[v3,00/12] Overhaul multi-page lookups for THP

Message

Matthew Wilcox Oct. 26, 2020, 4:13 a.m. UTC

This THP prep patchset changes several page cache iteration APIs to only
return head pages.

 - It's only possible to tag head pages in the page cache, so only
   return head pages, not all their subpages.
 - Factor a lot of common code out of the various batch lookup routines
 - Add mapping_seek_hole_data()
 - Unify find_get_entries() and pagevec_lookup_entries()
 - Make find_get_entries only return head pages, like find_get_entry().

These are only loosely connected, but they seem to make sense together
as a series.  Another ~30 MM patches to come after this batch to
enable THPs for filesystems.

Matthew Wilcox (Oracle) (12):
  mm: Make pagecache tagged lookups return only head pages
  mm/shmem: Use pagevec_lookup in shmem_unlock_mapping
  mm/filemap: Add helper for finding pages
  mm/filemap: Add mapping_seek_hole_data
  mm: Add and use find_lock_entries
  mm: Add an 'end' parameter to find_get_entries
  mm: Add an 'end' parameter to pagevec_lookup_entries
  mm: Remove nr_entries parameter from pagevec_lookup_entries
  mm: Pass pvec directly to find_get_entries
  mm: Remove pagevec_lookup_entries
  mm/truncate,shmem: Handle truncates that split THPs
  mm/filemap: Return only head pages from find_get_entries

 include/linux/pagemap.h |   5 +-
 include/linux/pagevec.h |   4 -
 mm/filemap.c            | 275 +++++++++++++++++++++++++++-------------
 mm/internal.h           |   5 +
 mm/shmem.c              | 213 +++++++------------------------
 mm/swap.c               |  38 +-----
 mm/truncate.c           | 249 ++++++++++++++----------------------
 7 files changed, 335 insertions(+), 454 deletions(-)