Transparent Hugepages for non-tmpfs filesystems

After months of merging prep patches, here's the end result.  It holds
up to xfstests on both shmem and xfs.  It's based on linux-next as of
a couple of days ago, plus several of the patches I've sent in the
last week:
https://lore.kernel.org/linux-mm/20201026041408.25230-1-w...
https://lore.kernel.org/linux-mm/20201026151849.24232-1-w...
https://lore.kernel.org/linux-mm/20201026183136.10404-1-w...

You can get a complete git tree here:
http://git.infradead.org/users/willy/pagecache.git/shortl...

This tree only includes support for XFS.  It would probably be
straightforward to add support to ZoneFS (which also uses iomap), but I
haven't looked into it.  Dave Howells has AFS support working based on
these patches:
https://git.kernel.org/pub/scm/linux/kernel/git/dhowells/...

Matthew Wilcox (Oracle) (18):
  XArray: Expose xas_destroy
  mm: Use multi-index entries in the page cache
  mm: Support arbitrary THP sizes
  mm: Change NR_FILE_THPS to account in base pages
  mm/filemap: Rename generic_file_buffered_read subfunctions
  mm/filemap: Change calling convention for gfbr_ functions
  mm/filemap: Use head pages in generic_file_buffered_read
  mm/filemap: Add __page_cache_alloc_order
  mm/filemap: Allow THPs to be added to the page cache
  mm/vmscan: Optimise shrink_page_list for smaller THPs
  mm/filemap: Allow PageReadahead to be set on head pages
  mm: Pass a sleep state to put_and_wait_on_page_locked
  mm/filemap: Support readpage splitting a page
  mm/filemap: Inline __wait_on_page_locked_async into caller
  mm/readahead: Add THP readahead
  mm/readahead: Switch to page_cache_ra_order
  mm/filemap: Support VM_HUGEPAGE for file mappings
  selftests/vm/transhuge-stress: Support file-backed THPs

William Kucharski (1):
  mm/readahead: Align THP mappings for non-DAX

 drivers/base/node.c                           |   3 +-
 fs/proc/meminfo.c                             |   2 +-
 include/linux/huge_mm.h                       |   8 +-
 include/linux/mm.h                            |  42 +-
 include/linux/mmzone.h                        |   2 +-
 include/linux/page-flags.h                    |   4 +-
 include/linux/pagemap.h                       |  37 +-
 include/linux/xarray.h                        |   1 +
 lib/xarray.c                                  |   7 +-
 mm/filemap.c                                  | 399 ++++++++++--------
 mm/huge_memory.c                              |  31 +-
 mm/internal.h                                 |   4 +-
 mm/khugepaged.c                               |  15 +-
 mm/migrate.c                                  |  12 +-
 mm/readahead.c                                | 102 ++++-
 mm/shmem.c                                    |  11 +-
 mm/vmscan.c                                   |   3 +-
 tools/testing/selftests/vm/transhuge-stress.c |  36 +-
 18 files changed, 430 insertions(+), 289 deletions(-)

-- 
2.28.0