On Mon, 14 Apr 2014, Peter Zijlstra wrote: > On Mon, Apr 14, 2014 at 10:59:11AM +0200, Peter Zijlstra wrote: > > > Why not using braces here and moving the use_default code block inside > > > it instead? > > > > I didn't because there's two goto use_default sites, but sure, I can do > > that.
Ah, I initially missed the second site, but still. > --- > Subject: sched,idle: Reflow cpuidle_idle_call() > From: Peter Zijlstra <pet...@infradead.org> > Date: Fri Apr 11 13:55:48 CEST 2014 > > Apply goto to reduce lines and nesting levels. > > Cc: Nicolas Pitre <nicolas.pi...@linaro.org> > Cc: Daniel Lezcano <daniel.lezc...@linaro.org> > Cc: Thomas Gleixner <t...@linutronix.de> > Signed-off-by: Peter Zijlstra <pet...@infradead.org> > Link: http://lkml.kernel.org/n/tip-xt260n72av3ip7jsaef2p...@git.kernel.org Acked-by: Nicolas Pitre <n...@linaro.org> > --- > kernel/sched/idle.c | 131 > +++++++++++++++++++++++----------------------------- > 1 file changed, 58 insertions(+), 73 deletions(-) > > --- a/kernel/sched/idle.c > +++ b/kernel/sched/idle.c > @@ -73,7 +73,7 @@ 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; > + int next_state, entered_state; > bool broadcast; > > /* > @@ -102,90 +102,75 @@ static int cpuidle_idle_call(void) > * 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); > - > + if (cpuidle_enabled(drv, dev)) { > +use_default: > /* > - * The idle task must be scheduled, it is pointless to > - * go to idle, just update no idle residency and get > - * out of this function > + * We can't use the cpuidle framework, let's use the default > + * idle routine. > */ > - if (current_clr_polling_and_test()) { > - dev->last_residency = 0; > - entered_state = next_state; > + if (current_clr_polling_and_test()) > 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); > - } > - } > + else > + arch_cpu_idle(); > + > + goto exit_idle; > } > > /* > - * We can't use the cpuidle framework, let's use the default > - * idle routine > + * Ask the governor to choose an idle state it thinks > + * it is convenient to go to. There is *always* a > + * convenient idle state > */ > - if (ret) { > - if (!current_clr_polling_and_test()) > - arch_cpu_idle(); > - else > - local_irq_enable(); > + 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(); > + goto exit_idle; > } > > + broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP); > + > + /* > + * 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 > + */ > + if (broadcast && > + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu)) > + goto use_default; > + > + 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); > + > +exit_idle: > __current_set_polling(); > > /* > - * It is up to the idle functions to enable back the local > - * interrupt > + * It is up to the idle functions to reenable local interrupts > */ > if (WARN_ON_ONCE(irqs_disabled())) > local_irq_enable(); > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
