linux-kernel - Re: [PATCH 2/6] cpufreq: schedutil: ignore the sugov kthread for frequencies selections

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Date:   Wed, 15 Mar 2017 18:02:51 +0000
From:   Patrick Bellasi <patrick.bellasi@....com>
To:     Steven Rostedt <rostedt@...dmis.org>
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        Viresh Kumar <viresh.kumar@...aro.org>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        John Stultz <john.stultz@...aro.org>,
        Juri Lelli <juri.lelli@....com>, Todd Kjos <tkjos@...roid.com>,
        Tim Murray <timmurray@...gle.com>,
        Andres Oportus <andresoportus@...gle.com>,
        Joel Fernandes <joelaf@...gle.com>,
        Morten Rasmussen <morten.rasmussen@....com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Chris Redpath <chris.redpath@....com>,
        Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@...el.com>
Subject: Re: [PATCH 2/6] cpufreq: schedutil: ignore the sugov kthread for
 frequencies selections

On 06-Mar 09:35, Steven Rostedt wrote:
> On Thu,  2 Mar 2017 15:45:03 +0000
> Patrick Bellasi <patrick.bellasi@....com> wrote:
>  
> > @@ -287,6 +289,10 @@ static void sugov_update_shared(struct update_util_data *hook, u64 time,
> >  		goto done;
> >  	}
> >  
> > +	/* Skip updates generated by sugov kthreads */
> > +	if (curr == sg_policy->thread)
> 
> I think you want to put in an "unlikely()" around that statement. I'm
> assuming you don't care about he performance of scheduling in the sugov
> thread. At least tell gcc to optimize for the false path.

Right, good point! Will add it in the next posting! +1

Thanks!

-- 
#include <best/regards.h>

Patrick Bellasi