История изменений

!*===========================================================================*
!*				idle_task				     *
!*===========================================================================*
_idle_task:			! executed when there is no work
	jmp	_idle_task	! a "hlt" before this fails in protected mode

/*===========================================================================*
 *				idle					     * 
 *===========================================================================*/
static void idle(void)
{
	struct proc * p;

	/* This function is called whenever there is no work to do.
	 * Halt the CPU, and measure how many timestamp counter ticks are
	 * spent not doing anything. This allows test setups to measure
	 * the CPU utilization of certain workloads with high precision.
	 */

	p = get_cpulocal_var(proc_ptr) = get_cpulocal_var_ptr(idle_proc);
	if (priv(p)->s_flags & BILLABLE)
		get_cpulocal_var(bill_ptr) = p;

	switch_address_space_idle();

#ifdef CONFIG_SMP
	get_cpulocal_var(cpu_is_idle) = 1;
	/* we don't need to keep time on APs as it is handled on the BSP */
	if (cpuid != bsp_cpu_id)
		stop_local_timer();
	else
#endif
	{
		/*
		 * If the timer has expired while in kernel we must
		 * rearm it before we go to sleep
		 */
		restart_local_timer();
	}

	/* start accounting for the idle time */
	context_stop(proc_addr(KERNEL));
#if !SPROFILE
	halt_cpu();
#else
	if (!sprofiling)
		halt_cpu();
	else {
		volatile int * v;

		v = get_cpulocal_var_ptr(idle_interrupted);
		interrupts_enable();
		while (!*v)
			arch_pause();
		interrupts_disable();
		*v = 0;
	}
#endif
	/*
	 * end of accounting for the idle task does not happen here, the kernel
	 * is handling stuff for quite a while before it gets back here!
	 */
}

!*===========================================================================*
!*				idle_task				     *
!*===========================================================================*
_idle_task:			! executed when there is no work
	jmp	_idle_task	! a "hlt" before this fails in protected mode