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2025-05-31selftests/mm: two fixes for the pfnmap testDavid Hildenbrand
When unregistering the signal handler, we have to pass SIG_DFL, and blindly reading from PFN 0 and PFN 1 seems to be problematic on !x86 systems. In particularly, on arm64 tx2 machines where noting resides at these physical memory locations, we can generate RAS errors. Let's fix it by scanning /proc/iomem for actual "System RAM". Link: https://lkml.kernel.org/r/20250528195244.1182810-1-david@redhat.com Fixes: 2616b370323a ("selftests/mm: add simple VM_PFNMAP tests based on mmap'ing /dev/mem") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Ryan Roberts <ryan.roberts@arm.com> Closes: https://lore.kernel.org/all/232960c2-81db-47ca-a337-38c4bce5f997@arm.com/T/#u Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Aishwarya TCV <aishwarya.tcv@arm.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/khugepaged: fix race with folio split/free using temporary referenceShivank Garg
hpage_collapse_scan_file() calls is_refcount_suitable(), which in turn calls folio_mapcount(). folio_mapcount() checks folio_test_large() before proceeding to folio_large_mapcount(), but there is a race window where the folio may get split/freed between these checks, triggering: VM_WARN_ON_FOLIO(!folio_test_large(folio), folio) Take a temporary reference to the folio in hpage_collapse_scan_file(). This stabilizes the folio during refcount check and prevents incorrect large folio detection due to concurrent split/free. Use helper folio_expected_ref_count() + 1 to compare with folio_ref_count() instead of using is_refcount_suitable(). Link: https://lkml.kernel.org/r/20250526182818.37978-1-shivankg@amd.com Fixes: 05c5323b2a34 ("mm: track mapcount of large folios in single value") Signed-off-by: Shivank Garg <shivankg@amd.com> Reported-by: syzbot+2b99589e33edbe9475ca@syzkaller.appspotmail.com Closes: https://lore.kernel.org/all/6828470d.a70a0220.38f255.000c.GAE@google.com Suggested-by: David Hildenbrand <david@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Dev Jain <dev.jain@arm.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Bharata B Rao <bharata@amd.com> Cc: Fengwei Yin <fengwei.yin@intel.com> 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> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: add CONFIG_PAGE_BLOCK_ORDER to select page block orderJuan Yescas
Problem: On large page size configurations (16KiB, 64KiB), the CMA alignment requirement (CMA_MIN_ALIGNMENT_BYTES) increases considerably, and this causes the CMA reservations to be larger than necessary. This means that system will have less available MIGRATE_UNMOVABLE and MIGRATE_RECLAIMABLE page blocks since MIGRATE_CMA can't fallback to them. The CMA_MIN_ALIGNMENT_BYTES increases because it depends on MAX_PAGE_ORDER which depends on ARCH_FORCE_MAX_ORDER. The value of ARCH_FORCE_MAX_ORDER increases on 16k and 64k kernels. For example, in ARM, the CMA alignment requirement when: - CONFIG_ARCH_FORCE_MAX_ORDER default value is used - CONFIG_TRANSPARENT_HUGEPAGE is set: PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES ----------------------------------------------------------------------- 4KiB | 10 | 9 | 4KiB * (2 ^ 9) = 2MiB 16Kib | 11 | 11 | 16KiB * (2 ^ 11) = 32MiB 64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB There are some extreme cases for the CMA alignment requirement when: - CONFIG_ARCH_FORCE_MAX_ORDER maximum value is set - CONFIG_TRANSPARENT_HUGEPAGE is NOT set: - CONFIG_HUGETLB_PAGE is NOT set PAGE_SIZE | MAX_PAGE_ORDER | pageblock_order | CMA_MIN_ALIGNMENT_BYTES ------------------------------------------------------------------------ 4KiB | 15 | 15 | 4KiB * (2 ^ 15) = 128MiB 16Kib | 13 | 13 | 16KiB * (2 ^ 13) = 128MiB 64KiB | 13 | 13 | 64KiB * (2 ^ 13) = 512MiB This affects the CMA reservations for the drivers. If a driver in a 4KiB kernel needs 4MiB of CMA memory, in a 16KiB kernel, the minimal reservation has to be 32MiB due to the alignment requirements: reserved-memory { ... cma_test_reserve: cma_test_reserve { compatible = "shared-dma-pool"; size = <0x0 0x400000>; /* 4 MiB */ ... }; }; reserved-memory { ... cma_test_reserve: cma_test_reserve { compatible = "shared-dma-pool"; size = <0x0 0x2000000>; /* 32 MiB */ ... }; }; Solution: Add a new config CONFIG_PAGE_BLOCK_ORDER that allows to set the page block order in all the architectures. The maximum page block order will be given by ARCH_FORCE_MAX_ORDER. By default, CONFIG_PAGE_BLOCK_ORDER will have the same value that ARCH_FORCE_MAX_ORDER. This will make sure that current kernel configurations won't