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* mm: clear uffd-wp PTE/PMD state on mremap()Ryan Roberts5 days1-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When mremap()ing a memory region previously registered with userfaultfd as write-protected but without UFFD_FEATURE_EVENT_REMAP, an inconsistency in flag clearing leads to a mismatch between the vma flags (which have uffd-wp cleared) and the pte/pmd flags (which do not have uffd-wp cleared). This mismatch causes a subsequent mprotect(PROT_WRITE) to trigger a warning in page_table_check_pte_flags() due to setting the pte to writable while uffd-wp is still set. Fix this by always explicitly clearing the uffd-wp pte/pmd flags on any such mremap() so that the values are consistent with the existing clearing of VM_UFFD_WP. Be careful to clear the logical flag regardless of its physical form; a PTE bit, a swap PTE bit, or a PTE marker. Cover PTE, huge PMD and hugetlb paths. Link: https://lkml.kernel.org/r/20250107144755.1871363-2-ryan.roberts@arm.com Co-developed-by: Mikołaj Lenczewski <miko.lenczewski@arm.com> Signed-off-by: Mikołaj Lenczewski <miko.lenczewski@arm.com> Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Closes: https://lore.kernel.org/linux-mm/810b44a8-d2ae-4107-b665-5a42eae2d948@arm.com/ Fixes: 63b2d4174c4a ("userfaultfd: wp: add the writeprotect API to userfaultfd ioctl") Cc: David Hildenbrand <david@redhat.com> Cc: Jann Horn <jannh@google.com> Cc: Liam R. Howlett <Liam.Howlett@Oracle.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Muchun Song <muchun.song@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: Shuah Khan <shuah@kernel.org> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: huge_memory: handle strsep not finding delimiterLeo Stone2024-12-191-1/+1
| | | | | | | | | | | | split_huge_pages_write() does not handle the case where strsep finds no delimiter in the given string and sets the input buffer to NULL, which allows this reproducer to trigger a protection fault. Link: https://lkml.kernel.org/r/20241216042752.257090-2-leocstone@gmail.com Signed-off-by: Leo Stone <leocstone@gmail.com> Reported-by: syzbot+8a3da2f1bbf59227c289@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=8a3da2f1bbf59227c289 Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: convert partially_mapped set/clear operations to be atomicUsama Arif2024-12-191-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Other page flags in the 2nd page, like PG_hwpoison and PG_anon_exclusive can get modified concurrently. Changes to other page flags might be lost if they are happening at the same time as non-atomic partially_mapped operations. Hence, make partially_mapped operations atomic. Link: https://lkml.kernel.org/r/20241212183351.1345389-1-usamaarif642@gmail.com Fixes: 8422acdc97ed ("mm: introduce a pageflag for partially mapped folios") Reported-by: David Hildenbrand <david@redhat.com> Link: https://lore.kernel.org/all/e53b04ad-1827-43a2-a1ab-864c7efecf6e@redhat.com/ Signed-off-by: Usama Arif <usamaarif642@gmail.com> Acked-by: David Hildenbrand <david@redhat.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Acked-by: Roman Gushchin <roman.gushchin@linux.dev> Cc: Barry Song <baohua@kernel.org> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport (Microsoft) <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Yu Zhao <yuzhao@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: use clear_user_(high)page() for arch with special user folio handlingZi Yan2024-12-191-4/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Some architectures have special handling after clearing user folios: architectures, which set cpu_dcache_is_aliasing() to true, require flushing dcache; arc, which sets cpu_icache_is_aliasing() to true, changes folio->flags to make icache coherent to dcache. So __GFP_ZERO using only clear_page() is not enough to zero user folios and clear_user_(high)page() must be used. Otherwise, user data will be corrupted. Fix it by always clearing user folios with clear_user_(high)page() when cpu_dcache_is_aliasing() is true or cpu_icache_is_aliasing() is true. Rename alloc_zeroed() to user_alloc_needs_zeroing() and invert the logic to clarify its intend. Link: https://lkml.kernel.org/r/20241209182326.2955963-2-ziy@nvidia.com Fixes: 5708d96da20b ("mm: avoid zeroing user movable page twice with init_on_alloc=1") Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: Geert Uytterhoeven <geert+renesas@glider.be> Closes: https://lore.kernel.org/linux-mm/CAMuHMdV1hRp_NtR5YnJo=HsfgKQeH91J537Gh4gKk3PFZhSkbA@mail.gmail.com/ Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Alexander Potapenko <glider@google.com> Cc: David Hildenbrand <david@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vineet Gupta <vgupta@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* Merge tag 'mm-stable-2024-11-18-19-27' of ↵Linus Torvalds2024-11-231-77/+150
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: - The series "zram: optimal post-processing target selection" from Sergey Senozhatsky improves zram's post-processing selection algorithm. This leads to improved memory savings. - Wei Yang has gone to town on the mapletree code, contributing several series which clean up the implementation: - "refine mas_mab_cp()" - "Reduce the space to be cleared for maple_big_node" - "maple_tree: simplify mas_push_node()" - "Following cleanup after introduce mas_wr_store_type()" - "refine storing null" - The series "selftests/mm: hugetlb_fault_after_madv improvements" from David Hildenbrand fixes this selftest for s390. - The series "introduce pte_offset_map_{ro|rw}_nolock()" from Qi Zheng implements some rationaizations and cleanups in the page mapping code. - The series "mm: optimize shadow entries removal" from Shakeel Butt optimizes the file truncation code by speeding up the handling of shadow entries. - The series "Remove PageKsm()" from Matthew Wilcox completes the migration of this flag over to being a folio-based flag. - The series "Unify hugetlb into arch_get_unmapped_area functions" from Oscar Salvador implements a bunch of consolidations and cleanups in the hugetlb code. - The series "Do not shatter hugezeropage on wp-fault" from Dev Jain takes away the wp-fault time practice of turning a huge zero page into small pages. Instead we replace the whole thing with a THP. More consistent cleaner and potentiall saves a large number of pagefaults. - The series "percpu: Add a test case and fix for clang" from Andy Shevchenko enhances and fixes the kernel's built in percpu test code. - The series "mm/mremap: Remove extra vma tree walk" from Liam Howlett optimizes mremap() by avoiding doing things which we didn't need to do. - The series "Improve the tmpfs large folio read performance" from Baolin Wang teaches tmpfs to copy data into userspace at the folio size rather than as individual pages. A 20% speedup was observed. - The series "mm/damon/vaddr: Fix issue in damon_va_evenly_split_region()" fro Zheng Yejian fixes DAMON splitting. - The series "memcg-v1: fully deprecate charge moving" from Shakeel Butt removes the long-deprecated memcgv2 charge moving feature. - The series "fix error handling in mmap_region() and refactor" from Lorenzo Stoakes cleanup up some of the mmap() error handling and addresses some potential performance issues. - The series "x86/module: use large ROX pages for text allocations" from Mike Rapoport teaches x86 to use large pages for read-only-execute module text. - The series "page allocation tag compression" from Suren Baghdasaryan is followon maintenance work for the new page allocation profiling feature. - The series "page->index removals in mm" from Matthew Wilcox remove most references to page->index in mm/. A slow march towards shrinking struct page. - The series "damon/{self,kunit}tests: minor fixups for DAMON debugfs interface tests" from Andrew Paniakin performs maintenance work for DAMON's self testing code. - The series "mm: zswap swap-out of large folios" from Kanchana Sridhar improves zswap's batching of compression and decompression. It is a step along the way towards using Intel IAA hardware acceleration for this zswap operation. - The series "kasan: migrate the last module test to kunit" from Sabyrzhan Tasbolatov completes the migration of the KASAN built-in tests over to the KUnit framework. - The series "implement lightweight guard pages" from Lorenzo Stoakes permits userapace to place fault-generating guard pages within a single VMA, rather than requiring that multiple VMAs be created for this. Improved efficiencies for userspace memory allocators are expected. - The series "memcg: tracepoint for flushing stats" from JP Kobryn uses tracepoints to provide increased visibility into memcg stats flushing activity. - The series "zram: IDLE flag handling fixes" from Sergey Senozhatsky fixes a zram buglet which potentially affected performance. - The series "mm: add more kernel parameters to control mTHP" from Maíra Canal enhances our ability to control/configuremultisize THP from the kernel boot command line. - The series "kasan: few improvements on kunit tests" from Sabyrzhan Tasbolatov has a couple of fixups for the KASAN KUnit tests. - The series "mm/list_lru: Split list_lru lock into per-cgroup scope" from Kairui Song optimizes list_lru memory utilization when lockdep is enabled. * tag 'mm-stable-2024-11-18-19-27' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (215 commits) cma: enforce non-zero pageblock_order during cma_init_reserved_mem() mm/kfence: add a new kunit test test_use_after_free_read_nofault() zram: fix NULL pointer in comp_algorithm_show() memcg/hugetlb: add hugeTLB counters to memcg vmstat: call fold_vm_zone_numa_events() before show per zone NUMA event mm: mmap_lock: check trace_mmap_lock_$type_enabled() instead of regcount zram: ZRAM_DEF_COMP should depend on ZRAM MAINTAINERS/MEMORY MANAGEMENT: add document files for mm Docs/mm/damon: recommend academic papers to read and/or cite mm: define general function pXd_init() kmemleak: iommu/iova: fix transient kmemleak false positive mm/list_lru: simplify the list_lru walk callback function mm/list_lru: split the lock to per-cgroup scope mm/list_lru: simplify reparenting and initial allocation mm/list_lru: code clean up for reparenting mm/list_lru: don't export list_lru_add mm/list_lru: don't pass unnecessary key parameters kasan: add kunit tests for kmalloc_track_caller, kmalloc_node_track_caller kasan: change kasan_atomics kunit test as KUNIT_CASE_SLOW kasan: use EXPORT_SYMBOL_IF_KUNIT to export symbols ...
