preempt_disable();
void cpu_idle(void){	/* endless idle loop with no priority at all */	for (;;) {		/* If current->work.need_resched is zero we should really		 * setup for a system wakup event and execute a shutdown		 * instruction.		 *		 * But this requires writing back the contents of the		 * L2 cache etc. so implement this later. -DaveM		 */		while (!need_resched())			barrier();		schedule();		check_pgt_cache();	}}