예제 #1
0
static int default_idle(void)
{
	long oldval;
	unsigned int cpu = smp_processor_id();

	while (1) {
		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);

		if (!oldval) {
			set_thread_flag(TIF_POLLING_NRFLAG);

			while (!need_resched() && !cpu_is_offline(cpu)) {
				barrier();
				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();
			}

			HMT_medium();
			clear_thread_flag(TIF_POLLING_NRFLAG);
		} else {
			set_need_resched();
		}

		schedule();
		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}

	return 0;
}
예제 #2
0
/*
 * The body of the idle task.
 */
void cpu_idle(void)
{
	if (ppc_md.idle_loop)
		ppc_md.idle_loop();	/* doesn't return */

	set_thread_flag(TIF_POLLING_NRFLAG);
	while (1) {
		tick_nohz_idle_enter();
		rcu_idle_enter();

		while (!need_resched() && !cpu_should_die()) {
			ppc64_runlatch_off();

			if (ppc_md.power_save) {
				clear_thread_flag(TIF_POLLING_NRFLAG);
				/*
				 * smp_mb is so clearing of TIF_POLLING_NRFLAG
				 * is ordered w.r.t. need_resched() test.
				 */
				smp_mb();
				local_irq_disable();

				/* Don't trace irqs off for idle */
				stop_critical_timings();

				/* check again after disabling irqs */
				if (!need_resched() && !cpu_should_die())
					ppc_md.power_save();

				start_critical_timings();

				/* Some power_save functions return with
				 * interrupts enabled, some don't.
				 */
				if (irqs_disabled())
					local_irq_enable();
				set_thread_flag(TIF_POLLING_NRFLAG);

			} else {
				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();
			}
		}

		HMT_medium();
		ppc64_runlatch_on();
		rcu_idle_exit();
		tick_nohz_idle_exit();
		if (cpu_should_die()) {
			sched_preempt_enable_no_resched();
			cpu_die();
		}
		schedule_preempt_disabled();
	}
}
예제 #3
0
/*
 * The body of the idle task.
 */
void cpu_idle(void)
{
	if (ppc_md.idle_loop)
		ppc_md.idle_loop();	/* doesn't return */

	set_thread_flag(TIF_POLLING_NRFLAG);
	while (1) {
		hrtimer_stop_sched_tick();

		while (!need_resched() && !need_resched_delayed() &&
				!cpu_should_die()) {
			ppc64_runlatch_off();
			/*
			 *
			 * We have irqs disabled here, so stop latency tracing
			 * at this point and restart it after we return:
			 */
			stop_critical_timing();

			if (ppc_md.power_save) {
				clear_thread_flag(TIF_POLLING_NRFLAG);
				/*
				 * smp_mb is so clearing of TIF_POLLING_NRFLAG
				 * is ordered w.r.t. need_resched() test.
				 */
				smp_mb();
				local_irq_disable();

				/* check again after disabling irqs */
				if (!need_resched() && !cpu_should_die())
					ppc_md.power_save();

				local_irq_enable();
				set_thread_flag(TIF_POLLING_NRFLAG);

			} else {
				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();
			}

			touch_critical_timing();
		}

		HMT_medium();
		ppc64_runlatch_on();
		if (cpu_should_die())
			cpu_die();

		hrtimer_restart_sched_tick();
		__preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}
예제 #4
0
static int pseries_dedicated_idle(void)
{
	long oldval;
	struct paca_struct *lpaca = get_paca();
	unsigned int cpu = smp_processor_id();
	unsigned long start_snooze;
	unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);

	while (1) {
		/*
		 * Indicate to the HV that we are idle. Now would be
		 * a good time to find other work to dispatch.
		 */
		lpaca->lppaca.idle = 1;

		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
		if (!oldval) {
			set_thread_flag(TIF_POLLING_NRFLAG);

			start_snooze = __get_tb() +
				*smt_snooze_delay * tb_ticks_per_usec;

			while (!need_resched() && !cpu_is_offline(cpu)) {
				ppc64_runlatch_off();

				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();

				if (*smt_snooze_delay != 0 &&
				    __get_tb() > start_snooze) {
					HMT_medium();
					dedicated_idle_sleep(cpu);
				}

			}

			HMT_medium();
			clear_thread_flag(TIF_POLLING_NRFLAG);
		} else {
			set_need_resched();
		}

		lpaca->lppaca.idle = 0;
		ppc64_runlatch_on();

		schedule();