| * mm: huge_memory: use strscpy() instead of strcpy()Maíra Canal2024-11-111-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace strcpy() with strscpy() in mm/huge_memory.c strcpy() has been deprecated because it is generally unsafe, so help to eliminate it from the kernel source. Link: https://github.com/KSPP/linux/issues/88 Link: https://lkml.kernel.org/r/20241101165719.1074234-7-mcanal@igalia.com Signed-off-by: Maíra Canal <mcanal@igalia.com> Reviewed-by: Lance Yang <ioworker0@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: move ``get_order_from_str()`` to internal.hMaíra Canal2024-11-111-23/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In order to implement a kernel parameter similar to ``thp_anon=`` for shmem, we'll need the function ``get_order_from_str()``. Instead of duplicating the function, move the function to a shared header, in which both mm/shmem.c and mm/huge_memory.c will be able to use it. Link: https://lkml.kernel.org/r/20241101165719.1074234-5-mcanal@igalia.com Signed-off-by: Maíra Canal <mcanal@igalia.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: add per-order mTHP swpin countersBarry Song2024-11-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This helps profile the sizes of folios being swapped in. Currently, only mTHP swap-out is being counted. The new interface can be found at: /sys/kernel/mm/transparent_hugepage/hugepages-<size>/stats swpin For example, cat /sys/kernel/mm/transparent_hugepage/hugepages-64kB/stats/swpin 12809 cat /sys/kernel/mm/transparent_hugepage/hugepages-32kB/stats/swpin 4763 [v-songbaohua@oppo.com: add a blank line in doc] Link: https://lkml.kernel.org/r/20241030233423.80759-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20241026082423.26298-1-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Chris Li <chrisl@kernel.org> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Kairui Song <kasong@tencent.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Cc: Usama Arif <usamaarif642@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: swap: count successful large folio zswap stores in hugepage zswpout statsKanchana P Sridhar2024-11-111-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Added a new MTHP_STAT_ZSWPOUT entry to the sysfs transparent_hugepage stats so that successful large folio zswap stores can be accounted under the per-order sysfs "zswpout" stats: /sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/zswpout Other non-zswap swap device swap-out events will be counted under the existing sysfs "swpout" stats: /sys/kernel/mm/transparent_hugepage/hugepages-*kB/stats/swpout Also, added documentation for the newly added sysfs per-order hugepage "zswpout" stats. The documentation clarifies that only non-zswap swapouts will be accounted in the existing "swpout" stats. Link: https://lkml.kernel.org/r/20241001053222.6944-8-kanchana.p.sridhar@intel.com Signed-off-by: Kanchana P Sridhar <kanchana.p.sridhar@intel.com> Reviewed-by: Nhat Pham <nphamcs@gmail.com> Cc: Chengming Zhou <chengming.zhou@linux.dev> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Wajdi Feghali <wajdi.k.feghali@intel.com> Cc: Yosry Ahmed <yosryahmed@google.com> Cc: "Zou, Nanhai" <nanhai.zou@intel.com> Cc: Barry Song <21cnbao@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: remove references to page->index in huge_memory.cMatthew Wilcox (Oracle)2024-11-071-9/+9
| | | | | | | | | | | | | | | | | | We already have folios in all these places; it's just a matter of using them instead of the pages. Link: https://lkml.kernel.org/r/20241005200121.3231142-7-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: huge_memory: move file_thp_enabled() into huge_memory.cKefeng Wang2024-11-071-0/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | file_thp_enabled() is only used in __thp_vma_allowable_orders(), so move it into huge_memory.c, also check READ_ONLY_THP_FOR_FS ahead to avoid unnecessary code if config disabled. Link: https://lkml.kernel.org/r/20241017141457.1169092-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: avoid zeroing user movable page twice with init_on_alloc=1Zi Yan2024-11-071-1/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 6471384af2a6 ("mm: security: introduce init_on_alloc=1 and init_on_free=1 boot options") forces allocated page to be zeroed in post_alloc_hook() when init_on_alloc=1. For order-0 folios, if arch does not define vma_alloc_zeroed_movable_folio(), the default implementation again zeros the page return from the buddy allocator. So the page is zeroed twice. Fix it by passing __GFP_ZERO instead to avoid double page zeroing. At the moment, s390,arm64,x86,alpha,m68k are not impacted since they define their own vma_alloc_zeroed_movable_folio(). For >0 order folios (mTHP and PMD THP), folio_zero_user() is called to zero the folio again. Fix it by calling folio_zero_user() only if init_on_alloc is set. All arch are impacted. Add alloc_zeroed() helper to encapsulate the init_on_alloc check. [ziy@nvidia.com: comment fixes, per David] Link: https://lkml.kernel.org/r/97DB52E1-C594-49B5-9736-89AC302FAB01@nvidia.com Link: https://lkml.kernel.org/r/20241011150304.709590-1-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: David Hildenbrand <david@redhat.com> Cc: Alexander Potapenko <glider@google.com> Cc: "Huang, Ying" <ying.huang@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Kees Cook <keescook@chromium.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Miaohe Lin <linmiaohe@huawei.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: remove unused hugepage for vma_alloc_folio()Kefeng Wang2024-11-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The hugepage parameter was deprecated since commit ddc1a5cbc05d ("mempolicy: alloc_pages_mpol() for NUMA policy without vma"), for PMD-sized THP, it still tries only preferred node if possible in vma_alloc_folio() by checking the order of the folio allocation. Link: https://lkml.kernel.org/r/20241010061556.1846751-1-wangkefeng.wang@huawei.com Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Reviewed-by: Barry Song <baohua@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: allocate THP on hugezeropage wp-faultDev Jain2024-11-071-1/+40
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce do_huge_zero_wp_pmd() to handle wp-fault on a hugezeropage and replace it with a PMD-mapped THP. Remember to flush TLB entry corresponding to the hugezeropage. In case of failure, fallback to splitting the PMD. Link: https://lkml.kernel.org/r/20241008061746.285961-3-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dev Jain <dev.jain@arm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: abstract THP allocationDev Jain2024-11-071-41/+57
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Do not shatter hugezeropage on wp-fault", v7. It was observed at [1] and [2] that the current kernel behaviour of shattering a hugezeropage is inconsistent and suboptimal. For a VMA with a THP allowable order, when we write-fault on it, the kernel installs a PMD-mapped THP. On the other hand, if we first get a read fault, we get a PMD pointing to the hugezeropage; subsequent write will trigger a write-protection fault, shattering the hugezeropage into one writable page, and all the other PTEs write-protected. The conclusion being, as compared to the case of a single write-fault, applications have to suffer 512 extra page faults if they were to use the VMA as such, plus we get the overhead of khugepaged trying to replace that area with a THP anyway. Instead, replace the hugezeropage with a THP on wp-fault. [1]: https://lore.kernel.org/all/3743d7e1-0b79-4eaf-82d5-d1ca29fe347d@arm.com/ [2]: https://lore.kernel.org/all/1cfae0c0-96a2-4308-9c62-f7a640520242@arm.com/ This patch (of 2): In preparation for the second patch, abstract away the THP allocation logic present in the create_huge_pmd() path, which corresponds to the faulting case when no page is present. There should be no functional change as a result of applying this patch, except that, as David notes at [1], a PMD-aligned address should be passed to update_mmu_cache_pmd(). [1]: https://lore.kernel.org/all/ddd3fcd2-48b3-4170-bcaa-2fe66e093f43@redhat.com/ Link: https://lkml.kernel.org/r/20241008061746.285961-1-dev.jain@arm.com Link: https://lkml.kernel.org/r/20241008061746.285961-2-dev.jain@arm.com Signed-off-by: Dev Jain <dev.jain@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Alistair Popple <apopple@nvidia.com> Cc: Aneesh Kumar K.V <aneesh.kumar@kernel.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Barry Song <baohua@kernel.org> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christoph Lameter <cl@gentwo.org> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jan Kara <jack@suse.cz> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Mark Rutland <mark.rutland@arm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michal Hocko <mhocko@suse.com> Cc: Peter Xu <peterx@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Will Deacon <will@kernel.org> Cc: Yang Shi <yang@os.amperecomputing.