Created attachment 1552941 [details]
Description of problem:
After longish use of KDE Plasma session, Xorg server runs out of an anonymous file handles (a count of 1024 by default). I.e. /proc/`pidof Xorg`/fd fills up entries like:
lrwx------. 1 root root 64 Apr 6 10:55 95 -> '/memfd:xshmfence (deleted)'
lrwx------. 1 root root 64 Apr 6 13:18 96 -> '/memfd:xshmfence (deleted)'
lrwx------. 1 root root 64 Apr 6 10:55 97 -> '/memfd:xshmfence (deleted)'
lrwx------. 1 root root 64 Apr 6 10:55 98 -> '/memfd:xshmfence (deleted)'
lrwx------. 1 root root 64 Apr 6 10:55 99 -> '/memfd:xshmfence (deleted)'
And when Xorg has run out of system file limit, random problems start to appear:
- key bindings may lost and/or have no desired effect
- mouse clicks / drags have no effect
- $HOME/.cache corrupts somehow
Version-Release number of selected component(s):
Steps to Reproduce:
1. login to Plasma session
2. open dozens of appications so that Task Manager starts grouping task instances
3. observe content of /proc/`pidof Xorg`/fd by commands ls and wc
4. induce creation of memfd:xshmfence fds by hovering on panel (Task Manager), over group of open tasks so that Task Manager shows thumbnails of windows of open applications. This step will increase fds by number of window thumbnails of hovered group
5. repeat from 3. until system file limit is hit
plasmashell shall release rendering related memory stuff right after use
Hovering on Pager or on System Tray in a such way that popup window appears does not consume an anonymous file handles on X server permanently. Only via Task Manager does.
Created attachment 1552942 [details]
I encourage you to report this upstream at bugs.kde.org, particularly if you have an easy way to reproduce it.
thanks for the suggestion. I reported and slightly edited to add clarifications here and there:
Plasma update 5.57.0-2.fc29 fixed this issue, it contains patch: