Plasmashell memory leak

[GreyGeek]

I got home today to find plasmashell using 5.5Gb swap and 2.3Gb ram on Kubuntu 18.04. WHY?

Other threads suggest that certain widgets leak memory, now I do have a custom layout - a single panel on the left hand side, so that could be a factor. So I am going to have to remove them one at a time until I figure out which one is eating my ram. As a long-time linux user this is seriously disheartening. Why can't plasmashell monitor and limit the memory usage of its widgets? Why does the end user have to debug this largely on their own?

Influential Linux nerds recommended KDE Plasma to me as being a light-weight stable functional desktop environment, but I find it to be over-complicated (it took me over half an hour to find the only way to remove a widget from a panel, why isn't it an option in the right-click menu?), buggy (I have to restart kwin every other day because the entire desktop freezes up) and way to greedy in the memory department.

Is there any hope or should I install Unity which has the reputation of using rather a lot of ram from the get-go, but which is as stable as a rock?

With absolutely no info to go on it is impossible to say what your problems are. The "Influential Linux nerds"? I agree with them 100%. Kubuntu 18.04 has been and is as stable as a rock since I installed it right after it went gold. I'm running three internal HDs with 16GB of RAM, an i7 CPU and an NVidia GT 650M GPU that is not settable in the BIOS as the primary but behaves as the primary because of nvidia-390, and runs faultlessly everything I throw at it. BTW, I'm running sddm. (Simple Desktop Display Manager). Here is my kwin usage:

Process 1274 - kwin_x11

Summary

The process kwin_x11 (with pid 1274) is using approximately 64.9 MB of memory.
It is using 53.6 MB privately, and a further 65.4 MB that is, or could be, shared with other programs.
Dividing up the shared memory between all the processes sharing that memory we get a reduced shared memory usage of 11.3 MB. Adding that to the private usage, we get the above mentioned total memory footprint of 64.9 MB.
Library Usage

The memory usage of a process is found by adding up the memory usage of each of its libraries, 
plus the process's own heap, stack and any other mappings, plus the stack of its 5 threads. 
Private
more
24300 KB    [heap]
16612 KB    /dev/nvidiactl
4176 KB    /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.390.48
2732 KB    /usr/lib/x86_64-linux-gnu/libkwin.so.5.12.6
1028 KB    /usr/lib/x86_64-linux-gnu/libkwin4_effect_builtins.so.1.0.0
Shared
more
10740 KB    /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.390.48
4472 KB    /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5.9.5
4008 KB    /usr/lib/x86_64-linux-gnu/libQt5Core.so.5.9.5
3376 KB    /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.9.5
2852 KB    /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.9.5
...
[SIZE=3][B]AND, MY Plasmashell[/B][/SIZE]
Process 1278 - plasmashell

Summary

The process plasmashell (with pid 1278) is using approximately 259.2 MB of memory.
It is using 242.4 MB privately, and a further 86.0 MB that is, or could be, shared with other programs.
Dividing up the shared memory between all the processes sharing that memory we get a reduced shared memory usage of 16.8 MB. Adding that to the private usage, we get the above mentioned total memory footprint of 259.2 MB.
Library Usage

The memory usage of a process is found by adding up the memory usage of each of its libraries, plus the process's own heap, stack and any other mappings, plus the stack of its 17 threads. 
Private
more
149756 KB    [heap]
69508 KB    /dev/nvidiactl
2672 KB    /usr/lib/x86_64-linux-gnu/libQt5XmlPatterns.so.5.9.5
2036 KB    /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.390.48
1668 KB    /home/jerry/.cache/plasma_theme_default_v5.30.kcache
Shared
more
10584 KB    /usr/lib/x86_64-linux-gnu/libnvidia-glcore.so.390.48
4696 KB    /usr/lib/x86_64-linux-gnu/libQt5Gui.so.5.9.5
4360 KB    /usr/lib/x86_64-linux-gnu/libQt5Core.so.5.9.5
3548 KB    /usr/lib/x86_64-linux-gnu/libQt5Qml.so.5.9.5
3356 KB    /usr/lib/x86_64-linux-gnu/libQt5Quick.so.5.9.5

As far as your suggestion that plasma developers "monitor and limit the memory usage of its widgets" ... that would be impractical if not impossible. How is a plasma developer supposed to know what the widget developer's intentions are with regard to memory usage? Some widget use a lot of memory and some do not. The KDE dev crew is not responsible for what widget developers do or don't do.

