Re: [PATCH v3 2/3] sched/fair: Take thermal pressure into account while estimating energy

From: Lukasz Luba
Date: Mon Jun 14 2021 - 14:22:12 EST




On 6/14/21 5:03 PM, Vincent Guittot wrote:
On Thu, 10 Jun 2021 at 17:03, Lukasz Luba <lukasz.luba@xxxxxxx> wrote:

[snip]

In the existing code the raw value of arch_scale_cpu_capacity() is used
for clamping the returned CPU utilization from effective_cpu_util().
This patch fixes issue with too big single CPU utilization, by introducing
clamping to the allowed CPU capacity. The allowed CPU capacity is a CPU
capacity reduced by thermal pressure signal. We rely on this load avg

you don't rely on load avg value but on raw thermal pressure value now

Good catch, I'll change that description.


geometric series in similar way as other mechanisms in the scheduler.


[snip]


+ thermal_pressure = arch_scale_thermal_pressure(cpumask_first(pd_mask));

Do you really need to use this intermediate variable thermal_pressure
? Seems to be used only below

True, it's used only here. I'll remove this variable in the v4.


With these 2 comments above fixed,

Reviewed-by: Vincent Guittot <vincent.guittot@xxxxxxxxxx>

Thank you for the review!

Regards,
Lukasz