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Date:   Thu, 17 Oct 2019 10:25:37 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Douglas Raillard <douglas.raillard@arm.com>
Cc:     Patrick Bellasi <patrick.bellasi@arm.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        linux-kernel <linux-kernel@vger.kernel.org>,
        Ingo Molnar <mingo@redhat.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Viresh Kumar <viresh.kumar@linaro.org>,
        Quentin Perret <quentin.perret@arm.com>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Morten Rasmussen <morten.rasmussen@arm.com>,
        Juri Lelli <juri.lelli@redhat.com>
Subject: Re: [PATCH] sched/fair: util_est: fast ramp-up EWMA on utilization
 increases
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On Mon, Oct 14, 2019 at 05:16:02PM +0100, Douglas Raillard wrote:

> random idea: Since these things are much easier to understand by looking at a graph
> of util over time, we may agree on some mailing-list-friendly way to convey graphs.

I don't think that this patch warrants something like that. It is fairly
clear what it does.

For other stuff, maybe.

> For example, a simple CSV with:
> * before/after delimiters (line of # or =)
> * graph title
> * one point per signal transition, so that it can be plotted with gnuplot style "steps" or matplotlib drawstyle='steps-post'
> * consistent column names:
>    - time: in seconds (scientific notation for nanoseconds)
>    - activation: 1 when the task is actually running, 0 otherwise
>     (so it can be turned into transparent coloured bands like using gnuplot filledcurves, like in [1])
>    - util: util_avg of the task being talked about
> 
> The delimiters allow writing a scripts to render graphs directly out of an mbox file or ML archive URL.
> This won't solve the issue for the commit message itself, but that may ease the ML discussions.

Something like that could work; mutt can easily pipe emails into
scripts. OTOH gnuplot also has ASCII output, so one can easily stick
something like that into email.