Uploaded image for project: 'Qt'
  1. Qt
  2. QTBUG-72360

High CPU usage when updating elements on macOS Mojave.

XMLWordPrintable

    • Icon: Bug Bug
    • Resolution: Done
    • Icon: P1: Critical P1: Critical
    • 5.12.3, 5.14.0 Alpha
    • 5.10.1, 5.12.0
    • Widgets: Layout
    • None
    • macOS
    • 77a4915bf900aac0c96260018c0a4ccfbdd7c094 (qt/qtbase/5.12)

      When updating a label like ~30 times a second the user interface will freeze.

      This issue is only detected on macOS Mojave.

      I've created an Instruments log where you can see QImage is used frequently for updating just a label. See the attachment with the log. When the window will be made bigger or more elements are added, CPU will easily hit the 100% for a simple application. This also freezes the network elements etc.

      Possibly it's affected on all versions of Qt. Tested on 5.10.1 and 5.12.0. 

       

        1. Code.zip
          3 kB
        2. High CPU macOS Mojave 480p.mov
          6.70 MB
        3. Normal CPU macOS Sierra 720p.mov
          5.22 MB
        4. test.png
          test.png
          654 kB
        No reviews matched the request. Check your Options in the drop-down menu of this sections header.

            vestbo Tor Arne Vestbø
            niek Niek Berenschot
            Votes:
            1 Vote for this issue
            Watchers:
            6 Start watching this issue

              Created:
              Updated:
              Resolved:

                There are no open Gerrit changes