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: move mm flags to mm_types.hNanyong Sun2024-11-061-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The types of mm flags are now far beyond the core dump related features. This patch moves mm flags from linux/sched/coredump.h to linux/mm_types.h. The linux/sched/coredump.h has include the mm_types.h, so the C files related to coredump does not need to change head file inclusion. In addition, the inclusion of sched/coredump.h now can be deleted from the C files that irrelevant to core dump. Link: https://lkml.kernel.org/r/20240926074922.2721274-1-sunnanyong@huawei.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Masami Hiramatsu <mhiramat@kernel.org> Cc: Matthew Wilcox <willy@infradead.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | mm/thp: fix deferred split queue not partially_mapped: fixHugh Dickins2024-11-121-1/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Though even more elusive than before, list_del corruption has still been seen on THP's deferred split queue. The idea in commit e66f3185fa04 was right, but its implementation wrong. The context omitted an important comment just before the critical test: "split_folio() removes folio from list on success." In ignoring that comment, when a THP split succeeded, the code went on to release the preceding safe folio, preserving instead an irrelevant (formerly head) folio: which gives no safety because it's not on the list. Fix the logic. Link: https://lkml.kernel.org/r/3c995a30-31ce-0998-1b9f-3a2cb9354c91@google.com Fixes: e66f3185fa04 ("mm/thp: fix deferred split queue not partially_mapped") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/thp: fix deferred split unqueue naming and lockingHugh Dickins2024-11-061-9/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent changes are putting more pressure on THP deferred split queues: under load revealing long-standing races, causing list_del corruptions, "Bad page state"s and worse (I keep BUGs in both of those, so usually don't get to see how badly they end up without). The relevant recent changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin, improved swap allocation, and underused THP splitting. Before fixing locking: rename misleading folio_undo_large_rmappable(), which does not undo large_rmappable, to folio_unqueue_deferred_split(), which is what it does. But that and its out-of-line __callee are mm internals of very limited usability: add comment and WARN_ON_ONCEs to check usage; and return a bool to say if a deferred split was unqueued, which can then be used in WARN_ON_ONCEs around safety checks (sparing callers the arcane conditionals in __folio_unqueue_deferred_split()). Just omit the folio_unqueue_deferred_split() from free_unref_folios(), all of whose callers now call it beforehand (and if any forget then bad_page() will tell) - except for its caller put_pages_list(), which itself no longer has any callers (and will be deleted separately). Swapout: mem_cgroup_swapout() has been resetting folio->memcg_data 0 without checking and unqueueing a THP folio from deferred split list; which is unfortunate, since the split_queue_lock depends on the memcg (when memcg is enabled); so swapout has been unqueueing such THPs later, when freeing the folio, using the pgdat's lock instead: potentially corrupting the memcg's list. __remove_mapping() has frozen refcount to 0 here, so no problem with calling folio_unqueue_deferred_split() before resetting memcg_data. That goes back to 5.4 commit 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware"): which included a check on swapcache before adding to deferred queue, but no check on deferred queue before adding THP to swapcache. That worked fine with the usual sequence of events in reclaim (though there were a couple of rare ways in which a THP on deferred queue could have been swapped out), but 6.12 commit dafff3f4c850 ("mm: split underused THPs") avoids splitting underused THPs in reclaim, which makes swapcache THPs on deferred queue commonplace. Keep the check on swapcache before adding to deferred queue? Yes: it is no longer essential, but preserves the existing behaviour, and is likely to be a worthwhile optimization (vmstat showed much more traffic on the queue under swapping load if the check was removed); update its comment. Memcg-v1 move (deprecated): mem_cgroup_move_account() has been changing folio->memcg_data without checking and unqueueing a THP folio from the deferred list, sometimes corrupting "from" memcg's list, like swapout. Refcount is non-zero here, so folio_unqueue_deferred_split() can only be used in a WARN_ON_ONCE to validate the fix, which must be done earlier: mem_cgroup_move_charge_pte_range() first try to split the THP (splitting of course unqueues), or skip it if that fails. Not ideal, but moving charge has been requested, and khugepaged should repair the THP later: nobody wants new custom unqueueing code just for this deprecated case. The 87eaceb3faa5 commit did have the code to move from one deferred list to another (but was not conscious of its unsafety while refcount non-0); but that was removed by 5.6 commit fac0516b5534 ("mm: thp: don't need care deferred split queue in memcg charge move path"), which argued that the existence of a PMD mapping guarantees that the THP cannot be on a deferred list. As above, false in rare cases, and now commonly false. Backport to 6.11 should be straightforward. Earlier backports must take care that other _deferred_list fixes and dependencies are included. There is not a strong case for backports, but they can fix cornercases. Link: https://lkml.kernel.org/r/8dc111ae-f6db-2da7-b25c-7a20b1effe3b@google.com Fixes: 87eaceb3faa5 ("mm: thp: make deferred split shrinker memcg aware") Fixes: dafff3f4c850 ("mm: split underused THPs") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Yang Shi <shy828301@gmail.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/thp: fix deferred split queue not partially_mappedHugh Dickins2024-11-061-4/+17
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Recent changes are putting more pressure on THP deferred split queues: under load revealing long-standing races, causing list_del corruptions, "Bad page state"s and worse (I keep BUGs in both of those, so usually don't get to see how badly they end up without). The relevant recent changes being 6.8's mTHP, 6.10's mTHP swapout, and 6.12's mTHP swapin, improved swap allocation, and underused THP splitting. The new unlocked list_del_init() in deferred_split_scan() is buggy. I gave bad advice, it looks plausible since that's a local on-stack list, but the fact is that it can race with a third party freeing or migrating the preceding folio (properly unqueueing it with refcount 0 while holding split_queue_lock), thereby corrupting the list linkage. The obvious answer would be to take split_queue_lock there: but it has a long history of contention, so I'm reluctant to add to that. Instead, make sure that there is always one safe (raised refcount) folio before, by delaying its folio_put(). (And of course I was wrong to suggest updating split_queue_len without the lock: leave that until the splice.) And remove two over-eager partially_mapped checks, restoring those tests to how they were before: if uncharge_folio() or free_tail_page_prepare() finds _deferred_list non-empty, it's in trouble whether or not that folio is partially_mapped (and the flag was already cleared in the latter case). Link: https://lkml.kernel.org/r/81e34a8b-113a-0701-740e-2135c97eb1d7@google.com Fixes: dafff3f4c850 ("mm: split underused THPs") Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Usama Arif <usamaarif642@gmail.com> Reviewed-by: David Hildenbrand <david@redhat.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: Zi Yan <ziy@nvidia.com> Cc: Barry Song <baohua@kernel.org> Cc: Chris Li <chrisl@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Nhat Pham <nphamcs@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Wei Yang <richard.weiyang@gmail.com> Cc: Yang Shi <shy828301@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm: huge_memory: add vma_thp_disabled() and thp_disabled_by_hw()Kefeng Wang2024-10-171-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: don't install PMD mappings when THPs are disabled by the hw/process/vma". During testing, it was found that we can get PMD mappings in processes where THP (and more precisely, PMD mappings) are supposed to be disabled. While it works as expected for anon+shmem, the pagecache is the problematic bit. For s390 KVM this currently means that a VM backed by a file located on filesystem with large folio support can crash when KVM tries accessing the problematic page, because the readahead logic might decide to use a PMD-sized THP and faulting it into the page tables will install a PMD mapping, something that s390 KVM cannot tolerate. This might also be a problem with HW that does not support PMD mappings, but I did not try reproducing it. Fix it by respecting the ways to disable THPs when deciding whether we can install a PMD mapping. khugepaged should already be taking care of not collapsing if THPs are effectively disabled for the hw/process/vma. This patch (of 2): Add vma_thp_disabled() and thp_disabled_by_hw() helpers to be shared by shmem_allowable_huge_orders() and __thp_vma_allowable_orders(). [david@redhat.com: rename to vma_thp_disabled(), split out thp_disabled_by_hw() ] Link: https://lkml.kernel.org/r/20241011102445.934409-2-david@redhat.com Fixes: 793917d997df ("mm/readahead: Add large folio readahead") Signed-off-by: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: Leo Fu <bfu@redhat.com> Tested-by: Thomas Huth <thuth@redhat.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Cc: Boqiao Fu <bfu@redhat.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Hugh Dickins <hughd@google.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* mm/huge_memory: check pmd_special() only after pmd_present()David Hildenbrand2024-10-091-1/+1
