From: Vincent Guittot <vincent.guittot@linaro.org>
To: Dietmar Eggemann <dietmar.eggemann@arm.com>
Cc: juri.lelli@redhat.com, peterz@infradead.org,
catalin.marinas@arm.com, robert.moore@intel.com,
bsegall@google.com, conor.dooley@microchip.com,
pierre.gondois@arm.com, linux-riscv@lists.infradead.org,
will@kernel.org, acpica-devel@lists.linuxfoundation.org,
vschneid@redhat.com, ajones@ventanamicro.com,
linux@armlinux.org.uk, linux-acpi@vger.kernel.org,
mingo@redhat.com, bristot@redhat.com, lftan@kernel.org,
viresh.kumar@linaro.org, mgorman@suse.de, aou@eecs.berkeley.edu,
linux-pm@vger.kernel.org, rostedt@goodmis.org,
paul.walmsley@sifive.com, linux-arm-kernel@lists.infradead.org,
gregkh@linuxfoundation.org, linux-kernel@vger.kernel.org,
palmer@dabbelt.com, sudeep.holla@arm.com, suagrfillet@gmail.com,
lenb@kernel.org, ionela.voinescu@arm.com, lukasz.luba@arm.com
Subject: Re: [Acpica-devel] [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency
Date: Thu, 26 Oct 2023 17:13:31 +0200 [thread overview]
Message-ID: <CAKfTPtBJRT56dL7+UW-viZuK3wKfGimQfrkvtuCQ_20g4N5LPQ@mail.gmail.com> (raw)
In-Reply-To: <f5e398f3-fbb7-4840-9084-14c8254b2118@arm.com>
On Wed, 25 Oct 2023 at 22:13, Dietmar Eggemann <dietmar.eggemann@arm.com> wrote:
>
> On 18/10/2023 18:25, Vincent Guittot wrote:
> > cpuinfo.max_freq can change at runtime because of boost as an example. This
> > implies that the value could be different than the one that has been
> > used when computing the capacity of a CPU.
> >
> > The new arch_scale_freq_ref() returns a fixed and coherent reference
> > frequency that can be used when computing a frequency based on utilization.
> >
> > Use this arch_scale_freq_ref() when available and fallback to
> > policy otherwise.
> >
> > Signed-off-by: Vincent Guittot <vincent.guittot@linaro.org>
> > Reviewed-by: Lukasz Luba <lukasz.luba@arm.com>
> > Tested-by: Lukasz Luba <lukasz.luba@arm.com>
> >
> > ---
> > kernel/sched/cpufreq_schedutil.c | 26 ++++++++++++++++++++++++--
> > 1 file changed, 24 insertions(+), 2 deletions(-)
> >
> > diff --git a/kernel/sched/cpufreq_schedutil.c b/kernel/sched/cpufreq_schedutil.c
> > index 458d359f5991..6e4030482ae8 100644
> > --- a/kernel/sched/cpufreq_schedutil.c
> > +++ b/kernel/sched/cpufreq_schedutil.c
> > @@ -114,6 +114,28 @@ static void sugov_deferred_update(struct sugov_policy *sg_policy)
> > }
> > }
> >
> > +/**
> > + * cpufreq_get_capacity_ref_freq - get the reference frequency of a given CPU that
>
> s/cpufreq_get_capacity_ref_freq/get_capacity_ref_freq
>
> s/of a given CPU/for a given cpufreq policy ? (of which the CPU managing
> it is used for the arch_scale_freq_ref() call in the function.
>
> > + * has been used to correlate frequency and compute capacity.
> > + * @policy: the cpufreq policy of the CPU in question.
> > + * @use_current: Fallback to current freq instead of policy->cpuinfo.max_freq.
>
> Looks like use_current does not exists as a parameter.
Thanks for the review. I'm going to apply your comments
>
> > + *
> > + * Return: the reference CPU frequency to compute a capacity.
> > + */
> > +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;
> > +}
>
> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
>
>
>
next prev parent reply other threads:[~2023-10-26 15:13 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-10-18 16:25 [Acpica-devel] [PATCH v3 0/6] consolidate and cleanup CPU capacity Vincent Guittot
2023-10-18 16:25 ` [Acpica-devel] [PATCH v3 1/6] topology: add a new arch_scale_freq_reference Vincent Guittot
2023-10-18 16:25 ` [Acpica-devel] [PATCH v3 2/6] cpufreq: use the fixed and coherent frequency for scaling capacity Vincent Guittot
2023-10-18 17:23 ` Rafael J. Wysocki
2023-10-18 16:25 ` [Acpica-devel] [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency Vincent Guittot
2023-10-18 17:22 ` Rafael J. Wysocki
2023-10-25 11:53 ` Peter Zijlstra
2023-10-25 12:51 ` Vincent Guittot
2023-10-25 20:13 ` Dietmar Eggemann
2023-10-26 15:13 ` Vincent Guittot [this message]
2023-10-18 16:25 ` [Acpica-devel] [PATCH v3 4/6] energy_model: " Vincent Guittot
2023-10-25 11:54 ` Peter Zijlstra
2023-10-25 12:11 ` Peter Zijlstra
2023-10-25 12:24 ` Rafael J. Wysocki
2023-10-25 12:54 ` Vincent Guittot
2023-10-18 16:25 ` [Acpica-devel] [PATCH v3 5/6] cpufreq/cppc: set the frequency used for computing the capacity Vincent Guittot
2023-10-18 17:27 ` Rafael J. Wysocki
2023-10-20 16:05 ` Pierre Gondois
2023-10-24 9:56 ` Vincent Guittot
2023-10-18 16:25 ` [Acpica-devel] [RFC v3 6/6] arm64/amu: use capacity_ref_freq to set AMU ratio Vincent Guittot
2023-10-23 20:58 ` Ionela Voinescu
2023-10-24 9:58 ` Vincent Guittot
2023-10-26 11:19 ` Dietmar Eggemann
2023-10-26 14:30 ` Vincent Guittot
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