		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}
}
예제 #5
0
void cpu_idle(void)
{
	if (ppc_md.idle_loop)
		ppc_md.idle_loop();	

	set_thread_flag(TIF_POLLING_NRFLAG);
	while (1) {
		tick_nohz_idle_enter();
		rcu_idle_enter();

		while (!need_resched() && !cpu_should_die()) {
			ppc64_runlatch_off();

			if (ppc_md.power_save) {
				clear_thread_flag(TIF_POLLING_NRFLAG);
				smp_mb();
				local_irq_disable();

				
				stop_critical_timings();

				
				if (!need_resched() && !cpu_should_die())
					ppc_md.power_save();

				start_critical_timings();

				if (irqs_disabled())
					local_irq_enable();
				set_thread_flag(TIF_POLLING_NRFLAG);

			} else {
				HMT_low();
				HMT_very_low();
			}
		}

		HMT_medium();
		ppc64_runlatch_on();
		rcu_idle_exit();
		tick_nohz_idle_exit();
		if (cpu_should_die()) {
			sched_preempt_enable_no_resched();
			cpu_die();
		}
		schedule_preempt_disabled();
	}
}
예제 #6
0
파일: idle.c 프로젝트: 274914765/C
/*
 * The body of the idle task.
 */
void cpu_idle(void)
{
    if (ppc_md.idle_loop)
        ppc_md.idle_loop();    /* doesn't return */

    set_thread_flag(TIF_POLLING_NRFLAG);
    while (1) {
        tick_nohz_stop_sched_tick();
        while (!need_resched() && !cpu_should_die()) {
            ppc64_runlatch_off();

            if (ppc_md.power_save) {
                clear_thread_flag(TIF_POLLING_NRFLAG);
                /*
                 * smp_mb is so clearing of TIF_POLLING_NRFLAG
                 * is ordered w.r.t. need_resched() test.
                 */
                smp_mb();
                local_irq_disable();

                /* check again after disabling irqs */
                if (!need_resched() && !cpu_should_die())
                    ppc_md.power_save();

                local_irq_enable();
                set_thread_flag(TIF_POLLING_NRFLAG);

            } else {
                /*
                 * Go into low thread priority and possibly
                 * low power mode.
                 */
                HMT_low();
                HMT_very_low();
            }
        }

        HMT_medium();
        ppc64_runlatch_on();
        tick_nohz_restart_sched_tick();
        if (cpu_should_die())
            cpu_die();
        preempt_enable_no_resched();
        schedule();
        preempt_disable();
    }
}
예제 #7
0
static int pseries_shared_idle(void)
{
	struct paca_struct *lpaca = get_paca();
	unsigned int cpu = smp_processor_id();

	while (1) {
		/*
		 * Indicate to the HV that we are idle. Now would be
		 * a good time to find other work to dispatch.
		 */
		lpaca->lppaca.idle = 1;

		while (!need_resched() && !cpu_is_offline(cpu)) {
			local_irq_disable();
			ppc64_runlatch_off();

			/*
			 * Yield the processor to the hypervisor.  We return if
			 * an external interrupt occurs (which are driven prior
			 * to returning here) or if a prod occurs from another
			 * processor. When returning here, external interrupts
			 * are enabled.
			 *
			 * Check need_resched() again with interrupts disabled
			 * to avoid a race.
			 */
			if (!need_resched())
				cede_processor();
			else
				local_irq_enable();

			HMT_medium();
		}

		lpaca->lppaca.idle = 0;
		ppc64_runlatch_on();

		schedule();

		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}

	return 0;
}
/*
 * The idle thread, has rather strange semantics for calling pm_idle,
 * but this is what x86 does and we need to do the same, so that
 * things like cpuidle get called in the same way.  The only difference
 * is that we always respect 'hlt_counter' to prevent low power idle.
 */
void cpu_idle(void)
{
	local_fiq_enable();

	/* endless idle loop with no priority at all */
	while (1) {
		idle_notifier_call_chain(IDLE_START);
		tick_nohz_idle_enter();
		rcu_idle_enter();
		while (!need_resched()) {
			/*
			 * We need to disable interrupts here
			 * to ensure we don't miss a wakeup call.
			 */
			local_irq_disable();
#ifdef CONFIG_PL310_ERRATA_769419
			wmb();
#endif
			if (hlt_counter) {
				local_irq_enable();
				cpu_relax();
			} else if (!need_resched()) {
				stop_critical_timings();
				if (cpuidle_idle_call())
					pm_idle();
				start_critical_timings();
				/*
				 * pm_idle functions must always
				 * return with IRQs enabled.
				 */
				WARN_ON(irqs_disabled());
			} else
				local_irq_enable();
		}
		rcu_idle_exit();
		tick_nohz_idle_exit();
		idle_notifier_call_chain(IDLE_END);
		schedule_preempt_disabled();
#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_is_offline(smp_processor_id()))
			cpu_die();
#endif
	}
}
예제 #9
0
/*
 * The body of the idle task.
 */
void cpu_idle(void)
{
	int cpu = smp_processor_id();

	for (;;) {
		while (!need_resched()) {
			if (ppc_md.idle != NULL)
				ppc_md.idle();
			else
				default_idle();
		}

