CPU load increases by mouse moving



  • Hello. I've tested a nearly Qt Quick Application (only the ApplicationWindow) on our embedded system. If I move the mouse back and forth the CPU load increase up to 14 %. From 2 % before. But I don't understand what's the reason for that rise.

    Does somebody know what the application is doing internally if the mouse will be moved. With 14 % CPU load something is going on. But what ?

    Thanks. Best regards

    Snoopy


  • Moderators

    @Snoopy said in CPU load increases by mouse moving:

    If I move the mouse back and forth the CPU load increase up to 14 %. From 2 % before. But I don't understand what's the reason for that rise.

    On an embedded board it is entirely possible that 14% represents the Operating System handling of mouse move. It was definitely the case in Raspberry Pi, I also remember similar effects on older PCs. Does that rise happen only within the Qt application, or elsewhere as well?

    Does somebody know what the application is doing internally if the mouse will be moved. With 14 % CPU load something is going on. But what ?

    Do you enable hover in any QML component of your app? It could be responsible.



  • Hello,

    I've find out that if there is running no application the CPU load while mouse moving is negligible. It increases from 3 % to 4 %. It's a Linux Kernel OS and CPU is ARM V7 architecture.
    If the Qt Quick Application (Qt 5.10.0) is running the CPU load increases to 14 %. The application contains only the empty ApplicationWindow There is no MouseArea inside the app and so I don't have the the hoverEnabled property.

    If there is running an application with Items like Images, Rectangles, ListView etc. CPU load increases to 23 % while mouse moving

    Best regards,

    Snoopy


  • Moderators

    Then I don't know what's causing that, sorry.


Log in to reply
 

Looks like your connection to Qt Forum was lost, please wait while we try to reconnect.