be affected by this change. It is a opt-in change. This patch will allow to have the same CMA alignment requirements for large page sizes (16KiB, 64KiB) as that in 4kb kernels by setting a lower pageblock_order. Tests: - Verified that HugeTLB pages work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. - Verified that Transparent Huge Pages work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. - Verified that dma-buf heaps allocations work when pageblock_order is 1, 7, 10 on 4k and 16k kernels. Benchmarks: The benchmarks compare 16kb kernels with pageblock_order 10 and 7. The reason for the pageblock_order 7 is because this value makes the min CMA alignment requirement the same as that in 4kb kernels (2MB). - Perform 100K dma-buf heaps (/dev/dma_heap/system) allocations of SZ_8M, SZ_4M, SZ_2M, SZ_1M, SZ_64, SZ_8, SZ_4. Use simpleperf (https://developer.android.com/ndk/guides/simpleperf) to measure the # of instructions and page-faults on 16k kernels. The benchmark was executed 10 times. The averages are below: # instructions | #page-faults order 10 | order 7 | order 10 | order 7 -------------------------------------------------------- 13,891,765,770 | 11,425,777,314 | 220 | 217 14,456,293,487 | 12,660,819,302 | 224 | 219 13,924,261,018 | 13,243,970,736 | 217 | 221 13,910,886,504 | 13,845,519,630 | 217 | 221 14,388,071,190 | 13,498,583,098 | 223 | 224 13,656,442,167 | 12,915,831,681 | 216 | 218 13,300,268,343 | 12,930,484,776 | 222 | 218 13,625,470,223 | 14,234,092,777 | 219 | 218 13,508,964,965 | 13,432,689,094 | 225 | 219 13,368,950,667 | 13,683,587,37 | 219 | 225 ------------------------------------------------------------------- 13,803,137,433 | 13,131,974,268 | 220 | 220 Averages There were 4.85% #instructions when order was 7, in comparison with order 10. 13,803,137,433 - 13,131,974,268 = -671,163,166 (-4.86%) The number of page faults in order 7 and 10 were the same. These results didn't show any significant regression when the pageblock_order is set to 7 on 16kb kernels. - Run speedometer 3.1 (https://browserbench.org/Speedometer3.1/) 5 times on the 16k kernels with pageblock_order 7 and 10. order 10 | order 7 | order 7 - order 10 | (order 7 - order 10) % ------------------------------------------------------------------- 15.8 | 16.4 | 0.6 | 3.80% 16.4 | 16.2 | -0.2 | -1.22% 16.6 | 16.3 | -0.3 | -1.81% 16.8 | 16.3 | -0.5 | -2.98% 16.6 | 16.8 | 0.2 | 1.20% ------------------------------------------------------------------- 16.44 16.4 -0.04 -0.24% Averages The results didn't show any significant regression when the pageblock_order is set to 7 on 16kb kernels. Link: https://lkml.kernel.org/r/20250521215807.1860663-1-jyescas@google.com Signed-off-by: Juan Yescas <jyescas@google.com> Acked-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Cc: Liam R. Howlett <Liam.Howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: David Hildenbrand <david@redhat.com> Cc: Mike Rapoport <rppt@kernel.org> Cc: Suren Baghdasaryan <surenb@google.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mmu_notifiers: remove leftover stub macrosJann Horn
Commit ec8832d007cb ("mmu_notifiers: don't invalidate secondary TLBs as part of mmu_notifier_invalidate_range_end()") removed the main definitions of {ptep,pmdp_huge,pudp_huge}_clear_flush_notify; just their !CONFIG_MMU_NOTIFIER stubs are left behind, remove them. Link: https://lkml.kernel.org/r/20250523-mmu-notifier-cleanup-unused-v1-1-cc1f47ebec33@google.com Signed-off-by: Jann Horn <jannh@google.com> Reviewed-by: Alistair Popple <apopple@nvidia.com> Reviewed-by: Qi Zheng <zhengqi.arch@bytedance.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31selftests/mm: deduplicate test names in madv_populateMark Brown
The madv_populate selftest has some repetitive code for several different cases that it covers, included repeated test names used in ksft_test_result() reports. This causes problems for automation, the test name is used to both track the test between runs and distinguish between multiple tests within the same run. Fix this by tweaking the messages with duplication to be more specific about the contexts they're in. Link: https://lkml.kernel.org/r/20250522-selftests-mm-madv-populate-dedupe-v1-1-fd1dedd79b4b@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Reviewed-by: Liam R. Howlett <Liam.Howlett@oracle.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31kcov: rust: add flags for KCOV with RustAlice Ryhl
