[PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[Arnd Bergmann]

get_monotonic_boottime() is deprecated, so let's convert this to
the simpler ktime_get_boot_ns().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
---
 drivers/leds/trigger/ledtrig-activity.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
index 5081894082bd..589c1bc4d0b9 100644
--- a/drivers/leds/trigger/ledtrig-activity.c
+++ b/drivers/leds/trigger/ledtrig-activity.c
@@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t)
 	struct activity_data *activity_data = from_timer(activity_data, t,
 							 timer);
 	struct led_classdev *led_cdev = activity_data->led_cdev;
-	struct timespec boot_time;
 	unsigned int target;
 	unsigned int usage;
 	int delay;
@@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t)
 		return;
 	}
 
-	get_monotonic_boottime(&boot_time);
+	curr_boot = ktime_get_boot_ns();
 
 	cpus = 0;
 	curr_used = 0;
@@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t)
 	 * down to 16us, ensuring we won't overflow 32-bit computations below
 	 * even up to 3k CPUs, while keeping divides cheap on smaller systems.
 	 */
-	curr_boot = timespec_to_ns(&boot_time) * cpus;
 	diff_boot = (curr_boot - activity_data->last_boot) >> 16;
 	diff_used = (curr_used - activity_data->last_used) >> 16;
 	activity_data->last_boot = curr_boot;
-- 
2.9.0

Re: [PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[Pavel Machek]

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Hi!

> get_monotonic_boottime() is deprecated, so let's convert this to
> the simpler ktime_get_boot_ns().
> 
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>

Have you tested it?

> diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
> index 5081894082bd..589c1bc4d0b9 100644
> --- a/drivers/leds/trigger/ledtrig-activity.c
> +++ b/drivers/leds/trigger/ledtrig-activity.c
> @@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t)
>  	struct activity_data *activity_data = from_timer(activity_data, t,
>  							 timer);
>  	struct led_classdev *led_cdev = activity_data->led_cdev;
> -	struct timespec boot_time;
>  	unsigned int target;
>  	unsigned int usage;
>  	int delay;
> @@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t)
>  		return;
>  	}
>  
> -	get_monotonic_boottime(&boot_time);
> +	curr_boot = ktime_get_boot_ns();
>  
>  	cpus = 0;
>  	curr_used = 0;
> @@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t)
>  	 * down to 16us, ensuring we won't overflow 32-bit computations below
>  	 * even up to 3k CPUs, while keeping divides cheap on smaller systems.
>  	 */
> -	curr_boot = timespec_to_ns(&boot_time) * cpus;

Original code is pretty weird (notice the * cpus), so I'm
double-checking.

									Pavel
-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[Arnd Bergmann]

On Mon, Jun 18, 2018 at 5:07 PM, Pavel Machek <pavel@ucw.cz> wrote:
> Hi!
>
>> get_monotonic_boottime() is deprecated, so let's convert this to
>> the simpler ktime_get_boot_ns().
>>
>> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
>
> Have you tested it?

No, only build-tested.

>> diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
>> index 5081894082bd..589c1bc4d0b9 100644
>> --- a/drivers/leds/trigger/ledtrig-activity.c
>> +++ b/drivers/leds/trigger/ledtrig-activity.c
>> @@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t)
>>       struct activity_data *activity_data = from_timer(activity_data, t,
>>                                                        timer);
>>       struct led_classdev *led_cdev = activity_data->led_cdev;
>> -     struct timespec boot_time;
>>       unsigned int target;
>>       unsigned int usage;
>>       int delay;
>> @@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t)
>>               return;
>>       }
>>
>> -     get_monotonic_boottime(&boot_time);
>> +     curr_boot = ktime_get_boot_ns();
>>
>>       cpus = 0;
>>       curr_used = 0;
>> @@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t)
>>        * down to 16us, ensuring we won't overflow 32-bit computations below
>>        * even up to 3k CPUs, while keeping divides cheap on smaller systems.
>>        */
>> -     curr_boot = timespec_to_ns(&boot_time) * cpus;
>
> Original code is pretty weird (notice the * cpus), so I'm
> double-checking.

