| Summary: | kwin deadlock on disconnect/reconnect external monitor | ||
|---|---|---|---|
| Product: | [Plasma] kwin | Reporter: | Ike Devolder <ike.devolder> |
| Component: | multi-screen | Assignee: | KWin default assignee <kwin-bugs-null> |
| Status: | RESOLVED FIXED | ||
| Severity: | major | CC: | nate, xaver.hugl |
| Priority: | NOR | Keywords: | multiscreen |
| Version: | 6.1.90 | ||
| Target Milestone: | --- | ||
| Platform: | Arch Linux | ||
| OS: | Linux | ||
| Latest Commit: | https://invent.kde.org/plasma/kwin/-/commit/35e50d6f87ec632c939b059011a3b39389e2092b | Version Fixed In: | 6.2.0 |
| Sentry Crash Report: | |||
| Attachments: | konsole window rule | ||
|
Description
Ike Devolder
2024-09-28 11:50:45 UTC
If you can debug the process, could you check if KWin ever steps out of PlacementTracker::restore? I did an attempt to debug and have pasted the info here: https://pastebin.com/cFWUBPCE Maybe this was a better try:
```
(gdb) attach 1984
Attaching to process 1984
[New LWP 33811]
[New LWP 33810]
[New LWP 2078]
[New LWP 2077]
[New LWP 2076]
[New LWP 2074]
[New LWP 2068]
[New LWP 2067]
[New LWP 2060]
[New LWP 2059]
[New LWP 2046]
[New LWP 2038]
[New LWP 2036]
[New LWP 2035]
[New LWP 2027]
[Thread debugging using libthread_db enabled]
Using host libthread_db library "/usr/lib/libthread_db.so.1".
KWin::Window::desktops (this=this@entry=0x55f67e8d3460) at /usr/include/qt6/QtCore/qarraydata.h:60
warning: Source file is more recent than executable.
60 return true;
(gdb) finish
Run till exit from #0 KWin::Window::desktops (this=this@entry=0x55f67e8d3460) at /usr/include/qt6/QtCore/qarraydata.h:60
KWin::Window::isOnAllDesktops (this=0x55f67e8d3460) at /usr/src/debug/kwin/kwin-6.1.90/src/window.h:2047
2047 return desktops().isEmpty();
Value returned is $1 = {<QListSpecialMethods<KWin::VirtualDesktop*>> = {<QListSpecialMethodsBase<KWin::VirtualDesktop*>> = {<No data fields>}, <No data fields>}, d = {d = 0x55f67cd30df0, ptr = 0x55f67cd30e00, size = 1}}
(gdb) finish
Run till exit from #0 KWin::Window::isOnAllDesktops (this=0x55f67e8d3460) at /usr/src/debug/kwin/kwin-6.1.90/src/window.h:2047
KWin::Workspace::clientArea (this=0x55f67cf2b9e0, opt=KWin::MaximizeArea, window=0x55f67e8d3460, output=0x55f67de6a620) at /usr/src/debug/kwin/kwin-6.1.90/src/workspace.cpp:2444
2444 desktop = VirtualDesktopManager::self()->currentDesktop();
(gdb) finish
Run till exit from #0 KWin::Workspace::clientArea (this=0x55f67cf2b9e0, opt=KWin::MaximizeArea, window=0x55f67e8d3460, output=0x55f67de6a620)
at /usr/src/debug/kwin/kwin-6.1.90/src/workspace.cpp:2444
0x00007f617d1aa089 in KWin::XdgToplevelWindow::maximize (this=0x55f67e8d3460, mode=KWin::MaximizeRestore) at /usr/src/debug/kwin/kwin-6.1.90/src/xdgshellwindow.cpp:1563
1563 const QRectF clientArea = isElectricBorderMaximizing() ? workspace()->clientArea(MaximizeArea, this, interactiveMoveResizeAnchor()) : workspace()->clientArea(MaximizeArea, this, moveResizeOutput());
Value returned is $2 = {xp = 0, yp = 36, w = 1920, h = 1164}
(gdb) finish
Run till exit from #0 0x00007f617d1aa089 in KWin::XdgToplevelWindow::maximize (this=0x55f67e8d3460, mode=KWin::MaximizeRestore)
at /usr/src/debug/kwin/kwin-6.1.90/src/xdgshellwindow.cpp:1563
KWin::Window::setQuickTileMode (this=0x55f67e8d3460, mode=..., tileAtPoint=...) at /usr/src/debug/kwin/kwin-6.1.90/src/window.cpp:3516
