x86: debug: double-check the empty zero page

temporary debugging - remove before this hits v2.6.25.
Signed-off-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NThomas Gleixner <tglx@linutronix.de>

arch/x86/mm/init_64.c

@@ -497,6 +497,14 @@ void __init mem_init(void)
 
 	/* clear_bss() already clear the empty_zero_page */
 
+	/* temporary debugging - double check it's true: */
+	{
+		int i;
+
+		for (i = 0; i < 1024; i++)
+			WARN_ON_ONCE(empty_zero_page[i]);
+	}
+
 	reservedpages = 0;
 
 	/* this will put all low memory onto the freelists */