Re: [RFC PATCH 2/3] cpuidle: move the cpuidle_idle_call function toidle.c

From: Nicolas Pitre
Date: Thu Jan 30 2014 - 14:43:09 EST


On Thu, 30 Jan 2014, Daniel Lezcano wrote:

> Now the cpuidle_idle_call does nothing more than calling the three individuals
> function, we can move this function into the idle task code to ensure better
> proximity to the scheduler code.
>
> Signed-off-by: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>

Acked-by: Nicolas Pitre <nico@xxxxxxxxxx>

> ---
> drivers/cpuidle/cpuidle.c | 37 -------------------------------------
> include/linux/cpuidle.h | 2 --
> kernel/sched/idle.c | 44 ++++++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 44 insertions(+), 39 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index a8fbb28..a039344 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -176,43 +176,6 @@ void cpuidle_reflect(struct cpuidle_device *dev, int index)
> EXPORT_SYMBOL(cpuidle_reflect);
>
> /**
> - * cpuidle_idle_call - the main idle loop
> - *
> - * NOTE: no locks or semaphores should be used here
> - * return non-zero on failure
> - */
> -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;
> -
> - /* ask the governor for the next state */
> - 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 */
> - cpuidle_reflect(dev, next_state);
> - local_irq_enable();
> - return 0;
> - }
> -
> - trace_cpu_idle_rcuidle(next_state, 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 */
> - cpuidle_reflect(dev, entered_state);
> -
> - return 0;
> -}
> -
> -/**
> * cpuidle_install_idle_handler - installs the cpuidle idle loop handler
> */
> void cpuidle_install_idle_handler(void)
> diff --git a/include/linux/cpuidle.h b/include/linux/cpuidle.h
> index 1ebe9ff..74cdfc9 100644
> --- a/include/linux/cpuidle.h
> +++ b/include/linux/cpuidle.h
> @@ -126,7 +126,6 @@ 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);
> extern struct cpuidle_driver *cpuidle_driver_ref(void);
> @@ -148,7 +147,6 @@ 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_idle_call(void) { return -ENODEV; }
> static inline int cpuidle_register_driver(struct cpuidle_driver *drv)
> {return -ENODEV; }
> static inline struct cpuidle_driver *cpuidle_get_driver(void) {return NULL; }
> diff --git a/kernel/sched/idle.c b/kernel/sched/idle.c
> index 65d0427..3e85d38 100644
> --- a/kernel/sched/idle.c
> +++ b/kernel/sched/idle.c
> @@ -62,6 +62,50 @@ void __weak arch_cpu_idle(void)
> local_irq_enable();
> }
>
> +#ifdef CONFIG_CPU_IDLE
> +/**
> + * cpuidle_idle_call - the main idle function
> + *
> + * NOTE: no locks or semaphores should be used here
> + * return non-zero on failure
> + */
> +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;
> +
> + /* ask the governor for the next state */
> + 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 */
> + cpuidle_reflect(dev, next_state);
> + local_irq_enable();
> + return 0;
> + }
> +
> + trace_cpu_idle_rcuidle(next_state, 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 */
> + cpuidle_reflect(dev, entered_state);
> +
> + return 0;
> +}
> +#else
> +static inline int cpuidle_idle_call(void)
> +{
> + return -ENODEV;
> +}
> +#endif
> +
> /*
> * Generic idle loop implementation
> */
> --
> 1.7.9.5
>
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