale on large multi-NUMA
hosts, this improves TCP and UDP RX performances significantly on
such HW
- Increase the default socket memory buffer limits from 256K to 4M to
better fit modern link speeds
- Improve handling of setups with a large number of nexthop, making
dump operating scaling linearly and avoiding unneeded
synchronize_rcu() on delete
- Improve bridge handling of VLAN FDB, storing a single entry per
bridge instead of one entry per port; this makes the dump order of
magnitude faster on large switches
- Restore IP ID correctly for encapsulated packets at GSO
segmentation time, allowing GRO to merge packets in more scenarios
- Improve netfilter matching performance on large sets
- Improve MPTCP receive path performance by leveraging recently
introduced core infrastructure (skb deferral free) and adopting
recent TCP autotuning changes
- Allow bridges to redirect to a backup port when the bridge port is
administratively down
- Introduce MPTCP 'laminar' endpoint that con be used only once per
connection and simplify common MPTCP setups
- Add RCU safety to dst->dev, closing a lot of possible races
- A significant crypto library API for SCTP, MPTCP and IPv6 SR,
reducing code duplication
- Supports pulling data from an skb frag into the linear area of an
XDP buffer
Things we sprinkled into general kernel code:
- Generate netlink documentation from YAML using an integrated YAML
parser
Driver API:
- Support using IPv6 Flow Label in Rx hash computation and RSS queue
selection
- Introduce API for fetching the DMA device for a given queue,
allowing TCP zerocopy RX on more H/W setups
- Make XDP helpers compatible with unreadable memory, allowing more
easily building DevMem-enabled drivers with a unified XDP/skbs
datapath
- Add a new dedicated ethtool callback enabling drivers to provide
the number of RX rings directly, improving efficiency and clarity
in RX ring queries and RSS configuration
- Introduce a burst period for the health reporter, allowing better
handling of multiple errors due to the same root cause
- Support for DPLL phase offset exponential moving average,
controlling the average smoothing factor
Device drivers:
- Add a new Huawei driver for 3rd gen NIC (hinic3)
- Add a new SpacemiT driver for K1 ethernet MAC
- Add a generic abstraction for shared memory communication
devices (dibps)
- Ethernet high-speed NICs:
- nVidia/Mellanox:
- Use multiple per-queue doorbell, to avoid MMIO contention
issues
- support adjacent functions, allowing them to delegate their
SR-IOV VFs to sibling PFs
- support RSS for IPSec offload
- support exposing raw cycle counters in PTP and mlx5
- support for disabling host PFs.
- Intel (100G, ice, idpf):
- ice: support for SRIOV VFs over an Active-Active link
aggregate
- ice: support for firmware logging via debugfs
- ice: support for Earliest TxTime First (ETF) hardware offload
- idpf: support basic XDP functionalities and XSk
- Broadcom (bnxt):
- support Hyper-V VF ID
- dynamic SRIOV resource allocations for RoCE
- Meta (fbnic):
- support queue API, zero-copy Rx and Tx
- support basic XDP functionalities
- devlink health support for FW crashes and OTP mem corruptions
- expand hardware stats coverage to FEC, PHY, and Pause
- Wangxun:
- support ethtool coalesce options
- support for multiple RSS contexts
- Ethernet virtual:
- Macsec:
- replace custom netlink attribute checks with policy-level
checks
- Bonding:
- support aggregator selection based on port priority
- Microsoft vNIC:
- use page pool fragments for RX buffers instead of full pages
to improve memory efficiency
- Ethernet NICs consumer, and embedded:
- Qualcomm: support Ethernet function for IPQ9574 SoC
- Airoha: implement wlan offloading via NPU
- Freescale
- enetc: add NETC timer PTP driver and add PTP support
- fec: enable the Jumbo frame support for i.MX8QM
- Renesas (R-Car S4):
- support HW offloading for layer 2 switching
- support for RZ/{T2H, N2H} SoCs
- Cadence (macb): support TAPRIO traffic scheduling
- TI:
- support for Gigabit ICSS ethernet SoC (icssm-prueth)
- Synopsys (stmmac): a lot of cleanups
- Ethernet PHYs:
- Support 10g-qxgmi phy-mode for AQR412C, Felix DSA and Lynx PCS
driver
- Support bcm63268 GPHY power control
- Support for Micrel lan8842 PHY and PTP
- Support for Aquantia AQR412 and AQR115
- CAN:
- a large CAN-XL preparation work
- reorganize raw_sock and uniqframe struct to minimize memory
usage
- rcar_canfd: update the CAN-FD handling
- WiFi:
- extended Neighbor Awareness Networking (NAN) support
- S1G channel representation cleanup
- improve S1G support
- WiFi drivers:
- Intel (iwlwifi):
- major refactor and cleanup
- Broadcom (brcm80211):
- support for AP isolation
- RealTek (rtw88/89) rtw88/89:
- preparation work for RTL8922DE support
- MediaTek (mt76):
- HW restart improvements
- MLO support
- Qualcomm/Atheros (ath10k):
- GTK rekey fixes
- Bluetooth drivers:
- btusb: support for several new IDs for MT7925
- btintel: support for BlazarIW core
- btintel_pcie: support for _suspend() / _resume()
- btintel_pcie: support for Scorpious, Panther Lake-H484 IDs"
* tag 'net-next-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next: (1536 commits)
net: stmmac: Add support for Allwinner A523 GMAC200
dt-bindings: net: sun8i-emac: Add A523 GMAC200 compatible
Revert "Documentation: net: add flow control guide and document ethtool API"
octeontx2-pf: fix bitmap leak
octeontx2-vf: fix bitmap leak
net/mlx5e: Use extack in set rxfh callback
net/mlx5e: Introduce mlx5e_rss_params for RSS configuration
net/mlx5e: Introduce mlx5e_rss_init_params
net/mlx5e: Remove unused mdev param from RSS indir init
net/mlx5: Improve QoS error messages with actual depth values
net/mlx5e: Prevent entering switchdev mode with inconsistent netns
net/mlx5: HWS, Generalize complex matchers
net/mlx5: Improve write-combining test reliability for ARM64 Grace CPUs
selftests/net: add tcp_port_share to .gitignore
Revert "net/mlx5e: Update and set Xon/Xoff upon MTU set"
net: add NUMA awareness to skb_attempt_defer_free()
net: use llist for sd->defer_list
net: make softnet_data.defer_count an atomic
selftests: drv-net: psp: add tests for destroying devices
selftests: drv-net: psp: add test for auto-adjusting TCP MSS
...