Rust code is currently not instrumented properly when KCOV is enabled. Thus, add the relevant flags to perform instrumentation correctly. This is necessary for efficient fuzzing of Rust code. The sanitizer-coverage features of LLVM have existed for long enough that they are available on any LLVM version supported by rustc, so we do not need any Kconfig feature detection. The coverage level is set to 3, as that is the level needed by trace-pc. We do not instrument `core` since when we fuzz the kernel, we are looking for bugs in the kernel, not the Rust stdlib. Link: https://lkml.kernel.org/r/20250501-rust-kcov-v2-1-b71e83e9779f@google.com Signed-off-by: Alice Ryhl <aliceryhl@google.com> Co-developed-by: Matthew Maurer <mmaurer@google.com> Signed-off-by: Matthew Maurer <mmaurer@google.com> Reviewed-by: Alexander Potapenko <glider@google.com> Tested-by: Aleksandr Nogikh <nogikh@google.com> Acked-by: Miguel Ojeda <ojeda@kernel.org> Cc: Andreas Hindborg <a.hindborg@kernel.org> Cc: Andrey Konovalov <andreyknvl@gmail.com> Cc: Benno Lossin <benno.lossin@proton.me> Cc: Bill Wendling <morbo@google.com> Cc: Björn Roy Baron <bjorn3_gh@protonmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Danilo Krummrich <dakr@kernel.org> Cc: Dmitriy Vyukov <dvyukov@google.com> Cc: Gary Guo <gary@garyguo.net> Cc: Justin Stitt <justinstitt@google.com> Cc: Masahiro Yamada <masahiroy@kernel.org> Cc: Nathan Chancellor <nathan@kernel.org> Cc: Trevor Gross <tmgross@umich.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: rust: make CONFIG_MMU ifdefs more narrowAlice Ryhl
Currently the entire kernel::mm module is ifdef'd out when CONFIG_MMU=n. However, there are some downstream users of the module in rust/kernel/task.rs and rust/kernel/miscdevice.rs. Thus, update the cfgs so that only MmWithUserAsync is removed with CONFIG_MMU=n. The code is moved into a new file, since the #[cfg()] annotation otherwise has to be duplicated several times. Link: https://lkml.kernel.org/r/20250516193219.2987032-1-aliceryhl@google.com Reported-by: kernel test robot <lkp@intel.com> Closes: https://lore.kernel.org/oe-kbuild-all/202505071753.kldNHYVQ-lkp@intel.com/ Closes: https://lore.kernel.org/oe-kbuild-all/202505072116.eSYC8igT-lkp@intel.com/ Fixes: 5bb9ed6cdfeb ("mm: rust: add abstraction for struct mm_struct") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Reviewed-by: Boqun Feng <boqun.feng@gmail.com> Cc: Boqun Feng <boqun.feng@gmail.com> Cc: Liam Howlett <liam.howlett@oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mmu_gather: move tlb flush for VM_PFNMAP/VM_MIXEDMAP vmas into free_pgtables()Roman Gushchin
Commit b67fbebd4cf9 ("mmu_gather: Force tlb-flush VM_PFNMAP vmas") added a forced tlbflush to tlb_vma_end(), which is required to avoid a race between munmap() and unmap_mapping_range(). However it added some overhead to other paths where tlb_vma_end() is used, but vmas are not removed, e.g. madvise(MADV_DONTNEED). Fix this by moving the tlb flush out of tlb_end_vma() into new tlb_flush_vmas() called from free_pgtables(), somewhat similar to the stable version of the original commit: commit 895428ee124a ("mm: Force TLB flush for PFNMAP mappings before unlink_file_vma()"). Note, that if tlb->fullmm is set, no flush is required, as the whole mm is about to be destroyed. Link: https://lkml.kernel.org/r/20250522012838.163876-1-roman.gushchin@linux.dev Signed-off-by: Roman Gushchin <roman.gushchin@linux.dev> Reviewed-by: Jann Horn <jannh@google.com> Acked-by: Hugh Dickins <hughd@google.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Will Deacon <will@kernel.org> Cc: "Aneesh Kumar K.V" <aneesh.kumar@kernel.org> Cc: Nick Piggin <npiggin@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/damon/Kconfig: enable CONFIG_DAMON by defaultSeongJae Park
As of this writing, multiple major distros including Alma, Amazon, Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON (set CONFIG_DAMON[1]). Enabling it by default will save configuration setup time for the current and future DAMON users. Build-enabling DAMON does not introduce a real risk since it makes no behavioral change by default. It requires explicit user requests to do anything. Only one potential risk is making the size of the kernel a little bit larger. On a production-purpose configuration, it increases the resulting kernel package size by about 0.1 % of the final package file. I believe that's too small to be a real problem in common setups. Hence, the benefit of enabling CONFIG_DAMON outweighs the potential risk. Set CONFIG_DAMON by default. Link: https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON [1] Link: https://lkml.kernel.org/r/20250521042755.39653-3-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/damon/Kconfig: set DAMON_{VADDR,PADDR,SYSFS} default to DAMONSeongJae Park
