535504 - Firefox 3.6 beta hangs with 100% cpu load on almost every event

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Lyle Lasheimok]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.1.5) Gecko/20091123 Firefox/3.0.14 (like Firefox/3.5.5; Debian-3.5.5-1)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-GB; rv:1.9.2b4) Gecko/20091124 Firefox/3.6b4

When returning to the workspace showing Firefox, it hangs while consuming 100%. It takes several seconds until it finally redraws its UI and the page.

That happens almost every single time.

Same happens at almost every other event (going to a different tab, clicking on a link, scrolling, ...). Same behaviour. For several seconds Cpu load is 100%, Firefox UI doesn't redraw and doesn't react to anything. After a few seconds Cpu load drops and Firefox continues to run normally.

Until I click somewhere else.

It may be related to some of the extensions, I can't tell. At first I thought it was Operator, as it caused Firefox 3.5 to hang while it was parsing the site (at least that's what I thought it was). So I disabled Operator, and Firefox seemed to run fine, but a few days later this behaviour returned. This time I thought it was related to the Test Pilot test that was running last week, but now the test is over and Firefox still hangs whenever I try to use it.

I thought about disabling extensions to see whether one of the extensions causes this behaviour, but since disabling Operator seemed to help for a few days, this would be difficult, as all of the results would be random.

Reproducible: Sometimes

Steps to Reproduce:
1. Start Firefox
2. Load a page
3. Use it for a while
Actual Results:  
After almost every click any other event Firefox will become unresponsive for several seconds, with 100% processor load, before it continues as normal.

Expected Results:  
Firefox should react quickly, or at least within less than a second.

about:buildconfig

Source

Built from http://hg.mozilla.org/releases/mozilla-1.9.2/rev/4c488520d1bf
Build platform
target
i686-pc-linux-gnu

Build tools
Compiler 	Version 	Compiler flags
/tools/gcc/bin/gcc 	gcc version 4.1.2 20061011 (Red Hat 4.1.1-29) 	-Wall -W -Wno-unused -Wpointer-arith -Wcast-align -W -Wno-long-long -pedantic -gstabs+ -fno-strict-aliasing -pthread -pipe -DNDEBUG -DTRIMMED -Os -freorder-blocks -fno-reorder-functions -finline-limit=50
/tools/gcc/bin/g++ 	gcc version 4.1.2 20061011 (Red Hat 4.1.1-29) 	-fno-rtti -fno-exceptions -Wall -Wpointer-arith -Woverloaded-virtual -Wsynth -Wno-ctor-dtor-privacy -Wno-non-virtual-dtor -Wcast-align -Wno-invalid-offsetof -Wno-long-long -pedantic -gstabs+ -fno-strict-aliasing -fshort-wchar -pthread -pipe -DNDEBUG -DTRIMMED -Os -freorder-blocks -fno-reorder-functions -finline-limit=50

Configure arguments
--enable-application=browser --enable-optimize --enable-update-channel=beta --enable-update-packaging --disable-debug --disable-tests --enable-official-branding 


Also I use the following extensions:

About:Tab 0.0.36
Adblock Plus 1.1.2
Add-on Compatibility Reporter 0.4
CustomizeGoogle 0.76
EventBug 0.1a2
Firebug 1.5X.0b6
FireRainbow 1.0
Firesomething for all version Firefox 2.6
Fission 1.0.9
Hide Menubar 1.0.20090929
Novel Moonlight 1.99.7
Operator 0.9.5.1 (disabled)
Page Speed 1.3.0.1
Pixel Perfect 1.1.0
SenSEO 1.1.0
Test Pilot 0.4
Ubiquity 0.5.4
Xmarks 3.4.3
YSlow 2.0.2

Comment 1

[Ria Klaassen (not reading all bugmail)]

Do you see the same in safe-mode? http://support.mozilla.com/en-US/kb/Safe+Mode

Comment 2

[Lyle Lasheimok]

I disabled all extensions and Firefox was running fine again (normal mode, not safe-mode).

Then I enabled all extension except Operator and EventBug. Still running fine.

So maybe it was EventBug, which is reported to not be compatible with Firefox 3.6.

Then again, disabling Operator had the same effect, but only for a few days.

Anyway, it's working now. I'll post again if the behaviour returns.

Thanx for your help! :)

Comment 3

[Ria Klaassen (not reading all bugmail)]

Thanks for your response. Resolving WFM per comment 2. Please reopen if you still see the problem.