Re: [PATCH 1/2] cpuidle: fix finding state with min power_usage

From: Rafael J. Wysocki
Date: Fri Dec 14 2012 - 18:56:59 EST


On Friday, December 14, 2012 03:17:36 PM Sivaram Nair wrote:
> Since cpuidle_state.power_usage is a signed value, use INT_MAX (instead
> of -1) to init the local copies so that functions that tries to find
> cpuidle states with minimum power usage works correctly even if they use
> non-negative values.

I'm queuing this up for submission as v3.8 material.

Thanks,
Rafael


> Signed-off-by: Sivaram Nair <sivaramn@xxxxxxxxxx>
> ---
> drivers/cpuidle/cpuidle.c | 2 +-
> drivers/cpuidle/governors/menu.c | 2 +-
> 2 files changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c
> index 8df53dd..fb4a7dd 100644
> --- a/drivers/cpuidle/cpuidle.c
> +++ b/drivers/cpuidle/cpuidle.c
> @@ -70,7 +70,7 @@ int cpuidle_play_dead(void)
> struct cpuidle_device *dev = __this_cpu_read(cpuidle_devices);
> struct cpuidle_driver *drv = cpuidle_get_cpu_driver(dev);
> int i, dead_state = -1;
> - int power_usage = -1;
> + int power_usage = INT_MAX;
>
> if (!drv)
> return -ENODEV;
> diff --git a/drivers/cpuidle/governors/menu.c b/drivers/cpuidle/governors/menu.c
> index bd40b94..20ea33a 100644
> --- a/drivers/cpuidle/governors/menu.c
> +++ b/drivers/cpuidle/governors/menu.c
> @@ -312,7 +312,7 @@ static int menu_select(struct cpuidle_driver *drv, struct cpuidle_device *dev)
> {
> struct menu_device *data = &__get_cpu_var(menu_devices);
> int latency_req = pm_qos_request(PM_QOS_CPU_DMA_LATENCY);
> - int power_usage = -1;
> + int power_usage = INT_MAX;
> int i;
> int multiplier;
> struct timespec t;
>
--
I speak only for myself.
Rafael J. Wysocki, Intel Open Source Technology Center.
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