Re: [Patch v9 5/8] sched/fair: update cpu_capacity to reflect thermal pressure

[Thara Gopinath]

On 02/13/2020 07:47 AM, Amit Kucheria wrote:
> On Wed, Jan 29, 2020 at 4:06 AM Thara Gopinath
> <thara.gopinath@xxxxxxxxxx> wrote:
>>
>> cpu_capacity initially reflects the maximum possible capacity of a cpu.
>> Thermal pressure on a cpu means this maximum possible capacity is
>> unavailable due to thermal events. This patch subtracts the average thermal
>> pressure for a cpu from its maximum possible capacity so that cpu_capacity
>> reflects the actual maximum currently available capacity.
>>
>> Signed-off-by: Thara Gopinath <thara.gopinath@xxxxxxxxxx>
>> ---
>>
>> v8->v9:
>>         - Use thermal_load_avg to read rq->avg_thermal.load_avg.
>>
>>  kernel/sched/fair.c | 7 +++++++
>>  1 file changed, 7 insertions(+)
>>
>> diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c
>> index 5f58c03..d879077 100644
>> --- a/kernel/sched/fair.c
>> +++ b/kernel/sched/fair.c
>> @@ -7753,8 +7753,15 @@ static unsigned long scale_rt_capacity(struct sched_domain *sd, int cpu)
>>         if (unlikely(irq >= max))
>>                 return 1;
>>
>> +       /*
>> +        * avg_rt.util avg and avg_dl.util track binary signals
> 
> For avg_rt, s/util avg/util_avg/
> For avg_dl, s/util/util_avg/    ?

Yep. Will fix it.

> 
>> +        * (running and not running) with weights 0 and 1024 respectively.
>> +        * avg_thermal.load_avg tracks thermal pressure and the weighted
>> +        * average uses the actual delta max capacity(load).
>> +        */
>>         used = READ_ONCE(rq->avg_rt.util_avg);
>>         used += READ_ONCE(rq->avg_dl.util_avg);
>> +       used += thermal_load_avg(rq);
>>
>>         if (unlikely(used >= max))
>>                 return 1;
>> --
>> 2.1.4
>>


-- 
Warm Regards
Thara