On Tue, 11 Feb 2014, Daniel Lezcano wrote: > In order to allow better integration between the cpuidle framework and the > scheduler, reducing the distance between these two sub-components will > facilitate this integration by moving part of the cpuidle code in the idle > task file and, because idle.c is in the sched directory, we have access to > the scheduler's private structures. > > This patch splits the cpuidle_idle_call main entry function into 3 calls > to a newly added API: > 1. select the idle state > 2. enter the idle state > 3. reflect the idle state > > The cpuidle_idle_call calls these three functions to implement the main > idle entry function. > > Signed-off-by: Daniel Lezcano <[email protected]>
Acked-by: Nicolas Pitre <[email protected]> > --- > drivers/cpuidle/cpuidle.c | 102 > ++++++++++++++++++++++++++++++++------------- > include/linux/cpuidle.h | 14 +++++++ > 2 files changed, 87 insertions(+), 29 deletions(-) > > diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c > index a55e68f..172ab6a 100644 > --- a/drivers/cpuidle/cpuidle.c > +++ b/drivers/cpuidle/cpuidle.c > @@ -108,6 +108,71 @@ int cpuidle_enter_state(struct cpuidle_device *dev, > struct cpuidle_driver *drv, > } > > /** > + * cpuidle_select - ask the cpuidle framework to choose an idle state > + * > + * @drv: the cpuidle driver > + * @dev: the cpuidle device > + * > + * Returns the index of the idle state. On error it returns: > + * -NODEV : the cpuidle framework is not available > + * -EBUSY : the cpuidle framework is not initialized > + */ > +int cpuidle_select(struct cpuidle_driver *drv, struct cpuidle_device *dev) > +{ > + if (off || !initialized) > + return -ENODEV; > + > + if (!drv || !dev || !dev->enabled) > + return -EBUSY; > + > + return cpuidle_curr_governor->select(drv, dev); > +} > + > +/** > + * cpuidle_enter - enter into the specified idle state > + * > + * @drv: the cpuidle driver tied with the cpu > + * @dev: the cpuidle device > + * @index: the index in the idle state table > + * > + * Returns the index in the idle state, < 0 in case of error. > + * The error code depends on the backend driver > + */ > +int cpuidle_enter(struct cpuidle_driver *drv, struct cpuidle_device *dev, > + int index) > +{ > + int entered_state; > + bool broadcast = !!(drv->states[index].flags & CPUIDLE_FLAG_TIMER_STOP); > + > + if (broadcast) > + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); > + > + if (cpuidle_state_is_coupled(dev, drv, index)) > + entered_state = cpuidle_enter_state_coupled(dev, drv, index); > + else > + entered_state = cpuidle_enter_state(dev, drv, index); > + > + if (broadcast) > + clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); > + > + return entered_state; > +} > + > +/** > + * cpuidle_reflect - tell the underlying governor what was the state > + * we were in > + * > + * @dev : the cpuidle device > + * @index: the index in the idle state table > + * > + */ > +void cpuidle_reflect(struct cpuidle_device *dev, int index) > +{ > + if (cpuidle_curr_governor->reflect) > + cpuidle_curr_governor->reflect(dev, index); > +} > + > +/** > * cpuidle_idle_call - the main idle loop > * > * NOTE: no locks or semaphores should be used here > @@ -116,51 +181,30 @@ int cpuidle_enter_state(struct cpuidle_device *dev, > struct cpuidle_driver *drv, > int cpuidle_idle_call(void) > { > struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices); > - struct cpuidle_driver *drv; > + struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev); > int next_state, entered_state; > - bool broadcast; > - > - if (off || !initialized) > - return -ENODEV; > - > - /* check if the device is ready */ > - if (!dev || !dev->enabled) > - return -EBUSY; > - > - drv = cpuidle_get_cpu_driver(dev); > > /* ask the governor for the next state */ > - next_state = cpuidle_curr_governor->select(drv, dev); > + next_state = cpuidle_select(drv, dev); > + if (next_state < 0) > + return next_state; > + > if (need_resched()) { > dev->last_residency = 0; > /* give the governor an opportunity to reflect on the outcome */ > - if (cpuidle_curr_governor->reflect) > - cpuidle_curr_governor->reflect(dev, next_state); > + cpuidle_reflect(dev, next_state); > local_irq_enable(); > return 0; > } > > trace_cpu_idle_rcuidle(next_state, dev->cpu); > > - broadcast = !!(drv->states[next_state].flags & CPUIDLE_FLAG_TIMER_STOP); > - > - if (broadcast) > - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_ENTER, &dev->cpu); > - > - if (cpuidle_state_is_coupled(dev, drv, next_state)) > - entered_state = cpuidle_enter_state_coupled(dev, drv, > - next_state); > - else > - entered_state = cpuidle_enter_state(dev, drv, next_state); > - > - if (broadcast) > - clockevents_notify(CLOCK_EVT_NOTIFY_BROADCAST_EXIT, &dev->cpu); > + entered_state = cpuidle_enter(drv, dev, next_state); > > trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu); > > /* give the governor an opportunity to reflect on the outcome */ > - if (cpuidle_curr_governor->reflect) > - cpuidle_curr_governor->reflect(dev, entered_state); > + cpuidle_reflect(dev, entered_state); > > return 0; > } > diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h > index 50fcbb0..bf06f37 100644 > --- a/include/linux/cpuidle.h > +++ b/include/linux/cpuidle.h > @@ -119,6 +119,13 @@ struct cpuidle_driver { > > #ifdef CONFIG_CPU_IDLE > extern void disable_cpuidle(void); > + > +extern int cpuidle_select(struct cpuidle_driver *drv, > + struct cpuidle_device *dev); > +extern int cpuidle_enter(struct cpuidle_driver *drv, > + struct cpuidle_device *dev, int index); > +extern void cpuidle_reflect(struct cpuidle_device *dev, int index); > + > extern int cpuidle_idle_call(void); > extern int cpuidle_register_driver(struct cpuidle_driver *drv); > extern struct cpuidle_driver *cpuidle_get_driver(void); > @@ -141,6 +148,13 @@ extern int cpuidle_play_dead(void); > extern struct cpuidle_driver *cpuidle_get_cpu_driver(struct cpuidle_device > *dev); > #else > static inline void disable_cpuidle(void) { } > +static inline int cpuidle_select(struct cpuidle_driver *drv, > + struct cpuidle_device *dev) > +{return -ENODEV; } > +static inline int cpuidle_enter(struct cpuidle_driver *drv, > + struct cpuidle_device *dev, int index) > +{return -ENODEV; } > +static inline void cpuidle_reflect(struct cpuidle_device *dev, int index) { } > static inline int cpuidle_idle_call(void) { return -ENODEV; } > static inline int cpuidle_register_driver(struct cpuidle_driver *drv) > {return -ENODEV; } > -- > 1.7.9.5 > -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
