[poppler] Re: poppler profiling on geode with cairo backend

Tomeu Vizoso tomeu at tomeuvizoso.net
Thu Nov 9 00:35:18 PST 2006

That's fantastic!

Tonight will try to hack the code to avoid this condition and will
profile again on the board.

Thanks again for your interest,


On Wed, 2006-11-08 at 21:51 -0500, Jeff Muizelaar wrote:
> On Wed, Nov 08, 2006 at 11:02:34AM +0100, Tomeu Vizoso wrote:
> > Hi,
> > 
> > this is the sysprof result of rendering several pages on evince, each
> > taking approx. 4 seconds.
> > 
> > It would be great if you found any opportunity to improve the
> > performance of the cairo backend on this particular case (for example
> > using less expensive operations than compositing).
> So I had a look at why pixman_compositeGeneral is being hit during text
> rendering. It looks like this gets called for text when the document is
> being rendered at weird scaling factors. 
> For example with the pdf you provided: calling
>   poppler_page_render_to_pixbuf(..., scale=1.0, ...)
> does not trigger any calls to pixman_compositeGeneral. Neither does:
>   poppler_page_render_to_pixbuf(..., scale=2.0, ...)
> However,
>   poppler_page_render_to_pixbuf(..., scale=0.5, ...)
> does. As does:
>   poppler_page_render_to_pixbuf(..., scale=1.1, ...)
> I will follow up with the cairo people about why this happens and if
> anything can be done to improve the situation. In the mean time it may
> be possible to work around the problem by avoiding bad scaling factors.
> -Jeff

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