1 files changed, 9 insertions, 4 deletions
diff --git a/mm/gup.c b/mm/gup.c
index be2a41feec7d..f0af462ac1e2 100644
--- a/mm/gup.c
+++ b/mm/gup.c
@@ -642,12 +642,17 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma,
 	}
 retry:
 	if (!pmd_present(pmdval)) {
+		/*
+		 * Should never reach here, if thp migration is not supported;
+		 * Otherwise, it must be a thp migration entry.
+		 */
+		VM_BUG_ON(!thp_migration_supported() ||
+				  !is_pmd_migration_entry(pmdval));
+
 		if (likely(!(flags & FOLL_MIGRATION)))
 			return no_page_table(vma, flags);
-		VM_BUG_ON(thp_migration_supported() &&
-				  !is_pmd_migration_entry(pmdval));
-		if (is_pmd_migration_entry(pmdval))
-			pmd_migration_entry_wait(mm, pmd);
+
+		pmd_migration_entry_wait(mm, pmd);
 		pmdval = READ_ONCE(*pmd);
 		/*
 		 * MADV_DONTNEED may convert the pmd to null because