Confidential computing:
- Add support for accepting secrets from firmware (e.g. ACPI CCEL)
and mapping them with appropriate attributes.
CPU features:
- Advertise atomic floating-point instructions to userspace.
- Extend Spectre workarounds to cover additional Arm CPU variants.
- Extend list of CPUs that support break-before-make level 2 and
guarantee not to generate TLB conflict aborts for changes of mapping
granularity (BBML2_NOABORT).
- Add GCS support to our uprobes implementation.
Documentation:
- Remove bogus SME documentation concerning register state when
entering/exiting streaming mode.
Entry code:
- Switch over to the generic IRQ entry code (GENERIC_IRQ_ENTRY).
- Micro-optimise syscall entry path with a compiler branch hint.
Memory management:
- Enable huge mappings in vmalloc space even when kernel page-table
dumping is enabled.
- Tidy up the types used in our early MMU setup code.
- Rework rodata= for closer parity with the behaviour on x86.
- For CPUs implementing BBML2_NOABORT, utilise block mappings in the
linear map even when rodata= applies to virtual aliases.
- Don't re-allocate the virtual region between '_text' and '_stext',
as doing so confused tools parsing /proc/vmcore.
Miscellaneous:
- Clean-up Kconfig menuconfig text for architecture features.
- Avoid redundant bitmap_empty() during determination of supported
SME vector lengths.
- Re-enable warnings when building the 32-bit vDSO object.
- Avoid breaking our eggs at the wrong end.
Perf and PMUs:
- Support for v3 of the Hisilicon L3C PMU.
- Support for Hisilicon's MN and NoC PMUs.
- Support for Fujitsu's Uncore PMU.
- Support for SPE's extended event filtering feature.
- Preparatory work to enable data source filtering in SPE.
- Support for multiple lanes in the DWC PCIe PMU.
- Support for i.MX94 in the IMX DDR PMU driver.
- MAINTAINERS update (Thank you, Yicong).
- Minor driver fixes (PERF_IDX2OFF() overflow, CMN register offsets).
Selftests:
- Add basic LSFE check to the existing hwcaps test.
- Support nolibc in GCS tests.
- Extend SVE ptrace test to pass unsupported regsets and invalid vector
lengths.
- Minor cleanups (typos, cosmetic changes).
System registers:
- Fix ID_PFR1_EL1 definition.
- Fix incorrect signedness of some fields in ID_AA64MMFR4_EL1.
- Sync TCR_EL1 definition with the latest Arm ARM (L.b).
- Be stricter about the input fed into our AWK sysreg generator script.
- Typo fixes and removal of redundant definitions.
ACPI, EFI and PSCI:
- Decouple Arm's "Software Delegated Exception Interface" (SDEI)
support from the ACPI GHES code so that it can be used by platforms
booted with device-tree.
- Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
runtime calls.
- Fix a node refcount imbalance in the PSCI device-tree code.
CPU Features:
- Ensure register sanitisation is applied to fields in ID_AA64MMFR4.
- Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM guests
can reliably query the underlying CPU types from the VMM.
- Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
to our context-switching, signal handling and ptrace code.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux
Pull arm64 updates from Will Deacon:
"There's good stuff across the board, including some nice mm
improvements for CPUs with the 'noabort' BBML2 feature and a clever
patch to allow ptdump to play nicely with block mappings in the
vmalloc area.
Confidential computing:
- Add support for accepting secrets from firmware (e.g. ACPI CCEL)
and mapping them with appropriate attributes.
CPU features:
- Advertise atomic floating-point instructions to userspace
- Extend Spectre workarounds to cover additional Arm CPU variants
- Extend list of CPUs that support break-before-make level 2 and
guarantee not to generate TLB conflict aborts for changes of
mapping granularity (BBML2_NOABORT)
- Add GCS support to our uprobes implementation.
Documentation:
- Remove bogus SME documentation concerning register state when
entering/exiting streaming mode.
Entry code:
- Switch over to the generic IRQ entry code (GENERIC_IRQ_ENTRY)
- Micro-optimise syscall entry path with a compiler branch hint.
Memory management:
- Enable huge mappings in vmalloc space even when kernel page-table
dumping is enabled
- Tidy up the types used in our early MMU setup code
- Rework rodata= for closer parity with the behaviour on x86
- For CPUs implementing BBML2_NOABORT, utilise block mappings in the
linear map even when rodata= applies to virtual aliases
- Don't re-allocate the virtual region between '_text' and '_stext',
as doing so confused tools parsing /proc/vmcore.
Miscellaneous:
- Clean-up Kconfig menuconfig text for architecture features
- Avoid redundant bitmap_empty() during determination of supported
SME vector lengths
- Re-enable warnings when building the 32-bit vDSO object
- Avoid breaking our eggs at the wrong end.
Perf and PMUs:
- Support for v3 of the Hisilicon L3C PMU
- Support for Hisilicon's MN and NoC PMUs
- Support for Fujitsu's Uncore PMU
- Support for SPE's extended event filtering feature
- Preparatory work to enable data source filtering in SPE
- Support for multiple lanes in the DWC PCIe PMU
- Support for i.MX94 in the IMX DDR PMU driver
- MAINTAINERS update (Thank you, Yicong)
- Minor driver fixes (PERF_IDX2OFF() overflow, CMN register offsets).
Selftests:
- Add basic LSFE check to the existing hwcaps test
- Support nolibc in GCS tests
- Extend SVE ptrace test to pass unsupported regsets and invalid
vector lengths
- Minor cleanups (typos, cosmetic changes).
System registers:
- Fix ID_PFR1_EL1 definition
- Fix incorrect signedness of some fields in ID_AA64MMFR4_EL1
- Sync TCR_EL1 definition with the latest Arm ARM (L.b)
- Be stricter about the input fed into our AWK sysreg generator
script
- Typo fixes and removal of redundant definitions.
ACPI, EFI and PSCI:
- Decouple Arm's "Software Delegated Exception Interface" (SDEI)
support from the ACPI GHES code so that it can be used by platforms
booted with device-tree
- Remove unnecessary per-CPU tracking of the FPSIMD state across EFI
runtime calls
- Fix a node refcount imbalance in the PSCI device-tree code.
CPU Features:
- Ensure register sanitisation is applied to fields in ID_AA64MMFR4
- Expose AIDR_EL1 to userspace via sysfs, primarily so that KVM
guests can reliably query the underlying CPU types from the VMM
- Re-enabling of SME support (CONFIG_ARM64_SME) as a result of fixes
to our context-switching, signal handling and ptrace code"
* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (93 commits)
arm64: cpufeature: Remove duplicate asm/mmu.h header
arm64: Kconfig: Make CPU_BIG_ENDIAN depend on BROKEN
perf/dwc_pcie: Fix use of uninitialized variable
arm/syscalls: mark syscall invocation as likely in invoke_syscall
Documentation: hisi-pmu: Add introduction to HiSilicon V3 PMU
Documentation: hisi-pmu: Fix of minor format error
drivers/perf: hisi: Add support for L3C PMU v3
drivers/perf: hisi: Refactor the event configuration of L3C PMU
drivers/perf: hisi: Extend the field of tt_core
drivers/perf: hisi: Extract the event filter check of L3C PMU
drivers/perf: hisi: Simplify the probe process of each L3C PMU version
drivers/perf: hisi: Export hisi_uncore_pmu_isr()
drivers/perf: hisi: Relax the event ID check in the framework
perf: Fujitsu: Add the Uncore PMU driver
arm64: map [_text, _stext) virtual address range non-executable+read-only
arm64/sysreg: Update TCR_EL1 register
arm64: Enable vmalloc-huge with ptdump
arm64: cpufeature: add Neoverse-V3AE to BBML2 allow list
arm64: errata: Apply workarounds for Neoverse-V3AE
arm64: cputype: Add Neoverse-V3AE definitions
...
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Merge tag 'vfs-6.18-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs writeback updates from Christian Brauner:
"This contains work adressing lockups reported by users when a systemd
unit reading lots of files from a filesystem mounted with the lazytime
mount option exits.
With the lazytime mount option enabled we can be switching many dirty
inodes on cgroup exit to the parent cgroup. The numbers observed in
practice when systemd slice of a large cron job exits can easily reach
hundreds of thousands or millions.
The logic in inode_do_switch_wbs() which sorts the inode into
appropriate place in b_dirty list of the target wb however has linear
complexity in the number of dirty inodes thus overall time complexity
of switching all the inodes is quadratic leading to workers being
pegged for hours consuming 100% of the CPU and switching inodes to the
parent wb.
Simple reproducer of the issue:
FILES=10000
# Filesystem mounted with lazytime mount option
MNT=/mnt/
echo "Creating files and switching timestamps"
for (( j = 0; j < 50; j ++ )); do
mkdir $MNT/dir$j
for (( i = 0; i < $FILES; i++ )); do
echo "foo" >$MNT/dir$j/file$i
done
touch -a -t 202501010000 $MNT/dir$j/file*
done
wait
echo "Syncing and flushing"
sync
echo 3 >/proc/sys/vm/drop_caches
echo "Reading all files from a cgroup"
mkdir /sys/fs/cgroup/unified/mycg1 || exit
echo $$ >/sys/fs/cgroup/unified/mycg1/cgroup.procs || exit
for (( j = 0; j < 50; j ++ )); do
cat /mnt/dir$j/file* >/dev/null &
done
wait
echo "Switching wbs"
# Now rmdir the cgroup after the script exits
This can be solved by:
- Avoiding contention on the wb->list_lock when switching inodes by
running a single work item per wb and managing a queue of items
switching to the wb
- Allowing rescheduling when switching inodes over to a different
cgroup to avoid softlockups
- Maintaining the b_dirty list ordering instead of sorting it"
* tag 'vfs-6.18-rc1.writeback' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
writeback: Add tracepoint to track pending inode switches
writeback: Avoid excessively long inode switching times
writeback: Avoid softlockup when switching many inodes
writeback: Avoid contention on wb->list_lock when switching inodes
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Merge tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull misc vfs updates from Christian Brauner:
"This contains the usual selections of misc updates for this cycle.
Features:
- Add "initramfs_options" parameter to set initramfs mount options.
This allows to add specific mount options to the rootfs to e.g.,
limit the memory size
- Add RWF_NOSIGNAL flag for pwritev2()
Add RWF_NOSIGNAL flag for pwritev2. This flag prevents the SIGPIPE
signal from being raised when writing on disconnected pipes or
sockets. The flag is handled directly by the pipe filesystem and
converted to the existing MSG_NOSIGNAL flag for sockets
- Allow to pass pid namespace as procfs mount option
Ever since the introduction of pid namespaces, procfs has had very
implicit behaviour surrounding them (the pidns used by a procfs
mount is auto-selected based on the mounting process's active
pidns, and the pidns itself is basically hidden once the mount has
been constructed)
This implicit behaviour has historically meant that userspace was
required to do some special dances in order to configure the pidns
of a procfs mount as desired. Examples include:
* In order to bypass the mnt_too_revealing() check, Kubernetes
creates a procfs mount from an empty pidns so that user
namespaced containers can be nested (without this, the nested
containers would fail to mount procfs)
But this requires forking off a helper process because you cannot
just one-shot this using mount(2)
* Container runtimes in general need to fork into a container
before configuring its mounts, which can lead to security issues
in the case of shared-pidns containers (a privileged process in
the pidns can interact with your container runtime process)
While SUID_DUMP_DISABLE and user namespaces make this less of an
issue, the strict need for this due to a minor uAPI wart is kind
of unfortunate
Things would be much easier if there was a way for userspace to
just specify the pidns they want. So this pull request contains
changes to implement a new "pidns" argument which can be set
using fsconfig(2):
fsconfig(procfd, FSCONFIG_SET_FD, "pidns", NULL, nsfd);
fsconfig(procfd, FSCONFIG_SET_STRING, "pidns", "/proc/self/ns/pid", 0);
or classic mount(2) / mount(8):
// mount -t proc -o pidns=/proc/self/ns/pid proc /tmp/proc
mount("proc", "/tmp/proc", "proc", MS_..., "pidns=/proc/self/ns/pid");
Cleanups:
- Remove the last references to EXPORT_OP_ASYNC_LOCK
- Make file_remove_privs_flags() static
- Remove redundant __GFP_NOWARN when GFP_NOWAIT is used
- Use try_cmpxchg() in start_dir_add()
- Use try_cmpxchg() in sb_init_done_wq()
- Replace offsetof() with struct_size() in ioctl_file_dedupe_range()
- Remove vfs_ioctl() export
- Replace rwlock() with spinlock in epoll code as rwlock causes
priority inversion on preempt rt kernels
- Make ns_entries in fs/proc/namespaces const
- Use a switch() statement() in init_special_inode() just like we do
in may_open()
- Use struct_size() in dir_add() in the initramfs code
- Use str_plural() in rd_load_image()
- Replace strcpy() with strscpy() in find_link()
- Rename generic_delete_inode() to inode_just_drop() and
generic_drop_inode() to inode_generic_drop()
- Remove unused arguments from fcntl_{g,s}et_rw_hint()
Fixes:
- Document @name parameter for name_contains_dotdot() helper
- Fix spelling mistake
- Always return zero from replace_fd() instead of the file descriptor
number
- Limit the size for copy_file_range() in compat mode to prevent a
signed overflow
- Fix debugfs mount options not being applied
- Verify the inode mode when loading it from disk in minixfs
- Verify the inode mode when loading it from disk in cramfs
- Don't trigger automounts with RESOLVE_NO_XDEV
If openat2() was called with RESOLVE_NO_XDEV it didn't traverse
through automounts, but could still trigger them
- Add FL_RECLAIM flag to show_fl_flags() macro so it appears in
tracepoints
- Fix unused variable warning in rd_load_image() on s390
- Make INITRAMFS_PRESERVE_MTIME depend on BLK_DEV_INITRD
- Use ns_capable_noaudit() when determining net sysctl permissions
- Don't call path_put() under namespace semaphore in listmount() and
statmount()"
* tag 'vfs-6.18-rc1.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (38 commits)
fcntl: trim arguments
listmount: don't call path_put() under namespace semaphore
statmount: don't call path_put() under namespace semaphore
pid: use ns_capable_noaudit() when determining net sysctl permissions
fs: rename generic_delete_inode() and generic_drop_inode()
init: INITRAMFS_PRESERVE_MTIME should depend on BLK_DEV_INITRD
initramfs: Replace strcpy() with strscpy() in find_link()
initrd: Use str_plural() in rd_load_image()
initramfs: Use struct_size() helper to improve dir_add()
initrd: Fix unused variable warning in rd_load_image() on s390
fs: use the switch statement in init_special_inode()
fs/proc/namespaces: make ns_entries const
filelock: add FL_RECLAIM to show_fl_flags() macro
eventpoll: Replace rwlock with spinlock
selftests/proc: add tests for new pidns APIs
procfs: add "pidns" mount option
pidns: move is-ancestor logic to helper
openat2: don't trigger automounts with RESOLVE_NO_XDEV
namei: move cross-device check to __traverse_mounts
namei: remove LOOKUP_NO_XDEV check from handle_mounts
...