| | | | | | | | | | | | | | | | | | We should only check for pmd_special() after we made sure that we have a present PMD. For example, if we have a migration PMD, pmd_special() might indicate that we have a special PMD although we really don't. This fixes confusing migration entries as PFN mappings, and not doing what we are supposed to do in the "is_swap_pmd()" case further down in the function -- including messing up COW, page table handling and accounting. Link: https://lkml.kernel.org/r/20240926154234.2247217-1-david@redhat.com Fixes: bc02afbd4d73 ("mm/fork: accept huge pfnmap entries") Signed-off-by: David Hildenbrand <david@redhat.com> Reported-by: syzbot+bf2c35fa302ebe3c7471@syzkaller.appspotmail.com Closes: https://lore.kernel.org/lkml/66f15c8d.050a0220.c23dd.000f.GAE@google.com/ Reviewed-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* [tree-wide] finally take no_llseek outAl Viro2024-09-271-1/+0
| | | | | | | | | | | | | | | | | | | | | | | | no_llseek had been defined to NULL two years ago, in commit 868941b14441 ("fs: remove no_llseek") To quote that commit, At -rc1 we'll need do a mechanical removal of no_llseek - git grep -l -w no_llseek | grep -v porting.rst | while read i; do sed -i '/\<no_llseek\>/d' $i done would do it. Unfortunately, that hadn't been done. Linus, could you do that now, so that we could finally put that thing to rest? All instances are of the form .llseek = no_llseek, so it's obviously safe. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge tag 'mm-stable-2024-09-20-02-31' of ↵Linus Torvalds2024-09-211-118/+471
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm Pull MM updates from Andrew Morton: "Along with the usual shower of singleton patches, notable patch series in this pull request are: - "Align kvrealloc() with krealloc()" from Danilo Krummrich. Adds consistency to the APIs and behaviour of these two core allocation functions. This also simplifies/enables Rustification. - "Some cleanups for shmem" from Baolin Wang. No functional changes - mode code reuse, better function naming, logic simplifications. - "mm: some small page fault cleanups" from Josef Bacik. No functional changes - code cleanups only. - "Various memory tiering fixes" from Zi Yan. A small fix and a little cleanup. - "mm/swap: remove boilerplate" from Yu Zhao. Code cleanups and simplifications and .text shrinkage. - "Kernel stack usage histogram" from Pasha Tatashin and Shakeel Butt. This is a feature, it adds new feilds to /proc/vmstat such as $ grep kstack /proc/vmstat kstack_1k 3 kstack_2k 188 kstack_4k 11391 kstack_8k 243 kstack_16k 0 which tells us that 11391 processes used 4k of stack while none at all used 16k. Useful for some system tuning things, but partivularly useful for "the dynamic kernel stack project". - "kmemleak: support for percpu memory leak detect" from Pavel Tikhomirov. Teaches kmemleak to detect leaksage of percpu memory. - "mm: memcg: page counters optimizations" from Roman Gushchin. "3 independent small optimizations of page counters". - "mm: split PTE/PMD PT table Kconfig cleanups+clarifications" from David Hildenbrand. Improves PTE/PMD splitlock detection, makes powerpc/8xx work correctly by design rather than by accident. - "mm: remove arch_make_page_accessible()" from David Hildenbrand. Some folio conversions which make arch_make_page_accessible() unneeded. - "mm, memcg: cg2 memory{.swap,}.peak write handlers" fro David Finkel. Cleans up and fixes our handling of the resetting of the cgroup/process peak-memory-use detector. - "Make core VMA operations internal and testable" from Lorenzo Stoakes. Rationalizaion and encapsulation of the VMA manipulation APIs. With a view to better enable testing of the VMA functions, even from a userspace-only harness. - "mm: zswap: fixes for global shrinker" from Takero Funaki. Fix issues in the zswap global shrinker, resulting in improved performance. - "mm: print the promo watermark in zoneinfo" from Kaiyang Zhao. Fill in some missing info in /proc/zoneinfo. - "mm: replace follow_page() by folio_walk" from David Hildenbrand. Code cleanups and rationalizations (conversion to folio_walk()) resulting in the removal of follow_page(). - "improving dynamic zswap shrinker protection scheme" from Nhat Pham. Some tuning to improve zswap's dynamic shrinker. Significant reductions in swapin and improvements in performance are shown. - "mm: Fix several issues with unaccepted memory" from Kirill Shutemov. Improvements to the new unaccepted memory feature, - "mm/mprotect: Fix dax puds" from Peter Xu. Implements mprotect on DAX PUDs. This was missing, although nobody seems to have notied yet. - "Introduce a store type enum for the Maple tree" from Sidhartha Kumar. Cleanups and modest performance improvements for the maple tree library code. - "memcg: further decouple v1 code from v2" from Shakeel Butt. Move more cgroup v1 remnants away from the v2 memcg code. - "memcg: initiate deprecation of v1 features" from Shakeel Butt. Adds various warnings telling users that memcg v1 features are deprecated. - "mm: swap: mTHP swap allocator base on swap cluster order" from Chris Li. Greatly improves the success rate of the mTHP swap allocation. - "mm: introduce numa_memblks" from Mike Rapoport. Moves various disparate per-arch implementations of numa_memblk code into generic code. - "mm: batch free swaps for zap_pte_range()" from Barry Song. Greatly improves the performance of munmap() of swap-filled ptes. - "support large folio swap-out and swap-in for shmem" from Baolin Wang. With this series we no longer split shmem large folios into simgle-page folios when swapping out shmem. - "mm/hugetlb: alloc/free gigantic folios" from Yu Zhao. Nice performance improvements and code reductions for gigantic folios. - "support shmem mTHP collapse" from Baolin Wang. Adds support for khugepaged's collapsing of shmem mTHP folios. - "mm: Optimize mseal checks" from Pedro Falcato. Fixes an mprotect() performance regression due to the addition of mseal(). - "Increase the number of bits available in page_type" from Matthew Wilcox. Increases the number of bits available in page_type! - "Simplify the page flags a little" from Matthew Wilcox. Many legacy page flags are now folio flags, so the page-based flags and their accessors/mutators can be removed. - "mm: store zero pages to be swapped out in a bitmap" from Usama Arif. An optimization which permits us to avoid writing/reading zero-filled zswap pages to backing store. - "Avoid MAP_FIXED gap exposure" from Liam Howlett. Fixes a race window which occurs when a MAP_FIXED operqtion is occurring during an unrelated vma tree walk. - "mm: remove vma_merge()" from Lorenzo Stoakes. Major rotorooting of the vma_merge() functionality, making ot cleaner, more testable and better tested. - "misc fixups for DAMON {self,kunit} tests" from SeongJae Park. Minor fixups of DAMON selftests and kunit tests. - "mm: memory_hotplug: improve do_migrate_range()" from Kefeng Wang. Code cleanups and folio conversions. - "Shmem mTHP controls and stats improvements" from Ryan Roberts. Cleanups for shmem controls and stats. - "mm: count the number of anonymous THPs per size" from Barry Song. Expose additional anon THP stats to userspace for improved tuning. - "mm: finish isolate/putback_lru_page()" from Kefeng Wang: more folio conversions and removal of now-unused page-based APIs. - "replace per-quota region priorities histogram buffer with per-context one" from SeongJae Park. DAMON histogram rationalization. - "Docs/damon: update GitHub repo URLs and maintainer-profile" from SeongJae Park. DAMON documentation updates. - "mm/vdpa: correct misuse of non-direct-reclaim __GFP_NOFAIL and improve related doc and warn" from Jason Wang: fixes usage of page allocator __GFP_NOFAIL and GFP_ATOMIC flags. - "mm: split underused THPs" from Yu Zhao. Improve THP=always policy. This was overprovisioning THPs in sparsely accessed memory areas. - "zram: introduce custom comp backends API" frm Sergey Senozhatsky. Add support for zram run-time compression algorithm tuning. - "mm: Care about shadow stack guard gap when getting an unmapped area" from Mark Brown. Fix up the various arch_get_unmapped_area() implementations to better respect guard areas. - "Improve mem_cgroup_iter()" from Kinsey Ho. Improve the reliability of mem_cgroup_iter() and various code cleanups. - "mm: Support huge pfnmaps" from Peter Xu. Extends the usage of huge pfnmap support. - "resource: Fix region_intersects() vs add_memory_driver_managed()" from Huang Ying. Fix a bug in region_intersects() for