Bug#1037268: kwin-x11: resource leak: the number of threads increases over time, boundlessly
Package: kwin-x11
Version: 4:5.27.5-3
Severity: normal
Tags: upstream
After 17 days, the number of threads of /usr/bin/kwin_x11 process has exceeded 2700 and it keeps increasing. At the beginning of a session, the process starts with 34 threads.
I could find that such leak happens when viewing videos fullscreen e.g. with mpv. Can anyone reproduce it ? More precisely:
1. start mpv without --fs -> thread count does not change
2. switch to fullscreen -> usually -2 threads
3. leaves fullscreen -> usually +17 threads
4. exit mpv -> thread count does not change
Such a leak is at least a severe issue for anyone like me who set a nproc limit to protect against fork-bombs, in particular because it causes mysterious process crashes. I only understood the problem when I wanted to build a software that spawned a lot of processes. It also makes nproc limiting quite unusable without restarting KDE from time to time.
Version 4:5.27.2-2 was affected too. I previously had 4:5.24.4-1 and I'm almost sure it had no leak.
A few notes that may be specific to my setup:
- I do have a 4k intel display. And regularly, for less than 1s, the display is corrupted. I haven't tried Wayland yet and I hope it will fix it.
- I use mpv from deb-multimedia.
- mpv conf: vo = gpu
I couldn't find anything on bug.kde.org: should I forward ?
Julien
-- System Information:
Debian Release: 12.0
APT prefers testing
APT policy: (900, 'testing'), (800, 'unstable'), (700, 'proposed-updates'), (700, 'stable'), (500, 'unstable-debug'), (500, 'testing-debug'), (500, 'stable-security'), (500, 'stable-debug'), (500, 'oldstable-proposed-updates'), (500, 'oldstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386
Kernel: Linux 6.1.0-9-amd64 (SMP w/16 CPU threads; PREEMPT)
Kernel taint flags: TAINT_UNSIGNED_MODULE
Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE not set
Shell: /bin/sh linked to /usr/bin/dash
Init: systemd (via /run/systemd/system)
Versions of packages kwin-x11 depends on:
ii kwin-common 4:5.27.5-3
ii libc6 2.36-9
ii libepoxy0 1.5.10-1
ii libgcc-s1 12.2.0-14
ii libkdecorations2-5v5 4:5.27.5-2
ii libkf5configcore5 5.103.0-2
ii libkf5configgui5 5.103.0-2
ii libkf5configwidgets5 5.103.0-1
ii libkf5coreaddons5 5.103.0-1
ii libkf5crash5 5.103.0-1
ii libkf5globalaccel-bin 5.103.0-1
ii libkf5globalaccel5 5.103.0-1
ii libkf5i18n5 5.103.0-1
ii libkf5notifications5 5.103.0-1
ii libkf5plasma5 5.103.0-1
ii libkf5service-bin 5.103.0-1
ii libkf5service5 5.103.0-1
ii libkf5windowsystem5 5.103.0-1
ii libkwineffects14 4:5.27.5-3
ii libkwinglutils14 4:5.27.5-3
ii libqaccessibilityclient-qt5-0 0.4.1-1+b1
ii libqt5core5a 5.15.8+dfsg-11
ii libqt5dbus5 5.15.8+dfsg-11
ii libqt5gui5 5.15.8+dfsg-11
ii libqt5qml5 5.15.8+dfsg-3
ii libqt5quick5 5.15.8+dfsg-3
ii libqt5widgets5 5.15.8+dfsg-11
ii libqt5x11extras5 5.15.8-2
ii libstdc++6 12.2.0-14
ii libx11-6 2:1.8.4-2
ii libxcb-composite0 1.15-1
ii libxcb-keysyms1 0.4.0-1+b2
ii libxcb-randr0 1.15-1
ii libxcb-render0 1.15-1
ii libxcb-shape0 1.15-1
ii libxcb-xfixes0 1.15-1
ii libxcb-xkb1 1.15-1
ii libxcb1 1.15-1
ii libxi6 2:1.8-1+b1
ii libxkbcommon-x11-0 1.5.0-1
ii libxkbcommon0 1.5.0-1
kwin-x11 recommends no packages.
kwin-x11 suggests no packages.
-- no debconf information
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