		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}
예제 #10
0
파일: process.c 프로젝트: E-LLP/n900
/*
 * The idle thread.  We try to conserve power, while trying to keep
 * overall latency low.  The architecture specific idle is passed
 * a value to indicate the level of "idleness" of the system.
 */
void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		void (*idle)(void) = pm_idle;

#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_is_offline(smp_processor_id()))
			cpu_die();
#endif
		if (!idle)
			idle = default_idle;
		tick_nohz_stop_sched_tick(1);
		while (!need_resched())
			idle();
		tick_nohz_restart_sched_tick();
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}
예제 #11
0
void cpu_idle(void)
{
	
	while (1) {
		void (*idle)(void) = pm_idle;

#ifdef CONFIG_HOTPLUG_CPU
		if (cpu_is_offline(smp_processor_id()))
			cpu_die();
#endif
		if (!idle)
			idle = default_idle;
		tick_nohz_idle_enter();
		rcu_idle_enter();
		while (!need_resched())
			idle();
		rcu_idle_exit();
		tick_nohz_idle_exit();
		schedule_preempt_disabled();
	}
}
예제 #12
0
/*
 * The idle thread. There's no useful work to be done, so just try to conserve
 * power and have a low exit latency (ie sit in a loop waiting for somebody to
 * say that they'd like to reschedule)
 */
ATTRIB_NORET void cpu_idle(void)
{
	/* endless idle loop with no priority at all */
	while (1) {
		while (!need_resched()) {
#ifdef CONFIG_SMTC_IDLE_HOOK_DEBUG
			extern void smtc_idle_loop_hook(void);

			smtc_idle_loop_hook();
#endif
#ifdef CONFIG_HOTPLUG_CPU
			if (cpu_is_offline(smp_processor_id()))
				cpu_die();
#endif
			if (cpu_wait)
				(*cpu_wait)();
		}
		preempt_enable_no_resched();
		schedule();
		preempt_disable();
	}
}
예제 #13
0
파일: process.c 프로젝트: 1800alex/linux
void arch_cpu_idle_dead(void)
{
	cpu_die();
}
예제 #14
0
int dedicated_idle(void)
{
	long oldval;
	struct paca_struct *lpaca = get_paca(), *ppaca;
	unsigned long start_snooze;
	unsigned long *smt_snooze_delay = &__get_cpu_var(smt_snooze_delay);
	unsigned int cpu = smp_processor_id();

	ppaca = &paca[cpu ^ 1];

	while (1) {
		/*
		 * Indicate to the HV that we are idle. Now would be
		 * a good time to find other work to dispatch.
		 */
		lpaca->lppaca.xIdle = 1;

		oldval = test_and_clear_thread_flag(TIF_NEED_RESCHED);
		if (!oldval) {
			set_thread_flag(TIF_POLLING_NRFLAG);
			start_snooze = __get_tb() +
				*smt_snooze_delay * tb_ticks_per_usec;
			while (!need_resched() && !cpu_is_offline(cpu)) {
				/*
				 * Go into low thread priority and possibly
				 * low power mode.
				 */
				HMT_low();
				HMT_very_low();

				if (*smt_snooze_delay == 0 ||
				    __get_tb() < start_snooze)
					continue;

				HMT_medium();

				if (!(ppaca->lppaca.xIdle)) {
					local_irq_disable();

					/*
					 * We are about to sleep the thread
					 * and so wont be polling any
					 * more.
					 */
					clear_thread_flag(TIF_POLLING_NRFLAG);

					/*
					 * SMT dynamic mode. Cede will result
					 * in this thread going dormant, if the
					 * partner thread is still doing work.
					 * Thread wakes up if partner goes idle,
					 * an interrupt is presented, or a prod
					 * occurs.  Returning from the cede
					 * enables external interrupts.
					 */
					if (!need_resched())
						cede_processor();
					else
						local_irq_enable();
				} else {
					/*
					 * Give the HV an opportunity at the
					 * processor, since we are not doing
					 * any work.
					 */
					poll_pending();
				}
			}

			clear_thread_flag(TIF_POLLING_NRFLAG);
		} else {
			set_need_resched();
		}

		HMT_medium();
		lpaca->lppaca.xIdle = 0;
		schedule();
		if (cpu_is_offline(cpu) && system_state == SYSTEM_RUNNING)
			cpu_die();
	}
	return 0;
}