systems with CXL memory. - "mm: hwpoison: two more poison recovery" from Kefeng Wang. Teaches a couple more code paths to correctly recover from the encountering of poisoned memry. - "mm: enable large folios swap-in support" from Barry Song. Support the swapin of mTHP memory into appropriately-sized folios, rather than into single-page folios" * tag 'mm-stable-2024-09-20-02-31' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (416 commits) zram: free secondary algorithms names uprobes: turn xol_area->pages[2] into xol_area->page uprobes: introduce the global struct vm_special_mapping xol_mapping Revert "uprobes: use vm_special_mapping close() functionality" mm: support large folios swap-in for sync io devices mm: add nr argument in mem_cgroup_swapin_uncharge_swap() helper to support large folios mm: fix swap_read_folio_zeromap() for large folios with partial zeromap mm/debug_vm_pgtable: Use pxdp_get() for accessing page table entries set_memory: add __must_check to generic stubs mm/vma: return the exact errno in vms_gather_munmap_vmas() memcg: cleanup with !CONFIG_MEMCG_V1 mm/show_mem.c: report alloc tags in human readable units mm: support poison recovery from copy_present_page() mm: support poison recovery from do_cow_fault() resource, kunit: add test case for region_intersects() resource: make alloc_free_mem_region() works for iomem_resource mm: z3fold: deprecate CONFIG_Z3FOLD vfio/pci: implement huge_fault support mm/arm64: support large pfn mappings mm/x86: support large pfn mappings ...
| * mm/fork: accept huge pfnmap entriesPeter Xu2024-09-171-3/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Teach the fork code to properly copy pfnmaps for pmd/pud levels. Pud is much easier, the write bit needs to be persisted though for writable and shared pud mappings like PFNMAP ones, otherwise a follow up write in either parent or child process will trigger a write fault. Do the same for pmd level. Link: https://lkml.kernel.org/r/20240826204353.2228736-8-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: David Hildenbrand <david@redhat.com> Cc: Gavin Shan <gshan@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Jason Gunthorpe <jgg@nvidia.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: allow THP orders for PFNMAPsPeter Xu2024-09-171-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This enables PFNMAPs to be mapped at either pmd/pud layers. Generalize the dax case into vma_is_special_huge() so as to cover both. Meanwhile, rename the macro to THP_ORDERS_ALL_SPECIAL. Link: https://lkml.kernel.org/r/20240826204353.2228736-5-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Gavin Shan <gshan@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Zi Yan <ziy@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: mark special bits for huge pfn mappings when injectPeter Xu2024-09-171-0/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We need these special bits to be around on pfnmaps. Mark properly for !devmap case, reflecting that there's no page struct backing the entry. Link: https://lkml.kernel.org/r/20240826204353.2228736-4-peterx@redhat.com Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Signed-off-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gavin Shan <gshan@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: drop is_huge_zero_pud()Peter Xu2024-09-171-12/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | It constantly returns false since 2017. One assertion is added in 2019 but it should never have triggered, IOW it means what is checked should be asserted instead. If it didn't exist for 7 years maybe it's good idea to remove it and only add it when it comes. Link: https://lkml.kernel.org/r/20240826204353.2228736-3-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Reviewed-by: Jason Gunthorpe <jgg@nvidia.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Alex Williamson <alex.williamson@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Gavin Shan <gshan@redhat.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Niklas Schnelle <schnelle@linux.ibm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Will Deacon <will@kernel.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/codetag: fix pgalloc_tag_split()Yu Zhao2024-09-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current assumption is that a large folio can only be split into order-0 folios. That is not the case for hugeTLB demotion, nor for THP split: see commit c010d47f107f ("mm: thp: split huge page to any lower order pages"). When a large folio is split into ones of a lower non-zero order, only the new head pages should be tagged. Tagging tail pages can cause imbalanced "calls" counters, since only head pages are untagged by pgalloc_tag_sub() and the "calls" counts on tail pages are leaked, e.g., # echo 2048kB >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote_size # echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/nr_hugepages # time echo 700 >/sys/kernel/mm/hugepages/hugepages-1048576kB/demote # echo 0 >/sys/kernel/mm/hugepages/hugepages-2048kB/nr_hugepages # grep alloc_gigantic_folio /proc/allocinfo Before this patch: 0 549427200 mm/hugetlb.c:1549 func:alloc_gigantic_folio real 0m2.057s user 0m0.000s sys 0m2.051s After this patch: 0 0 mm/hugetlb.c:1549 func:alloc_gigantic_folio real 0m1.711s user 0m0.000s sys 0m1.704s Not tagging tail pages also improves the splitting time, e.g., by about 15% when demoting 1GB hugeTLB folios to 2MB ones, as shown above. Link: https://lkml.kernel.org/r/20240906042108.1150526-2-yuzhao@google.com Fixes: be25d1d4e822 ("mm: create new codetag references during page splitting") Signed-off-by: Yu Zhao <yuzhao@google.com> Acked-by: Suren Baghdasaryan <surenb@google.com> Cc: Kent Overstreet <kent.overstreet@linux.dev> Cc: Muchun Song <muchun.song@linux.dev> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: thp: simplify split_huge_pages_pid()Nanyong Sun2024-09-101-6/+1
| | | | | | | | | | | | | | | | | | | | | | | | The helper find_get_task_by_vpid() can totally replace the task_struct find logic in split_huge_pages_pid(), so use it to simplify the code. Also delete the needless comments for the helper function name already explains what it's doing here. Link: https://lkml.kernel.org/r/20240905153028.1205128-1-sunnanyong@huawei.com Signed-off-by: Nanyong Sun <sunnanyong@huawei.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm,tmpfs: consider end of file write in shmem_is_hugeRik van Riel2024-09-101-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Take the end of a file write into consideration when deciding whether or not to use huge pages for tmpfs files when the tmpfs filesystem is mounted with huge=within_size This allows large writes that append to the end of a file to automatically use large pages. Doing 4MB sequential writes without fallocate to a 16GB tmpfs file with fio. The numbers without THP or with huge=always stay the same, but the performance with huge=within_size now matches that of huge=always. huge before after 4kB pages 1560 MB/s 1560 MB/s within_size 1560 MB/s 4720 MB/s always: 4720 MB/s 4720 MB/s [akpm@linux-foundation.org: coding-style cleanups] Link: https://lkml.kernel.org/r/20240903111928.7171e60c@imladris.surriel.com Signed-off-by: Rik van Riel <riel@surriel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Darrick J. Wong <djwong@kernel.org> Cc: Hugh Dickins <hughd@google.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: add sysfs entry to disable splitting underused THPsUsama Arif2024-09-101-0/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If disabled, THPs faulted in or collapsed will not be added to _deferred_list, and therefore won't be considered for splitting under memory pressure if underused. Link: https://lkml.kernel.org/r/20240830100438.3623486-7-usamaarif642@gmail.com Signed-off-by: Usama Arif <usamaarif642@gmail.com> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <ryncsn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuang Zhai <zhais@google.com> Cc: Shuang Zhai <szhai2@cs.rochester.edu> Cc: Yu Zhao <yuzhao@google.com> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: split underused THPsUsama Arif2024-09-101-2/+58
