Messages in this thread | | | Subject | Re: [PATCH v2 1/4] PM / EM: add devices to Energy Model | From | Dietmar Eggemann <> | Date | Thu, 13 Feb 2020 11:59:59 +0100 |
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On 06/02/2020 14:46, lukasz.luba@arm.com wrote: > From: Lukasz Luba <lukasz.luba@arm.com>
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> @@ -26,7 +28,7 @@ framework, and interested clients reading the data from it::
s/::/: ?
> | Thermal (IPA) | | Scheduler (EAS) | | Other | > +---------------+ +-----------------+ +---------------+ > | | em_pd_energy() | > - | | em_cpu_get() | > + | em_get_pd() | em_cpu_get() | > +---------+ | +---------+
em_get_pd() and em_cpu_get()? Why not em_pd_get()? em_cpu_get() is a specific em_get_pd(). right?
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> @@ -85,13 +89,20 @@ API. > 2.3 Accessing performance domains > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > > +There is two API functions which provide the access to the energy model: > +em_cpu_get() which takes CPU id as an argument and em_get_pd() with device > +pointer as an argument. It depends on the subsystem which interface it is > +going to use, but in case of CPU devices both functions return the same > +performance domain.
There is probably a reason why we need this specific function for CPU devices? The reason should be described. People might ask why em_get_pd() is not sufficient.
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> - * A "performance domain" represents a group of CPUs whose performance is > - * scaled together. All CPUs of a performance domain must have the same > - * micro-architecture. Performance domains often have a 1-to-1 mapping with > - * CPUFreq policies. > + * In case of CPU device, a "performance domain" represents a group of CPUs > + * whose performance is scaled together. All CPUs of a performance domain > + * must have the same micro-architecture. Performance domains often have > + * a 1-to-1 mapping with CPUFreq policies. > + * In case of other devices the 'priv' field is unused. > */ > struct em_perf_domain { > - struct em_cap_state *table; > - int nr_cap_states; > - unsigned long cpus[0]; > + struct em_perf_state *table; > + int nr_perf_states; > + void *priv;
In case you go back to the variable length field plus type field to distingush EM devices, keep cpus[0] as the name.
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> /** > - * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. domain > + * em_pd_energy() - Estimates the energy consumed by the CPUs of a perf. > + domain
Why this change?
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> @@ -141,12 +210,12 @@ static struct em_perf_domain *em_create_pd(cpumask_t *span, int nr_states, > */ > opp_eff = freq / power; > if (opp_eff >= prev_opp_eff) > - pr_warn("pd%d: hertz/watts ratio non-monotonically decreasing: em_cap_state %d >= em_cap_state%d\n", > - cpu, i, i - 1); > + dev_warn(dev, "energy_model: hertz/watts ratio non-monotonically decreasing: em_perf_state %d >= em_perf_state%d\n",
s/energy_model/EM ?
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