linux-kernel - Re: [PATCH v2 6/6] arm64: use activity monitors for frequency invariance

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Message-ID: <ec71a41d-5274-c29c-a391-4ed92839d58f@arm.com>
Date:   Thu, 30 Jan 2020 16:11:56 +0000
From:   Valentin Schneider <valentin.schneider@....com>
To:     Ionela Voinescu <ionela.voinescu@....com>
Cc:     catalin.marinas@....com, will@...nel.org, mark.rutland@....com,
        maz@...nel.org, suzuki.poulose@....com, sudeep.holla@....com,
        dietmar.eggemann@....com, peterz@...radead.org, mingo@...hat.com,
        ggherdovich@...e.cz, vincent.guittot@...aro.org,
        linux-arm-kernel@...ts.infradead.org, linux-doc@...r.kernel.org,
        linux-kernel@...r.kernel.org
Subject: Re: [PATCH v2 6/6] arm64: use activity monitors for frequency
 invariance

On 30/01/2020 15:49, Ionela Voinescu wrote:
> Okay, I'll add this as a separate patch to the series and put you as
> author. That is if you want me to tie this check to this usecase that
> proves its usefulness. Otherwise it can stand on its own as well if
> you want to submit it separately.
> 

It's pretty much standalone, but it does make sense to bundle it with this
series, I think. Feel free to grab ownership (I didn't test it) ;)

> In regards to the ratio computation for frequency invariance where this
> plays a role, I'll do a check and bail out if the ratio is 0, which I'm
> ashamed to not have added before :).

That does sound like something we very much want to have.

> 
> Thanks,
> Ionela.
> 
> 
>>> Long story short, we're probably fine, but it would nice to shove some of
>>> the above into comments (especially the SCHED_CAPACITY_SCALE² trick)
>>>