high CPU use specific case

[squalou]

Hi,

just to mention a use case that may, or may not not, be useful for future performance improvements.

Basically happening right now : writing this issue in firefox brings cosmic-comp use to 30% of a core on my hardware. More than frefox-bin itself.

Now a funny part :

• open firefox in a worskpace, start a meeting, cocmic-comp up to 35%, someimes more.
• hide the meeting tab (open another tab) : same thing
• put another window in front : same thing

but

change active workspace : cpu use goes does down.

As if visible or not, provided a window is on the visible workspace, cosmic-comp works for it.

Maybe that's totally normal, maybe not.

Feel free to instantly close this as it's not really an issue, more a real life observation, and you all maybe already know this.

All in all when I compare to 22.04 with pop extension on gnome shell, the cpu use difference is huge. The average for a similar use (8 cores average reported by top, so not very precise) : under COSMIC : around 5% idle, versus less than 1%.

[Drakulix]

Do you use firefox with or without client-side decorations?

[squalou]

If I refer to this old article : I'd say with CSD

(untick "Title Bar" in menu customization) https://vitux.com/how-to-try-firefox-client-side-decoration-csd-on-ubuntu/

Maybe there's another way to make sure ?

[squalou]

(i'm giving a try without CSD to see what happens, doing it right now and it's far better but, can't judge in 30 seconds, will tell after some real work)

[Drakulix]

Guessing this is the same bug as stacks causing higher cpu load then. Basically whenever the compositor has to render text this happens.

[squalou]

Indeed after a few hours without CSD, I can confirm that it's correlated to it.

adding reference #703