[0/7] thp/khugepaged improvements and CoW semantics

Message

Kirill A. Shutemov March 27, 2020, 5:05 p.m. UTC

The patchset adds khugepaged selftest (anon-THP only for now), expands
cases khugepaged can handle and switches anon-THP copy-on-write handling
to 4k.

Please review and consider applying.

Kirill A. Shutemov (7):
  khugepaged: Add self test
  khugepaged: Do not stop collapse if less than half PTEs are referenced
  khugepaged: Drain LRU add pagevec to get rid of extra pins
  khugepaged: Allow to callapse a page shared across fork
  khugepaged: Allow to collapse PTE-mapped compound pages
  thp: Change CoW semantics for anon-THP
  khugepaged: Introduce 'max_ptes_shared' tunable

 Documentation/admin-guide/mm/transhuge.rst |   7 +
 mm/huge_memory.c                           | 247 +-----
 mm/khugepaged.c                            | 124 ++-
 tools/testing/selftests/vm/Makefile        |   1 +
 tools/testing/selftests/vm/khugepaged.c    | 924 +++++++++++++++++++++
 5 files changed, 1057 insertions(+), 246 deletions(-)
 create mode 100644 tools/testing/selftests/vm/khugepaged.c