diff --git a/arch/x86/mm/init.c b/arch/x86/mm/init.c
index 4393af3c2bd5..5d35b555115a 100644
--- a/arch/x86/mm/init.c
+++ b/arch/x86/mm/init.c
@@ -783,6 +783,7 @@ void update_cache_mode_entry(unsigned entry, enum page_cache_mode cache)
 	__pte2cachemode_tbl[entry] = cache;
 }
 
+#ifdef CONFIG_SWAP
 unsigned long max_swapfile_size(void)
 {
 	unsigned long pages;
@@ -803,3 +804,4 @@ unsigned long max_swapfile_size(void)
 	}
 	return pages;
 }
+#endif