KDE Will Nicely Notify You When Apps Are Being Killed Due To Out-Of-Memory

[geerge]

I'm not in kde, but a prominent out of memory error would've saved me a few hours of debugging why a vm would crash rarely. I only have 32GB of memory and there's 4 workloads that can consume north of 10GB each but don't normally run at once, except when they do.

[curfew]

Very nice!

I hope this comes to GNOME too.

Gnome has had it for a long time. 🤦🏿♀️

You don't need features that you have no use for.

[uid313]

Gnome has had it for a long time. 🤦🏿♀️

You don't need features that you have no use for.

I don't remember seeing such a notification on GNOME when my RAM ran out.

[rmfx]

They should really hire some ui/ux specialists to align the elements on their panels properly…

[moonwalker]

Maybe consider optimizing/rewriting Plasma first:

https://itvision.altervista.org/linux-desktop-environments-system-usage.html

The absolute worst DE in terms of RAM consumption on Linux. I can redo the comparison but so far no one has been interested.

"make things right once and for all" - that's the most idiotic thing I've ever heard about something that changes all the time. Also, the article is applicable only to Fedora spins, on different distros you may see a completely different picture. E.g. on Debian Unstable, when I did a similar test about a year or two earlier, GNOME was the heaviest, while XFCE and LXQt barely had any advantage over KDE Plasma. In fact, I was able to run Plasma (with zram swap though) even on RPi1 as recently as two and a half years ago.

I do have to say though that Plasma 6.x is indeed much heavier than 5.x when running on my rig, something I'm very unhappy about. The picture may be very different for other people, of course.

[intelfx]

Very nice!

I hope this comes to GNOME too.

I don't have a swap file or a swap partition, my experience when my system runs out of RAM is that everything freezes, then if I wait a minute or two then some process gets killed and things work again.

It's already there. GNOME Shell has had built-in OOM notifications for quite some time now.

But, to make it work, you'd also need something (a system daemon) to actually perform userspace OOM monitoring, just like with KDE.

[moonwalker]

You are so wrong. Plasma uses only ~700MB on my computer.

This is FC41 KDE spin with 32GB RAM and a GTX1650 GPU

"free -h" with SSH logon from network, only SDDM running, no other users

total used free shared buff/cache available
Mem: 31Gi 1.1Gi 28Gi 9.0Mi 1.9Gi 30Gi
Swap: 8.0Gi 0B 8.0Gi
​

"free -h" on the Plasma 6.2.2 session, only Konsole running

total used free shared buff/cache available
Mem: 31Gi 1.8Gi 27Gi 21Mi 2.1Gi 29Gi
Swap: 8.0Gi 0B 8.0Gi

Don't reply, no discussion necessary.

He's not wrong per se, it's just that his measurements are only applicable to a very specific setup at a specific point in time - specific distro runing specific versions of software configured in a specific way and running on a specific hardware. Change hardware - and you may see a different pattern. Change distro - and you may see a different pattern. Change how the system is configured - you may see a different pattern. Keep all the same, but use different versions of the same software - hopefully, by now you get the idea. Heck, even something like screen resolution/pixel density (and thus scaling) may cause pattern to be different for different DEs/distros/configurations, e.g. when Plasma 5.x wouldn't noticeably grow RAM usage on multi-4k-display setup I have, Plasma 6.x RAM usage skyrockets compared to the same rig connected to a single low-resolution (1280x800) display.

[intelfx]

And we've got shit only by #2...

A quick code skim seems to indicate that the OOM notifications are delivered, ultimately, by systemd-oomd, which...might not be started on some customized setups. Not sure if there is a kernel uevent interface for OOM.

I'm not sure about uevents and KDE, but GNOME's OOM notifications can in fact happen even without a userspace daemon.

I use MGLRU with working set thrashing prevention enabled and cgroups to enforce memory limits on specific apps, and I receive OOM notifications from GNOME Shell from time to time.

[Vistaus]

It's not about "Qt6 is better, case closed". Its just almost 2 year old measurements are not revelant for current state.
Problem still can exist, but you don't know it. You need relatively fresh data.

Exactly. If we were talking about e.g. Windows 11 two years later, chances are relatively high that not much has changed in that regard. But KDE is constantly improving itself plus has done Qt 5 to Qt 6, so new data is definitely needed.

Though I will agree that KDE is a bit harsh, even on my very well equipped almost 3-year old system, but that seems more CPU/GPU-related than RAM-related. And it's not like it causes huge issues, just a bit of sluggishness, which is not a total dealbreaker for most people.

[pWe00Iri3e7Z9lHOX2Qx]

Maybe consider optimizing/rewriting Plasma first:

https://itvision.altervista.org/linux-desktop-environments-system-usage.html

The absolute worst DE in terms of RAM consumption on Linux. I can redo the comparison but so far no one has been interested.

I think tests like this without launching any apps are better to make your claim. Because you aren't just looking at Plasma memory usage. You are looking at Plasma + Dolphin + Konsole. Or just call your test what it is and say it's a DE + terminal + file manager memory usage test.

The last time I did this years ago, also with Fedora, it was Xfce -> Plasma (only slightly more RAM usage) -> GNOME (considerably more). Once Xfce moved to GTK3, RAM usage didn't seem that light anymore.