Re: [RESEND PATCH V3] PM / EM: Micro optimization in em_cpu_energy

From: Rafael J. Wysocki
Date: Tue Dec 08 2020 - 12:25:39 EST


On Sat, Nov 28, 2020 at 3:21 AM Pavankumar Kondeti
<pkondeti@xxxxxxxxxxxxxx> wrote:
>
> When the sum of the utilization of CPUs in a power domain is zero,
> return the energy as 0 without doing any computations.
>
> Acked-by: Quentin Perret <qperret@xxxxxxxxxx>
> Reviewed-by: Dietmar Eggemann <dietmar.eggemann@xxxxxxx>
> Signed-off-by: Pavankumar Kondeti <pkondeti@xxxxxxxxxxxxxx>
> ---
> include/linux/energy_model.h | 3 +++
> 1 file changed, 3 insertions(+)
>
> diff --git a/include/linux/energy_model.h b/include/linux/energy_model.h
> index b67a51c..8810f1f 100644
> --- a/include/linux/energy_model.h
> +++ b/include/linux/energy_model.h
> @@ -103,6 +103,9 @@ static inline unsigned long em_cpu_energy(struct em_perf_domain *pd,
> struct em_perf_state *ps;
> int i, cpu;
>
> + if (!sum_util)
> + return 0;
> +
> /*
> * In order to predict the performance state, map the utilization of
> * the most utilized CPU of the performance domain to a requested
> --

Applied as 5.11 material, thanks!