[v3,0/8] mm: migrate: more folio conversion and unification

Message

Kefeng Wang Sept. 13, 2023, 9:51 a.m. UTC

Convert more migrate functions to use a folio, it is also a preparation
for large folio migration support when numa balance.

The patch 1~2	remove unexpected specific assert for PageTransHuge page.

The Patch 3~6	convert several more migration functions to use folio. 
		1) add_page_for_migration() used by move_pages
		2) migrate_misplaced_page()/numamigrate_isolate_page()
		   used by numa balance

The patch 7	remove PageHead() check to make hugetlb to migrate the
		entire hugetlb page instead of -EACCES errno return when
		passed the address of a tail page.

The patch 8	cleanup to unify and simplify code a bit in
		add_page_for_migration()

Thanks for all comments and suggestions from Matthew, Hugh, Zi, Mike, Huang.

v3:
- update changelog of patch1
- use folio_estimated_sharers and comment it in migrate_misplaced_folio()
- collect RB/ACK
- rebased on 6.6-rc1

v2:
- keep page_mapcount() check and remove specific assert for
  PageTransHuge page.
- separate patch7 to migrate the entire hugetlb page if a tail page passed,
  which unified the behavior between HUGETLB and THP when move_page().

Kefeng Wang (8):
  mm: migrate: remove PageTransHuge check in numamigrate_isolate_page()
  mm: migrate: remove THP mapcount check in numamigrate_isolate_page()
  mm: migrate: convert numamigrate_isolate_page() to
    numamigrate_isolate_folio()
  mm: migrate: convert migrate_misplaced_page() to
    migrate_misplaced_folio()
  mm: migrate: use __folio_test_movable()
  mm: migrate: use a folio in add_page_for_migration()
  mm: migrate: remove PageHead() check for HugeTLB in
    add_page_for_migration()
  mm: migrate: remove isolated variable in add_page_for_migration()

 include/linux/migrate.h |   4 +-
 mm/huge_memory.c        |   2 +-
 mm/memory.c             |   2 +-
 mm/migrate.c            | 126 ++++++++++++++++++----------------------
 4 files changed, 62 insertions(+), 72 deletions(-)