Created attachment 154051 [details] kwin support information SUMMARY When a window is opened, kwin seems to allocate some memory to store its icon. However, this memory is not freed when the window is closed. heaptrack output: https://drive.google.com/file/d/1xkhCrdzyPWCX6wtRDGubhhkyOfE-jeaN/view?usp=sharing (it is too big to attach here, 5 MB) STEPS TO REPRODUCE 1. `heaptrack kwin_x11 --replace` 2. Run the following loop in bash: ``` while true do sleep 5 dolphin & sleep 5 killall dolphin -u kishore done ``` 3. Wait for some time 4. Kill kwin. 5. `heaptrack_gui $name_of_output_file` OBSERVED RESULT Kwin's memory usage grows linearly with time (heaptrack output attached). The backtrace to which heaptrack associates most of the memory is: ``` readIcon in libKF5WindowSystem.so.5 NETWinInfo::update(QFlags<NET::Property>, QFlags<NET::Property2>) in libKF5WindowSystem.so.5 KWin::WinInfo::WinInfo(KWin::X11Window*, unsigned int, unsigned int, QFlags<NET::Property>, QFlags<NET::Property2>) in libkwin.so.5 KWin::X11Window::manage(unsigned int, bool) in libkwin.so.5 KWin::Workspace::createX11Window(unsigned int, bool) in libkwin.so.5 KWin::Workspace::workspaceEvent(xcb_generic_event_t*) in libkwin.so.5 QAbstractEventDispatcher::filterNativeEvent(QByteArray const&, void*, long*) in libQt5Core.so.5 QXcbConnection::handleXcbEvent(xcb_generic_event_t*) in libQt5XcbQpa.so.5 QXcbConnection::processXcbEvents(QFlags<QEventLoop::ProcessEventsFlag>) in libQt5XcbQpa.so.5 <unresolved function> in libQt5XcbQpa.so.5 g_main_context_dispatch in libglib-2.0.so.0 <unresolved function> in libglib-2.0.so.0 g_main_context_iteration in libglib-2.0.so.0 QEventDispatcherGlib::processEvents(QFlags<QEventLoop::ProcessEventsFlag>) in libQt5Core.so.5 QEventLoop::exec(QFlags<QEventLoop::ProcessEventsFlag>) in libQt5Core.so.5 QCoreApplication::exec() in libQt5Core.so.5 main in kwin_x11 ``` EXPECTED RESULT Memory usage should reach steady state after some time. SOFTWARE/OS VERSIONS Operating System: Arch Linux KDE Plasma Version: 5.26.3 KDE Frameworks Version: 5.100.0 Qt Version: 5.15.7 Kernel Version: 5.15.79-1-lts (64-bit) Graphics Platform: X11 Graphics Processor: virgl Manufacturer: QEMU ADDITIONAL INFORMATION A. I'm not sure if the same thing happens on Wayland. B. I installed debug symbols for kwin and kwindowsystem. C. kwin support information (`qdbus org.kde.KWin /KWin supportInformation`) is attached D. heaptrack output: https://drive.google.com/file/d/1xkhCrdzyPWCX6wtRDGubhhkyOfE-jeaN/view?usp=sharing (it is too big to attach here, 5 MB)
Thank you for the bug report! Please note that Plasma 5.25.3 is not supported for much longer by KDE; supported versions are 5.24, and 5.26 or newer. If at all possible please upgrade to a supported version and verify that the bug is still happening there. If you're unsure how to do this, contact your distributor about it.
Cannot reproduce
(In reply to Fushan Wen from comment #2) > Cannot reproduce I can still reproduce this on Operating System: Arch Linux KDE Plasma Version: 5.26.5 KDE Frameworks Version: 5.101.0 Qt Version: 5.15.8 Kernel Version: 5.15.86-1-lts (64-bit) Graphics Platform: X11 mesa 22.3.2-3 I also noticed that the memory usage shown in ksysguard (for the kwin_x11 process) is much lower than that reported by heaptrack. Does this mean the leaks found by heaptrack are false positives?
I find memory is not released when there is still plenty of free memory, so ksysguard may not report the accurate used memory.
I can't see who deletes: ``` icons[i].data = new unsigned char[size]; ``` The array is cleaned up, but our array contains malloc'ed data. It's cleaned up if we readIcons multiple times, but not in the NetWinInfo destructor
Edit, it's cleaned up in `refdec_nwi`
The memory allocator may not release some memory, which unfortunately is expected, e.g. due to fragmentation, etc. But as for that code, it looks like it frees memory as expected, although it wouldn't hurt to port that code away from `new` and `delete`.