The VM_BUG_ON_PAGE avoids the generation of any code, even if that
expression has side-effects when !CONFIG_DEBUG_VM.

Fixes: e5dfacebe4a4 ("mm/hugetlb.c: just use put_page_testzero() instead of 
page_count()")
Signed-off-by: Muchun Song <[email protected]>
Cc: <[email protected]>
---
 mm/hugetlb.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/mm/hugetlb.c b/mm/hugetlb.c
index a6bad1f686c5..082ed643020b 100644
--- a/mm/hugetlb.c
+++ b/mm/hugetlb.c
@@ -2047,13 +2047,16 @@ static int gather_surplus_pages(struct hstate *h, long 
delta)
 
        /* Free the needed pages to the hugetlb pool */
        list_for_each_entry_safe(page, tmp, &surplus_list, lru) {
+               int zeroed;
+
                if ((--needed) < 0)
                        break;
                /*
                 * This page is now managed by the hugetlb allocator and has
                 * no users -- drop the buddy allocator's reference.
                 */
-               VM_BUG_ON_PAGE(!put_page_testzero(page), page);
+               zeroed = put_page_testzero(page);
+               VM_BUG_ON_PAGE(!zeroed, page);
                enqueue_huge_page(h, page);
        }
 free:
-- 
2.11.0

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