[PATCHv2 00/12] Fix few rmap-related THP bugs

From: Kirill A. Shutemov
Date: Wed Jan 25 2017 - 13:27:09 EST

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

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.

- 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 page_vma_mapped_walk()
mm: convert try_to_unmap_one() to page_vma_mapped_walk()
mm, ksm: convert write_protect_page() to page_vma_mapped_walk()
mm, uprobes: convert __replace_page() to page_vma_mapped_walk()
mm: convert page_mapped_in_vma() to page_vma_mapped_walk()
mm: drop page_check_address{,_transhuge}
mm: convert remove_migration_pte() to 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 | 211 ++++++++++++++++++
mm/rmap.c | 574 +++++++++++++++++++-----------------------------
10 files changed, 566 insertions(+), 509 deletions(-)
create mode 100644 mm/page_vma_mapped.c