Re: [PATCH] cpuidle: governor: menu: move repeated correction factor check to init

From: Tuukka Tikkanen
Date: Thu Apr 10 2014 - 10:27:41 EST


On 10 April 2014 16:43, Chander Kashyap <chander.kashyap@xxxxxxxxxx> wrote:
> In menu_select function we check for correction factor every time.
> If it is zero we are initializing to unity. Hence move it to init function
> and initialise by unity, hence avoid repeated comparisons.
>
> Signed-off-by: Chander Kashyap <chander.kashyap@xxxxxxxxxx>
> ---
> drivers/cpuidle/governors/menu.c | 15 ++++++++-------
> 1 file changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
> index cf7f2f0..048f6d9 100644
> --- a/drivers/cpuidle/governors/menu.c
> +++ b/drivers/cpuidle/governors/menu.c
> @@ -315,13 +315,6 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
> multiplier = performance_multiplier();
>
> /*
> - * if the correction factor is 0 (eg first time init or cpu hotplug
> - * etc), we actually want to start out with a unity factor.
> - */
> - if (data->correction_factor[data->bucket] == 0)
> - data->correction_factor[data->bucket] = RESOLUTION * DECAY;
> -
> - /*
> * Force the result of multiplication to be 64 bits even if both
> * operands are 32 bits.
> * Make sure to round up for half microseconds.
> @@ -453,9 +446,17 @@ static int menu_enable_device(struct cpuidle_driver *drv,
> struct cpuidle_device *dev)
> {
> struct menu_device *data = &per_cpu(menu_devices, dev->cpu);
> + int i;
>
> memset(data, 0, sizeof(struct menu_device));
>
> + /*
> + * if the correction factor is 0 (eg first time init or cpu hotplug
> + * etc), we actually want to start out with a unity factor.
> + */
> + for(i = 0; i < BUCKETS; i++)
> + data->correction_factor[i] = RESOLUTION * DECAY;
> +
> return 0;
> }
>
> --
> 1.7.9.5
>

Reviewed-by: Tuukka Tikkanen <tuukka.tikkanen@xxxxxxxxxx>
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/