--- a/arch/i386/kernel/io_apic.c
+++ b/arch/i386/kernel/io_apic.c
@@ -2034,7 +2034,9 @@
 	.disable 	= mask_IO_APIC_irq,
 	.ack 		= ack_edge_ioapic,
 	.end 		= end_edge_ioapic,
+#ifdef CONFIG_SMP
 	.set_affinity 	= set_ioapic_affinity,
+#endif
 };
 #endif