linux-kernel - Re: [RFC][PATCH 3/3] cpuidle,teo: Improve state selection

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Message-ID: <20230729084644.GC3945851@hirez.programming.kicks-ass.net>
Date:   Sat, 29 Jul 2023 10:46:44 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     "Rafael J. Wysocki" <rafael@...nel.org>
Cc:     anna-maria@...utronix.de, tglx@...utronix.de, frederic@...nel.org,
        gautham.shenoy@....com, linux-kernel@...r.kernel.org,
        daniel.lezcano@...aro.org, linux-pm@...r.kernel.org,
        mingo@...hat.com, juri.lelli@...hat.com,
        vincent.guittot@...aro.org, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, vschneid@...hat.com
Subject: Re: [RFC][PATCH 3/3] cpuidle,teo: Improve state selection

On Fri, Jul 28, 2023 at 07:07:02PM +0200, Rafael J. Wysocki wrote:
> On Fri, Jul 28, 2023 at 5:01 PM Peter Zijlstra <peterz@...radead.org> wrote:
> >
> > When selecting a state, stop when history tells us 66% of recent idles
> > were at or below our current state.
> 
> This is not really about "recent idles" AFAICS.  It stops the
> selection when 66% of the total sum of the "hits" and "intercepts"
> signals comes from the current state and the states below it.  This
> covers the entire history, while the "recent" ones are counted
> separately.

Ah, bad wording perhaps. I found that 'recent' list teo has very hard to
use, also the regular state isn't that long lived as per the reply on
the previous patch.