Patch series "mm/damon: build-enable essential DAMON components by default". As of this writing, multiple major distros including Alma, Amazon, Android, CentOS, Debian, Fedora, and Oracle are build-enabling DAMON (set CONFIG_DAMON[1]). Configuring DAMON is not very easy, since it is disabled by default, and there are multiple essential options that need to be manually turned on, one by one. Make it easier, by grouping essential configurations to be enabled with one selection, and enabling build of the essential parts of DAMON by default. Note that build-enabling DAMON does not introduce any real risk, since it makes no behavioral change by default. It requires explicit user requests to do anything. Only one potential risk is making the size of the kernel a little bit larger. On a production-purpose configuration, it increases the resulting kernel package binary size by about 0.1 % of the final package file. I believe that's too small to be a real problem in common setups. DAMON_{VADDR,PADDR,SYSFS} are de-facto essential parts of DAMON for normal usages. Because those need to be enabled one by one, however, and there are other test-purpose or non-essential configurations, it is easy to be confused and make mistakes at setup. Make the essential configurations default to CONFIG_DAMON, so that those can be enabled by default with a single change. Link: https://oracle.github.io/kconfigs/?config=UTS_RELEASE&config=DAMON [1] Link: https://lkml.kernel.org/r/20250521042755.39653-1-sj@kernel.org Link: https://lkml.kernel.org/r/20250521042755.39653-2-sj@kernel.org Signed-off-by: SeongJae Park <sj@kernel.org> Acked-by: Honggyu Kim <honggyu.kim@sk.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31hugetlb: show nr_huge_pages in report_hugepages()Wenjie Xu
The number of pre-allocated huge pages should be nr_huge_pages, not free_huge_pages, although they are same during booting stage Link: https://lkml.kernel.org/r/20250515114231.65824-1-xuwenjie04@baidu.com Signed-off-by: Wenjie Xu <xuwenjie04@baidu.com> Signed-off-by: Li RongQing <lirongqing@baidu.com> Acked-by: Oscar Salvador <osalvador@suse.de> Cc: Muchun Song <muchun.song@linux.dev> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31selftests/mm: skip hugevm test if kernel config file is not presentZi Yan
When running hugevm tests in a machine without kernel config present, e.g., a VM running a kernel without CONFIG_IKCONFIG_PROC nor /boot/config-*, skip hugevm tests, which reads kernel config to get page table level information. Link: https://lkml.kernel.org/r/20250516132938.356627-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Adam Sindelar <adam@wowsignal.io> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Pedro Falcato <pfalcato@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31selftests/mm: skip guard_regions.uffd tests when uffd is not presentZi Yan
Patch series "Skip mm selftests instead when kernel features are not present", v2. Two guard_regions tests on userfaultfd fail when userfaultfd is not present. Skip them instead. hugevm test reads kernel config to get page table level information and fails when neither /proc/config.gz nor /boot/config-* is present. Skip it instead. This patch (of 2): When userfaultfd is not compiled into kernel, userfaultfd() returns -1, causing guard_regions.uffd tests to fail. Skip the tests instead. Link: https://lkml.kernel.org/r/20250516132938.356627-1-ziy@nvidia.com Link: https://lkml.kernel.org/r/20250516132938.356627-2-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Reviewed-by: Pedro Falcato <pfalcato@suse.de> Cc: Adam Sindelar <adam@wowsignal.io> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/shmem: remove unneeded xa_is_value() check in shmem_unuse_swap_entries()Kemeng Shi
As only value entry will be added to fbatch in shmem_find_swap_entries(), there is no need to do xa_is_value() check in shmem_unuse_swap_entries(). Link: https://lkml.kernel.org/r/20250516170939.965736-6-shikemeng@huaweicloud.com Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: kernel test robot <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: shmem: only remove inode from swaplist when it's swapped page count is 0Kemeng Shi
Even if we fail to allocate a swap entry, the inode might have previously allocated entry and we might take inode containing swap entry off swaplist. As a result, try_to_unuse() may enter a potential dead loop to repeatedly look for inode and clean it's swap entry. Only take inode off swaplist when it's swapped page count is 0 to fix the issue. Link: https://lkml.kernel.org/r/20250516170939.965736-5-shikemeng@huaweicloud.com Fixes: b487a2da3575 ("mm, swap: simplify folio swap allocation") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Kairui Song <kasong@tencent.com> Reported-by: kernel test robot <oliver.sang@intel.com> Closes: https://lore.kernel.org/oe-lkp/202505161438.9009cf47-lkp@intel.com Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/shmem: fix potential dead loop in shmem_unuse()Kemeng Shi
