[PATCH v2 02/25] mm: Optimise find_subpage for !THP

Matthew Wilcox
2020-02-12T04:20:31Z

From: "Matthew Wilcox (Oracle)" <willy@infradead.org>

If THP is disabled, find_subpage can become a no-op.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
---
include/linux/pagemap.h | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h
index 75bdfec49710..0842622cca90 100644
--- a/include/linux/pagemap.h
+++ b/include/linux/pagemap.h
@@ -340,7 +340,7 @@ static inline struct page *find_subpage(struct page *page, pgoff_t offset)

VM_BUG_ON_PAGE(PageTail(page), page);

- return page + (offset & (compound_nr(page) - 1));
+ return page + (offset & (hpage_nr_pages(page) - 1));
}

struct page *find_get_entry(struct address_space *mapping, pgoff_t offset);
--
2.25.0