[RFC Patch 00/11] Convert huge page split API to folio-style

[Wei Yang <richard.weiyang@gmail.com>]

This patch series continues the effort to modernize the huge page
management layer by converting internal users to the folio-style API
and eliminating redundant, older page-style interfaces.

Currently, the code maintains two parallel sets of APIs for huge page
splitting, which adds unnecessary complexity and maintenance burden:

page-style APIs:

    __split_huge_page_to_list_to_order
    split_huge_page_to_list_to_order
    split_huge_page_to_order
    split_huge_page

folio-style APIs:

    try_folio_split_to_order
    folio_split_unmapped
    folio_split
    split_folio
    split_folio_to_list
    split_folio_to_order
    split_folio_to_list_to_order

After cleanup, we would have:

page-style:

    split_huge_page

folio-style:

    try_folio_split_to_order
    folio_split_unmapped
    folio_split
    folio_split_uniform
    split_folio
    split_folio_to_list
    split_folio_to_order

The only page-style API left is split_huge_page() which requires a 
specified page to be locked after split. It is possible to rename and 
convert it to folio-style. Currently it is left to get some comment.

Wei Yang (11):
  mm/huge_memory: relocate fundamental folio split comment to
    __folio_split()
  mm/huge_memory: remove split_folio_to_list_to_order() helper
  mm/huge_memory: convert try_folio_split_to_order() to use
    split_folio_to_order()
  mm/memory-failure: convert try_to_split_thp_page() to use
    split_folio_to_order()
  mm/huge_memory: remove unused function split_huge_page_to_order()
  mm/huge_memory: introduce __split_folio_and_update_stats() to
    consolidate split task
  mm/huge_memory: separate uniform/non uniform split logic in
    __split_unmapped_folio()
  mm/huge_memory: restrict @split_at check to non-uniform splits
  mm/huge_memory: introduce folio_split_uniform() helper for uniform
    splitting
  mm/huge_memory: convert folio split helpers to use
    folio_split_uniform()
  mm/huge_memory: simplify split_huge_page() by calling __folio_split()
    directly

 include/linux/huge_mm.h |  48 +++--------
 mm/huge_memory.c        | 181 ++++++++++++++++++++++------------------
 mm/memory-failure.c     |   7 +-
 3 files changed, 116 insertions(+), 120 deletions(-)

-- 
2.34.1