[PATCHv3 00/12] Fix few rmap-related THP bugs

["Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>]

The patch fixes handing PTE-mapped THPs in page_referenced() and
page_idle_clear_pte_refs().

To achieve that I've intrdocued new helper -- page_vma_mapped_walk() -- which
replaces all page_check_address{,_transhuge}() and covers all THP cases.

Patchset overview:
  - First patch fixes one uprobe bug (unrelated to the rest of the
    patchset, just spotted it at the same time);

  - Patches 2-5 fix handling PTE-mapped THPs in page_referenced(),
    page_idle_clear_pte_refs() and rmap core;

  - Patches 6-12 convert all page_check_address{,_transhuge}() users (plus
    remove_migration_pte()) to page_vma_mapped_walk() and drop unused helpers.

I think the fixes are not critical enough for stable@ as they don't lead
to crashes or hangs, only suboptimal behaviour.

Please review and consider applying.

v3:
  - fix page_vma_mapped_walk() breakage;
  - fix one more build error reported by 0-day testing;
  - Add few Acked-by/Reviewed-by;
v2:
  - address feedback from Andrew;
  - fix build errors noticed by 0-day testing.

Kirill A. Shutemov (12):
  uprobes: split THPs before trying replace them
  mm: introduce page_vma_mapped_walk()
  mm: fix handling PTE-mapped THPs in page_referenced()
  mm: fix handling PTE-mapped THPs in page_idle_clear_pte_refs()
  mm, rmap: check all VMAs that PTE-mapped THP can be part of
  mm: convert page_mkclean_one() to use page_vma_mapped_walk()
  mm: convert try_to_unmap_one() to use page_vma_mapped_walk()
  mm, ksm: convert write_protect_page() to use page_vma_mapped_walk()
  mm, uprobes: convert __replace_page() to use page_vma_mapped_walk()
  mm: convert page_mapped_in_vma() to use page_vma_mapped_walk()
  mm: drop page_check_address{,_transhuge}
  mm: convert remove_migration_pte() to use page_vma_mapped_walk()

 include/linux/rmap.h    |  52 ++---
 kernel/events/uprobes.c |  26 ++-
 mm/Makefile             |   6 +-
 mm/huge_memory.c        |  25 +--
 mm/internal.h           |   9 +-
 mm/ksm.c                |  34 +--
 mm/migrate.c            | 104 ++++-----
 mm/page_idle.c          |  34 +--
 mm/page_vma_mapped.c    | 218 ++++++++++++++++++
 mm/rmap.c               | 574 +++++++++++++++++++-----------------------------
 10 files changed, 573 insertions(+), 509 deletions(-)
 create mode 100644 mm/page_vma_mapped.c

-- 
2.11.0

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