KDE6 performance

[Goverp]

Since yesterday I notice my laptop consuming a lot more power.
htop shows two processes - plasmashell and kwin_wayland, taking 20-30% of a cpu (I have only two on this pathetic little thing).
It drops a lot if I move the cursor over the start bar thingy (not sure what it's called, the bar at the edge with start, activities, etc. etc.)
It's an AMD setup.
Any ideas how I might investigate further?
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Greybeard

[astroe]

Check the news. When Plasma was updated to version 6, Wayland has just become the default Plasma session. Wayland takes up a lot of CPU if it can't leverage the hardware acceleration capabilities of your graphics card.

Your options are to either (1) manually switch back to the Plasma-X11 session instead of Plasma-wayland when you login or (2) try your hand at setting up Wayland to use hardware acceleration.

[dmpogo]

[Goverp]

Nope, I've been running KDE5 with Wayland for about a year, and not hit this issue. It's new with KDE6.

I might try playing with some of the new settings - one change that might be relevant is "shake cursor", which I enabled (or maybe is default). I'm not on the laptop at the moment, and my desktop machine has so many cores the problem isn't visible!
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Greybeard

[Goverp]

It's not KDE6 per se, it's firefox. And at least if I move the cursor out of the firefox window, it stops....
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Greybeard

[sinatosk]

Hi,

I'm now using Gentoo with a Framework Laptop 16 ( AMD Ryzen 7 7840HS with Radeon 780M ) and KDE Plasma 6.1.4 with Wayland

I've recently moved from another distribution where I was using KDE Plasma 5.27 which I later upgraded to 6.0 and then 6.1, moved to Gentoo ( recently ) and enabled 6.1 testing and then later reverted it to stable after Gentoo recently stabilized 6.1.

In those 5.27/6.0/6.1 instances I noticed that plasmashell was using an unnecessary amount of CPU ( 10-30%~ ), later found that not having my panels auto-hide and not floating reduced this usage to 0-2%~.

In those same 6.0/6.1 instances ( I don't remember 5.27 ) I noticed high usage with Firefox when just looking at an idle page like the Gentoo forums, reddit.com with nothing changing on the pages

I found some other people experiencing similar issues and replied there (take a look) with some details

I later rebuilt (remerged?) Firefox with Wayland local USE flag disabled ( forcing Firefox to use Xwayland ) and the CPU usage has drastically dropped and sometimes just gone (0%~).

Firefox is doing something unnecessary ( maybe bug(s) ) when it's using Wayland, so I'm just using Firefox with Wayland support disabled ( Firefox only ) for now.

I haven't got around to reporting the plasmashell and/or panel issue yet to kde bugzilla ( this one has been bothering me since February/March )

[dmpogo]

[sinatosk]

[dmpogo]

[sinatosk]

[Goverp]

A bit more play, and I retract my statement blaming firefox. The behaviour I noticed is with any window: if my mouse cursor is over the Panel (what I called the start bar), cpu usage is negligible. If it's over the anywhere else, it's about 30%.

Ahah! If I make the Panel "always visible", then with the cursor over the desktop, cpu usage is 1-2%. If it's over a firefox home page it varies between 1 and 4%, and in the forum "Post a reply" text box I'm using now, it's 10-14%. Reverting to "autohide", but changing "Adaptive" to "Opaque" Opacity (I think that's new), it exhibits the same behaviour. So I think it's the Panel Opacity code that's to blame. Disabling "Adaptive" looks good move if you use "Autohide".

If the behaviour is consistent over the next day, I'll open a KDE bug, though based on my previous KDE bugs, some of which I opened years ago, and AFAICR none of which have received any response, I won't hold my breath.
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Greybeard

[asturm]

Regardless, give as much information as you can in your bug report. Successful bug resolution is not just a one way street.

[sinatosk]

The KDE panel setting Visibility set to "Always visible", Opacity set to "Adaptive", changed to "Opaque" and then changed to "Translucent", the plasmashell usage issue is not there for me

When I change the Visibility to "Auto hide", regardless of the Opacitiy setting, the plasmashell issue is there for me. When my mouse cursor is over the KDE panel, the usage drops to 0-2%~

=======

regardless of the KDE panel Visibility and Opacity setting with Firefox viewing reddit.com front main page and another showing gentoo forum "portage & programming" ( it doesn't happen on all websites )

Firefox Xwayland support ( USE = X -wayland ) and the usage of CPU and GPU is low as expected

Firefox with Wayland support ( USE = -X wayland ) or ( USE = X wayland ) and the usage of CPU and GPU is high unless I minimize Firefox, but after maximizing again the issue comes back

I'm using amdgpu_top to monitor the GPU usage

=======

I think there are two sets of issues here, plasmashell and Firefox

edit: this is with Firefox 130 but it has happened with previous versions of Firefox ( 129 and 128 I do remember )

[asturm]

Maybe these will get you somewhere:

https://bugs.kde.org/show_bug.cgi?id=487895
https://bugs.kde.org/show_bug.cgi?id=491034

[sinatosk]

[Goverp]

487895 looks right for me.
I noticed a strange icon on my panel - turns out to be a Plasma 5 widget that won't run on Plasma 6. Unhelpfully, Plasma doesn't tell me the name.
On my first trial, it appears reverting to an "Adaptive" panel no longer triggers the high cpu. But I'll give it some time before I'm sure...
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Greybeard