On Wed, Mar 02, 2022 at 06:09:12PM +0000, Ionela Voinescu wrote: > Define topology_init_cpu_capacity_cppc() to use highest performance > values from _CPC objects to obtain and set maximum capacity information > for each CPU. acpi_cppc_processor_probe() is a good point at which to > trigger the initialization of CPU (u-arch) capacity values, as at this > point the highest performance values can be obtained from each CPU's > _CPC objects. Architectures can therefore use this functionality > through arch_init_invariance_cppc(). > > The performance scale used by CPPC is a unified scale for all CPUs in > the system. Therefore, by obtaining the raw highest performance values > from the _CPC objects, and normalizing them on the [0, 1024] capacity > scale, used by the task scheduler, we obtain the CPU capacity of each > CPU. > > While an ACPI Notify(0x85) could alert about a change in the highest > performance value, which should in turn retrigger the CPU capacity > computations, this notification is not currently handled by the ACPI > processor driver. When supported, a call to arch_init_invariance_cppc() > would perform the update. > > Signed-off-by: Ionela Voinescu <ionela.voinescu@xxxxxxx> > Tested-by: Valentin Schneider <valentin.schneider@xxxxxxx> > Cc: Sudeep Holla <sudeep.holla@xxxxxxx> Looks good to me. FWIW, Acked-by: Sudeep Holla <sudeep.holla@xxxxxxx> -- Regards, Sudeep
