Ryan Roberts <ryan.roberts@xxxxxxx> writes: > With the introduction of large folios for anonymous memory, we would > like to be able to split them when they have unmapped subpages, in order > to free those unused pages under memory pressure. So remove the > artificial requirement that the large folio needed to be at least > PMD-sized. > > Signed-off-by: Ryan Roberts <ryan.roberts@xxxxxxx> > Reviewed-by: Yu Zhao <yuzhao@xxxxxxxxxx> > Reviewed-by: Yin Fengwei <fengwei.yin@xxxxxxxxx> > --- > mm/rmap.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/mm/rmap.c b/mm/rmap.c > index 82ef5ba363d1..bbcb2308a1c5 100644 > --- a/mm/rmap.c > +++ b/mm/rmap.c > @@ -1474,7 +1474,7 @@ void page_remove_rmap(struct page *page, struct vm_area_struct *vma, > * page of the folio is unmapped and at least one page > * is still mapped. > */ > - if (folio_test_pmd_mappable(folio) && folio_test_anon(folio)) > + if (folio_test_large(folio) && folio_test_anon(folio)) > if (!compound || nr < nr_pmdmapped) > deferred_split_folio(folio); > } One possible issue is that even for large folios mapped only in one process, in zap_pte_range(), we will always call deferred_split_folio() unnecessarily before freeing a large folio. Best Regards, Huang, Ying