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is an attempt to mitigate the issue of running out of memory when THP is always enabled. During runtime whenever a THP is being faulted in (__do_huge_pmd_anonymous_page) or collapsed by khugepaged (collapse_huge_page), the THP is added to _deferred_list. Whenever memory reclaim happens in linux, the kernel runs the deferred_split shrinker which goes through the _deferred_list. If the folio was partially mapped, the shrinker attempts to split it. If the folio is not partially mapped, the shrinker checks if the THP was underused, i.e. how many of the base 4K pages of the entire THP were zero-filled. If this number goes above a certain threshold (decided by /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none), the shrinker will attempt to split that THP. Then at remap time, the pages that were zero-filled are mapped to the shared zeropage, hence saving memory. Link: https://lkml.kernel.org/r/20240830100438.3623486-6-usamaarif642@gmail.com Signed-off-by: Usama Arif <usamaarif642@gmail.com> Suggested-by: Rik van Riel <riel@surriel.com> Co-authored-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <ryncsn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuang Zhai <zhais@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Shuang Zhai <szhai2@cs.rochester.edu> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: introduce a pageflag for partially mapped foliosUsama Arif2024-09-101-11/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently folio->_deferred_list is used to keep track of partially_mapped folios that are going to be split under memory pressure. In the next patch, all THPs that are faulted in and collapsed by khugepaged are also going to be tracked using _deferred_list. This patch introduces a pageflag to be able to distinguish between partially mapped folios and others in the deferred_list at split time in deferred_split_scan. Its needed as __folio_remove_rmap decrements _mapcount, _large_mapcount and _entire_mapcount, hence it won't be possible to distinguish between partially mapped folios and others in deferred_split_scan. Eventhough it introduces an extra flag to track if the folio is partially mapped, there is no functional change intended with this patch and the flag is not useful in this patch itself, it will become useful in the next patch when _deferred_list has non partially mapped folios. Link: https://lkml.kernel.org/r/20240830100438.3623486-5-usamaarif642@gmail.com Signed-off-by: Usama Arif <usamaarif642@gmail.com> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <ryncsn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuang Zhai <zhais@google.com> Cc: Yu Zhao <yuzhao@google.com> Cc: Shuang Zhai <szhai2@cs.rochester.edu> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: remap unused subpages to shared zeropage when splitting isolated thpYu Zhao2024-09-101-4/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: split underused THPs", v5. The current upstream default policy for THP is always. However, Meta uses madvise in production as the current THP=always policy vastly overprovisions THPs in sparsely accessed memory areas, resulting in excessive memory pressure and premature OOM killing. Using madvise + relying on khugepaged has certain drawbacks over THP=always. Using madvise hints mean THPs aren't "transparent" and require userspace changes. Waiting for khugepaged to scan memory and collapse pages into THP can be slow and unpredictable in terms of performance (i.e. you dont know when the collapse will happen), while production environments require predictable performance. If there is enough memory available, its better for both performance and predictability to have a THP from fault time, i.e. THP=always rather than wait for khugepaged to collapse it, and deal with sparsely populated THPs when the system is running out of memory. This patch series is an attempt to mitigate the issue of running out of memory when THP is always enabled. During runtime whenever a THP is being faulted in or collapsed by khugepaged, the THP is added to a list. Whenever memory reclaim happens, the kernel runs the deferred_split shrinker which goes through the list and checks if the THP was underused, i.e. how many of the base 4K pages of the entire THP were zero-filled. If this number goes above a certain threshold, the shrinker will attempt to split that THP. Then at remap time, the pages that were zero-filled are mapped to the shared zeropage, hence saving memory. This method avoids the downside of wasting memory in areas where THP is sparsely filled when THP is always enabled, while still providing the upside THPs like reduced TLB misses without having to use madvise. Meta production workloads that were CPU bound (>99% CPU utilzation) were tested with THP shrinker. The results after 2 hours are as follows: | THP=madvise | THP=always | THP=always | | | + shrinker series | | | + max_ptes_none=409 ----------------------------------------------------------------------------- Performance improvement | - | +1.8% | +1.7% (over THP=madvise) | | | ----------------------------------------------------------------------------- Memory usage | 54.6G | 58.8G (+7.7%) | 55.9G (+2.4%) ----------------------------------------------------------------------------- max_ptes_none=409 means that any THP that has more than 409 out of 512 (80%) zero filled filled pages will be split. To test out the patches, the below commands without the shrinker will invoke OOM killer immediately and kill stress, but will not fail with the shrinker: echo 450 > /sys/kernel/mm/transparent_hugepage/khugepaged/max_ptes_none mkdir /sys/fs/cgroup/test echo $$ > /sys/fs/cgroup/test/cgroup.procs echo 20M > /sys/fs/cgroup/test/memory.max echo 0 > /sys/fs/cgroup/test/memory.swap.max # allocate twice memory.max for each stress worker and touch 40/512 of # each THP, i.e. vm-stride 50K. # With the shrinker, max_ptes_none of 470 and below won't invoke OOM # killer. # Without the shrinker, OOM killer is invoked immediately irrespective # of max_ptes_none value and kills stress. stress --vm 1 --vm-bytes 40M --vm-stride 50K This patch (of 5): Here being unused means containing only zeros and inaccessible to userspace. When splitting an isolated thp under reclaim or migration, the unused subpages can be mapped to the shared zeropage, hence saving memory. This is particularly helpful when the internal fragmentation of a thp is high, i.e. it has many untouched subpages. This is also a prerequisite for THP low utilization shrinker which will be introduced in later patches, where underutilized THPs are split, and the zero-filled pages are freed saving memory. Link: https://lkml.kernel.org/r/20240830100438.3623486-1-usamaarif642@gmail.com Link: https://lkml.kernel.org/r/20240830100438.3623486-3-usamaarif642@gmail.com Signed-off-by: Yu Zhao <yuzhao@google.com> Signed-off-by: Usama Arif <usamaarif642@gmail.com> Tested-by: Shuang Zhai <zhais@google.com> Cc: Alexander Zhu <alexlzhu@fb.com> Cc: Barry Song <baohua@kernel.org> Cc: David Hildenbrand <david@redhat.com> Cc: Domenico Cerasuolo <cerasuolodomenico@gmail.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Kairui Song <ryncsn@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Mike Rapoport <rppt@kernel.org> Cc: Nico Pache <npache@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Roman Gushchin <roman.gushchin@linux.dev> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shakeel Butt <shakeel.butt@linux.dev> Cc: Shuang Zhai <szhai2@cs.rochester.edu> Cc: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: count the number of partially mapped anonymous THPs per sizeBarry Song2024-09-101-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When a THP is added to the deferred_list due to partially mapped, its partial pages are unused, leading to wasted memory and potentially increasing memory reclamation pressure. Detailing the specifics of how unmapping occurs is quite difficult and not that useful, so we adopt a simple approach: each time a THP enters the deferred_list, we increment the count by 1; whenever it leaves for any reason, we decrement the count by 1. Link: https://lkml.kernel.org/r/20240824010441.21308-3-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Chuanhua Han <hanchuanhua@oppo.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuai Yuan <yuanshuai@oppo.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: count the number of anonymous THPs per sizeBarry Song2024-09-101-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "mm: count the number of anonymous THPs per size", v4. Knowing the number of transparent anon THPs in the system is crucial for performance analysis. It helps in understanding the ratio and distribution of THPs versus small folios throughout the system. Additionally, partial unmapping by userspace can lead to significant waste of THPs over time and increase memory reclamation pressure. We need this information for comprehensive system tuning. This patch (of 2): Let's track for each anonymous THP size, how many of them are currently allocated. We'll track the complete lifespan of an anon THP, starting when it becomes an anon THP ("large anon folio") (->mapping gets set), until it gets freed (->mapping gets cleared). Introduce a new "nr_anon" counter per THP size and adjust the corresponding counter in the following cases: * We allocate a new THP and call folio_add_new_anon_rmap() to map it the first time and turn it into an anon THP. * We split an anon THP into multiple smaller ones. * We migrate an anon THP, when we prepare the destination. * We free an anon THP back to the buddy. Note that AnonPages in /proc/meminfo currently tracks the total number of *mapped* anonymous *pages*, and therefore has slightly different semantics. In the future, we might also want to track "nr_anon_mapped" for each THP size, which might be helpful when comparing it to the number of allocated anon THPs (long-term pinning, stuck in swapcache, memory leaks, ...). Further note that for now, we only track anon THPs after they got their ->mapping set, for example via folio_add_new_anon_rmap(). If we would allocate some in the swapcache, they will only show up in the statistics for now after they have been mapped to user space the first time, where we call folio_add_new_anon_rmap(). [akpm@linux-foundation.org: documentation fixups, per David] Link: https://lkml.kernel.org/r/3e8add35-e26b-443b-8a04-1078f4bc78f6@redhat.com Link: https://lkml.kernel.org/r/20240824010441.21308-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240824010441.21308-2-21cnbao@gmail.com Signed-off-by: Barry Song <v-songbaohua@oppo.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Chris Li <chrisl@kernel.org> Cc: Chuanhua Han <hanchuanhua@oppo.com> Cc: Kairui Song <kasong@tencent.com> Cc: Kalesh Singh <kaleshsingh@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Cc: Shuai Yuan <yuanshuai@oppo.com> Cc: Usama Arif <usamaarif642@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: tidy up shmem mTHP controls and statsRyan Roberts2024-09-101-28/+112
