Re: [PATCH v4 0/4] Clarify abstract scale usage for power values in Energy Model, EAS and IPA

From: Lukasz Luba
Date: Tue Nov 17 2020 - 04:24:44 EST




On 11/10/20 7:32 PM, Rafael J. Wysocki wrote:
On Wed, Nov 4, 2020 at 11:58 AM Lukasz Luba <lukasz.luba@xxxxxxx> wrote:

Hi Rafael,

On 11/3/20 9:05 AM, Lukasz Luba wrote:
Hi all,

The Energy Model supports power values expressed in an abstract scale.
This has an impact on Intelligent Power Allocation (IPA) and should be
documented properly. Kernel sub-systems like EAS, IPA and DTPM
(new comming PowerCap framework) would use the new flag to capture
potential miss-configuration where the devices have registered different
power scales, thus cannot operate together.

There was a discussion below v2 of this patch series, which might help
you to get context of these changes [2].

The agreed approach is to have the DT as a source of power values expressed
always in milli-Watts and the only way to submit with abstract scale values
is via the em_dev_register_perf_domain() API.

Changes:
v4:
- change bool to int type for 'miliwatts' in struct em_perf_domain
(suggested by Quentin)
- removed one sentence from patch 2/4 in IPA doc power_allocator.rst
(suggested by Quentin)
- added reviewed-by from Quentin to 1/4, 3/4, 4/4 patches

There was no major objections in the v3 and this v4 just addressed
minor comments. The important discussions mostly happen in v2.

Could you take the patches via your tree, please?

Applied as 5.11 material, thanks!


Thank you Rafael!

Regards,
Lukasz