Encapsulate the large portion of cpuidle_idle_call inside another function so when CONFIG_CPU_IDLE=n, the code will be compiled out. Also that is benefitial for the clarity of the code as it removes a nested indentation level.
Signed-off-by: Daniel Lezcano daniel.lezcano@linaro.org --- kernel/sched/idle.c | 161 +++++++++++++++++++++++++++------------------------ 1 file changed, 86 insertions(+), 75 deletions(-)
diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c index 8f4390a..e877dd4 100644 --- a/kernel/sched/idle.c +++ b/kernel/sched/idle.c @@ -63,6 +63,90 @@ void __weak arch_cpu_idle(void) local_irq_enable(); }
+#ifdef CONFIG_CPU_IDLE +static int __cpuidle_idle_call(void) +{ + struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); + int next_state, entered_state, ret; + bool broadcast; + + /* + * Check if the cpuidle framework is ready, otherwise fallback + * to the default arch specific idle method + */ + ret = cpuidle_enabled(drv, dev); + if (ret) + return ret; + + /* + * Ask the governor to choose an idle state it thinks + * it is convenient to go to. There is *always* a + * convenient idle state + */ + next_state = cpuidle_select(drv, dev); + + /* + * The idle task must be scheduled, it is pointless to + * go to idle, just update no idle residency and get + * out of this function + */ + if (current_clr_polling_and_test()) { + dev->last_residency = 0; + entered_state = next_state; + local_irq_enable(); + } else { + broadcast = !!(drv->states[next_state].flags & + CPUIDLE_FLAG_TIMER_STOP); + + if (broadcast) + /* + * Tell the time framework to switch to a + * broadcast timer because our local timer + * will be shutdown. If a local timer is used + * from another cpu as a broadcast timer, this + * call may fail if it is not available + */ + ret = clockevents_notify( + CLOCK_EVT_NOTIFY_BROADCAST_ENTER, + &dev->cpu); + + if (!ret) { + trace_cpu_idle_rcuidle(next_state, dev->cpu); + + /* + * Enter the idle state previously returned by + * the governor decision. This function will + * block until an interrupt occurs and will + * take care of re-enabling the local + * interrupts + */ + entered_state = cpuidle_enter(drv, dev, next_state); + + trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); + + if (broadcast) + clockevents_notify( + CLOCK_EVT_NOTIFY_BROADCAST_EXIT, + &dev->cpu); + + /* + * Give the governor an opportunity to reflect + * on the outcome + */ + cpuidle_reflect(dev, entered_state); + } + } + + return 0; +} +#else +static int inline __cpuidle_idle_call(void) +{ + return -ENOSYS; +} +#endif + /** * cpuidle_idle_call - the main idle function * @@ -71,10 +155,7 @@ void __weak arch_cpu_idle(void) */ static int cpuidle_idle_call(void) { - struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); - struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); - int next_state, entered_state, ret; - bool broadcast; + int ret;
/* * Check if the idle task must be rescheduled. If it is the @@ -101,80 +182,10 @@ static int cpuidle_idle_call(void) rcu_idle_enter();
/* - * Check if the cpuidle framework is ready, otherwise fallback - * to the default arch specific idle method - */ - ret = cpuidle_enabled(drv, dev); - - if (!ret) { - /* - * Ask the governor to choose an idle state it thinks - * it is convenient to go to. There is *always* a - * convenient idle state - */ - next_state = cpuidle_select(drv, dev); - - /* - * The idle task must be scheduled, it is pointless to - * go to idle, just update no idle residency and get - * out of this function - */ - if (current_clr_polling_and_test()) { - dev->last_residency = 0; - entered_state = next_state; - local_irq_enable(); - } else { - broadcast = !!(drv->states[next_state].flags & - CPUIDLE_FLAG_TIMER_STOP); - - if (broadcast) - /* - * Tell the time framework to switch - * to a broadcast timer because our - * local timer will be shutdown. If a - * local timer is used from another - * cpu as a broadcast timer, this call - * may fail if it is not available - */ - ret = clockevents_notify( - CLOCK_EVT_NOTIFY_BROADCAST_ENTER, - &dev->cpu); - - if (!ret) { - trace_cpu_idle_rcuidle(next_state, dev->cpu); - - /* - * Enter the idle state previously - * returned by the governor - * decision. This function will block - * until an interrupt occurs and will - * take care of re-enabling the local - * interrupts - */ - entered_state = cpuidle_enter(drv, dev, - next_state); - - trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, - dev->cpu); - - if (broadcast) - clockevents_notify( - CLOCK_EVT_NOTIFY_BROADCAST_EXIT, - &dev->cpu); - - /* - * Give the governor an opportunity to reflect on the - * outcome - */ - cpuidle_reflect(dev, entered_state); - } - } - } - - /* * We can't use the cpuidle framework, let's use the default * idle routine */ + ret = __cpuidle_idle_call(); if (ret) arch_cpu_idle();