[Bug 383435] [NEW] Firefox lags when scrolling

[Keepiru]

Public bug reported:

Binary package hint: firefox-3.0

Scrolling lags badly in Firefox.  It's not a consistent problem, but
seems to build the longer I keep the browser open.  After a day or so, I
can spin my scroll wheel ten clicks...  Wait...  Nothing happens...
Start to wonder if it's hung...  And then the ten scroll events happen.
The delay is very inconsistent, which from a usability standpoint is
worse.  Instead of just knowing it lags, it has feel like I mistakenly
tried to scroll with the wrong window focused.  My guess is that there's
some garbage collection or something that happens periodically, and if I
scroll during it, it has to wait until the *whatever* job is done.

I keep saying scrolling here because it's the most obvious case, but I'm
pretty sure all browser operations freeze during the lag time.

This started under 8.10, and seemed to get better when I first switched
to 9.04, but it's happening all the time again now.  When it gets really
bad, Flash videos start having problems too where they'll freeze for
several seconds, much like the scrolling freezes.  Clicking links to
open pages also seems to be affected, again having some sporadic lag.
Sadly, Firefox on my old P3-600 with 8.04 feels more responsive than on
9.04 on my Athlon64-5200.

If I exit when it's really bad, Firefox consumes 100% CPU for 10 to 20
seconds after the window closes, but before the process exits.  The time
seems to be related to how much trouble I'm having with the lag.  It'd
be awfully interesting to know what it's cleaning up during that time,
but I don't know how to find out.

I have a workaround that seems to make it somewhat better:  kill
firefox, delete localstore.rdf, restart.  This seems to work better than
just restarting, but it's really hard to do side by side comparisons,
since it takes a while to build up to the nasty lag.

I've gone through many gyrations of deleting my profile and reimporting
my bookmarks, disabling plugins, and removing Flash, all to no avail.

ProblemType: Bug
Architecture: i386
DistroRelease: Ubuntu 9.04
NonfreeKernelModules: nvidia
Package: firefox-3.0 3.0.10+nobinonly-0ubuntu0.9.04.1
ProcEnviron:
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: firefox-3.0
Uname: Linux 2.6.28-11-generic i686

** Affects: firefox-3.0 (Ubuntu)
     Importance: Undecided
         Status: New


** Tags: apport-bug i386

-- 
Firefox lags when scrolling
https://bugs.launchpad.net/bugs/383435
You received this bug notification because you are a member of Mozilla
Bugs, which is subscribed to firefox-3.0 in ubuntu.