* [PATCH] thermal: power_allocator: using round the division when re-divvying up power
@ 2021-03-15 8:25 gao.yunxiao6
2021-03-15 9:51 ` Lukasz Luba
0 siblings, 1 reply; 5+ messages in thread
From: gao.yunxiao6 @ 2021-03-15 8:25 UTC (permalink / raw)
To: lukasz.luba, rui.zhang, daniel.lezcano, amitk
Cc: linux-pm, linux-kernel, orsonzhai, zhang.lyra, jeson.gao
From: "jeson.gao" <jeson.gao@unisoc.com>
The division is used directly in re-divvying up power, the decimal part will
be discarded, devices will get less than the extra_actor_power - 1.
if using round the division to make the calculation more accurate.
For example:
actor0 received more than it's max_power, it has the extra_power 759
actor1 received less than it's max_power, it require extra_actor_power 395
actor2 received less than it's max_power, it require extra_actor_power 365
actor1 and actor2 require the total capped_extra_power 760
using division in re-divvying up power
actor1 would actually get the extra_actor_power 394
actor2 would actually get the extra_actor_power 364
if using round the division in re-divvying up power
actor1 would actually get the extra_actor_power 394
actor2 would actually get the extra_actor_power 365
Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
---
drivers/thermal/gov_power_allocator.c | 8 +++++---
1 file changed, 5 insertions(+), 3 deletions(-)
diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
index 92acae53df49..2802a0e13c88 100644
--- a/drivers/thermal/gov_power_allocator.c
+++ b/drivers/thermal/gov_power_allocator.c
@@ -374,9 +374,11 @@ static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors,
*/
extra_power = min(extra_power, capped_extra_power);
if (capped_extra_power > 0)
- for (i = 0; i < num_actors; i++)
- granted_power[i] += (extra_actor_power[i] *
- extra_power) / capped_extra_power;
+ for (i = 0; i < num_actors; i++) {
+ u64 extra_range = (u64)extra_actor_power[i] * extra_power;
+ granted_power[i] += DIV_ROUND_CLOSEST_ULL(extra_range,
+ capped_extra_power);
+ }
}
static int allocate_power(struct thermal_zone_device *tz,
--
2.28.0
^ permalink raw reply related [flat|nested] 5+ messages in thread* Re: [PATCH] thermal: power_allocator: using round the division when re-divvying up power
2021-03-15 8:25 [PATCH] thermal: power_allocator: using round the division when re-divvying up power gao.yunxiao6
@ 2021-03-15 9:51 ` Lukasz Luba
2021-03-16 13:15 ` Daniel Lezcano
0 siblings, 1 reply; 5+ messages in thread
From: Lukasz Luba @ 2021-03-15 9:51 UTC (permalink / raw)
To: gao.yunxiao6, daniel.lezcano
Cc: rui.zhang, amitk, linux-pm, linux-kernel, orsonzhai, zhang.lyra,
jeson.gao
On 3/15/21 8:25 AM, gao.yunxiao6@gmail.com wrote:
> From: "jeson.gao" <jeson.gao@unisoc.com>
>
> The division is used directly in re-divvying up power, the decimal part will
> be discarded, devices will get less than the extra_actor_power - 1.
> if using round the division to make the calculation more accurate.
>
> For example:
> actor0 received more than it's max_power, it has the extra_power 759
> actor1 received less than it's max_power, it require extra_actor_power 395
> actor2 received less than it's max_power, it require extra_actor_power 365
> actor1 and actor2 require the total capped_extra_power 760
>
> using division in re-divvying up power
> actor1 would actually get the extra_actor_power 394
> actor2 would actually get the extra_actor_power 364
>
> if using round the division in re-divvying up power
> actor1 would actually get the extra_actor_power 394
> actor2 would actually get the extra_actor_power 365
>
> Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
> ---
> drivers/thermal/gov_power_allocator.c | 8 +++++---
> 1 file changed, 5 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/thermal/gov_power_allocator.c b/drivers/thermal/gov_power_allocator.c
> index 92acae53df49..2802a0e13c88 100644
> --- a/drivers/thermal/gov_power_allocator.c
> +++ b/drivers/thermal/gov_power_allocator.c
> @@ -374,9 +374,11 @@ static void divvy_up_power(u32 *req_power, u32 *max_power, int num_actors,
> */
> extra_power = min(extra_power, capped_extra_power);
> if (capped_extra_power > 0)
> - for (i = 0; i < num_actors; i++)
> - granted_power[i] += (extra_actor_power[i] *
> - extra_power) / capped_extra_power;
> + for (i = 0; i < num_actors; i++) {
> + u64 extra_range = (u64)extra_actor_power[i] * extra_power;
> + granted_power[i] += DIV_ROUND_CLOSEST_ULL(extra_range,
> + capped_extra_power);
> + }
> }
>
> static int allocate_power(struct thermal_zone_device *tz,
>
Make sense. There is already DIV_ROUND_CLOSEST_ULL() in that function,
so let's align both. There might be a bit overhead on 32bit machines,
but IPA polling isn't so often there.
Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
Regards,
Lukasz
^ permalink raw reply [flat|nested] 5+ messages in thread* Re: [PATCH] thermal: power_allocator: using round the division when re-divvying up power
2021-03-15 9:51 ` Lukasz Luba
@ 2021-03-16 13:15 ` Daniel Lezcano
2021-03-16 13:16 ` Lukasz Luba
0 siblings, 1 reply; 5+ messages in thread
From: Daniel Lezcano @ 2021-03-16 13:15 UTC (permalink / raw)
To: Lukasz Luba, gao.yunxiao6
Cc: rui.zhang, amitk, linux-pm, linux-kernel, orsonzhai, zhang.lyra,
jeson.gao
On 15/03/2021 10:51, Lukasz Luba wrote:
>
>
> On 3/15/21 8:25 AM, gao.yunxiao6@gmail.com wrote:
>> From: "jeson.gao" <jeson.gao@unisoc.com>
>>
>> The division is used directly in re-divvying up power, the decimal
>> part will
>> be discarded, devices will get less than the extra_actor_power - 1.
>> if using round the division to make the calculation more accurate.
>>
>> For example:
>> actor0 received more than it's max_power, it has the extra_power 759
>> actor1 received less than it's max_power, it require extra_actor_power
>> 395
>> actor2 received less than it's max_power, it require extra_actor_power
>> 365
>> actor1 and actor2 require the total capped_extra_power 760
>>
>> using division in re-divvying up power
>> actor1 would actually get the extra_actor_power 394
>> actor2 would actually get the extra_actor_power 364
>>
>> if using round the division in re-divvying up power
>> actor1 would actually get the extra_actor_power 394
>> actor2 would actually get the extra_actor_power 365
>>
>> Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
>> ---
Applied, thanks
--
<http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs
Follow Linaro: <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] thermal: power_allocator: using round the division when re-divvying up power
2021-03-16 13:15 ` Daniel Lezcano
@ 2021-03-16 13:16 ` Lukasz Luba
2021-03-17 11:20 ` gao yunxiao
0 siblings, 1 reply; 5+ messages in thread
From: Lukasz Luba @ 2021-03-16 13:16 UTC (permalink / raw)
To: Daniel Lezcano
Cc: gao.yunxiao6, rui.zhang, amitk, linux-pm, linux-kernel,
orsonzhai, zhang.lyra, jeson.gao
On 3/16/21 1:15 PM, Daniel Lezcano wrote:
> On 15/03/2021 10:51, Lukasz Luba wrote:
>>
>>
>> On 3/15/21 8:25 AM, gao.yunxiao6@gmail.com wrote:
>>> From: "jeson.gao" <jeson.gao@unisoc.com>
>>>
>>> The division is used directly in re-divvying up power, the decimal
>>> part will
>>> be discarded, devices will get less than the extra_actor_power - 1.
>>> if using round the division to make the calculation more accurate.
>>>
>>> For example:
>>> actor0 received more than it's max_power, it has the extra_power 759
>>> actor1 received less than it's max_power, it require extra_actor_power
>>> 395
>>> actor2 received less than it's max_power, it require extra_actor_power
>>> 365
>>> actor1 and actor2 require the total capped_extra_power 760
>>>
>>> using division in re-divvying up power
>>> actor1 would actually get the extra_actor_power 394
>>> actor2 would actually get the extra_actor_power 364
>>>
>>> if using round the division in re-divvying up power
>>> actor1 would actually get the extra_actor_power 394
>>> actor2 would actually get the extra_actor_power 365
>>>
>>> Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
>>> ---
>
> Applied, thanks
>
thank you Daniel!
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCH] thermal: power_allocator: using round the division when re-divvying up power
2021-03-16 13:16 ` Lukasz Luba
@ 2021-03-17 11:20 ` gao yunxiao
0 siblings, 0 replies; 5+ messages in thread
From: gao yunxiao @ 2021-03-17 11:20 UTC (permalink / raw)
To: Lukasz Luba
Cc: Daniel Lezcano, rui.zhang, amitk, linux-pm, linux-kernel,
orsonzhai, zhang.lyra, jeson.gao
Lukasz,Daniel, Thank you for your review!
On 16/03/2021, Lukasz Luba <lukasz.luba@arm.com> wrote:
>
>
> On 3/16/21 1:15 PM, Daniel Lezcano wrote:
>> On 15/03/2021 10:51, Lukasz Luba wrote:
>>>
>>>
>>> On 3/15/21 8:25 AM, gao.yunxiao6@gmail.com wrote:
>>>> From: "jeson.gao" <jeson.gao@unisoc.com>
>>>>
>>>> The division is used directly in re-divvying up power, the decimal
>>>> part will
>>>> be discarded, devices will get less than the extra_actor_power - 1.
>>>> if using round the division to make the calculation more accurate.
>>>>
>>>> For example:
>>>> actor0 received more than it's max_power, it has the extra_power 759
>>>> actor1 received less than it's max_power, it require extra_actor_power
>>>> 395
>>>> actor2 received less than it's max_power, it require extra_actor_power
>>>> 365
>>>> actor1 and actor2 require the total capped_extra_power 760
>>>>
>>>> using division in re-divvying up power
>>>> actor1 would actually get the extra_actor_power 394
>>>> actor2 would actually get the extra_actor_power 364
>>>>
>>>> if using round the division in re-divvying up power
>>>> actor1 would actually get the extra_actor_power 394
>>>> actor2 would actually get the extra_actor_power 365
>>>>
>>>> Signed-off-by: Jeson Gao <jeson.gao@unisoc.com>
>>>> ---
>>
>> Applied, thanks
>>
>
> thank you Daniel!
>
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-03-17 11:21 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2021-03-15 8:25 [PATCH] thermal: power_allocator: using round the division when re-divvying up power gao.yunxiao6
2021-03-15 9:51 ` Lukasz Luba
2021-03-16 13:15 ` Daniel Lezcano
2021-03-16 13:16 ` Lukasz Luba
2021-03-17 11:20 ` gao yunxiao
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).