--- linux-2.5.69-ia64-perfmon/arch/ia64/kernel/mca.c	2003-05-12 13:21:54.000000000 +0200
+++ linux-2.5.69-ia64-030509.orig/arch/ia64/kernel/mca.c	2003-05-14 14:16:48.000000000 +0200
@@ -344,7 +344,9 @@
 	unw_init_from_interruption(&info, current, pt, sw);
 	ia64_do_show_stack(&info, NULL);
 
+#ifdef CONFIG_SMP
 	if (!tasklist_lock.write_lock)
+#endif
 		read_lock(&tasklist_lock);
 	{
 		struct task_struct *g, *t;
@@ -356,7 +358,9 @@
 			show_stack(t);
 		} while_each_thread (g, t);
 	}
+#ifdef CONFIG_SMP
 	if (!tasklist_lock.write_lock)
+#endif
 		read_unlock(&tasklist_lock);
 
 	printk("\nINIT dump complete.  Please reboot now.\n");