linux-kernel - Re: [PATCH v2] cpufreq/schedutil: Cleanup, document and fix iowait boost

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Message-ID: <20180411143921.GP14248@e110439-lin>
Date:   Wed, 11 Apr 2018 15:39:21 +0100
From:   Patrick Bellasi <patrick.bellasi@....com>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Ingo Molnar <mingo@...hat.com>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Joel Fernandes <joelaf@...gle.com>,
        Steve Muckle <smuckle@...gle.com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>
Subject: Re: [PATCH v2] cpufreq/schedutil: Cleanup, document and fix iowait
 boost

On 11-Apr 12:58, Peter Zijlstra wrote:
> On Wed, Apr 11, 2018 at 11:44:45AM +0100, Patrick Bellasi wrote:
> > > > - sugov_set_iowait_boost: is now in charge only to set/increase the IO
> > > >      wait boost, every time a task wakes up from an IO wait.
> > > > 
> > > > - sugov_iowait_boost: is now in charge to reset/reduce the IO wait
> > > >      boost, every time a sugov update is triggered, as well as
> > > >      to (eventually) enforce the currently required IO boost value.
> > > 
> > > I'm not sold on those function names; feels like we can do better,
> > > although I'm struggling to come up with anything sensible just now.
> > 
> > What about something like:
> > 
> >  sugov_iowait_init()
> >  since here we are mainly initializing the iowait boost
> > 
> >  sugov_iowait_boost()
> >  since here we are mainly applying the proper boost to each cpu
> > 
> > Although they are not really so different...
> 
> How about:
> 
>   sugov_iowait_boost() -- does the actual impulse/boost
>   sugov_iowait_apply() -- applies the boost state
> 
> ?

Whould say it can work too, and it also allows to add a:

    sugov_iowait_reset() -- resets boots state after
                            TICK_NSEC CPU idle time

Viresh, Rafael, Joel: any preferences or other suggestions?

-- 
#include <best/regards.h>

Patrick Bellasi