Patches concerning the speed of mouse-movement over the profile.

[Tomaz Canabrava]

On Thu, Jan 15, 2015 at 9:15 AM, Lubomir I. Ivanov <neolit123 at gmail.com>
wrote:

> On 15 January 2015 at 02:56, Tomaz Canabrava <tcanabrava at kde.org> wrote:
> > Lubomir,
> >
> > I'v removed almost every allocation that I could find. can you try this 8
> > patches and tell me if anything worked to reduce the cpu usage?
> >
> >
> > We can still do some stuff to not remove the animations  ( yup, I like
> them
> > )
> > like using a square instead of a rounded - rect notification panel.
> >
> >
>
> unfortunately the patches did not improve the performance much for me
> - it's still above 20%.
> but i suggest you skip any more fixes for this ATM, because we have no
> user complains.
>
> the allocations boosted it, but setText(), setPixmap() and the little
> graph drawing still require high CPU usage.
>

We can also try to move the Profile to OpenGL ( I'v always wanted to learn
that and that's a pretty damn good excuse. )


>
> it started to smell to me as a FPU denormal issue, so i tested that
> because i've noticed the GCC uses FPU instructions for this particular
> part and the control word flag was unset, but it ain't the cause,
> unless Qt updates the FPU between calls.
>
> -O3 doesn't helps which means that calls to another library are heavy
> (e.g. Qt).
>
> i've also tried using S&H on refresh() to reduce the amounts of calls
> on power of two intervals and that is the only thing that helps, but
> reduces the smoothness of the tooltip itself and isn't pretty; a
> factor of 4 is tolerable but still caps at more than 16% CPU usage.
>
> perhaps there are other tricks to try, but i don't have the time.
>

But I do have. :)
I'll try to do other things:
- use raster graphics
- do not use paths
- do not use translucency
- try to test the profile in other ways ( OpenGL, perhaps )


>
> overall i'm very surprised that such as simple UI element is so slow
> in Qt. i've written *much more* complicated UI in other languages and
> frameworks and it was blazing fast compared to this.
>
> but like i said, leave it be for now IMHO.
>
> lubomir
> --
>
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