[Interest] CPU load in busy indicator widget based on Q(Variant)Animation

André Pönitz apoenitz at t-online.de
Fri Oct 4 23:56:13 CEST 2019

On Fri, Oct 04, 2019 at 10:58:44PM +0200, René J. V. Bertin wrote:
> Giuseppe D'Angelo via Interest wrote:
> > By default non-QQ2 related animations run every 16ms. Do you have a
> > minimal testcase showcasing a suspicious activity of an animation?
> I never said anything about suspicious activity (and the idea that
> something could be wrong with Q*Animation on my systems didn't come
> from me).  But:
> >> github.com/RJVB/kbusygadget
> You'll need a CPU-load measuring tool, of course (I used top, as
> mentioned previously, I'm not particularly interested in more advanced
> performance analysis).
> If animations run at 60Hz as you say, how do you explain that the app
> above runs with essentially the same CPU load on a 1.6Ghz N3150 and a
> 2.7Ghz Core i7? The latter CPU should spend significantly more time
> waiting to display the next frame.
> I looked for a way to control the animation frequency but couldn't
> find one; what did I overlook?

I'd take a step back here and check what is really needed for the

Just because one can, in principle, put a vector graphic in svg,
than in an icon, and then draw in a transformed painter, steered
by a QVariantAnimation, does not really mean that one has to,
especially as soon as someone complains about performance.

I haven't checked, but I am ready to bet that "finger painting"
the in the paintEvent(), triggered by a timer calling update will
take significantly less resources.


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