On Wed, Dec 08, 2021 at 04:22:13AM +0000, Matthew Wilcox (Oracle) wrote:

+static inline void folio_batch_release(struct folio_batch *fbatch)
+{
+	pagevec_release((struct pagevec *)fbatch);
+}
+
+static inline void folio_batch_remove_exceptionals(struct folio_batch *fbatch)
+{
+	pagevec_remove_exceptionals((struct pagevec *)fbatch);
+}

I think these casts need documentation, both here and at the
struct folio_batch and struct pagevec definitions.

Alternatively I wonder if a union in stuct pagevec so that it can store
folios or pages might be the better option.