Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 19 Dec 2023 10:58:17 +0000 | Subject | Re: [PATCH v5 04/23] PM: EM: Refactor em_pd_get_efficient_state() to be more flexible | From | Lukasz Luba <> |
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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.
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