427940 - Moving the mouse within firefox window causes 100% CPU usage.

Status: RESOLVED FIXED

(Firefox :: General, defect)

Description

[holgbert]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008032619 Firefox/3.0b5
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008032619 Firefox/3.0b5

AMD Athlon(tm) XP 2800+
Ubuntu Linux 2.6.22-14-generic
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9b5) Gecko/2008032619 Firefox/3.0b5

Mouse movement over the firefox window, that is the displayed site(even about:blank), tabbar, menus, sidebar, statusbar...  causes 100% CPU usage.
The problem is not present over extra windows such as:
Add-ons, Downloads, Preferences, page source, ...

This is a major performance issue that might also be the source of various autoscroll performance issues.


Reproducible: Always

Steps to Reproduce:
Move mouse over firefox window



I'm not sure but I think this was resolved once already and reintroduced recently.

Comment 1

[Ria Klaassen (not reading all bugmail)]

Also in safe-mode?
http://kb.mozillazine.org/Safe_Mode_(Firefox)

Comment 2

[holgbert]

Oh, excuse me, after a system reboot the problem vanished.
I will have to check again on how to reproduce it.

Reproducible: unknown

Comment 3

[holgbert]

Over the last days the problem slowly reemerged several times after longer use.
Restarting Firefox helps and newly opened windows are also not affected right away.
I can now reproduce this quickly (This also works in safe-mode) :

Reproducible:
-open firefox.
-create and close about a hundred tabs.
  - hold CTRL-T  /  CTRL-W   for convenience
-end up with one blank tab.
-moving the mouse within the browser window produces high CPU load.

Comment 4

[holgbert]

I tracked it down to the answers.com Add-on.
Without it, the problem does not occur.
Of course it does not work in safe-mode but another normal mode instance prevented safe-mode when I tried.

sorry for the hassle.

Comment 5

[Asher Szmulewicz]

I uploaded a new version of the answers.com Add-on 2.2.47 (in the the sandbox right now) which fixes this problem.
The mousemove listener is now initialized when there is a mousedown and the AnswerTip is visible and the mousemove listener is removed when there is a mouseup. In the earlier versions the mouse move was initialized at tab onload and never removed.
I am just wondering why when closing the tab, the browser does not remove all mouse event listeners, even if the case of implementing an undo tab close, the mouse event listeners should be removed.

Comment 6

[Asher Szmulewicz]

Version 2.2.48 of the Answers.com extension compatible with Firefox 3.0 was approved by Mozilla. This version fixes the bug. Please close the bug

Comment 7

[holgbert]

Thanks!