Commit 820c4e2e authored Sep 30, 2020 by Matthew Wilcox (Oracle)

mm/vmscan: Free non-shmem folios without splitting them

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>

parent 84fbbe21

mm/vmscan.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1739,8 +1739,8 @@ static unsigned int shrink_page_list(struct list_head *page_list,
		/* 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;
		}