Hi all This patchset adds a new buddy allocator like large folio split to the total number of resulting folios, the amount of memory needed for multi-index xarray split, and keep more large folios after a split. It is on top of linux-next-20241204 and just a resend of v3. Instead of duplicating existing split_huge_page*() code, __folio_split() is introduced as the shared backend code for both split_huge_page_to_list_to_order() and folio_split(). __folio_split() can support both uniform split and buddy allocator like split. All existing split_huge_page*() users can be gradually converted to use folio_split() if possible. In this patchset, I converted truncate_inode_partial_folio() to use folio_split(). THP tests in selftesting passed for split_huge_page*() runs and I also tested folio_split() for anon large folio, pagecache folio, and truncate. Changelog ===
