Canvas drawing in Inkscape is quite slow. It takes almost 2 seconds for a 1920x1200 window to draw.
Created attachment 21026 [details] A profile from OProfile
Inkscape seems to be hitting a UXA fallback in uxa_copy_n_to_n.
Xorg components as of Wed Dec 10 21:25:52 EST 2008 drm: c99566fb810c9d8cae5e9cd39d1772b55e2f514c xf86-video-intel: 83377b543defdca7226d7c1a7794e4ff3d8b4c84 mesa: a0d5c3cfe6582f8294154f6877319193458158a2 xserver: 7c8720c1433d2c3b85bbf4b811cc54c2df4c0080 Linux mercury.localdomain 2.6.28-rc7 #6 SMP Tue Dec 9 19:36:02 EST 2008 x86_64 x86_64 x86_64 GNU/Linux
With old cairo, I see cairo triggering fallbacks that suck 30% cpu resizing the blank canvas window. With new cairo, that's gone, and I now see 5 different core rendering fallbacks, of which copy_n_to_n is one (though check_poly_fill_rect ranks higher). I'm going to try a gtt mapping hack, which will probably cut the cost of a lot of fallbacks greatly.
This should be fixed in commit aae4008096399a0e84abc7c016b35092caf9db25 Author: Eric Anholt <eric@anholt.net> Date: Wed Dec 17 14:25:22 2008 -0800 uxa: Do a hack to use the aperture mapping instead of bo_map in sw fallbacks.
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