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Date:   Sat, 14 Sep 2019 12:57:08 +0200
From:   Quentin Perret <qperret@qperret.net>
To:     Giovanni Gherdovich <ggherdovich@suse.cz>
Cc:     srinivas.pandruvada@linux.intel.com, tglx@linutronix.de,
        mingo@redhat.com, peterz@infradead.org, bp@suse.de,
        lenb@kernel.org, rjw@rjwysocki.net, x86@kernel.org,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        mgorman@techsingularity.net, matt@codeblueprint.co.uk,
        viresh.kumar@linaro.org, juri.lelli@redhat.com, pjt@google.com,
        vincent.guittot@linaro.org, dietmar.eggemann@arm.com
Subject: Re: [PATCH 1/2] x86,sched: Add support for frequency invariance
Message-ID: <20190914105708.GA12877@qperret.net>
References: <20190909024216.5942-1-ggherdovich@suse.cz>
 <20190909024216.5942-2-ggherdovich@suse.cz>
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Hi Giovanni

On Monday 09 Sep 2019 at 04:42:15 (+0200), Giovanni Gherdovich wrote:
> +static inline long arch_scale_freq_capacity(int cpu)
> +{
> +	if (static_cpu_has(X86_FEATURE_APERFMPERF))
> +		return per_cpu(arch_cpu_freq, cpu);

So, if this is conditional, perhaps you could also add this check in an
x86-specific implementation of arch_scale_freq_invariant() ? That would
guide sugov in the right path (see get_next_freq()) if APERF/MPERF are
unavailable.

> +	return 1024 /* SCHED_CAPACITY_SCALE */;
> +}

Thanks,
Quentin