Re: [PATCH] drm/lima: add governor data with pre-defined thresholds

[Lukasz Luba]

On 1/27/21 10:24 AM, Lukasz Luba wrote:
> Hi Christian,
>
> On 1/25/21 8:18 AM, Christian Hewitt wrote:
> > This patch adapts the panfrost pre-defined thresholds change [0] to the
> > lima driver to improve real-world performance. The upthreshold value has
> > been set to ramp GPU frequency to max freq faster (compared to panfrost)
> > to compensate for the lower overall performance of utgard devices.
> >
> > [0] 
> > https://patchwork.kernel.org/project/dri-devel/patch/20210121170445.19761-1-lukasz.luba@xxxxxxx/ 
> >
> >
> > Signed-off-by: Christian Hewitt <christianshewitt@xxxxxxxxx>
> > ---
> > I have been using Kodi as my test application. If you scroll in library
> > views with hundreds of list items and the panfrost values the slow GPU
> > ramp up is quite noticeable and the GUI feels sluggish. As everything
> > lima runs on is inherently slower than panfrost using devices I believe
> > it's better to ramp up to max freq quicker.
>
> It's quite low value for the upthreshold, but I believe you have
> experimented and observed that a bit higher (30, 40?) don't work well.
> I don't know the Kodi system, though.
>
> You can check if the other frequencies are also used in statistics for
> devfreq device:
> cat /sys/class/devfreq/<your_gpu>/trans_stats
>
> If they are also used, then it OK (better than stuck at min freq).

I've just realized that your board might suffer a another issue.
Please apply this patch [1] and run your experiments with upthresholds.


[1] https://lore.kernel.org/lkml/20210127105121.20345-1-lukasz.luba@xxxxxxx/