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Previously we had a situation where shmem mTHP controls and stats were not exposed for some supported sizes and were exposed for some unsupported sizes. So let's clean that up. Anon mTHP can support all large orders [2, PMD_ORDER]. But shmem can support all large orders [1, MAX_PAGECACHE_ORDER]. However, per-size shmem controls and stats were previously being exposed for all the anon mTHP orders, meaning order-1 was not present, and for arm64 64K base pages, orders 12 and 13 were exposed but were not supported internally. Tidy this all up by defining ctrl and stats attribute groups for anon and file separately. Anon ctrl and stats groups are populated for all orders in THP_ORDERS_ALL_ANON and file ctrl and stats groups are populated for all orders in THP_ORDERS_ALL_FILE_DEFAULT. Additionally, create "any" ctrl and stats attribute groups which are populated for all orders in (THP_ORDERS_ALL_ANON | THP_ORDERS_ALL_FILE_DEFAULT). swpout stats use this since they apply to anon and shmem. The side-effect of all this is that different hugepage-*kB directories contain different sets of controls and stats, depending on which memory types support that size. This approach is preferred over the alternative, which is to populate dummy controls and stats for memory types that do not support a given size. [ryan.roberts@arm.com: file pages and shmem can also be split] Link: https://lkml.kernel.org/r/f7ced14c-8bc5-405f-bee7-94f63980f525@arm.comLink: https://lkml.kernel.org/r/20240808111849.651867-3-ryan.roberts@arm.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Tested-by: Barry Song <baohua@kernel.org> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: David Hildenbrand <david@redhat.com> Cc: Gavin Shan <gshan@redhat.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * x86: remove PG_uncachedMatthew Wilcox (Oracle)2024-09-041-1/+3
| | | | | | | | | | | | | | | | | | Convert x86 to use PG_arch_2 instead of PG_uncached and remove PG_uncached. Link: https://lkml.kernel.org/r/20240821193445.2294269-11-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: remove PageUnevictableMatthew Wilcox (Oracle)2024-09-041-8/+8
| | | | | | | | | | | | | | | | | | There is only one caller of PageUnevictable() left; convert it to call folio_test_unevictable() and remove all the page accessors. Link: https://lkml.kernel.org/r/20240821193445.2294269-6-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: override mTHP "enabled" defaults at kernel cmdlineRyan Roberts2024-09-021-1/+97
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add thp_anon= cmdline parameter to allow specifying the default enablement of each supported anon THP size. The parameter accepts the following format and can be provided multiple times to configure each size: thp_anon=<size>,<size>[KMG]:<value>;<size>-<size>[KMG]:<value> An example: thp_anon=16K-64K:always;128K,512K:inherit;256K:madvise;1M-2M:never See Documentation/admin-guide/mm/transhuge.rst for more details. Configuring the defaults at boot time is useful to allow early user space to take advantage of mTHP before its been configured through sysfs. [v-songbaohua@oppo.com: use get_oder() and check size is is_power_of_2] Link: https://lkml.kernel.org/r/20240814224635.43272-1-21cnbao@gmail.com [ryan.roberts@arm.com: some minor cleanup according to David's comments] Link: https://lkml.kernel.org/r/20240820105244.62703-1-21cnbao@gmail.com Link: https://lkml.kernel.org/r/20240814020247.67297-1-21cnbao@gmail.com Signed-off-by: Ryan Roberts <ryan.roberts@arm.com> Co-developed-by: Barry Song <v-songbaohua@oppo.com> Signed-off-by: Barry Song <v-songbaohua@oppo.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Tested-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Lance Yang <ioworker0@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/mprotect: fix dax pud handlingsPeter Xu2024-09-021-0/+52
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is only relevant to the two archs that support PUD dax, aka, x86_64 and ppc64. PUD THPs do not yet exist elsewhere, and hugetlb PUDs do not count in this case. DAX have had PUD mappings for years, but change protection path never worked. When the path is triggered in any form (a simple test program would be: call mprotect() on a 1G dev_dax mapping), the kernel will report "bad pud". This patch should fix that. The new change_huge_pud() tries to keep everything simple. For example, it doesn't optimize write bit as that will need even more PUD helpers. It's not too bad anyway to have one more write fault in the worst case once for 1G range; may be a bigger thing for each PAGE_SIZE, though. Neither does it support userfault-wp bits, as there isn't such PUD mappings that is supported; file mappings always need a split there. The same to TLB shootdown: the pmd path (which was for x86 only) has the trick of using _ad() version of pmdp_invalidate*() which can avoid one redundant TLB, but let's also leave that for later. Again, the larger the mapping, the smaller of such effect. There's some difference on handling "retry" for change_huge_pud() (where it can return 0): it isn't like change_huge_pmd(), as the pmd version is safe with all conditions handled in change_pte_range() later, thanks to Hugh's new pte_offset_map_lock(). In short, change_pte_range() is simply smarter. For that, change_pud_range() will need proper retry if it races with something else when a huge PUD changed from under us. The last thing to mention is currently the PUD path ignores the huge pte numa counter (NUMA_HUGE_PTE_UPDATES), not only because DAX is not applicable to NUMA, but also that it's ambiguous on its own to decide how to account pud in this case. In one earlier version of this patchset I proposed to remove the counter as it doesn't even look right to do the accounting as of now [1], but then a further discussion suggests we can leave that for later, as that doesn't block this series if we choose to ignore that counter. That's what this patch does, by ignoring it. When at it, touch up the comment in pgtable_split_needed() to make it generic to either pmd or pud file THPs. [1] https://lore.kernel.org/all/20240715192142.3241557-3-peterx@redhat.com/ [2] https://lore.kernel.org/r/added2d0-b8be-4108-82ca-1367a388d0b1@redhat.com Link: https://lkml.kernel.org/r/20240812181225.1360970-8-peterx@redhat.com Fixes: a00cc7d9dd93 ("mm, x86: add support for PUD-sized transparent hugepages") Fixes: 27af67f35631 ("powerpc/book3s64/mm: enable transparent pud hugepage") Signed-off-by: Peter Xu <peterx@redhat.com> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Dave Jiang <dave.jiang@intel.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Vlastimil Babka <vbabka@suse.cz> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: David Hildenbrand <david@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sean Christopherson <seanjc@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/x86: implement arch_check_zapped_pud()Peter Xu2024-09-021-1/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Introduce arch_check_zapped_pud() to sanity check shadow stack on PUD zaps. It has the same logic as the PMD helper. One thing to mention is, it might be a good idea to use page_table_check in the future for trapping wrong setups of shadow stack pgtable entries [1]. That is left for the future as a separate effort. [1] https://lore.kernel.org/all/59d518698f664e07c036a5098833d7b56b953305.camel@intel.com Link: https://lkml.kernel.org/r/20240812181225.1360970-6-peterx@redhat.com Signed-off-by: Peter Xu <peterx@redhat.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: "Edgecombe, Rick P" <rick.p.edgecombe@intel.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@linux.intel.com> Cc: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Jiang <dave.jiang@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Kirill A. Shutemov <kirill@shutemov.name> Cc: Matthew Wilcox <willy@infradead.