Ubuntu
firefox package

  1. Bug #32561
  2. Comment #36

Comment 36 for bug 32561

Revision history for this message
Gary Coady (garycoady) wrote : Re: Firefox in Dapper much slower than official upstream builds

I tried just taking one page, and scrolling up/down it quite a few times (www.huffingtonpost.com as it happens):
For mozilla.org builds:
X usage was 74%
Kernel was 25%
firefox CPU usage was < 1%

For ubuntu builds:
X usage was ~45%
Kernel was ~12.5%
firefox CPU usage was 46%

Within firefox, 41% of that came from libgfx_gtk.so.
Dividing that up, ~8% from gdk_draw_layout_line
~2% from gdk_rgb_xpixel_from_rgb
~1% from gdk_draw_rectangle
~25% from libpango

Within that 25% from libpango:
11% comes from FcFontSort (fontconfig) - this percentage would be a lot higher if I hadn't temporarily disabled most of the fonts installed on the system. With all the default fonts installed, plus around 100 extra in my ~/.fonts directory, FcFontSort used closer to 45% of total CPU.

(data taken using sysprof)