https://bugs.documentfoundation.org/show_bug.cgi?id=152911
--- Comment #13 from Michael Weghorn <[email protected]> --- (In reply to Michael Weghorn from comment #11) > So far, I cannot reproduce on Debian testing (qtbase packages at version > 5.15.10+dfsg-6). Both of the scenarios work fine for me when using > attachment 192315 [details] as document when testing. OK, I can somewhat reproduce something now: 1) open attachment 192315 with kf5/qt5/qt6 on Wayland 2) move through the document by dragging the handle in the vertical scrollbar There's a delay to update the view and it's sometimes stuck for maybe 1-2 seconds before the view updates. It's smooth when forcing the use of the x11 Qt backend (running via XWayland) by setting env variable QT_QPA_PLATFORM=xcb. Answering my own questions: > A flamegraph (see [1]) might give clues of where CPU time is spent. attachment 192316 is a flamegraph with qt6, using local LO and qtbase debug builds. It shows that most time seems to be spent in rendering the document, triggered by the scrolling. Maybe something is different in how Qt handles the mouse events on Wayland as compared to X11 (s. e.g. the QtWidget::mouseMoveEvent in the flamegraph), like maybe events are triggered more often now, so re-rendering the doc happens more often? (Just a wild guess.) This would need further analysis to be able to say anything specific and I don't see any obviously wrong in the flamegraph by itself otherwise, I'd expect the call stack to generally be the same with X11. > Does this also happen with the qt6 VCL plugin or only with qt5/kf5? Same with qt6. -- You are receiving this mail because: You are the assignee for the bug.