From the cover letter [1]:
This patch set introduces kmalloc_nolock() which is the next logical
step towards any context allocation necessary to remove bpf_mem_alloc
and get rid of preallocation requirement in BPF infrastructure.
In production BPF maps grew to gigabytes in size. Preallocation wastes
memory. Alloc from any context addresses this issue for BPF and other
subsystems that are forced to preallocate too.
This long task started with introduction of alloc_pages_nolock(), then
memcg and objcg were converted to operate from any context including
NMI, this set completes the task with kmalloc_nolock() that builds on
top of alloc_pages_nolock() and memcg changes.
After that BPF subsystem will gradually adopt it everywhere.
Link: https://lore.kernel.org/all/20250909010007.1660-1-alexei.starovoitov@gmail.com/ [1]
This series adds an opt-in percpu array-based caching layer to SLUB.
It has evolved to a state where kmem caches with sheaves are compatible
with all SLUB features (slub_debug, SLUB_TINY, NUMA locality
considerations). The plan is therefore that it will be later enabled for
all kmem caches and replace the complicated cpu (partial) slabs code.
Note the name "sheaf" was invented by Matthew Wilcox so we don't call
the arrays magazines like the original Bonwick paper. The per-NUMA-node
cache of sheaves is thus called "barn".
This caching may seem similar to the arrays we had in SLAB, but there
are some important differences:
- deals differently with NUMA locality of freed objects, thus there are
no per-node "shared" arrays (with possible lock contention) and no
"alien" arrays that would need periodical flushing
- instead, freeing remote objects (which is rare) bypasses the sheaves
- percpu sheaves thus contain only local objects (modulo rare races
and local node exhaustion)
- NUMA restricted allocations and strict_numa mode is still honoured
- improves kfree_rcu() handling by reusing whole sheaves
- there is an API for obtaining a preallocated sheaf that can be used
for guaranteed and efficient allocations in a restricted context, when
the upper bound for needed objects is known but rarely reached
- opt-in, not used for every cache (for now)
The motivation comes mainly from the ongoing work related to VMA locking
scalability and the related maple tree operations. This is why VMA and
maple nodes caches are sheaf-enabled in the patchset.
A sheaf-enabled cache has the following expected advantages:
- Cheaper fast paths. For allocations, instead of local double cmpxchg,
thanks to local_trylock() it becomes a preempt_disable() and no atomic
operations. Same for freeing, which is otherwise a local double cmpxchg
only for short term allocations (so the same slab is still active on the
same cpu when freeing the object) and a more costly locked double
cmpxchg otherwise.
- kfree_rcu() batching and recycling. kfree_rcu() will put objects to a
separate percpu sheaf and only submit the whole sheaf to call_rcu()
when full. After the grace period, the sheaf can be used for
allocations, which is more efficient than freeing and reallocating
individual slab objects (even with the batching done by kfree_rcu()
implementation itself). In case only some cpus are allowed to handle rcu
callbacks, the sheaf can still be made available to other cpus on the
same node via the shared barn. The maple_node cache uses kfree_rcu() and
thus can benefit from this.
Note: this path is currently limited to !PREEMPT_RT
- Preallocation support. A prefilled sheaf can be privately borrowed to
perform a short term operation that is not allowed to block in the
middle and may need to allocate some objects. If an upper bound (worst
case) for the number of allocations is known, but only much fewer
allocations actually needed on average, borrowing and returning a sheaf
is much more efficient then a bulk allocation for the worst case
followed by a bulk free of the many unused objects. Maple tree write
operations should benefit from this.
- Compatibility with slub_debug. When slub_debug is enabled for a cache,
we simply don't create the percpu sheaves so that the debugging hooks
(at the node partial list slowpaths) are reached as before. The same
thing is done for CONFIG_SLUB_TINY. Sheaf preallocation still works by
reusing the (ineffective) paths for requests exceeding the cache's
sheaf_capacity. This is in line with the existing approach where
debugging bypasses the fast paths and SLUB_TINY preferes memory
savings over performance.
The above is adapted from the cover letter [1], which contains also
in-kernel microbenchmark results showing the lower overhead of sheaves.
Results from Suren Baghdasaryan [2] using a mmap/munmap microbenchmark
also show improvements.
Results from Sudarsan Mahendran [3] using will-it-scale show both
benefits and regressions, probably due to overall noisiness of those
tests.
