[PATCH v3 19/25] mm: Allow large pages to be removed from the page cache

From: Matthew Wilcox
Date: Wed Apr 29 2020 - 09:37:47 EST


From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx>

page_cache_free_page() assumes compound pages are PMD_SIZE; fix
that assumption.

Signed-off-by: Matthew Wilcox (Oracle) <willy@xxxxxxxxxxxxx>
---
mm/filemap.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/mm/filemap.c b/mm/filemap.c
index 842afee3d066..8c174e6064d4 100644
--- a/mm/filemap.c
+++ b/mm/filemap.c
@@ -248,7 +248,7 @@ static void page_cache_free_page(struct address_space *mapping,
freepage(page);

if (PageTransHuge(page) && !PageHuge(page)) {
- page_ref_sub(page, HPAGE_PMD_NR);
+ page_ref_sub(page, hpage_nr_pages(page));
VM_BUG_ON_PAGE(page_count(page) <= 0, page);
} else {
put_page(page);
--
2.26.2