If multi shmem_unuse() for different swap type is called concurrently, a dead loop could occur as following: shmem_unuse(typeA) shmem_unuse(typeB) mutex_lock(&shmem_swaplist_mutex) list_for_each_entry_safe(info, next, ...) ... mutex_unlock(&shmem_swaplist_mutex) /* info->swapped may drop to 0 */ shmem_unuse_inode(&info->vfs_inode, type) mutex_lock(&shmem_swaplist_mutex) list_for_each_entry(info, next, ...) if (!info->swapped) list_del_init(&info->swaplist) ... mutex_unlock(&shmem_swaplist_mutex) mutex_lock(&shmem_swaplist_mutex) /* iterate with offlist entry and encounter a dead loop */ next = list_next_entry(info, swaplist); ... Restart the iteration if the inode is already off shmem_swaplist list to fix the issue. Link: https://lkml.kernel.org/r/20250516170939.965736-4-shikemeng@huaweicloud.com Fixes: b56a2d8af914 ("mm: rid swapoff of quadratic complexity") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: kernel test robot <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: shmem: add missing shmem_unacct_size() in __shmem_file_setup()Kemeng Shi
We will miss shmem_unacct_size() when is_idmapped_mnt() returns a failure. Move is_idmapped_mnt() before shmem_acct_size() to fix the issue. Link: https://lkml.kernel.org/r/20250516170939.965736-3-shikemeng@huaweicloud.com Fixes: 7a80e5b8c6fa ("shmem: support idmapped mounts for tmpfs") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kairui Song <kasong@tencent.com> Cc: kernel test robot <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: shmem: avoid unpaired folio_unlock() in shmem_swapin_folio()Kemeng Shi
Patch series "Some random fixes and cleanup to shmem", v3. This series contains some simple fixes and cleanup which are made during learning shmem. More details can be found in respective patches. This patch (of 5): If we get a folio from swap_cache_get_folio() successfully but encounter a failure before the folio is locked, we will unlock the folio which was not previously locked. Put the folio and set it to NULL when a failure occurs before the folio is locked to fix the issue. Link: https://lkml.kernel.org/r/20250516170939.965736-1-shikemeng@huaweicloud.com Link: https://lkml.kernel.org/r/20250516170939.965736-2-shikemeng@huaweicloud.com Fixes: 058313515d5a ("mm: shmem: fix potential data corruption during shmem swapin") Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Kairui Song <kasong@tencent.com> Cc: Hugh Dickins <hughd@google.com> Cc: kernel test robot <oliver.sang@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm/damon/core: avoid destroyed target reference from DAMOS quotaAkinobu Mita
When the number of the monitoring targets in running contexts is reduced, there may be DAMOS quotas referencing the targets that will be destroyed. Applying the scheme action for such DAMOS scheme will be skipped forever looking for the starting part of the region for the destroyed monitoring target. To fix this issue, when the monitoring target is destroyed, reset the starting part for all DAMOS quotas that reference the target. Link: https://lkml.kernel.org/r/20250517141852.142802-1-akinobu.mita@gmail.com Fixes: da87878010e5 ("mm/damon/sysfs: support online inputs update") Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Reviewed-by: SeongJae Park <sj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31memcg: make memcg_rstat_updated nmi safeShakeel Butt
Currently kernel maintains memory related stats updates per-cgroup to optimize stats flushing. The stats_updates is defined as atomic64_t which is not nmi-safe on some archs. Actually we don't really need 64bit atomic as the max value stats_updates can get should be less than nr_cpus * MEMCG_CHARGE_BATCH. A normal atomic_t should suffice. Also the function cgroup_rstat_updated() is still not nmi-safe but there is parallel effort to make it nmi-safe, so until then let's ignore it in the nmi context. Link: https://lkml.kernel.org/r/20250519063142.111219-6-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31memcg: nmi-safe slab stats updatesShakeel Butt
The objcg based kmem [un]charging can be called in nmi context and it may need to update NR_SLAB_[UN]RECLAIMABLE_B stats. So, let's correctly handle the updates of these stats in the nmi context. Link: https://lkml.kernel.org/r/20250519063142.111219-5-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31memcg: add nmi-safe update for MEMCG_KMEMShakeel Butt