Link: https://lore.kernel.org/all/20250910-slub-percpu-caches-v8-0-ca3099d8352c@suse.cz/ [1]
Link: https://lore.kernel.org/all/CAJuCfpEQ%3DRUgcAvRzE5jRrhhFpkm8E2PpBK9e9GhK26ZaJQt%3DQ@mail.gmail.com/ [2]
Link: https://lore.kernel.org/all/20250913000935.1021068-1-sudarsanm@google.com/ [3]
kmalloc_nolock() relies on ability of local_trylock_t to detect
the situation when per-cpu kmem_cache is locked.
In !PREEMPT_RT local_(try)lock_irqsave(&s->cpu_slab->lock, flags)
disables IRQs and marks s->cpu_slab->lock as acquired.
local_lock_is_locked(&s->cpu_slab->lock) returns true when
slab is in the middle of manipulating per-cpu cache
of that specific kmem_cache.
kmalloc_nolock() can be called from any context and can re-enter
into ___slab_alloc():
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> NMI -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
or
kmalloc() -> ___slab_alloc(cache_A) -> irqsave -> tracepoint/kprobe -> bpf ->
kmalloc_nolock() -> ___slab_alloc(cache_B)
Hence the caller of ___slab_alloc() checks if &s->cpu_slab->lock
can be acquired without a deadlock before invoking the function.
If that specific per-cpu kmem_cache is busy the kmalloc_nolock()
retries in a different kmalloc bucket. The second attempt will
likely succeed, since this cpu locked different kmem_cache.
Similarly, in PREEMPT_RT local_lock_is_locked() returns true when
per-cpu rt_spin_lock is locked by current _task_. In this case
re-entrance into the same kmalloc bucket is unsafe, and
kmalloc_nolock() tries a different bucket that is most likely is
not locked by the current task. Though it may be locked by a
different task it's safe to rt_spin_lock() and sleep on it.
Similar to alloc_pages_nolock() the kmalloc_nolock() returns NULL
immediately if called from hard irq or NMI in PREEMPT_RT.
kfree_nolock() defers freeing to irq_work when local_lock_is_locked()
and (in_nmi() or in PREEMPT_RT).
SLUB_TINY config doesn't use local_lock_is_locked() and relies on
spin_trylock_irqsave(&n->list_lock) to allocate,
while kfree_nolock() always defers to irq_work.
Note, kfree_nolock() must be called _only_ for objects allocated
with kmalloc_nolock(). Debug checks (like kmemleak and kfence)
were skipped on allocation, hence obj = kmalloc(); kfree_nolock(obj);
will miss kmemleak/kfence book keeping and will cause false positives.
large_kmalloc is not supported by either kmalloc_nolock()
or kfree_nolock().
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Since the combination of valid upper bits in slab->obj_exts with
OBJEXTS_ALLOC_FAIL bit can never happen,
use OBJEXTS_ALLOC_FAIL == (1ull << 0) as a magic sentinel
instead of (1ull << 2) to free up bit 2.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
kmalloc_nolock() can be called from any context
the ___slab_alloc() can acquire local_trylock_t (which is rt_spin_lock
in PREEMPT_RT) and attempt to acquire a different local_trylock_t
while in the same task context.
The calling sequence might look like:
kmalloc() -> tracepoint -> bpf -> kmalloc_nolock()
or more precisely:
__lock_acquire+0x12ad/0x2590
lock_acquire+0x133/0x2d0
rt_spin_lock+0x6f/0x250
___slab_alloc+0xb7/0xec0
kmalloc_nolock_noprof+0x15a/0x430
my_debug_callback+0x20e/0x390 [testmod]
___slab_alloc+0x256/0xec0
__kmalloc_cache_noprof+0xd6/0x3b0
Make LOCKDEP understand that local_trylock_t-s protect
different kmem_caches. In order to do that add lock_class_key
for each kmem_cache and use that key in local_trylock_t.
This stack trace is possible on both PREEMPT_RT and !PREEMPT_RT,
but teach lockdep about it only for PREEMPT_RT, since
in !PREEMPT_RT the ___slab_alloc() code is using
local_trylock_irqsave() when lockdep is on.
Note, this patch applies this logic to local_lock_t
while the next one converts it to local_trylock_t.
Both are mapped to rt_spin_lock in PREEMPT_RT.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Split alloc_pages_nolock() and introduce alloc_frozen_pages_nolock()
to be used by alloc_slab_page().
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Change alloc_pages_nolock() to default to __GFP_COMP when allocating
pages, since upcoming reentrant alloc_slab_page() needs __GFP_COMP.
Also allow __GFP_ACCOUNT flag to be specified,
since most of BPF infra needs __GFP_ACCOUNT except BPF streams.
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Reviewed-by: Shakeel Butt <shakeel.butt@linux.dev>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Create the vm_area_struct cache with percpu sheaves of size 32 to
improve its performance.
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Currently allocations asking for a specific node explicitly or via
mempolicy in strict_numa node bypass percpu sheaves. Since sheaves
contain mostly local objects, we can try allocating from them if the
local node happens to be the requested node or allowed by the mempolicy.
If we find the object from percpu sheaves is not from the expected node,
we skip the sheaves - this should be rare.
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Since we don't control the NUMA locality of objects in percpu sheaves,
allocations with node restrictions bypass them. Allocations without
restrictions may however still expect to get local objects with high
probability, and the introduction of sheaves can decrease it due to
freed object from a remote node ending up in percpu sheaves.
