Re: [PATCH v2 1/2] sched/fair: Only compute base_energy_pd if necessary

[Lukasz Luba]

Hi Pierre,

On 4/29/21 11:19 AM, Pierre.Gondois@xxxxxxx wrote:
> From: Pierre Gondois <Pierre.Gondois@xxxxxxx>
>
> find_energy_efficient_cpu() searches the best energy CPU
> to place a task on. To do so, the energy of each performance domain
> (pd) is computed w/ and w/o the task placed in each pd.
>
> The energy of a pd w/o the task (base_energy_pd) is computed prior
> knowing whether a CPU is available in the pd.
>
> Move the base_energy_pd computation after looping through the CPUs
> of a pd and only computes it if at least one CPU is available.
>
> Suggested-by: Xuewen Yan <xuewen.yan@xxxxxxxxxx>
> Signed-off-by: Pierre Gondois <Pierre.Gondois@xxxxxxx>
> ---
>   kernel/sched/fair.c | 38 ++++++++++++++++++++++----------------
>   1 file changed, 22 insertions(+), 16 deletions(-)

Make sense. I will speed-up feec() on Android devices for tasks
being moved into 'background' cgroup (limited to subset of CPUs,
e.g. to only Little cores). LGTM.

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

Regards,
Lukasz