On 27/03/2024 13:55, Dietmar Eggemann wrote: > On 26/03/2024 21:32, Lukasz Luba wrote: >> >> >> On 3/26/24 10:09, Dietmar Eggemann wrote: >>> On 22/03/2024 12:08, Lukasz Luba wrote: > > [...] > >>>> + return em_recalc_and_update(dev, pd, em_table); >>>> +} >>>> +EXPORT_SYMBOL_GPL(em_dev_update_chip_binning); >>> >>> In the previous version of 'chip-binning' you were using the new EM >>> interface em_dev_compute_costs() (1) which is now replaced by >>> em_recalc_and_update() -> em_compute_costs(). >>> >>> https://lkml.kernel.org/r/20231220110339.1065505-2-lukasz.luba@xxxxxxx >>> >>> Which leaves (1) still unused. >>> >>> That was why my concern back then that we shouldn't introduce EM >>> interfaces without a user: >>> >>> https://lkml.kernel.org/r/8fc499cf-fca1-4465-bff7-a93dfd36f3c8@xxxxxxx >>> >>> What happens now with em_dev_compute_costs()? >>> >> >> For now it's not used, but modules which will create new EMs >> with custom power values will use it. When such a module have >> e.g. 5 EMs for one PD and only switches on one of them, then >> this em_dev_compute_costs() will be used at setup for those >> 5 EMs. Later it won't be used. >> I don't wanted to combine the registration of new EM with >> the compute cost, because that will create overhead in the >> switching to new EM code path. Now we have only ~3us, which >> was the main goal. >> >> When our scmi-cpufreq get the support for EM update this >> compute cost will be used there. > > OK, I see. I checked the reloadable EM test module and > em_dev_compute_costs() is used there like you described it. I had a second look and IMHO the layout is like this: Internal (1) and external (2,3) 'reloadable EM' use cases: (EM alloc and free not depicted) 1. Late CPUs booting (CPU capacity adjustment) e3f1164fc9ee PM: EM: Support late CPUs booting and capacity adjustment schedule_delayed_work(&em_update_work, ...) em_update_workfn() em_check_capacity_update() em_adjust_new_capacity() em_recalc_and_update() <-- (i) em_compute_costs() <-- (ii) em_dev_update_perf_domain() <-- external 2. Reload EM from driver 22ea02848c07 PM: EM: Add em_dev_compute_costs() 977230d5d503 PM: EM: Introduce em_dev_update_perf_domain() for EM updates em_dev_compute_costs() <-- external em_compute_costs() <-- (ii) em_dev_update_perf_domain() <-- external 3. Chip binning this patchset PM: EM: Add em_dev_update_chip_binning() em_dev_update_chip_binning() <-- external em_recalc_and_update() <-- (i) em_compute_costs() <-- (ii) em_dev_update_perf_domain() <-- external
