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if the > trylock loses a race, the entries are left behind even though the folio > reference is dropped. The sub folios are still locked and unmapped > here, so just directly call folio_free_swap() directly under the lock, > unlock and drop the reference. This makes the swap cache freeing > deterministic and the reference drop explicit. > > Signed-off-by: Kairui Song > --- > mm/huge_memory.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index b80d0db63225..39c91c8e5bc8 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -4304,14 +4304,16 @@ static int __folio_split(struct folio *folio, uns= igned int new_order, > if (new_folio =3D=3D page_folio(lock_at)) > continue; > =20 > - folio_unlock(new_folio); > /* > * Subpages whose mapping has been zapped may be freed > * earlier, but freeing them requires taking the > * lru_lock, so we defer put_page() on tail pages until > * after the split completes. this comment needs some love. > */ > - free_folio_and_swap_cache(new_folio); > + if (is_swapcache) > + folio_free_swap(new_folio); > + folio_unlock(new_folio); > + folio_put(new_folio); > } > =20 > out: folio_split_unmaped()'s comment still refers to free_folio_and_swap_cache(). Otherwise, LGTM. Reviewed-by: Zi Yan --=20 Best Regards, Yan, Zi