It could be that 5.5GB of swap and 2.5GB of RAM is normal.

[Snowhog]

I got home today to find plasmashell using 5.5Gb swap and 2.3Gb ram on Kubuntu 18.04. WHY?

You aren't giving us much; heck, you aren't giving us anything; to go on. Are you leaving your PC on 24/7? What do you have running? What applications/widgets have you installed? What are your PC specs?

[jpeg729]

I got home today to find plasmashell using 5.5Gb swap and 2.3Gb ram on Kubuntu 18.04. WHY?

Other threads suggest that certain widgets leak memory, now I do have a custom layout - a single panel on the left hand side, so that could be a factor. So I am going to have to remove them one at a time until I figure out which one is eating my ram. As a long-time linux user this is seriously disheartening. Why can't plasmashell monitor and limit the memory usage of its widgets? Why does the end user have to debug this largely on their own?

Influential Linux nerds recommended KDE Plasma to me as being a light-weight stable functional desktop environment, but I find it to be over-complicated (it took me over half an hour to find the only way to remove a widget from a panel, why isn't it an option in the right-click menu?), buggy (I have to restart kwin every other day because the entire desktop freezes up) and way to greedy in the memory department.

Is there any hope or should I install Unity which has the reputation of using rather a lot of ram from the get-go, but which is as stable as a rock?

[GreyGeek]

That probably explains why your memory use is greater!

[bschelst]

16Gb over here

[GreyGeek]

I have only 6GB of RAM. Do you have more?

[bschelst]

mine is even bigger...

ptime;ps -u $USER -wo rss=,comm= --sort -rss | while read -r rss comm ; do echo $((rss/1024))"MB -" $comm; done && free -m
20:06:35 up 7:30, 3 users, load average: 1,02, 0,91, 0,90
3112MB - plasmashell
713MB - akonadi_ews_res
629MB - chrome
532MB - TeamViewer
408MB - chrome
402MB - mysqld
383MB - kmail
368MB - chrome
364MB - chrome

[GreyGeek]

$ ps -u $USER -wo rss=,comm= --sort -rss | while read -r rss comm ; do echo $((rss/1024))"MB -" $comm; done && free -m

Could you please explain ^^^

I've usually just looked at free -m. Understanding RAM usage in Linux can get pretty difficult for us non-technical users: https://www.linuxatemyram.com/

It's output is a listing of the total RAM used for each running process, and totals for each of the parts RAM is divided into. For a complete listing of possible command sequences see "man ps". It is a lot easier to get totals this way rather than using a calculator on ksysguard's output and trying to total them manually.

:~$ ps -u $USER -wo rss=,comm= --sort -rss | while read -r rss comm ; do echo $((rss/1024))"MB -" $comm; done && free -m
319MB - plasmashell
301MB - firefox
199MB - Web Content
103MB - kwin_x11
84MB - Web Content
78MB - krunner
63MB - kgpg
62MB - konsole
61MB - hp-systray
60MB - blueman-applet
58MB - evolution-calen
55MB - kded5
52MB - evolution-alarm
52MB - klauncher
51MB - ksmserver
50MB - kdeconnectd
48MB - evolution-calen
48MB - evolution-calen
46MB - polkit-kde-auth
45MB - kwalletd5
44MB - kaccess
43MB - org_kde_powerde
42MB - kglobalaccel5
32MB - kactivitymanage
27MB - kuiserver
27MB - gmenudbusmenupr
27MB - xembedsniproxy
25MB - distro-release-
24MB - kscreen_backend
24MB - hp-systray
24MB - kio_http_cache_
23MB - evolution-sourc
22MB - kdeinit5
18MB - evolution-addre
18MB - evolution-addre
16MB - hp-systray
11MB - pulseaudio
9MB - obexd
7MB - gnome-keyring-d
6MB - kwrapper5
6MB - gnome-keyring-d
6MB - at-spi2-registr
6MB - gvfsd
5MB - gconfd-2
5MB - bash
5MB - at-spi-bus-laun
5MB - bash
4MB - systemd
4MB - dconf-service
4MB - dbus-daemon
4MB - gconf-helper
3MB - dbus-daemon
3MB - ps
2MB - dbus-launch
2MB - (sd-pam)
1MB - ksysguardd
1MB - bash
1MB - startkde
0MB - gpg-agent
0MB - ssh-agent
0MB - start_kdeinit
              total        used        free      shared  buff/cache   available
Mem:           5801        1094        2440          56        2266        4290
Swap:             0           0           0