The fraction of such remote frees seems low (5% on an 8-node machine)
but it can be expected that some cache or workload specific corner cases
exist. We can either conclude that this is not a problem due to the low
fraction, or we can make remote frees bypass percpu sheaves and go
directly to their slabs. This will make the remote frees more expensive,
but if it's only a small fraction, most frees will still benefit from
the lower overhead of percpu sheaves.
This patch thus makes remote object freeing bypass percpu sheaves,
including bulk freeing, and kfree_rcu() via the rcu_free sheaf. However
it's not intended to be 100% guarantee that percpu sheaves will only
contain local objects. The refill from slabs does not provide that
guarantee in the first place, and there might be cpu migrations
happening when we need to unlock the local_lock. Avoiding all that could
be possible but complicated so we can leave it for later investigation
whether it would be worth it. It can be expected that the more selective
freeing will itself prevent accumulation of remote objects in percpu
sheaves so any such violations would have only short-term effects.
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
The possibility of many barn operations is determined by the current
number of full or empty sheaves. Taking the barn->lock just to find out
that e.g. there are no empty sheaves results in unnecessary overhead and
lock contention. Thus perform these checks outside of the lock with a
data_race() annotated variable read and fail quickly without taking the
lock.
Checks for sheaf availability that racily succeed have to be obviously
repeated under the lock for correctness, but we can skip repeating
checks if there are too many sheaves on the given list as the limits
don't need to be strict.
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Add functions for efficient guaranteed allocations e.g. in a critical
section that cannot sleep, when the exact number of allocations is not
known beforehand, but an upper limit can be calculated.
kmem_cache_prefill_sheaf() returns a sheaf containing at least given
number of objects.
kmem_cache_alloc_from_sheaf() will allocate an object from the sheaf
and is guaranteed not to fail until depleted.
kmem_cache_return_sheaf() is for giving the sheaf back to the slab
allocator after the critical section. This will also attempt to refill
it to cache's sheaf capacity for better efficiency of sheaves handling,
but it's not stricly necessary to succeed.
kmem_cache_refill_sheaf() can be used to refill a previously obtained
sheaf to requested size. If the current size is sufficient, it does
nothing. If the requested size exceeds cache's sheaf_capacity and the
sheaf's current capacity, the sheaf will be replaced with a new one,
hence the indirect pointer parameter.
kmem_cache_sheaf_size() can be used to query the current size.
The implementation supports requesting sizes that exceed cache's
sheaf_capacity, but it is not efficient - such "oversize" sheaves are
allocated fresh in kmem_cache_prefill_sheaf() and flushed and freed
immediately by kmem_cache_return_sheaf(). kmem_cache_refill_sheaf()
might be especially ineffective when replacing a sheaf with a new one of
a larger capacity. It is therefore better to size cache's
sheaf_capacity accordingly to make oversize sheaves exceptional.
CONFIG_SLUB_STATS counters are added for sheaf prefill and return
operations. A prefill or return is considered _fast when it is able to
grab or return a percpu spare sheaf (even if the sheaf needs a refill to
satisfy the request, as those should amortize over time), and _slow
otherwise (when the barn or even sheaf allocation/freeing has to be
involved). sheaf_prefill_oversize is provided to determine how many
prefills were oversize (counter for oversize returns is not necessary as
all oversize refills result in oversize returns).
When slub_debug is enabled for a cache with sheaves, no percpu sheaves
exist for it, but the prefill functionality is still provided simply by
all prefilled sheaves becoming oversize. If percpu sheaves are not
created for a cache due to not passing the sheaf_capacity argument on
cache creation, the prefills also work through oversize sheaves, but
there's a WARN_ON_ONCE() to indicate the omission.
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Extend the sheaf infrastructure for more efficient kfree_rcu() handling.
For caches with sheaves, on each cpu maintain a rcu_free sheaf in
addition to main and spare sheaves.
kfree_rcu() operations will try to put objects on this sheaf. Once full,
the sheaf is detached and submitted to call_rcu() with a handler that
will try to put it in the barn, or flush to slab pages using bulk free,
when the barn is full. Then a new empty sheaf must be obtained to put
more objects there.
It's possible that no free sheaves are available to use for a new
rcu_free sheaf, and the allocation in kfree_rcu() context can only use
GFP_NOWAIT and thus may fail. In that case, fall back to the existing
kfree_rcu() implementation.
Expected advantages:
- batching the kfree_rcu() operations, that could eventually replace the
existing batching
- sheaves can be reused for allocations via barn instead of being
flushed to slabs, which is more efficient
- this includes cases where only some cpus are allowed to process rcu
callbacks (CONFIG_RCU_NOCB_CPU)
Possible disadvantage:
- objects might be waiting for more than their grace period (it is
determined by the last object freed into the sheaf), increasing memory
usage - but the existing batching does that too.
Only implement this for CONFIG_KVFREE_RCU_BATCHED as the tiny
implementation favors smaller memory footprint over performance.
Also for now skip the usage of rcu sheaf for CONFIG_PREEMPT_RT as the
contexts where kfree_rcu() is called might not be compatible with taking
a barn spinlock or a GFP_NOWAIT allocation of a new sheaf taking a
spinlock - the current kfree_rcu() implementation avoids doing that.
