222844 - Unreasonably slow scrolling when page has position: fixed elements

Status: RESOLVED DUPLICATE of bug 201307

(Firefox :: General, defect)

Description

[bugzilla2005]

User-Agent:       Mozilla/5.0
Build Identifier: http://ftp.mozilla.org/pub/mozilla.org/firebird/releases/0.7/MozillaFirebird-0.7-i686-pc-linux-gnu.tar.gz

If a page has elements with the `position' CSS attribute set to `fixed',
scrolling becomes unreasonably slower compared to the scrolling speed of the
same page without the fixed elements. (Even on a 2GHz PC.)

(The demo page demonstrates the problem only if you switch to one of the `locked
menu' styles.)

Reproducible: Always

Steps to Reproduce:

Comment 1

[bugzilla2005]

Further testing shows that the slowness is much more visible if I use
antialiased fonts.  My font settings are:

user_pref("font.FreeType2.enable", true);
user_pref("font.freetype2.shared-library", "libfreetype.so.6");
user_pref("font.antialias.min",        10);
user_pref("font.scale.aa_bitmap.always", true);
user_pref("font.directory.truetype.1",
"/var/lib/defoma/x-ttcidfont-conf.d/dirs/TrueType");
user_pref("font.directory.truetype.2", "/usr/share/fonts/truetype");
user_pref("font.directory.truetype.3", "/usr/share/fonts/truetype/openoffice");

Comment 2

[José Jeria]

Dupe of bug 201307?

Comment 3

[bugzilla2005]

Yep.

*** This bug has been marked as a duplicate of 201307 ***