The objcg based kmem charging and uncharging code path needs to update MEMCG_KMEM appropriately. Let's add support to update MEMCG_KMEM in nmi-safe way for those code paths. Link: https://lkml.kernel.org/r/20250519063142.111219-4-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31memcg: nmi safe memcg stats for specific archsShakeel Butt
There are archs which have NMI but does not support this_cpu_* ops safely in the nmi context but they support safe atomic ops in nmi context. For such archs, let's add infra to use atomic ops for the memcg stats which can be updated in nmi. At the moment, the memcg stats which get updated in the objcg charging path are MEMCG_KMEM, NR_SLAB_RECLAIMABLE_B & NR_SLAB_UNRECLAIMABLE_B. Rather than adding support for all memcg stats to be nmi safe, let's just add infra to make these three stats nmi safe which this patch is doing. Link: https://lkml.kernel.org/r/20250519063142.111219-3-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31memcg: disable kmem charging in nmi for unsupported archShakeel Butt
Patch series "memcg: nmi-safe kmem charging", v4. Users can attached their BPF programs at arbitrary execution points in the kernel and such BPF programs may run in nmi context. In addition, these programs can trigger memcg charged kernel allocations in the nmi context. However memcg charging infra for kernel memory is not equipped to handle nmi context for all architectures. This series removes the hurdles to enable kmem charging in the nmi context for most of the archs. For archs without CONFIG_HAVE_NMI, this series is a noop. For archs with NMI support and have CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS, the previous work to make memcg stats re-entrant is sufficient for allowing kmem charging in nmi context. For archs with NMI support but without CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS and with ARCH_HAVE_NMI_SAFE_CMPXCHG, this series added infra to support kmem charging in nmi context. Lastly those archs with NMI support but without CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS and ARCH_HAVE_NMI_SAFE_CMPXCHG, kmem charging in nmi context is not supported at all. Mostly used archs have support for CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS and this series should be almost a noop (other than making memcg_rstat_updated nmi safe) for such archs. This patch (of 5): The memcg accounting and stats uses this_cpu* and atomic* ops. There are archs which define CONFIG_HAVE_NMI but does not define CONFIG_ARCH_HAS_NMI_SAFE_THIS_CPU_OPS and ARCH_HAVE_NMI_SAFE_CMPXCHG, so memcg accounting for such archs in nmi context is not possible to support. Let's just disable memcg accounting in nmi context for such archs. Link: https://lkml.kernel.org/r/20250519063142.111219-1-shakeel.butt@linux.dev Link: https://lkml.kernel.org/r/20250519063142.111219-2-shakeel.butt@linux.dev Signed-off-by: Shakeel Butt <shakeel.butt@linux.dev> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexei Starovoitov <ast@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31selftests/mm: deduplicate default page size test results in thuge-genMark Brown
The thuge-gen test program runs mmap() and shmget() tests for both every available page size and the default page size, resulting in two tests for the default size. These tests are distinct since the flags in the default case do not specify an explicit size, add the flags to the test name that is logged to deduplicate. Link: https://lkml.kernel.org/r/20250515-selfests-mm-thuge-gen-dup-v1-1-057d2836553f@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Dev Jain <dev.jain@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31selftests/mm: deduplicate test logging in test_mlock_lock()Mark Brown
The mlock2-tests test_mlock_lock() test reports two test results with an identical string, one reporitng if it successfully locked a block of memory and another reporting if the lock is still present after doing an unlock (following a similar pattern to other tests in the same program). This confuses test automation since the test string is used to deduplicate tests, change the post unlock test to report "Unlocked" instead like the other tests to fix this. Link: https://lkml.kernel.org/r/20250515-selftest-mm-mlock2-dup-v1-1-963d5d7d243a@kernel.org Signed-off-by: Mark Brown <broonie@kernel.org> Acked-by: Dev Jain <dev.jain@arm.com> Cc: Shuah Khan <shuah@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31zram: support deflate-specific paramsSergey Senozhatsky
