We have to allocate memory in order to split a file-backed folio, so
it's not a good idea to split them in the memory freeing path. It also
doesn't work for XFS because pages have an extra reference count from
page_has_private() and split_huge_page() expects that reference to have
already been removed. Unfortunately, we still have to split shmem THPs
because we can't handle swapping out an entire THP yet.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
/* Adding to swap updated mapping */
mapping = page_mapping(page);
}
- } else if (unlikely(PageTransHuge(page))) {
- /* Split file THP */
+ } else if (PageSwapBacked(page) && PageTransHuge(page)) {
+ /* Split shmem THP */
if (split_folio_to_list(folio, page_list))
goto keep_locked;
}