/* * 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(); } }
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(); } }
/* * Exit an interrupt context. Process softirqs if needed and possible: */ void irq_exit(void) { account_system_vtime(current); trace_hardirq_exit(); sub_preempt_count(IRQ_EXIT_OFFSET); if (!in_interrupt() && local_softirq_pending()) invoke_softirq(); #ifdef CONFIG_NO_HZ_COMMON /* Make sure that timer wheel updates are propagated */ if (idle_cpu(smp_processor_id()) && !in_interrupt() && !need_resched()) tick_nohz_irq_exit(); #endif rcu_irq_exit(); sched_preempt_enable_no_resched(); }