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Date: Thu, 30 Mar 2017 08:50:11 -0700
From: Vikram Mulukutla <markivx@codeaurora.org>
To: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Juri Lelli <juri.lelli@arm.com>, Peter Zijlstra <peterz@infradead.org>,
        mingo@redhat.com, viresh.kumar@linaro.org,
        linux-kernel@vger.kernel.org, linux-pm@vger.kernel.org,
        tglx@linutronix.de, vincent.guittot@linaro.org, rostedt@goodmis.org,
        luca.abeni@santannapisa.it, claudio@evidence.eu.com,
        tommaso.cucinotta@santannapisa.it, bristot@redhat.com,
        mathieu.poirier@linaro.org, tkjos@android.com, joelaf@google.com,
        andresoportus@google.com, morten.rasmussen@arm.com,
        dietmar.eggemann@arm.com, patrick.bellasi@arm.com,
        Ingo Molnar <mingo@kernel.org>,
        "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
        Mark Brown <broonie@kernel.org>, linux-kernel-owner@vger.kernel.org
Subject: Re: [RFD PATCH 3/5] sched/cpufreq_schedutil: make worker kthread be
 SCHED_DEADLINE
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 <1721120.3Th1GMboUn@aspire.rjw.lan>
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> OK
> 
> So there are two pieces here.
> 
> One is that if we want *all* drivers to work with schedutil, we need to 
> keep
> the kthread for the ones that will never be reworked (because nobody 
> cares
> etc).  But then perhaps the kthread implementation may be left alone 
> (because
> nobody cares etc).
> 
> The second one is that there are drivers operating in-context that work 
> with
> schedutil already, so I don't see major obstacles to making more 
> drivers work
> that way.  That would be only a matter of reworking the drivers in 
> question.
> 
> Thanks,
> Rafael

There are some MSM platforms that do need a kthread and would love to 
use
schedutil. This is all mainly due to the point that Vincent raised; 
having
to actually wait for voltage transitions before clock switches. I can't
speak about the future, but that's the situation right now. Leaving the
kthread alone for now would be appreciated!

Thanks,
Vikram