3516 if (!isResizable() || isAppletPopup()) {
(gdb) finish
Run till exit from #0 KWin::Window::setQuickTileMode (this=0x55f67e8d3460, mode=..., tileAtPoint=...) at /usr/src/debug/kwin/kwin-6.1.90/src/window.cpp:3516
```
There it gets stuck it seems
Maybe additional info that could be interesting: laptop screen resolution: 1920x1200 (16:10) external screen resolution: 1920x1080 (16:9) on an older laptop (with only intel gpu) I don't have this issue but there the internal screen and external screen are 1920x1080 (16:9) hmm, I couldn't reproduce this issue, even with two screens that have different resolutions. I found something else (https://invent.kde.org/plasma/kwin/-/merge_requests/6545), which could influence this, but it seems unlikely. Looking at the code, I don't understand how KWin can get stuck in Window::setQuickTileMode. Could you step through the function a bit and see if there's some more specific spot it gets stuck in? (In reply to Zamundaaa from comment #5) > hmm, I couldn't reproduce this issue, even with two screens that have > different resolutions. I found something else > (https://invent.kde.org/plasma/kwin/-/merge_requests/6545), which could > influence this, but it seems unlikely. > > Looking at the code, I don't understand how KWin can get stuck in > Window::setQuickTileMode. Could you step through the function a bit and see > if there's some more specific spot it gets stuck in? The pastebin from https://bugs.kde.org/show_bug.cgi?id=493778#c2 is not good for this? It is useful, but it suggests an infinite recursion between setMaximize(false, false) and setQuickTileMode, which should crash and not hang. Something else I see in there though... do you have a window rule that forces a window to be (not) maximized? A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/6547 If you do have a window rule like that, this MR should fix the hang Created attachment 174287 [details]
konsole window rule
I have a windowrule for konsole to have no titlebar and frame and be maximized both horizontally and vertically
On first glance: removing the window rule indeed fixes the issue, thank you very much Git commit 68015321e924e1dd54770df748cd42440aaf204f by Xaver Hugl. Committed on 01/10/2024 at 16:42. Pushed by zamundaaa into branch 'master'. window: prevent infinite recursion in setQuickTileMode If there's a window rule, setMaximize may not actually change the maximize mode, so this needs to be accounted for M +4 -0 src/window.cpp https://invent.kde.org/plasma/kwin/-/commit/68015321e924e1dd54770df748cd42440aaf204f Git commit 35e50d6f87ec632c939b059011a3b39389e2092b by Xaver Hugl. Committed on 01/10/2024 at 16:50. Pushed by zamundaaa into branch 'Plasma/6.2'. window: prevent infinite recursion in setQuickTileMode If there's a window rule, setMaximize may not actually change the maximize mode, so this needs to be accounted for (cherry picked from commit 68015321e924e1dd54770df748cd42440aaf204f) Co-authored-by: Xaver Hugl <xaver.hugl@gmail.com> M +4 -0 src/window.cpp https://invent.kde.org/plasma/kwin/-/commit/35e50d6f87ec632c939b059011a3b39389e2092b Great! Thank you for the extensive debugging info btw, this would've been impossible to track down otherwise Thank you for fixing it, I have re-build kwin with the patch + re-added the konsole window rules and it works properly now |