[PATCH 0/3] mm,thp,rmap: rework the use of subpages_mapcount

[Hugh Dickins]

Linus was underwhelmed by the earlier compound mapcounts series:
this series builds on top of it (as in next-20221117) to follow
up on his suggestions - except rmap.c still using lock_page_memcg(),
since I hesitate to steal the pleasure of deletion from Johannes.

1/3 mm,thp,rmap: subpages_mapcount of PTE-mapped subpages
2/3 mm,thp,rmap: subpages_mapcount COMPOUND_MAPPED if PMD-mapped
3/3 mm,thp,rmap: clean up the end of __split_huge_pmd_locked()

 Documentation/mm/transhuge.rst |  10 +-
 include/linux/mm.h             |  65 +++++++----
 include/linux/rmap.h           |  12 +-
 mm/debug.c                     |   2 +-
 mm/huge_memory.c               |  15 +--
 mm/rmap.c                      | 213 ++++++++++-------------------------
 6 files changed, 119 insertions(+), 198 deletions(-)

Hugh