[PW_SID:976439] [1/1] mm/rmap: make folio unmap batching safe and support partial batches#582
[PW_SID:976439] [1/1] mm/rmap: make folio unmap batching safe and support partial batches#582linux-riscv-bot wants to merge 2 commits into
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As pointed out by David[1], the batched unmap logic in try_to_unmap_one() can read past the end of a PTE table if a large folio is mapped starting at the last entry of that table. So let's fix the out-of-bounds read by refactoring the logic into a new helper, folio_unmap_pte_batch(). The new helper now correctly calculates the safe number of pages to scan by limiting the operation to the boundaries of the current VMA and the PTE table. In addition, the "all-or-nothing" batching restriction is removed to support partial batches. The reference counting is also cleaned up to use folio_put_refs(). [1] https://lore.kernel.org/linux-mm/a694398c-9f03-4737-81b9-7e49c857fcbe@redhat.com Fixes: 354dffd ("mm: support batched unmap for lazyfree large folios during reclamation") Suggested-by: David Hildenbrand <david@redhat.com> Suggested-by: Barry Song <baohua@kernel.org> Signed-off-by: Lance Yang <lance.yang@linux.dev> Signed-off-by: Linux RISC-V bot <linux.riscv.bot@gmail.com>
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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Patch 1: "[1/1] mm/rmap: make folio unmap batching safe and support partial batches" |
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PR for series 976439 applied to workflow__riscv__fixes
Name: [1/1] mm/rmap: make folio unmap batching safe and support partial batches
URL: https://patchwork.kernel.org/project/linux-riscv/list/?series=976439
Version: 1