From:   "Matthew Wilcox (Oracle)" <willy@infradead.org>
To:     linux-mm@kvack.org
Cc:     "Matthew Wilcox (Oracle)" <willy@infradead.org>,
        John Hubbard <jhubbard@nvidia.com>,
        Christoph Hellwig <hch@infradead.org>,
        William Kucharski <william.kucharski@oracle.com>,
        linux-kernel@vger.kernel.org, Jason Gunthorpe <jgg@ziepe.ca>
Subject: [PATCH v2 04/28] gup: Optimise compound_range_next()
Date:   Mon, 10 Jan 2022 04:23:42 +0000
Message-Id: <20220110042406.499429-5-willy@infradead.org>
In-Reply-To: <20220110042406.499429-1-willy@infradead.org>
References: <20220110042406.499429-1-willy@infradead.org>
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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@infradead.org>
---
 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