On 10 Mar 2025, at 12:14, Zi Yan wrote: > On 7 Mar 2025, at 12:39, Zi Yan wrote: > >> This is a preparation patch, both added functions are not used yet. >> >> The added __split_unmapped_folio() is able to split a folio with its >> mapping removed in two manners: 1) uniform split (the existing way), and >> 2) buddy allocator like (or non-uniform) split. >> >> The added __split_folio_to_order() can split a folio into any lower order. >> For uniform split, __split_unmapped_folio() calls it once to split the >> given folio to the new order. For buddy allocator like (non-uniform) >> split, __split_unmapped_folio() calls it (folio_order - new_order) times >> and each time splits the folio containing the given page to one lower >> order. >> >> Signed-off-by: Zi Yan <ziy@xxxxxxxxxx> >> Cc: Baolin Wang <baolin.wang@xxxxxxxxxxxxxxxxx> >> Cc: David Hildenbrand <david@xxxxxxxxxx> >> Cc: Hugh Dickins <hughd@xxxxxxxxxx> >> Cc: John Hubbard <jhubbard@xxxxxxxxxx> >> Cc: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx> >> Cc: Kirill A. Shuemov <kirill.shutemov@xxxxxxxxxxxxxxx> >> Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx> >> Cc: Miaohe Lin <linmiaohe@xxxxxxxxxx> >> Cc: Ryan Roberts <ryan.roberts@xxxxxxx> >> Cc: Yang Shi <yang@xxxxxxxxxxxxxxxxxxxxxx> >> Cc: Yu Zhao <yuzhao@xxxxxxxxxx> >> Cc: Kairui Song <kasong@xxxxxxxxxxx> >> --- >> mm/huge_memory.c | 348 ++++++++++++++++++++++++++++++++++++++++++++++- >> 1 file changed, 347 insertions(+), 1 deletion(-) > > Hi Andrew, > > The patch below should fix the issues discovered by Hugh. Please fold > it into this patch. Thank you for all the help. > Hi Andrew, This is the updated version including: 1. Hugh’s fix on unfreezing head folio correctly, 2. Hugh’s fix on drop the right number of refs on tail folio, 3. Matthew’s suggestion on using new_folio instead of new_head and using i instead of index.
