--- 2.6.3/drivers/acpi/sleep/poweroff.c	2004-03-02 17:16:16.000000000 +0800
+++ b/drivers/acpi/sleep/poweroff.c	2004-03-08 09:13:28.677822328 +0800
@@ -8,11 +8,14 @@
 #include <linux/pm.h>
 #include <linux/init.h>
 #include <acpi/acpi_bus.h>
+#include <linux/sched.h>
 
 static void
 acpi_power_off (void)
 {
 	printk("%s called\n",__FUNCTION__);
+	/* Some SMP machines only can poweroff in boot CPU */
+	set_cpus_allowed(current, cpumask_of_cpu(0));
 	acpi_enter_sleep_state_prep(ACPI_STATE_S5);
 	ACPI_DISABLE_IRQS();
 	acpi_enter_sleep_state(ACPI_STATE_S5);