Re: improve scroll performance of dillo-fltk

Hi Matthias,

On Fri, Oct 12, 2007 at 09:26:57PM +0200, Matthias Franz
wrote:
> On Fri, Oct 12, 2007 at 07:59:34PM +0200, Johannes
Hofmann wrote:
> > 000:<:c47f: 40: RENDERRequest(154):
RenderCompositeGlyphs8 op=Over(0x03) src=0x01c0000f
dst=0x01c00036 maskFormat=0x00000026 glyphset=0x01c00037
xSrc=0 ySrc=0 glyphcmds={deltax=5 deltay=554  
glyphs=0x5a,0x4b,0x48,0x51; };
> 
> Hi Johannes,
> 
> two additonal observation:
> 
> 1) I've had a look at the xtrace output of dillo1. It
seems not to use
> the RENDER extension (apart from two requests
> 
> 000:<:0029: 12: RENDERRequest(151):
RenderQueryVersion majorVersion=0 minorVersion=10
> 000:<:002a:  4: RENDERRequest(151):
RenderQueryPictFormats 
> 
> at the beginning).
> 
> 2) I've played around with 2D-acceleration and compared
CPU load while
> scrolling. Result:
> 
> dillo1: XAA: excellent (almost no load), EXA: very bad
(100%, delays)
> dillo2: XAA: bad (100%)                  EXA: slightly
better (75%)
> 
> I've read that the EXA implementation of my Xorg server
(7.1.1) is
> very bad, at least for my video driver (savage). On the
other hand,
> RENDER support is said to be better in EXA than in
XAA.
> 
> So could it be that it has to do with RENDER and that
most of you
> have decent hadware acceleration for that?

Yes, I guess that's the reason. You can compile fltk with
the
--disable-xft flag. In this case you will get the artefacts
you
mentioned before, but the performance should be similar to
dillo1.

We should try to get rid of those artefacts for users that
can't use
xft.

Cheers,
Johannes

_______________________________________________
Dillo-dev mailing list
Dillo-devdillo.org
http://lists.auriga.wearlab.de/cgi-bin/mailman/
listinfo/dillo-dev

On Fri, Oct 12, 2007 at 10:28:38PM +0200, Johannes Hofmann
wrote:
> > So could it be that it has to do with RENDER and
that most of you
> > have decent hadware acceleration for that?
> 
> Yes, I guess that's the reason. You can compile fltk
with the
> --disable-xft flag. In this case you will get the
artefacts you
> mentioned before, but the performance should be similar
to
> dillo1.

I've compiled fltk with "--disable-xft". Now it
doesn't use RENDER
any more (checked with xtrace). But I don't notice any
performance
difference to dillo2 with xft. In particular, performance is
far
from being that of dillo1. So, xft / RENDER does not seem to
be the
reason. Maybe a detailed comparison of the xtrace logs of
dillo1 and
dillo2-noxft could help? I've seen that dillo2 uses many
"ChangeGC",
"SetClipRectangles" and
"PolyFillRectangle" requests, which are not
used by dillo1. I don't know which requests are particularly
expensive.

> We should try to get rid of those artefacts for users
that can't use
> xft.

I agree. As Johannes has found out, this is an fltk bug.

Cheers,
-- 
Matthias Franz

_______________________________________________
Dillo-dev mailing list
Dillo-devdillo.org
http://lists.auriga.wearlab.de/cgi-bin/mailman/
listinfo/dillo-dev