[PATCH v1 04/11] mm: thp: simlify total_mapcount()

[David Hildenbrand <david@redhat.com>]

Let's simplify a bit, returning for PageHuge() early and using
head_compound_page() as we are only getting called for HEAD pages.

Note the VM_BUG_ON_PAGE(PageTail(page), page) check at the beginning of
total_mapcount().

This is a preparation for further changes.

Reviewed-by: Peter Xu <peterx@redhat.com>
Signed-off-by: David Hildenbrand <david@redhat.com>
---
 mm/huge_memory.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/mm/huge_memory.c b/mm/huge_memory.c
index 4751d03947da..826cabcad11a 100644
--- a/mm/huge_memory.c
+++ b/mm/huge_memory.c
@@ -2506,12 +2506,11 @@ int total_mapcount(struct page *page)
 
 	if (likely(!PageCompound(page)))
 		return atomic_read(&page->_mapcount) + 1;
+	if (PageHuge(page))
+		return head_compound_mapcount(page);
 
-	compound = compound_mapcount(page);
 	nr = compound_nr(page);
-	if (PageHuge(page))
-		return compound;
-	ret = compound;
+	ret = compound = head_compound_mapcount(page);
 	for (i = 0; i < nr; i++)
 		ret += atomic_read(&page[i]._mapcount) + 1;
 	/* File pages has compound_mapcount included in _mapcount */
-- 
2.31.1