Re: [PATCH v2 5/6] energy_model: use a fixed reference frequency

[Lukasz Luba]

Hi Vincent,


On 10/9/23 11:36, Vincent Guittot wrote:
> The last item of a performance domain is not always the performance point
> that has been used to compute CPU's capacity. This can lead to different
> target frequency compared with other part of the system like schedutil and
> would result in wrong energy estimation.
>
> A new arch_scale_freq_ref() is available to return a fixed and coherent
> frequency reference that can be used when computing the CPU's frequency
> for an level of utilization. Use this function to get this reference
> frequency.
>
> Energy model is never used without defining arch_scale_freq_ref() but
> can be compiled. Define a default arch_scale_freq_ref() returning 0
> in such case.
>
> Signed-off-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>
> ---
>   include/linux/energy_model.h | 14 +++++++++++---
>   1 file changed, 11 insertions(+), 3 deletions(-)

LGTM, taking into account the patch 2/6 that we don't include any
boost freq (so no changes w.r.t. current EAS situation)

Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx>