linux-kernel - Re: [PATCH V2 14/16] cpuidle: don't calculate time-diff if entered

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Date:	Wed, 20 Nov 2013 13:34:45 +0530
From:	Viresh Kumar <viresh.kumar@...aro.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Lists linaro-kernel <linaro-kernel@...ts.linaro.org>,
	Patch Tracking <patches@...aro.org>,
	"linux-pm@...r.kernel.org" <linux-pm@...r.kernel.org>,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Viresh Kumar <viresh.kumar@...aro.org>,
	Daniel Lezcano <daniel.lezcano@...aro.org>
Subject: Re: [PATCH V2 14/16] cpuidle: don't calculate time-diff if
 entered_state < 0

On 3 October 2013 21:26, Viresh Kumar <viresh.kumar@...aro.org> wrote:
> If entered_state < 0, we don't need to set dev->last_residency to 'diff' as we
> will be setting it to zero without using its new value.
>
> And so move calculation of diff also inside the "if" statement.
>
> Acked-by: Daniel Lezcano <daniel.lezcano@...aro.org>
> Signed-off-by: Viresh Kumar <viresh.kumar@...aro.org>
> ---
>  drivers/cpuidle/cpuidle.c | 17 +++++++++--------
>  1 file changed, 9 insertions(+), 8 deletions(-)

Missed applying this one too?

>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index b45257a..1a6e9f5 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -77,23 +77,22 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
>
>         struct cpuidle_state *target_state = &drv->states[index];
>         ktime_t time_start, time_end;
> -       s64 diff;
>
>         time_start = ktime_get();
>
>         entered_state = target_state->enter(dev, drv, index);
>
> -       time_end = ktime_get();
> +       if (entered_state >= 0) {
> +               s64 diff;
>
> -       local_irq_enable();
> +               time_end = ktime_get();
> +               diff = ktime_to_us(ktime_sub(time_end, time_start));
>
> -       diff = ktime_to_us(ktime_sub(time_end, time_start));
> -       if (diff > INT_MAX)
> -               diff = INT_MAX;
> +               if (diff > INT_MAX)
> +                       diff = INT_MAX;
>
> -       dev->last_residency = (int) diff;
> +               dev->last_residency = (int) diff;
>
> -       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.
> @@ -104,6 +103,8 @@ int cpuidle_enter_state(struct cpuidle_device *dev, struct cpuidle_driver *drv,
>                 dev->last_residency = 0;
>         }
>
> +       local_irq_enable();
> +
>         return entered_state;
>  }
>
> --
> 1.7.12.rc2.18.g61b472e
>
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