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Rik van Riel <riel@surriel.com> Cc: Sean Christopherson <seanjc@google.com> Cc: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/migrate: move common code to numa_migrate_check (was numa_migrate_prep)Zi Yan2024-09-021-18/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | do_numa_page() and do_huge_pmd_numa_page() share a lot of common code. To reduce redundancy, move common code to numa_migrate_prep() and rename the function to numa_migrate_check() to reflect its functionality. Now do_huge_pmd_numa_page() also checks shared folios to set TNF_SHARED flag. Link: https://lkml.kernel.org/r/20240809145906.1513458-4-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Suggested-by: David Hildenbrand <david@redhat.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Yang Shi <shy828301@gmail.com> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm/huge_memory: convert split_huge_pages_pid() from follow_page() to folio_walkDavid Hildenbrand2024-09-021-11/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Let's remove yet another follow_page() user. Note that we have to do the split without holding the PTL, after folio_walk_end(). We don't care about losing the secretmem check in follow_page(). [david@redhat.com: teach can_split_folio() that we are not holding an additional reference] Link: https://lkml.kernel.org/r/c75d1c6c-8ea6-424f-853c-1ccda6c77ba2@redhat.com Link: https://lkml.kernel.org/r/20240802155524.517137-8-david@redhat.com Signed-off-by: David Hildenbrand <david@redhat.com> Reviewed-by: Zi Yan <ziy@nvidia.com> Cc: Alexander Gordeev <agordeev@linux.ibm.com> Cc: Christian Borntraeger <borntraeger@linux.ibm.com> Cc: Claudio Imbrenda <imbrenda@linux.ibm.com> Cc: Gerald Schaefer <gerald.schaefer@linux.ibm.com> Cc: Heiko Carstens <hca@linux.ibm.com> Cc: Janosch Frank <frankja@linux.ibm.com> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Matthew Wilcox <willy@infradead.org> Cc: Sven Schnelle <svens@linux.ibm.com> Cc: Vasily Gorbik <gor@linux.ibm.com> Cc: Ryan Roberts <ryan.roberts@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * memory tiering: introduce folio_use_access_time() checkZi Yan2024-09-021-4/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | If memory tiering mode is on and a folio is not in the top tier memory, folio's cpupid field is repurposed to store page access time. Instead of an open coded check, use a function to encapsulate the check. Link: https://lkml.kernel.org/r/20240724130115.793641-3-ziy@nvidia.com Signed-off-by: Zi Yan <ziy@nvidia.com> Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Baolin Wang <baolin.wang@linux.alibaba.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * memory tiering: read last_cpupid correctly in do_huge_pmd_numa_page()Zi Yan2024-09-021-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Patch series "Various memory tiering fixes", v3. This patch (of 3): last_cpupid is only available when memory tiering is off or the folio is in toptier node. Complete the check to read last_cpupid when it is available. Before the fix, the default last_cpupid will be used even if memory tiering mode is turned off at runtime instead of the actual value. This can prevent task_numa_fault() from getting right numa fault stats, but should not cause any crash. User might see performance changes after the fix. Link: https://lkml.kernel.org/r/20240724130115.793641-1-ziy@nvidia.com Link: https://lkml.kernel.org/r/20240724130115.793641-2-ziy@nvidia.com Fixes: 33024536bafd ("memory tiering: hot page selection with hint page fault latency") Signed-off-by: Zi Yan <ziy@nvidia.com> Reported-by: David Hildenbrand <david@redhat.com> Closes: https://lore.kernel.org/linux-mm/9af34a6b-ca56-4a64-8aa6-ade65f109288@redhat.com/ Reviewed-by: "Huang, Ying" <ying.huang@intel.com> Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com> Acked-by: David Hildenbrand <david@redhat.com> Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com> Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: shmem: move shmem_huge_global_enabled() into shmem_allowable_huge_orders()Baolin Wang2024-09-021-9/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Move shmem_huge_global_enabled() into shmem_allowable_huge_orders(), so that shmem_allowable_huge_orders() can also help to find the allowable huge orders for tmpfs. Moreover the shmem_huge_global_enabled() can become static. While we are at it, passing the vma instead of mm for shmem_huge_global_enabled() makes code cleaner. No functional changes. Link: https://lkml.kernel.org/r/8e825146bb29ee1a1c7bd64d2968ff3e19be7815.1721626645.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
| * mm: shmem: rename shmem_is_huge() to shmem_huge_global_enabled()Baolin Wang2024-09-021-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | shmem_is_huge() is now used to check if the top-level huge page is enabled, thus rename it to reflect its usage. Link: https://lkml.kernel.org/r/da53296e0ab6359aa083561d9dc01e4223d60fbe.1721626645.git.baolin.wang@linux.alibaba.com Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com> Acked-by: David Hildenbrand <david@redhat.com> Cc: Barry Song <21cnbao@gmail.com> Cc: Hugh Dickins <hughd@google.com> Cc: Lance Yang <ioworker0@gmail.com> Cc: Matthew Wilcox (Oracle) <willy@infradead.org> Cc: Zi Yan <ziy@nvidia.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
* | Merge tag 'vfs-6.12.blocksize' of ↵Linus Torvalds2024-09-211-4/+61
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs Pull vfs blocksize updates from Christian Brauner: "This contains the vfs infrastructure as well as the xfs bits to enable support for block sizes (bs) larger than page sizes (ps) plus a few fixes to related infrastructure. There has been efforts over the last 16 years to enable enable Large Block Sizes (LBS), that is block sizes in filesystems where bs > page size. Through these efforts we have learned that one of the main blockers to supporting bs > ps in filesystems has been a way to allocate pages that are at least the filesystem block size on the page cache where bs > ps. Thanks to various previous efforts it is possible to support bs > ps in XFS with only a few changes in XFS itself. Most changes are to the page cache to support minimum order folio support for the target block size on the filesystem. A motivation for Large Block Sizes today is to support high-capacity (large amount of Terabytes) QLC SSDs where the internal Indirection Unit (IU) are typically greater than 4k to help reduce DRAM and so in turn cost and space. In practice this then allows different architectures to use a base page size of 4k while still enabling support for block sizes aligned to the larger IUs by relying on high order folios on the page cache when needed. It also allows to take advantage of the drive's support for atomics larger than 4k with buffered IO support in Linux. As described this year at LSFMM, supporting large atomics greater than 4k enables databases to remove the need to rely on their own journaling, so they can disable double buffered writes, which is a feature different cloud providers are already enabling through custom storage solutions" * tag 'vfs-6.12.blocksize' of gitolite.kernel.org:pub/scm/linux/kernel/git/vfs/vfs: (22 commits) Documentation: iomap: fix a typo iomap: remove the iomap_file_buffered_write_punch_delalloc return value iomap: pass the iomap to the punch callback iomap: pass flags to iomap_file_buffered_write_punch_delalloc iomap: improve shared block detection in iomap_unshare_iter iomap: handle a post-direct I/O invalidate race in iomap_write_delalloc_release docs:filesystems: fix spelling and grammar mistakes in iomap design page filemap: fix htmldoc warning for mapping_align_index() iomap: make zero range flush conditional on unwritten mappings iomap: fix handling of dirty folios over unwritten extents iomap: add a private argument for iomap_file_buffered_write iomap: remove set_memor_ro() on zero page xfs: enable block size larger than page size support xfs: make the calculation generic in xfs_sb_validate_fsb_count() xfs: expose block size in stat xfs: use kvmalloc for xattr buffers iomap: fix iomap_dio_zero() for fs bs > system page size filemap: cap PTE range to be created to allowed zero fill in folio_map_range() mm: split a folio in minimum folio order chunks readahead: allocate folios with mapping_min_order in readahead ...
| * | mm: split a folio in minimum folio order chunksLuis Chamberlain2024-09-021-4/+61
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | split_folio() and split_folio_to_list() assume order 0, to support minorder for non-anonymous folios, we must expand these to check the folio mapping order and use that. Set new_order to be at least minimum folio order if it is set in split_huge_page_to_list() so that we can maintain minimum folio order requirement in the page cache. Update the debugfs write files used for testing to ensure the order is respected as well. We simply enforce the min order when a file mapping is used. Signed-off-by: Luis Chamberlain <mcgrof@kernel.org> Signed-off-by: Pankaj Raghav <p.raghav@samsung.com> Link: https://lore.kernel.org/r/20240902124931.506061-2-kernel@pankajraghav.com # folded fix Link: https://lore.kernel.org/r/20240822135018.1931258-5-kernel@pankajraghav.com Tested-by: David Howells <dhowells@redhat.com> Reviewed-by: Hannes Reinecke <hare@suse.de> Reviewed-by: Zi Yan <ziy@nvidia.com> Signed-off-by: Christian Brauner <brauner@kernel.org>
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-18 09:59:09 +0100