Introduce support of algorithm specific parameters in algorithm_params device attribute. The expected format is algorithm.param=value. For starters, add support for deflate.winbits parameter. Link: https://lkml.kernel.org/r/20250514024825.1745489-3-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31zram: rename ZCOMP_PARAM_NO_LEVELSergey Senozhatsky
Patch series "zram: support algorithm-specific parameters". This patchset adds support for algorithm-specific parameters. For now, only deflate-specific winbits can be configured, which fixes deflate support on some s390 setups. This patch (of 2): Use more generic name because this will be default "un-set" value for more params in the future. Link: https://lkml.kernel.org/r/20250514024825.1745489-1-senozhatsky@chromium.org Link: https://lkml.kernel.org/r/20250514024825.1745489-2-senozhatsky@chromium.org Signed-off-by: Sergey Senozhatsky <senozhatsky@chromium.org> Reviewed-by: Mikhail Zaslonko <zaslonko@linux.ibm.com> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31iov: remove copy_page_from_iter_atomic()Matthew Wilcox (Oracle)
All callers now use copy_folio_from_iter_atomic(), so convert copy_page_from_iter_atomic(). While I'm in there, use kmap_local_folio() and pagefault_disable() instead of kmap_atomic(). That allows preemption and/or task migration to happen during the copy_from_user(). Also use the new folio_test_partial_kmap() predicate instead of open-coding it. Link: https://lkml.kernel.org/r/20250514170607.3000994-4-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31ntfs3: use folios more in ntfs_compress_write()Matthew Wilcox (Oracle)
Remove the local 'page' variable and do everything in terms of folios. Removes the last user of copy_page_from_iter_atomic() and a hidden call to compound_head() in ClearPageDirty(). Link: https://lkml.kernel.org/r/20250514170607.3000994-3-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31mm: rename page->index to page->__folio_indexMatthew Wilcox (Oracle)
All users of page->index have been converted to not refer to it any more. Update a few pieces of documentation that were missed and prevent new users from appearing (or at least make them easy to grep for). Link: https://lkml.kernel.org/r/20250514181508.3019795-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Acked-by: David Hildenbrand <david@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-05-31m68k: remove use of page->indexMatthew Wilcox (Oracle)
Switch to using struct ptdesc to store the markbits which will allow us to remove index from struct page. Link: https://lkml.kernel.org/r/20250516151332.3705351-1-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2025-06-01bcachefs: Add better logging to fsck_rename_dirent()Kent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-06-01bcachefs: Replace rcu_read_lock() with guardsKent Overstreet
The new guard(), scoped_guard() allow for more natural code. Some of the uses with creative flow control have been left. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-06-01bcachefs: CLASS(btree_trans)Kent Overstreet
Allow btree_trans to be used with CLASS(). Automatic cleanup, instead of manually calling bch2_trans_put(). We don't use DEFINE_CLASS because using a static inline for the constructor breaks bch2_trans_get()'s use of __func__, so we have to open code it. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31Merge tag 'mm-nonmm-stable-2025-05-31-15-28' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull non-MM updates from Andrew Morton: - "hung_task: extend blocking task stacktrace dump to semaphore" from Lance Yang enhances the hung task detector. The detector presently dumps the blocking tasks's stack when it is blocked on a mutex. Lance's series extends this to semaphores - "nilfs2: improve sanity checks in dirty state propagation" from Wentao Liang addresses a couple of minor flaws in nilfs2 - "scripts/gdb: Fixes related to lx_per_cpu()" from Illia Ostapyshyn fixes a couple of issues in the gdb scripts - "Support kdump with LUKS encryption by reusing LUKS volume keys" from Coiby Xu addresses a usability problem with kdump. When the dump device is LUKS-encrypted, the kdump kernel may not have the keys to the encrypted filesystem. A full writeup of this is in the series [0/N] cover letter - "sysfs: add counters for lockups and stalls" from Max Kellermann adds /sys/kernel/hardlockup_count and /sys/kernel/hardlockup_count and /sys/kernel/rcu_stall_count - "fork: Page operation cleanups in the fork code" from Pasha Tatashin implements a number of code cleanups in fork.c - "scripts/gdb/symbols: determine