| Message ID | 1615796737-4688-1-git-send-email-gao.yunxiao6@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Delegated to: | Daniel Lezcano |
| Headers | show |
| Series | thermal: power_allocator: using round the division when re-divvying up power | expand |
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
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
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!
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! >
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,