Bug 398544

Summary:	Plasmashell gotes to 100% cpu usage anytime display is resized
Product:	[Plasma] plasmashell	Reporter:	Adam Felson <adam.bugzilla>
Component:	general	Assignee:	David Edmundson <kde>
Status:	RESOLVED NOT A BUG
Severity:	major	CC:	plasma-bugs-null
Priority:	NOR
Version First Reported In:	5.10.5
Target Milestone:	1.0
Platform:	Ubuntu
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	kinfocenter, main page

Description Adam Felson 2018-09-12 15:07:26 UTC

Anytime screens are resized or enabled/disabled, plasmashell goes to 100% until it is killed and restarted.  
I'm marking this as a major bug as it nearly fried my laptop on my way to work.

This is a very old uncorrected bug.  I'm a bit tired of having to kill/restart it every morning when I pop my laptop into a docking station with two monitors.

Please don't kneejerk close this or mark it as a duplicate of a defect report that is invalid or wontfix.  Bug 356479 for example has had numerous new reports of the 100% cpu usage by plasmashell, which have been completely ignored because the internal cause isn't exactly what was fixed in the bug.

Comment 1 David Edmundson 2018-09-12 15:11:27 UTC

Is your version really 5.10?
Please include Qt and frameworks versions. See kinfocenter

I can't do anything without some data. 

Can you get some backtrace snapshots or ideally a perf log whilst it is using the high CPU.

Comment 2 Adam Felson 2018-09-12 19:17:23 UTC

I have been seeing this behavior in all 5.x versions.   I currently run kubuntu 17.10 with the latest updates.
It runs in a virtualbox VM on a win10 host, Version 5.2.18 r124319 (Qt5.6.2).

Which logs would you like?  .xsession-errors produced the following when I triggered the bug by resizing a screen.


trying to show an empty dialog
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:147:19: QML Loader: Binding loop detected for property "height"
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:147:19: QML Loader: Binding loop detected for property "height"
file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/FolderItemDelegate.qml:288:17: QML Text: Binding loop detected for property "width"
file:///usr/share/plasma/plasmoids/org.kde.desktopcontainment/contents/ui/FolderItemDelegate.qml:288:17: QML Text: Binding loop detected for property "width"
trying to show an empty dialog
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:147:19: QML Loader: Binding loop detected for property "height"
file:///usr/share/plasma/shells/org.kde.plasma.desktop/contents/views/Desktop.qml:147:19: QML Loader: Binding loop detected for property "height"

Comment 3 Adam Felson 2018-09-12 19:19:15 UTC

Xorg.0.log:  [631983.265] (II) modeset(0): EDID vendor "VBX", prod id 0
[631983.265] (II) modeset(0): DDCModeFromDetailedTiming: 1912x727 Warning: We only handle separate sync.
[631983.265] (II) modeset(0): Using hsync ranges from config file
[631983.265] (II) modeset(0): Using vrefresh ranges from config file
[631983.271] (II) modeset(0): EDID vendor "VBX", prod id 0
[631983.271] (II) modeset(0): DDCModeFromDetailedTiming: 1912x727 Warning: We only handle separate sync.
[631983.271] (II) modeset(0): Using hsync ranges from config file
[631983.271] (II) modeset(0): Using vrefresh ranges from config file
[631984.049] (II) modeset(0): Allocate new frame buffer 3832x987 stride
[631984.072] (II) modeset(0): EDID vendor "VBX", prod id 0
[631984.073] (II) modeset(0): DDCModeFromDetailedTiming: 1912x727 Warning: We only handle separate sync.
[631984.073] (II) modeset(0): Using hsync ranges from config file
[631984.073] (II) modeset(0): Using vrefresh ranges from config file
[631984.183] (II) modeset(0): EDID vendor "VBX", prod id 0
[631984.183] (II) modeset(0): DDCModeFromDetailedTiming: 1912x727 Warning: We only handle separate sync.
[631984.183] (II) modeset(0): Using hsync ranges from config file
[631984.183] (II) modeset(0): Using vrefresh ranges from config file
[631994.273] (II) modeset(0): EDID vendor "VBX", prod id 0
[631994.274] (II) modeset(0): DDCModeFromDetailedTiming: 1920x1057 Warning: We only handle separate sync.
[631994.274] (II) modeset(0): Using hsync ranges from config file
[631994.274] (II) modeset(0): Using vrefresh ranges from config file
[631994.280] (II) modeset(0): EDID vendor "VBX", prod id 0
[631994.281] (II) modeset(0): DDCModeFromDetailedTiming: 1920x1057 Warning: We only handle separate sync.
[631994.281] (II) modeset(0): Using hsync ranges from config file
[631994.281] (II) modeset(0): Using vrefresh ranges from config file
[631995.031] (II) modeset(0): Allocate new frame buffer 3840x1057 stride
[631995.101] (II) modeset(0): EDID vendor "VBX", prod id 0
[631995.102] (II) modeset(0): DDCModeFromDetailedTiming: 1920x1057 Warning: We only handle separate sync.
[631995.102] (II) modeset(0): Using hsync ranges from config file
[631995.102] (II) modeset(0): Using vrefresh ranges from config file
[631995.149] (II) modeset(0): EDID vendor "VBX", prod id 0
[631995.150] (II) modeset(0): DDCModeFromDetailedTiming: 1920x1057 Warning: We only handle separate sync.
[631995.150] (II) modeset(0): Using hsync ranges from config file
[631995.150] (II) modeset(0): Using vrefresh ranges from config file

Comment 4 Adam Felson 2018-09-12 19:22:48 UTC

Created attachment 114919 [details]
kinfocenter, main page

Comment 5 David Edmundson 2018-09-12 21:25:52 UTC

No, I needed gdb snapshots of what the program is busy doing.

That software is all super old. 

If you still have issues with Plasma > 5.13 and Qt > 5.12 I will write more on how to get the output I need, but there's no point for this. Sorry.

Comment 6 Adam Felson 2018-09-12 21:50:53 UTC

No problem.  I'm doing a release upgrade now.  I'll report if anything changes.

Comment 7 Adam Felson 2018-09-12 22:57:57 UTC

Upgrading to kubuntu 18.04 / kde 5.12.6 seems to have cured it.
thanks.