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

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Date:	Tue, 22 Apr 2014 15:24:21 +0530
From:	Chander Kashyap <chander.kashyap@...aro.org>
To:	"Rafael J. Wysocki" <rjw@...ysocki.net>
Cc:	Tuukka Tikkanen <tuukka.tikkanen@...aro.org>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	rafael.j.wysocki@...el.com,
	Daniel Lezcano <daniel.lezcano@...aro.org>,
	linux-pm@...r.kernel.org
Subject: Re: [PATCH] cpuidle: governor: menu: move repeated correction factor
 check to init

+cc
linux-pm@...r.kernel.org.

On 22 April 2014 15:33, Rafael J. Wysocki <rjw@...ysocki.net> wrote:
> On Tuesday, April 22, 2014 08:27:53 AM Chander Kashyap wrote:
>> ping
>
> Please CC cpuidle patches to linux-pm@...r.kernel.org.

+cc to linux-pm@...r.kernel.org.
Thanks Rafael

>
> Thanks!
>
>> On 10 April 2014 19:57, Tuukka Tikkanen <tuukka.tikkanen@...aro.org> wrote:
>> > On 10 April 2014 16:43, Chander Kashyap <chander.kashyap@...aro.org> 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@...aro.org>
>> >> ---
>> >>  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@...aro.org>
>>
>>
>>
>>
>
> --
> I speak only for myself.
> Rafael J. Wysocki, Intel Open Source Technology Center.



-- 
with warm regards,
Chander Kashyap
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