KDE Plasma 5.14's Lock Screen Will No Longer Eat Your CPU Resources On Old Hardware

[Nth_man]

Me too. I thought the only DE where parts of it eat your CPU resources was GNOME? Plasma was supposedly much more CPU-friendly, so how did this happen?

Martin Graesslin (Flösser) explained it just above your comment :-) , in https://www.phoronix.com/forums/foru...39#post1040439

[Nth_man]

So unless you have hardware which is older than ~10 years you would not hit this bug and even if you would have to run special settings. It's great that it got fixed, but a post here is well, too much attention to nothing.

Michael Larabel earns money with polemics. Sometimes it's worse, like when he writes fan insults in ["looks like puke"](https://www.phoronix.com/forums/foru...1#post812401):
[...] Michael Larabel quotes insults when they are aimed at KDE; when the insults aimed and e.g. Gnome, then he doesn't quote them, what an "informer". As usual, in his www.michaellarabel.com page he says that he has a "strong support for GNOME", who was going to guess what he understands as support?

[mulenmar]

A note to those poo-poohing this fix, and saying we should tell users their hardware doesn't meet the requirements: Not everyone can afford to upgrade, and NOBODY should be required to for something so banally simple as a lock screen's rendering. Not the cryptography, not the other security checks, the bit where you're drawing some text and a textbox.

A Thinkpad T60 is still a usable daily-driver for many people, despite being released in 2006 and supporting only OpenGL 1.4 (iirc). This issue being fixed is a boon to anyone running a Libreboot-ed T60, or to anyone else using KDE on older hardware.

This sort of BS is why open-source desktop developers should be *required* to use their desktop environment on 10-15 year old hardware, for no less than two weeks at a time, before they commit their Fancy New Major Feature/Rewrite code.

[shmerl]

While it's nice that developers support 15 year old hardware, claiming that they are required to do it is completely unreasonable. No, they are not required to support antique hardware at all. It's an extra burden that no reasonable user should expect to come for free.

[cbxbiker61]

I just converted my brothers old dual core Intel notebook to Linux since Windows updates were over for his old version. The notebook probably won't be used very much any more. I was wondering why the notebook was chewing up CPU resources when it was idle. Now I know. It's nice that it'll be fixed.

[FireBurn]

To provide the missing context. The user who reported the bug uses ancient hardware which does not provide OpenGL 2.1. Due to that everything using QtQuick was running on llvmpipe, which is not a good option when running on such old hardware (it seldom has multi-core and SSE4 which makes llvmpipe usable). My reaction to this report was telling the user that I'm sorry, but the hardware does not fulfill the hardware requirements.

David asked the user to try the 2D software renderer option for QtQuick and it turned out that this overall improved the system, but lockscreen was still affected. This was due to the settings not being read in kscreenlocker. David did a change to honor this setting also in kscreenlocker and that's what it's about.

So unless you have hardware which is older than ~10 years you would not hit this bug and even if you would have to run special settings. It's great that it got fixed, but a post here is well, too much attention to nothing.

You're default reaction is to mark all bugs as invalid

[M@yeulC]

So that's what has been plaguing me on my laptop (32 bit atom, I seldom use the GUI anyway). Nice to see a workaround, thanks a lot!

It was annoying to see the interface that was quite snappy (more so than xfce, I'd say) come to a crawl when the lockscreen was displayed (to the point of only displaying the background on the lockscreen, I usually unlocked it trough loginctl on another TTY). I wasn't aware that I had been using software rendering.

I also just noticed that the plasmashell CPU usage was jumping to 100% (er, 50% as it's a dual core) while playing with the selection rectangle on my desktop. Could it be the same issue?

To the naysayers: the lockscreen uses QML, which makes it quite versatile and aligned with the rest of the desktop, to (usually) very little cost.

[ferry]

It's too easy to dismiss this as a problem occurring only on 15 year old hardware. It will actually happen on even the most recent (or should I say in particular the most recent) hardware where no decent opengl drivers are available - for linux (Imagination Tech). I'm thinking of the problems I had with my FitPC (Atom + Poulsbo GMA500).

[oiaohm]

So unless you have hardware which is older than ~10 years you would not hit this bug and even if you would have to run special settings. It's great that it got fixed, but a post here is well, too much attention to nothing.

Ok I wish only 10 year old hardware.
1) Running side virtual machine using software rendering this bug will appear. In fact this is more painful that on 10 year old hardware.
2) trying out VKMS with 4.19 Linux kernel again software rendering the bug would appear.

Good to see it fixed.

[Hibbelharry]

Me too. I thought the only DE where parts of it eat your CPU resources was GNOME? Plasma was supposedly much more CPU-friendly, so how did this happen?

Both are great, but both have bugs, too. In reality there is not much difference in that matter as far as my impression goes. I personally break KDE sessions in roughly half the time i need to take down gnome, but others I trust say it's the other way around, so think of them being equal in quality.

A note to those poo-poohing this fix, and saying we should tell users their hardware doesn't meet the requirements: Not everyone can afford to upgrade, and NOBODY should be required to for something so banally simple as a lock screen's rendering. Not the cryptography, not the other security checks, the bit where you're drawing some text and a textbox.

A Thinkpad T60 is still a usable daily-driver for many people, despite being released in 2006 and supporting only OpenGL 1.4 (iirc). This issue being fixed is a boon to anyone running a Libreboot-ed T60, or to anyone else using KDE on older hardware.

This sort of BS is why open-source desktop developers should be *required* to use their desktop environment on 10-15 year old hardware, for no less than two weeks at a time, before they commit their Fancy New Major Feature/Rewrite code.

That's wrong. It's just not right that everyone needs to target old/slow hardware. Anyone might do, but noone needs to. If you target just upper class/newer hardware with any project, that's also a decent idea.