Re: [PATCH 3/3] cpuidle/drivers/mbed: Add new governor for embedded systems

From: Quentin Perret
Date: Tue Apr 02 2019 - 12:26:11 EST


On Tuesday 02 Apr 2019 at 18:02:02 (+0200), Daniel Lezcano wrote:
> I tried on a hikey960 with an android kernel 4.19.

OK. ISTR Hikey 960 had quite a few problems with idle states recently.
At some point it was so horribly broken that you could get something
like a 3x perf bonus in Jankbench _and_ save energy by just disabling
all idles states no ? I haven't been following closely but have these
issues been resolved ?

In any cases, your results seem to go in the right direction, and that's
not a blocker to go on with the review so :-)

>
> The used percentile is the 95%, the tests are jankbench list_view and
> edit_text, and exoplayer. Values are normalized against the menu governor:
>
> list_view:
> frame duration -35%
> count: +20%
> energy: +1%
>
> edit text:
> frame duration -45%
> count: +27%
> energy: -0.3%
>
> For audio and video playback, there is no frame drop.
>
> audio
> - energy: -2.8%
>
> video
> - energy: -3.8%
>
> These are preliminary results.

Thanks for the details. Assuming the board support isn't too broken,
these look pretty good.

Cheers,
Quentin