Re: [PATCHv3 1/5] cpuidle: refactor out cpuidle_enter_state

From: Rafael J. Wysocki
Date: Thu May 03 2012 - 16:45:23 EST


On Monday, April 30, 2012, Colin Cross wrote:
> Split the code to enter a state and update the stats into a helper
> function, cpuidle_enter_state, and export it. This function will
> be called by the coupled state code to handle entering the safe
> state and the final coupled state.
>
> Reviewed-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> Tested-by: Santosh Shilimkar <santosh.shilimkar@xxxxxx>
> Reviewed-by: Kevin Hilman <khilman@xxxxxx>
> Tested-by: Kevin Hilman <khilman@xxxxxx>
> Signed-off-by: Colin Cross <ccross@xxxxxxxxxxx>

Reviewed-by: Rafael J. Wysocki <rjw@xxxxxxx>

> ---
> drivers/cpuidle/cpuidle.c | 42 +++++++++++++++++++++++++++++-------------
> drivers/cpuidle/cpuidle.h | 2 ++
> 2 files changed, 31 insertions(+), 13 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index 2f0083a..3e3e3e4 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -103,6 +103,34 @@ int cpuidle_play_dead(void)
> }
>
> /**
> + * cpuidle_enter_state - enter the state and update stats
> + * @dev: cpuidle device for this cpu
> + * @drv: cpuidle driver for this cpu
> + * @next_state: index into drv->states of the state to enter
> + */
> +int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
> + int next_state)
> +{
> + int entered_state;
> +
> + entered_state = cpuidle_enter_ops(dev, drv, next_state);
> +
> + if (entered_state >= 0) {
> + /* Update cpuidle counters */
> + /* This can be moved to within driver enter routine
> + * but that results in multiple copies of same code.
> + */
> + dev->states_usage[entered_state].time +=
> + (unsigned long long)dev->last_residency;
> + dev->states_usage[entered_state].usage++;
> + } else {
> + dev->last_residency = 0;
> + }
> +
> + return entered_state;
> +}
> +
> +/**
> * cpuidle_idle_call - the main idle loop
> *
> * NOTE: no locks or semaphores should be used here
> @@ -143,23 +171,11 @@ int cpuidle_idle_call(void)
> trace_power_start_rcuidle(POWER_CSTATE, next_state, dev->cpu);
> trace_cpu_idle_rcuidle(next_state, dev->cpu);
>
> - entered_state = cpuidle_enter_ops(dev, drv, next_state);
> + entered_state = cpuidle_enter_state(dev, drv, next_state);
>
> trace_power_end_rcuidle(dev->cpu);
> trace_cpu_idle_rcuidle(PWR_EVENT_EXIT, dev->cpu);
>
> - if (entered_state >= 0) {
> - /* Update cpuidle counters */
> - /* This can be moved to within driver enter routine
> - * but that results in multiple copies of same code.
> - */
> - dev->states_usage[entered_state].time +=
> - (unsigned long long)dev->last_residency;
> - dev->states_usage[entered_state].usage++;
> - } else {
> - dev->last_residency = 0;
> - }
> -
> /* give the governor an opportunity to reflect on the outcome */
> if (cpuidle_curr_governor->reflect)
> cpuidle_curr_governor->reflect(dev, entered_state);
> diff --git a/drivers/cpuidle/cpuidle.h b/drivers/cpuidle/cpuidle.h
> index 7db1866..d8a3ccc 100644
> --- a/drivers/cpuidle/cpuidle.h
> +++ b/drivers/cpuidle/cpuidle.h
> @@ -14,6 +14,8 @@
> extern struct mutex cpuidle_lock;
> extern spinlock_t cpuidle_driver_lock;
> extern int cpuidle_disabled(void);
> +extern int cpuidle_enter_state(struct cpuidle_device *dev,
> + struct cpuidle_driver *drv, int next_state);
>
> /* idle loop */
> extern void cpuidle_install_idle_handler(void);
>

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