linux-kernel - Re: [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency

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Message-ID: <20231025115324.GC31201@noisy.programming.kicks-ass.net>
Date:   Wed, 25 Oct 2023 13:53:24 +0200
From:   Peter Zijlstra <peterz@...radead.org>
To:     Vincent Guittot <vincent.guittot@...aro.org>
Cc:     linux@...linux.org.uk, catalin.marinas@....com, will@...nel.org,
        paul.walmsley@...ive.com, palmer@...belt.com,
        aou@...s.berkeley.edu, sudeep.holla@....com,
        gregkh@...uxfoundation.org, rafael@...nel.org, mingo@...hat.com,
        juri.lelli@...hat.com, dietmar.eggemann@....com,
        rostedt@...dmis.org, bsegall@...gle.com, mgorman@...e.de,
        bristot@...hat.com, vschneid@...hat.com, viresh.kumar@...aro.org,
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        linux-arm-kernel@...ts.infradead.org, linux-kernel@...r.kernel.org,
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Subject: Re: [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency

On Wed, Oct 18, 2023 at 06:25:37PM +0200, Vincent Guittot wrote:

> +static __always_inline
> +unsigned long get_capacity_ref_freq(struct cpufreq_policy *policy)
> +{
> +	unsigned int freq = arch_scale_freq_ref(policy->cpu);
> +
> +	if (freq)
> +		return freq;
> +
> +	if (arch_scale_freq_invariant())
> +		return policy->cpuinfo.max_freq;
> +
> +	return policy->cur;
> +}

Hmm, what should x86 do here? I know it mostly doesn't use these things,
but would it make sense to stick the base frequency in ?