[webkit-qt] [Qt] Strong performance degradation with DirectFB since r122720

[Zoltan Horvath]

I opened a bug for tracking this:  
https://bugs.webkit.org/show_bug.cgi?id=97548

<Zoltan>

On Mon, 17 Sep 2012 15:34:07 +0200, Simon Hausmann  
<simon.hausmann at nokia.com> wrote:

> On Friday, September 14, 2012 04:25:18 PM ext Zoltan Horvath wrote:
>> Okay, then it seems reasonable to roll it out, so I'm going to revert it
>> next week.
>
> Further discussion with Jocelyn concluded that reverting is indeed the  
> least-
> effort way of fixing this regression.
>
> Simon
>
>> On Fri, 14 Sep 2012 16:12:00 +0200, <jocelyn.turcotte at nokia.com> wrote:
>> > Forget my last comment, this seems to be directly related to the use  
>> of
>> > QImage instead of QPixmaps.
>> >
>> > The directfb platform plugin uses QBlitterPaintEngine which handles
>> > drawPixmap in QDirectFbBlitter::drawPixmap rather than using straight
>> > CPU raster for drawImage.
>> >
>> > ________________________________________
>> > From: webkit-qt-bounces at lists.webkit.org
>> > [webkit-qt-bounces at lists.webkit.org] on behalf of Turcotte Jocelyn
>> > (Nokia-MP/Oslo)
>> > Sent: Friday, September 14, 2012 3:53 PM
>> > To: zoltan at webkit.org; webkit-qt at lists.webkit.org
>> > Subject: Re: [webkit-qt] [Qt] Strong performance degradation with
>> > DirectFB since r122720
>> >
>> > Ahh it's a canvas test, this might also be related to the deep-copy
>> > protection that was removed in the patch, when a QPainter is beginning
>> > on an existing image.
>> >
>> > ________________________________________
>> > From: webkit-qt-bounces at lists.webkit.org
>> > [webkit-qt-bounces at lists.webkit.org] on behalf of Turcotte Jocelyn
>> > (Nokia-MP/Oslo)
>> > Sent: Friday, September 14, 2012 3:35 PM
>> > To: zoltan at webkit.org; webkit-qt at lists.webkit.org
>> > Subject: Re: [webkit-qt] [Qt] Strong performance degradation with
>> > DirectFB since r122720
>> >
>> > Why was it necessary to switch from QPixmap to QImage?
>> >
>> > I don't think that this can be solved on the Qt side, it's a design
>> > advantage that QPixmap has in this kind of situations.
>> > As far as I know this might be mostly related to reusing a graphics
>> > buffer that already has been uploaded to graphics memory.
>> >
>> > Jocelyn
>> >
>> > ________________________________________
>> > From: webkit-qt-bounces at lists.webkit.org
>> > [webkit-qt-bounces at lists.webkit.org] on behalf of ext Zoltan Horvath
>> > [zoltan at webkit.org]
>> > Sent: Friday, September 14, 2012 3:17 PM
>> > To: webkit-qt at lists.webkit.org
>> > Subject: Re: [webkit-qt] [Qt] Strong performance degradation with
>> > DirectFB since r122720
>> >
>> > Hi there,
>> >
>> > Shouldn't we report this on Qt-side instead?
>> >
>> > Cheers,
>> > Zoltan
>> >
>> >
>> > On Fri, 14 Sep 2012 15:02:13 +0200, Allan Sandfeld Jensen
>> >
>> > <kde at carewolf.com> wrote:
>> >> On Friday 14 September 2012, Brianceau, Julien wrote:
>> >>> With r126284 based webkit version, I get 11,3 displayed fps, with a  
>> CPU
>> >>> usage of more than 95% With r126284 based webkit version with  
>> changeset
>> >>> 122720 reverted, I get 25,6 displayed fps, with a CPU usage of about
>> >>> 90%
>> >>
>> >> Yes with a 50% speed regression also on Qt5, I think we need to  
>> revert
>> >> the
>> >> patch in trunk, otherwise I would have suggested only reverting it in
>> >> QtWebKit
>> >> 2.3. But having as few difference as possible is better, so I am
>> >> actually
>> >> relieved it was also slower in Qt5.
>> >>
>> >> Cheers
>> >> `Allan
>> >> _______________________________________________
>> >> webkit-qt mailing list
>> >> webkit-qt at lists.webkit.org
>> >> http://lists.webkit.org/mailman/listinfo/webkit-qt
>> >
>> > _______________________________________________
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