Teach kvfree_rcu_barrier() to flush all rcu_free sheaves from all caches
that have them. This is not a cheap operation, but the barrier usage is
rare - currently kmem_cache_destroy() or on module unload.
Add CONFIG_SLUB_STATS counters free_rcu_sheaf and free_rcu_sheaf_fail to
count how many kfree_rcu() used the rcu_free sheaf successfully and how
many had to fall back to the existing implementation.
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
It is possible to hit a zero entry while traversing the vmas in unuse_mm()
called from swapoff path and accessing it causes the OOPS:
Unable to handle kernel NULL pointer dereference at virtual address
0000000000000446--> Loading the memory from offset 0x40 on the
XA_ZERO_ENTRY as address.
Mem abort info:
ESR = 0x0000000096000005
EC = 0x25: DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
FSC = 0x05: level 1 translation fault
The issue is manifested from the below race between the fork() on a
process and swapoff:
fork(dup_mmap()) swapoff(unuse_mm)
--------------- -----------------
1) Identical mtree is built using
__mt_dup().
2) copy_pte_range()-->
copy_nonpresent_pte():
The dst mm is added into the
mmlist to be visible to the
swapoff operation.
3) Fatal signal is sent to the parent
process(which is the current during the
fork) thus skip the duplication of the
vmas and mark the vma range with
XA_ZERO_ENTRY as a marker for this process
that helps during exit_mmap().
4) swapoff is tried on the
'mm' added to the 'mmlist' as
part of the 2.
5) unuse_mm(), that iterates
through the vma's of this 'mm'
will hit the non-NULL zero entry
and operating on this zero entry
as a vma is resulting into the
oops.
The proper fix would be around not exposing this partially-valid tree to
others when droping the mmap lock, which is being solved with [1]. A
simpler solution would be checking for MMF_UNSTABLE, as it is set if
mm_struct is not fully initialized in dup_mmap().
Thanks to Liam/Lorenzo/David for all the suggestions in fixing this
issue.
Link: https://lkml.kernel.org/r/20250924181138.1762750-1-charan.kalla@oss.qualcomm.com
Link: https://lore.kernel.org/all/20250815191031.3769540-1-Liam.Howlett@oracle.com/ [1]
Fixes: d240629148 ("fork: use __mt_dup() to duplicate maple tree in dup_mmap()")
Signed-off-by: Charan Teja Kalla <charan.kalla@oss.qualcomm.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Cc: Baoquan He <bhe@redhat.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Chris Li <chrisl@kernel.org>
Cc: Kairui Song <kasong@tencent.com>
Cc: Kemeng Shi <shikemeng@huaweicloud.com>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Nhat Pham <nphamcs@gmail.com>
Cc: Peng Zhang <zhangpeng.00@bytedance.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
When collapsing a pmd, there are two address in use:
* address points to the start of pmd
* address points to each individual page
Current naming makes it difficult to distinguish these two and is hence
error prone.
Considering the plan to collapse mTHP, name the first one `start_addr' and
the second `addr' for better readability and consistency.
Link: https://lkml.kernel.org/r/20250922140938.27343-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Suggested-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Nico Pache <npache@redhat.com>
Acked-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Dev Jain <dev.jain@arm.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Barry Song <baohua@kernel.org>
Cc: Lance Yang <lance.yang@linux.dev>
Cc: Liam Howlett <liam.howlett@oracle.com>
Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
Cc: Mariano Pache <npache@redhat.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
There is a boot failure when both CONFIG_DEBUG_KMEMLEAK and
CONFIG_MEM_ALLOC_PROFILING are enabled.
BUG: kernel NULL pointer dereference, address: 0000000000000000
RIP: 0010:__alloc_tagging_slab_alloc_hook+0x181/0x2f0
Call Trace:
kmem_cache_alloc_noprof+0x1c8/0x5c0
__alloc_object+0x2f/0x290
__create_object+0x22/0x80
kmemleak_init+0x122/0x190
mm_core_init+0xb6/0x160
start_kernel+0x39f/0x920
x86_64_start_reservations+0x18/0x30
x86_64_start_kernel+0x104/0x120
common_startup_64+0x12c/0x138
In kmemleak, mem_pool_alloc() directly calls kmem_cache_alloc_noprof(), as
a result, current->alloc_tag is NULL, leading to a null pointer
dereference.
Move the checks for SLAB_NO_OBJ_EXT, SLAB_NOLEAKTRACE, and
__GFP_NO_OBJ_EXT to the parent function __alloc_tagging_slab_alloc_hook()
to fix this.
Also this distinguishes the SLAB_NOLEAKTRACE case between the actual
memory allocation failures case, make CODETAG_FLAG_INACCURATE more
accurate.
Link: https://lkml.kernel.org/r/20250926080659.741991-1-ranxiaokai627@163.com
Fixes: b9e2f58ffb ("alloc_tag: mark inaccurate allocation counters in /proc/allocinfo output")
Signed-off-by: Ran Xiaokai <ran.xiaokai@zte.com.cn>
Reviewed-by: Harry Yoo <harry.yoo@oracle.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Reviewed-by: Suren Baghdasaryan <surenb@google.com>
Cc: Christoph Lameter (Ampere) <cl@gentwo.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Roman Gushchin <roman.gushchin@linux.dev>
Cc: Shakeel Butt <shakeel.butt@linux.dev>
Cc: Usama Arif <usamaarif642@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>