KASLR offset on s390 during early boot" from Ilya Leoshkevich fixes some s390 issues in the gdb scripts * tag 'mm-nonmm-stable-2025-05-31-15-28' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (67 commits) llist: make llist_add_batch() a static inline delayacct: remove redundant code and adjust indentation squashfs: add optional full compressed block caching crash_dump, nvme: select CONFIGFS_FS as built-in scripts/gdb/symbols: determine KASLR offset on s390 during early boot scripts/gdb/symbols: factor out pagination_off() scripts/gdb/symbols: factor out get_vmlinux() kernel/panic.c: format kernel-doc comments mailmap: update and consolidate Casey Connolly's name and email nilfs2: remove wbc->for_reclaim handling fork: define a local GFP_VMAP_STACK fork: check charging success before zeroing stack fork: clean-up naming of vm_stack/vm_struct variables in vmap stacks code fork: clean-up ifdef logic around stack allocation kernel/rcu/tree_stall: add /sys/kernel/rcu_stall_count kernel/watchdog: add /sys/kernel/{hard,soft}lockup_count x86/crash: make the page that stores the dm crypt keys inaccessible x86/crash: pass dm crypt keys to kdump kernel Revert "x86/mm: Remove unused __set_memory_prot()" crash_dump: retrieve dm crypt keys in kdump kernel ...
2025-05-31bcachefs: CLASS(darray)Kent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: CLASS(printbuf)Kent Overstreet
Add a DEFINE_CLASS() for printbufs. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: sysfs trigger_journal_commitKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: sysfs trigger_emergency_read_onlyKent Overstreet
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: darray_find(), darray_find_p()Kent Overstreet
New helpers to avoid open coded loops. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: Journal keys are retained until shutdown, or journal replay finishesKent Overstreet
If we don't finish journal replay we need to keep journal keys around until the filesystem shuts down - otherwise e.g. -o norecovery, various tools (dump, list) break, and eventually we'll be doing journal replay in the background. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: Improve error printing in btree_node_check_topology()Kent Overstreet
We had a bug report where the errors from btree_node_check_topology() don't seem to be getting printed; log_fsck_err() does some fancy ratelimiting-type stuff that we don't want here. Instead, just use bch2_count_fsck_err(); this is simpler, and modelled after how we're currently handling bucket ref update errors in buckets.c. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: bch2_readdir() now calls str_hash_check_key()Kent Overstreet
More self healing code: readdir will now notice if there are dirents hashed incorrectly, and it'll repair them if errors=fix_safe. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: bch2_str_hash_check_key() may now be called without snapshots_seenKent Overstreet
We don't track snapshot overwrites outside of fsck, so for this to be called at runtime outside of fsck we need to create it on demand, when we have repair to do. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: __bch2_insert_snapshot_whiteouts() refactoringKent Overstreet
Now uses bch2_get_snapshot_overwrites(), and much shorter. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: bch2_get_snapshot_overwrites()Kent Overstreet
New helper for getting a list of snapshot IDs that have overwritten a given key. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: bch2_dev_journal_bucket_delete()Kent Overstreet
Recover from "journal and btree in same bucket". Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: Runtime self healing for keys for deleted snapshotsKent Overstreet
If snapshot deletion incorrectly missing some keys and leaves keys for deleted snapshots, that causes a bit of a problem for data move - we can't move an extent for a nonexistent snapshot, because the extent might have to be fragmented, and maintaining correct visibility in child snapshots doesn't work if it doesn't have a snapshot. Previously we'd just skip these keys, but it turns out that causes copygc to spin. So we need runtime self healing, i.e. calling check_key_has_snapshot() from the data move path. Snapshot deletion v2 included sentinal values for deleted snapshot nodes, so this is quite safe. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
2025-05-31bcachefs: Don't unlock trans before data_update_init()Kent Overstreet
data_update_init() does need to do btree operations, delay doing the unlock-before-io. Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>