[PATCH v2 04/28] gup: Optimise compound_range_next()

From: Matthew Wilcox (Oracle)
Date: Sun Jan 09 2022 - 23:25:59 EST


By definition, a compound page has an order >= 1, so the second half
of the test was redundant. Also, this cannot be a tail page since
it's the result of calling compound_head(), so use PageHead() instead
of PageCompound().

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

diff --git a/mm/gup.c b/mm/gup.c
index 3c93d2fdf4da..6eedca605b3d 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -237,7 +237,7 @@ static inline struct page *compound_range_next(unsigned long i,

next = start + i;
page = compound_head(next);
- if (PageCompound(page) && compound_order(page) >= 1)
+ if (PageHead(page))
nr = min_t(unsigned int,
page + compound_nr(page) - next, npages - i);

--
2.33.0