Ok, dropping the *cpus was not intentional, I'll repost a version that puts
it that back. Thanks for pointing this out!

       Arnd

Re: [PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[Pavel Machek]

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> >> index 5081894082bd..589c1bc4d0b9 100644
> >> --- a/drivers/leds/trigger/ledtrig-activity.c
> >> +++ b/drivers/leds/trigger/ledtrig-activity.c
> >> @@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t)
> >>       struct activity_data *activity_data = from_timer(activity_data, t,
> >>                                                        timer);
> >>       struct led_classdev *led_cdev = activity_data->led_cdev;
> >> -     struct timespec boot_time;
> >>       unsigned int target;
> >>       unsigned int usage;
> >>       int delay;
> >> @@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t)
> >>               return;
> >>       }
> >>
> >> -     get_monotonic_boottime(&boot_time);
> >> +     curr_boot = ktime_get_boot_ns();
> >>
> >>       cpus = 0;
> >>       curr_used = 0;
> >> @@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t)
> >>        * down to 16us, ensuring we won't overflow 32-bit computations below
> >>        * even up to 3k CPUs, while keeping divides cheap on smaller systems.
> >>        */
> >> -     curr_boot = timespec_to_ns(&boot_time) * cpus;
> >
> > Original code is pretty weird (notice the * cpus), so I'm
> > double-checking.
> 
> Ok, dropping the *cpus was not intentional, I'll repost a version that puts
> it that back. Thanks for pointing this out!

Feel free to add my Acked-by to fixed version.

Thanks,
									Pavel

-- 
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html

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Re: [PATCH] leds: ledtrig-activity: use ktime_get_boot_ns()

[Willy Tarreau]

Hi Arnd,

On Mon, Jun 18, 2018 at 05:47:28PM +0200, Arnd Bergmann wrote:
> On Mon, Jun 18, 2018 at 5:07 PM, Pavel Machek <pavel@ucw.cz> wrote:
> >> diff --git a/drivers/leds/trigger/ledtrig-activity.c b/drivers/leds/trigger/ledtrig-activity.c
> >> index 5081894082bd..589c1bc4d0b9 100644
> >> --- a/drivers/leds/trigger/ledtrig-activity.c
> >> +++ b/drivers/leds/trigger/ledtrig-activity.c
> >> @@ -37,7 +37,6 @@ static void led_activity_function(struct timer_list *t)
> >>       struct activity_data *activity_data = from_timer(activity_data, t,
> >>                                                        timer);
> >>       struct led_classdev *led_cdev = activity_data->led_cdev;
> >> -     struct timespec boot_time;
> >>       unsigned int target;
> >>       unsigned int usage;
> >>       int delay;
> >> @@ -57,7 +56,7 @@ static void led_activity_function(struct timer_list *t)
> >>               return;
> >>       }
> >>
> >> -     get_monotonic_boottime(&boot_time);
> >> +     curr_boot = ktime_get_boot_ns();
> >>
> >>       cpus = 0;
> >>       curr_used = 0;
> >> @@ -76,7 +75,6 @@ static void led_activity_function(struct timer_list *t)
> >>        * down to 16us, ensuring we won't overflow 32-bit computations below
> >>        * even up to 3k CPUs, while keeping divides cheap on smaller systems.
> >>        */
> >> -     curr_boot = timespec_to_ns(&boot_time) * cpus;
> >
> > Original code is pretty weird (notice the * cpus), so I'm
> > double-checking.
> 
> Ok, dropping the *cpus was not intentional, I'll repost a version that puts
> it that back. Thanks for pointing this out!

Pavel is right, the *cpus is intentional. curr_boot contains the cumulated
time for all CPUs in order to measure an average usage over all of them.
By keeping it scaled by #cpus we avoid useless divides.

Cheers,
Willy
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