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From:   "Rafael J. Wysocki" <rjw@rjwysocki.net>
To:     Viresh Kumar <viresh.kumar@linaro.org>
Cc:     Peter Zijlstra <peterz@infradead.org>,
        Julia Lawall <julia.lawall@inria.fr>,
        Mel Gorman <mgorman@suse.de>, Ingo Molnar <mingo@redhat.com>,
        kernel-janitors@vger.kernel.org,
        Juri Lelli <juri.lelli@redhat.com>,
        Vincent Guittot <vincent.guittot@linaro.org>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
        Steven Rostedt <rostedt@goodmis.org>,
        Ben Segall <bsegall@google.com>,
        Daniel Bristot de Oliveira <bristot@redhat.com>,
        linux-kernel@vger.kernel.org,
        Valentin Schneider <valentin.schneider@arm.com>,
        Gilles Muller <Gilles.Muller@inria.fr>,
        srinivas.pandruvada@linux.intel.com, linux-pm@vger.kernel.org
Subject: Re: [PATCH] sched/fair: check for idle core
Date:   Fri, 23 Oct 2020 17:06:08 +0200
Message-ID: <2251006.PXaUfaNY4o@kreacher>
In-Reply-To: <20201023061246.irzbrl62baoawmqv@vireshk-i7>
References: <1603211879-1064-1-git-send-email-Julia.Lawall@inria.fr> <34115486.YmRjPRKJaA@kreacher> <20201023061246.irzbrl62baoawmqv@vireshk-i7>
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On Friday, October 23, 2020 8:12:46 AM CEST Viresh Kumar wrote:
> On 22-10-20, 13:45, Rafael J. Wysocki wrote:
> > On Thursday, October 22, 2020 12:47:03 PM CEST Viresh Kumar wrote:
> > > And I am not really sure why we always wanted this backup performance
> > > governor to be there unless the said governors are built as module.
> > 
> > Apparently, some old drivers had problems with switching frequencies fast enough
> > for ondemand to be used with them and the fallback was for those cases.  AFAICS.
> 
> Do we still need this ?

For the reasonably modern hardware, I don't think so.

> Or better ask those platforms to individually
> enable both of them.

Bu who knows what they are? :-)