| Message ID | 20230512095743.3393563-4-lukasz.luba@arm.com (mailing list archive) |
|---|---|
| State | RFC |
| Headers | show |
| Series | Introduce runtime modifiable Energy Model | expand |
On 12/05/2023 11:57, Lukasz Luba wrote: > Prepare em_pd_get_efficient_state() for the upcoming changes and > make it possible to re-use. Return an index for the best performance Don't get the `possible to re-use`? Did you mean `possible to be re-used`? But then `re-used` for what? > state. 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. This describes the WHAT but not the WHY. > Signed-off-by: Lukasz Luba <lukasz.luba@arm.com> > --- > 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 > + * @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)
On 5/30/23 12:06, Dietmar Eggemann wrote: > On 12/05/2023 11:57, Lukasz Luba wrote: >> Prepare em_pd_get_efficient_state() for the upcoming changes and >> make it possible to re-use. Return an index for the best performance > > Don't get the `possible to re-use`? Did you mean `possible to be > re-used`? But then `re-used` for what? The function will no longer get a pointer to 'struct em_perf_domain' but instead to 'struct em_perf_state'. It would also require to get the number of states from 'pd->nr_perf_states'. This is preparation for handling 2 tables: modifiable (a) and default (b). Then it also returns and ID not the pointer to state. It all makes it more generic and ready for those 2 tables. > >> state. 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. > > This describes the WHAT but not the WHY. I will add that description as 'why' in the header. I wanted to avoid mentioning in the patch description something which is coming in the next patch.
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)
Prepare em_pd_get_efficient_state() for the upcoming changes and make it possible to re-use. Return an index for the best performance state. 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> --- include/linux/energy_model.h | 30 +++++++++++++++++------------- 1 file changed, 17 insertions(+), 13 deletions(-)