On Jul 6, 2006, at 3:41 PM, Roo wrote: >>>> So basically: there are more variables than just GTK. >>> >>> Ok, so presumably there's a way to take gtk2-2.8.19-2.src.rpm (the >>> currently installed GTK2 on my FC5 system) and recompile it (or is >>> there an env var?) telling it not to use Cairo so I can see if >>> there's >>> a difference and hence narrow things down. >> >> Looking at configure.in in the GTK2.8 sources, it appears that there >> is >> no way to disable cairo. > > Right... so the GTK developers left normal users without the ability to > compare it directly. That makes a lot of sense if they wanted to find > out > the real facts and figures behind Cairo... Or maybe they just don't want to maintain two different sets of drawing code for every widget. >> I'd try cutting any non-default themes out first. And it looks like >> Cairo can't be removed, for better or worse. > > I don't think that's acceptable at all. Cairo pretty obviously has > major > performance problems (even if you accept that it is only on some > cards), > and the GTK developers forced everyone to use it without even a > fallback. But allowing Cairo to be removed would probably require the GTK devs to maintain two versions of the drawing code for every widget. Which is a significant hinderance to forward progress, makes maintenance a nightmare, and in general is not a good thing. Whatever the full reasoning, I'm convinced the GTK developers are not out to deliberately condemn all users to poor performance. >> Profile. What happens if you build Cairo, GTK and GTKperf or gtk-demo >> or something with profiling enabled, and look at the profiling data? >> Where are GTK and Cairo spending their time? > > But with what am I comparing it? I *know* it wasn't this bad with FC4 > (pre-Cairo), but the GTK developers have removed the option of testing > that without wiping the box. I'm sure you can see the utter frustration > involved here. No wonder performance problems never get fixed. The GTK > developers seem to go to great lengths to ensure that reports are very > ignorable. You're comparing it with itself. If the profiler reports that GTK is consistently spending 75% of its time in Cairo, then yeah, Cairo (or at least the manner in which GTK uses Cairo) is a problem. But if it spends 5% of its time in Cairo, and 60% of its time grooming a cat, then the problem is most likely elsewhere. - Michael _______________________________________________ gtk-list@xxxxxxxxx http://mail.gnome.org/mailman/listinfo/gtk-list