[pemartins]

@chimak111 thank you so much for the info, I really hope that link about the disk cache on ram is the explanation. Stuff like a 1 GB virus running on the background crossed my mind...

I'd love to be able to explain that command but unfortunately is most probable that we see Trump and Hillary dancing salsa together before I can understand what's on it It's a copy and paste from somewhere made some time ago, all I recall is that the command intents to display the ram use per application in the user session.

[chimak111]

$ ps -u $USER -wo rss=,comm= --sort -rss | while read -r rss comm ; do echo $((rss/1024))"MB -" $comm; done && free -m

Could you please explain ^^^

I've usually just looked at free -m. Understanding RAM usage in Linux can get pretty difficult for us non-technical users: https://www.linuxatemyram.com/

[pemartins]

The math is not right in my ram usage, if I do a total on all processes shown it should perhaps return a sum of about 600 MB or so; but as it shows in the printscreen, how can it be taking 1.6 GB of ram? What is using the extra 1 GB of ram not shown anywhere?



It just does not add up...

edit:

$ ps -u $USER -wo rss=,comm= --sort -rss | while read -r rss comm ; do echo $((rss/1024))"MB -" $comm; done && free -m
265MB - plasmashell
80MB - kded5
73MB - konsole
56MB - kwin_x11
27MB - krunner
27MB - ksmserver
24MB - http.so
24MB - http.so
22MB - firetools
15MB - kactivitymanage
15MB - klauncher
11MB - kdeconnectd
10MB - org_kde_powerde
10MB - python
10MB - polkit-kde-auth
10MB - kglobalaccel5
9MB - kwalletd5
9MB - kaccess
9MB - kuiserver5
9MB - pulseaudio
6MB - kdeinit5
5MB - xembedsniproxy
5MB - kscreen_backend
4MB - bash
3MB - xbindkeys
3MB - kio_http_cache_
3MB - ps
2MB - dbus-daemon
2MB - at-spi2-registr
2MB - gvfsd
2MB - redshift
2MB - systemd
2MB - at-spi-bus-laun
2MB - (sd-pam)
2MB - gconfd-2
1MB - dconf-service
1MB - bash
1MB - dbus-daemon
1MB - ksysguardd
0MB - gconf-helper
0MB - startkde
0MB - kwrapper5
0MB - ssh-agent
0MB - start_kdeinit
             total        used        free      shared  buff/cache   available
Mem:           3528        1649        1296           3         583        1654
Swap:          3672           2        3670

[GreyGeek]

You can use ksysguard (K System Monitor) and sort by %CPU usage or total memory, or run top in a Konsole, to see which process is using the most memory or CPU. If you set ksysguard to the tree display mode then you can follow a process down the tree to locate the guilty party (if it is in a treed process).

[pemartins]

I really can't tell. I have file search disabled, also unchecked search folder updater from autostart, both are off since I installed Kubuntu. But I do not know if there are other indexing services running like updatedb or something similar, nor do I know if they are stored at plasmashell.

[GreyGeek]

Was it "abnormal" activity, or normal indexing?

[pemartins]

I just remembered that yesterday I also did a lot of moving and deleting files on Dolphin. Usually when I do that and when a lot of files (and big amount of data) are moved or deleted, I notice that the panel hangs for a bit (noticed once that the clock was delayed a couple of minutes) after the action is done; then I get the activity notification of files being moved, but actually the job is already done and nothing is being moved and I have to close (press stop on the icon in the notifications) the notification because it only shows a transfer but no file names are displayed.

Today I've been using the pc normally and plasmashell remains as usual without signs of any memory leak. So I'll mark this one as solved since the abnormal activity seems to be what caused the memory leak and it's hard to reproduce the steps in order to try to replicate it.