Messages in this thread | | | From | Vincent Guittot <> | Date | Thu, 26 Oct 2023 17:13:31 +0200 | Subject | Re: [PATCH v3 3/6] cpufreq/schedutil: use a fixed reference frequency |
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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> > > >
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