firefox slowness with xorg 6.9.0

[Michel Dänzer]

On Tue, 2006-03-07 at 17:39 +0100, Roland Scheidegger wrote:
> Tommi Sakari Uimonen wrote:
> > I'm using debian unstable (also tried kanotix), both have xorg 6.9.0 and 
> > kde 3.5. Video card is ATI 7500. Firefox is 1.5
> > 
> > For reference, I have also oldish gentoo install with xorg 6.8.x and 
> > it's fast. top shows that X takes only about 30% and firefox 50% cpu 
> > while scrolling about:config page with mouse wheel while some other 
> > window is on top of firefox. Gentoo has firefox 1.0.4 and kde 3.4
> > 
> > I'm just compiling firefox 1.5 to gentoo to bring the two systems 
> > configurations closer to each other. Hopefully I accomplish a situation 
> > where only xorg version differs, and then I really can blame xorg for 
> > the slowness. It could be GTK slowness, because konqueror works fast 
> > with the same setup (same website and another window on top of konqueror)
> FWIW, I noticed some massive slowdowns when using firefox too recently, 
> but after some digging it seems firefox 1.5 is fully to blame. The 
> slowdowns only happen with firefox 1.5 or seamonkey 1.0, but firefox 1.0 
> is fast. Maybe it simply has to do how it's compiled (using gtk2 and 
> such), I don't know.
> Some quick profiling showed this however (scrolling on a VERY slow page 
> since it updated its layout, http://www.hardocp.com/):
> 8608     43.2107  libfb.so                 fbBlt
> 5168     25.9425  vmlinux                  default_idle
> 830       4.1665  libgklayout.so           (no symbols)
> 436       2.1886  Xorg                     (no symbols)
> 344       1.7268  libxpcom_core.so         (no symbols)
> 255       1.2801  libfb.so                 fbBltOne
> 188       0.9437  libmozjs.so              (no symbols)
> 157       0.7881  libgfx_gtk.so            (no symbols)
> 153       0.7680  libfb.so                 fbSolid
> So, firefox 1.5 causes some massive use of libfb.so which firefox 1.0 
> probably didn't (I did not profile firefox 1.0). As to why and how to 
> fix it, no idea... My setup used radeons too if it matters (7200, 9000 
> with xorg 6.9, and a x550 with xorg 6.8.2)

Have you guys tried with EXA? This sounds like the good old 'Cairo and
XAA don't mix well'. Cairo actually contains a bunch of workarounds for
XAA, but I think they're disabled with X.Org 6.9 or newer, as it was
assumed that XAA would get fixed. Also note that GTK+ 2.8.12+ has some
XAA workarounds again, so if you have an older version, you may want to
upgrade.


Hope this helps,


-- 
Earthling Michel Dänzer      |     Debian (powerpc), X and DRI developer
Libre software enthusiast    |   http://svcs.affero.net/rm.php?r=daenzer