linux-kernel - Re: [Patch v5 2/6] sched/fair: Add infrastructure to store and update instantaneous thermal pressure

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Date:   Tue, 5 Nov 2019 16:29:32 -0500
From:   Thara Gopinath <thara.gopinath@...aro.org>
To:     Ionela Voinescu <ionela.voinescu@....com>
Cc:     mingo@...hat.com, peterz@...radead.org, vincent.guittot@...aro.org,
        rui.zhang@...el.com, edubezval@...il.com, qperret@...gle.com,
        linux-kernel@...r.kernel.org, amit.kachhap@...il.com,
        javi.merino@...nel.org, daniel.lezcano@...aro.org
Subject: Re: [Patch v5 2/6] sched/fair: Add infrastructure to store and update
 instantaneous thermal pressure

On 11/05/2019 04:15 PM, Ionela Voinescu wrote:
> On Tuesday 05 Nov 2019 at 16:02:00 (-0500), Thara Gopinath wrote:
>> On 11/05/2019 03:21 PM, Ionela Voinescu wrote:
>>> Hi Thara,
>>>
>>> On Tuesday 05 Nov 2019 at 13:49:42 (-0500), Thara Gopinath wrote:
>>> [...]
>>>> +static void trigger_thermal_pressure_average(struct rq *rq)
>>>> +{
>>>> +#ifdef CONFIG_SMP
>>>> +	update_thermal_load_avg(rq_clock_task(rq), rq,
>>>> +				per_cpu(thermal_pressure, cpu_of(rq)));
>>>> +#endif
>>>> +}
>>>
>>> Why did you decide to keep trigger_thermal_pressure_average and not
>>> call update_thermal_load_avg directly?
>>>
>>> For !CONFIG_SMP you already have an update_thermal_load_avg function
>>> that does nothing, in kernel/sched/pelt.h, so you don't need that
>>> ifdef. 
>> Hi,
>>
>> Yes you are right. But later with the shift option added, I shift
>> rq_clock_task(rq) by the shift. I thought it is better to contain it in
>> a function that replicate it in three different places. I can remove the
>> CONFIG_SMP in the next version.
> 
> You could still keep that in one place if you shift the now argument of
> ___update_load_sum instead.

No. I cannot do this. The authors of the pelt framework  prefers not to
include a shift parameter there. I had discussed this with Vincent earlier.

> 
> To me that trigger_thermal_pressure_average function seems more code
> than it's worth for this.
> 
> Thanks,
> Ionela.
> 
>>>
>>> Thanks,
>>> Ionela.
>>>
>>>> +
>>>>  /*
>>>>   * All the scheduling class methods:
>>>>   */
>>>> -- 
>>>> 2.1.4
>>>>
>>
>>
>> -- 
>> Warm Regards
>> Thara


-- 
Warm Regards
Thara