| Message ID | 20231129110853.94344-5-lukasz.luba@arm.com |
|---|---|
| State | Superseded |
| Headers | show |
| Series | Introduce runtime modifiable Energy Model | expand |
On 29/11/2023 12:08, Lukasz Luba wrote: > The Energy Model (EM) is going to support runtime modification. There > are going to be 2 EM tables which store information. This patch aims > to prepare the code to be generic and use one of the tables. The function > will no longer get a pointer to 'struct em_perf_domain' (the EM) but > instead a pointer to 'struct em_perf_state' (which is one of the EM's > tables). I thought the 2 EM tables design is gone? IMHO it would be less code changes and hence a more enjoyable review experience if you would add the 'modifiable' feature to the existing EM (1) and not add (2) and then remove (1) in [21/23]. struct em_perf_domain { - struct em_perf_state *table; <-- (1) struct em_perf_table __rcu *runtime_table; <-- (2) > Prepare em_pd_get_efficient_state() for the upcoming changes and > make it possible to re-use. Return an index for the best performance s/make it possible to re-use/make it possible to be re-used ? > state for a given EM table. The function arguments that are introduced > should allow to work on different performance state arrays. The caller of > em_pd_get_efficient_state() should be able to use the index either > on the default or the modifiable EM table. > > Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> > Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> > --- > include/linux/energy_model.h | 30 +++++++++++++++++------------- > 1 file changed, 17 insertions(+), 13 deletions(-) > > diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h > index b9caa01dfac4..8069f526c9d8 100644 > --- a/include/linux/energy_model.h > +++ b/include/linux/energy_model.h > @@ -175,33 +175,35 @@ void em_dev_unregister_perf_domain(struct device *dev); > > /** > * em_pd_get_efficient_state() - Get an efficient performance state from the EM > - * @pd : Performance domain for which we want an efficient frequency > - * @freq : Frequency to map with the EM > + * @state: List of performance states, in ascending order (3) > + * @nr_perf_states: Number of performance states > + * @freq: Frequency to map with the EM > + * @pd_flags: Performance Domain flags > * > * It is called from the scheduler code quite frequently and as a consequence > * doesn't implement any check. > * > - * Return: An efficient performance state, high enough to meet @freq > + * Return: An efficient performance state id, high enough to meet @freq > * requirement. > */ > -static inline > -struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd, > - unsigned long freq) > +static inline int > +em_pd_get_efficient_state(struct em_perf_state *table, int nr_perf_states, > + unsigned long freq, unsigned long pd_flags) (3) but em_pd_get_efficient_state(struct em_perf_state *table ^^^^^ [...]
On 12/12/23 18:49, Dietmar Eggemann wrote: > On 29/11/2023 12:08, Lukasz Luba wrote: >> The Energy Model (EM) is going to support runtime modification. There >> are going to be 2 EM tables which store information. This patch aims >> to prepare the code to be generic and use one of the tables. The function >> will no longer get a pointer to 'struct em_perf_domain' (the EM) but >> instead a pointer to 'struct em_perf_state' (which is one of the EM's >> tables). > I thought the 2 EM tables design is gone? > > IMHO it would be less code changes and hence a more enjoyable review > experience if you would add the 'modifiable' feature to the existing EM > (1) and not add (2) and then remove (1) in [21/23]. I have explained that to some other your email: such approach would create a patch monster, touching all drivers and frameworks, to just make sure they still can compile. This is not the right approach. > > > struct em_perf_domain { > - struct em_perf_state *table; <-- (1) > struct em_perf_table __rcu *runtime_table; <-- (2) > >> Prepare em_pd_get_efficient_state() for the upcoming changes and >> make it possible to re-use. Return an index for the best performance > > s/make it possible to re-use/make it possible to be re-used ? OK > >> state for a given EM table. The function arguments that are introduced >> should allow to work on different performance state arrays. The caller of >> em_pd_get_efficient_state() should be able to use the index either >> on the default or the modifiable EM table. >> >> Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> >> Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org> >> --- >> include/linux/energy_model.h | 30 +++++++++++++++++------------- >> 1 file changed, 17 insertions(+), 13 deletions(-) >> >> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h >> index b9caa01dfac4..8069f526c9d8 100644 >> --- a/include/linux/energy_model.h >> +++ b/include/linux/energy_model.h >> @@ -175,33 +175,35 @@ void em_dev_unregister_perf_domain(struct device *dev); >> >> /** >> * em_pd_get_efficient_state() - Get an efficient performance state from the EM >> - * @pd : Performance domain for which we want an efficient frequency >> - * @freq : Frequency to map with the EM >> + * @state: List of performance states, in ascending order > > (3) > >> + * @nr_perf_states: Number of performance states >> + * @freq: Frequency to map with the EM >> + * @pd_flags: Performance Domain flags >> * >> * It is called from the scheduler code quite frequently and as a consequence >> * doesn't implement any check. >> * >> - * Return: An efficient performance state, high enough to meet @freq >> + * Return: An efficient performance state id, high enough to meet @freq >> * requirement. >> */ >> -static inline >> -struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd, >> - unsigned long freq) >> +static inline int >> +em_pd_get_efficient_state(struct em_perf_state *table, int nr_perf_states, >> + unsigned long freq, unsigned long pd_flags) > > (3) but em_pd_get_efficient_state(struct em_perf_state *table > ^^^^^ > [...] Good catch, I'll change that.
diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h index b9caa01dfac4..8069f526c9d8 100644 --- a/include/linux/energy_model.h +++ b/include/linux/energy_model.h @@ -175,33 +175,35 @@ void em_dev_unregister_perf_domain(struct device *dev); /** * em_pd_get_efficient_state() - Get an efficient performance state from the EM - * @pd : Performance domain for which we want an efficient frequency - * @freq : Frequency to map with the EM + * @state: List of performance states, in ascending order + * @nr_perf_states: Number of performance states + * @freq: Frequency to map with the EM + * @pd_flags: Performance Domain flags * * It is called from the scheduler code quite frequently and as a consequence * doesn't implement any check. * - * Return: An efficient performance state, high enough to meet @freq + * Return: An efficient performance state id, high enough to meet @freq * requirement. */ -static inline -struct em_perf_state *em_pd_get_efficient_state(struct em_perf_domain *pd, - unsigned long freq) +static inline int +em_pd_get_efficient_state(struct em_perf_state *table, int nr_perf_states, + unsigned long freq, unsigned long pd_flags) { struct em_perf_state *ps; int i; - for (i = 0; i < pd->nr_perf_states; i++) { - ps = &pd->table[i]; + for (i = 0; i < nr_perf_states; i++) { + ps = &table[i]; if (ps->frequency >= freq) { - if (pd->flags & EM_PERF_DOMAIN_SKIP_INEFFICIENCIES && + if (pd_flags & EM_PERF_DOMAIN_SKIP_INEFFICIENCIES && ps->flags & EM_PERF_STATE_INEFFICIENT) continue; - break; + return i; } } - return ps; + return nr_perf_states - 1; } /** @@ -226,7 +228,7 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, { unsigned long freq, scale_cpu; struct em_perf_state *ps; - int cpu; + int cpu, i; if (!sum_util) return 0; @@ -251,7 +253,9 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd, * Find the lowest performance state of the Energy Model above the * requested frequency. */ - ps = em_pd_get_efficient_state(pd, freq); + i = em_pd_get_efficient_state(pd->table, pd->nr_perf_states, freq, + pd->flags); + ps = &pd->table[i]; /* * The capacity of a CPU in the domain at the performance state (ps)