[Bug 1886293] [NEW] Kwin hangs in KWin::WindowPixmap::create() / xcb_request_check
Nathaniel Beaver
1886293 at bugs.launchpad.net
Sat Jul 4 23:04:04 UTC 2020
Public bug reported:
After several days using the KDE Plasma desktop, I suddenly found that
all of the windows had become unresponsive. I could still move the
mouse, but clicking didn't do anything. I could no longer change the
volume with the volume buttons. Also, the panel clock stopped ticking
upward. Fortunately, I could still use the keyboard to access a tty.
I would estimate this occurred roughly monthly.
I still cannot consistently reproduce, and I wasn't doing anything
unusual these interruptions occurred, just switching windows or typing
in a textbox.
This normally works from a tty:
DISPLAY=:0 xdpyinfo
but during these episodes it would just hang.
I believe this would also hang after running and switching back to the
graphical window:
DISPLAY=:0 qdbus org.kde.KWin /KWin supportInformation
But I don't recall for sure.
This also hung:
DISPLAY=:0 kwin --replace
and showed an error:
qt.qpa.screen: QXcbConnection: Could not connect to display :0
Next tried this:
DISPLAY=:0 kquitapp5 plasmashell && kstart5 plasmashell
Got a different error after a timeout:
"Quitting application plasmashell failed. Error reported was:\n\n
org.freedesktop.DBus.Error.NoReply: Did not receive a reply. Possible
causes include: the remote application did not send a reply, the message
bug security policy blocked the reply, the reply timeout expired, or the
network connection was broken."
In a later instance, I was able to revive the system like this:
kill -USR1 $(pgrep kwin_x11)
DISPLAY=:0 kwin --replace
I found this sufficiently convincing that is was an issue with Kwin and
not another component, so I thought I should report this bug. Backtraces
and strace logs are attached, as is my ~/.config/kwinrc and the output
of the "qdbus org.kde.KWin /KWin supportInformation" when it is in a
responsive state.
$ lsb_release -rd
Description: Ubuntu 18.04.4 LTS
Release: 18.04
Kernel Version: 5.3.0-61-generic
ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: kwin-x11 4:5.12.9.1-0ubuntu0.1
ProcVersionSignature: Ubuntu 5.3.0-61.55~18.04.1-generic 5.3.18
Uname: Linux 5.3.0-61-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.15
Architecture: amd64
CurrentDesktop: KDE
Date: Sat Jul 4 16:13:00 2020
InstallationDate: Installed on 2020-02-01 (154 days ago)
InstallationMedia: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
SourcePackage: kwin
UpgradeStatus: No upgrade log present (probably fresh install)
** Affects: kwin (Ubuntu)
Importance: Undecided
Status: New
** Tags: amd64 apport-bug bionic
** Attachment added: "Output of qdbus org.kde.KWin /KWin supportInformation"
https://bugs.launchpad.net/bugs/1886293/+attachment/5389751/+files/qdbus_good.txt
--
You received this bug notification because you are a member of Kubuntu
Bugs, which is subscribed to kwin in Ubuntu.
https://bugs.launchpad.net/bugs/1886293
Title:
Kwin hangs in KWin::WindowPixmap::create() / xcb_request_check
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/kwin/+bug/1886293/+subscriptions
More information about the kubuntu-bugs
mailing list