Re: [PATCH 1/3] sched/fair: Prepare variables for increased precision of EAS estimated energy

[Vincent Guittot]

On Wed, 7 Jul 2021 at 12:29, Lukasz Luba <lukasz.luba@xxxxxxx> wrote:
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>
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> On 7/7/21 11:11 AM, Vincent Guittot wrote:
> > On Wed, 7 Jul 2021 at 12:06, Lukasz Luba <lukasz.luba@xxxxxxx> wrote:
> >>
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> [snip]
>
> >> No. It's in 0.1uW scale, so 800Watts. Which is 16 CPUs * 64Watts
> >
> > Oh! you want 0.1uW precision .... This doesn't seem realistic at all.
> > I'm not even sure that the power model can even reach an accuracy of
> > 1mW
> >
>
> True, the EM is registering platform with 1mW precision, but 1uW

Do you mean 1uW or 0.1uW ?

> precision makes more sense for internal EAS calculation. I don't
> force platforms to report 1uW power, I just want to operate on
> it internally. PowerCap and DTPM also operate internally on 1uW,
> so it's not that unrealistic that some kernel components want
> better resolution.
>
> But as Peter suggested, we might skip 32bit platforms for this issue.
> I have to discussed this internally.