video acceleration

[Mark Dunn]

Setup:
I have installed the latest 20.04 LTS Ubuntu software on my raspberry pi 4b
The kernel was 5.4.0-1008.8
in config.txt I have
    ...
    dtoverlay=vc4-fkms-v3d
    max_framebuffers=2
    ...
I am running ubuntu-desktop

Problem:
When displaying the gnome-system-monitor (as an example) it uses 52% cpu
This is because this Ubuntu version has no hardware scrolling
when running glxgears it uses 100% cpu and achieves 42 frames/second

I am afraid I do not know how to build the official ubuntu kernel
Instead I used the rpi kernel -Linux ubuntu 5.4.35-v8+ #1 SMP PREEMPT Tue Apr 28 13:28:41 UTC 2020 aarch64 aarch64 aarch64 GNU/Linux

With this kernel
displaying gnome-system-monitor uses only 10% cpu as scrolling is performed by the hardware
when running glxgears it uses only 20% cpu and achieves 50 frames/second

I asked you to enable v3d in kernel 4.18 but it caused problems
https://bugs.launchpad.net/ubuntu/+source/linux-raspi2/+bug/1850876

If you could show me the official way to modify your raspi kernel, I am willing to check if those problems you encountered 6 months ago still exist. Failing that, could you guys please retry it?

In my opinion, this change transforms Ubuntu on PI from a toy to a working tool.
Two pieces of software I use in development (vscode and chromium-browser) lose the 'treacle' feel.