354931 - Firefox becomes unresponsive when finishing rendering a webpage

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[Artem S. Tashkinov]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.3) Gecko/20060326 Firefox/1.5.0.3 (Debian-1.5.dfsg+1.5.0.3-2)
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.8.0.3) Gecko/20060326 Firefox/1.5.0.3 (Debian-1.5.dfsg+1.5.0.3-2)

Open a webpage in a background tab, then when this webpage is getting rendered you cannot do anything in Firefox, i.e. it almost stalls for around a second or two. I'm using a ziproxy proxy server which compresses text data on the fly using gzip algorithm.

Here's the list of active extensions which I currently use:
Adblock Filterset.G Updater
Adblock Plus 0.5.11.4
Cache Fixer 1.0
Extended Link Properties 1.2.3
FireFTP 0.94.3
NoScript 1.1.4.1
PrefButtons 0.3.4
Stop-or-Reload Button 0.2
Work Offline 1.2

Reproducible: Always

Steps to Reproduce:
1. Open enough large and complex webpage in a background tab
2. Try scrolling the currently active tab (with smooth scrolling turned on) - when the background tab gets downloaded and rendered - you cannot simply scroll the active tab and CPU usage climbs up to 100% for a while


Expected Results:  
Real working multithreading with no lags in browser responsiveness when it's doing some background tasks

Tested and proved to be a bug in Firefox 2RC1.

Comment 1

[Steve Chapel]

Reporter, could you test in a recent trunk build with a new profile?

Comment 2

[Wladimir Palant]

That's the "DIV blocking" feature in this version of Adblock Plus, see http://adblockplus.org/en/faq_features#divblock. It can be disabled in the Adblock Preferences dialog, under Options.

Comment 3

[Artem S. Tashkinov]

(In reply to comment #2)
> That's the "DIV blocking" feature in this version of Adblock Plus, see
> http://adblockplus.org/en/faq_features#divblock. It can be disabled in the
> Adblock Preferences dialog, under Options.
> 

On the branch disabling that option didn't help.

(In reply to comment #1)
> Reporter, could you test in a recent trunk build with a new profile?
> 

I can do that later.

Comment 4

[Artem S. Tashkinov]

Nothing changed: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a1) Gecko/20061002 Minefield/3.0a1

Comment 5

[Tracy Walker [:tracy]]

reporter, can you reproduce this in safe mode? with other browsers; seamonkey?

Comment 6

[Artem S. Tashkinov]

Firefox version "Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a2pre) Gecko/20070123 Minefield/3.0a2pre" became somewhat defter and quicker at rendering pages, yet when a large (gzipped by a server) page is being loaded firefox almost hangs for few seconds.

It seems that adblock extension also adds some slowness but I'd like to repeat that this issue takes place with a fresh Firefox profile with no extensions installed.

Comment 7

[(no longer active)]

Reporter, can you provide a step by step guide on how to reproduce this bug, starting from opening Minefield, and navigating to specific URLs, and so on?

I can't reproduce this on alpha7pre.

Comment 8

[Artem S. Tashkinov]

<!-- I'm not sure if this step is really required: install a ziproxy caching and compressing proxy server. Route you Firefox via this server. -->

1) Enable smooth scrolling

2) Open any URL where you can scroll a page

3) Load http://download.fedora.redhat.com/pub/fedora/linux/releases/7/Everything/i386/os/Fedora/
in background tab

4) Try scrolling the page in the tab you've opened at first step, trying opening the menu or call Help->About. Firefox will slow down and behave like it's stalled.

Comment 9

[Artem S. Tashkinov]

Comment #8

s/at first step/at second step/
s/trying/try/

I'm sorry for my poor English - I should have slept more today. ;-)

Comment 10

[(no longer active)]

(In reply to comment #8)
> <!-- I'm not sure if this step is really required: install a ziproxy caching
> and compressing proxy server. Route you Firefox via this server. -->
> 
> 1) Enable smooth scrolling
> 
> 2) Open any URL where you can scroll a page
> 
> 3) Load
> http://download.fedora.redhat.com/pub/fedora/linux/releases/7/Everything/i386/os/Fedora/
> in background tab
> 
> 4) Try scrolling the page in the tab you've opened at first step, trying
> opening the menu or call Help->About. Firefox will slow down and behave like
> it's stalled.
> 

I didn't try ziproxy, but otherwise WORKSFORME.  Have you tried to reproduce this on the latest nightly builds?

(In reply to comment #9)
> Comment #8
> 
> s/at first step/at second step/
> s/trying/try/
> 
> I'm sorry for my poor English - I should have slept more today. ;-)
> 

No problem, not a native speaker myself.  :-)

Comment 11

[Artem S. Tashkinov]

Isn't Firefox alpha 7 recent enough? Should I try today's nightly build?

Comment 12

[(no longer active)]

(In reply to comment #11)
> Isn't Firefox alpha 7 recent enough? Should I try today's nightly build?
> 

You didn't indicate the version you used in your test.  Since alpha7 is not released yet, I assume you're using a nightly.

Can you reproduce this using a clean profile?  And also on another machine?

Comment 13

[Artem S. Tashkinov]

A related bug report: https://bugzilla.mozilla.org/show_bug.cgi?id=354931

Comment 14

[Steve Chapel]

That's this bug report. Can you reproduce the problem with Firefox 3.1 or Firefox 3.2 with a clean profile?

Comment 15

[Artem S. Tashkinov]

1. exit all firefox instances
2. mv $HOME/.mozilla  $HOME/.mozilla.save
3. open Firefox (Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.2a1pre) Gecko/20081219 Minefield/3.2a1pre)
4. Enable smooth scrolling (no really necessary)
5. Open this bug report in the first tab
6. Open http://download.fedora.redhat.com/pub/fedora/linux/releases/7/Everything/i386/os/Fedora/ in another tab, go back to the first tab.

Result: while a background tab is being loaded firefox UI completely stalls for up to 7 seconds; scrolling of the first tab is very choppy, sometimes you cannot even access menu items.

Comment 16

[Brian Carpenter [:geeknik]]

Is this still an issue with the latest versions? If not, please close this bug as WORKSFORME, otherwise, post a comment letting us know it is still an issue.

Comment 17

[Artem S. Tashkinov]

I'm willing to close it, but I can still easily reproduce this bug.

1) Go to http://download.fedora.redhat.com/pub/fedora/linux/releases/13/Everything/i386/os/
2) Open Packages directory, wait for it to complete downloading
3) Return to the 1)
4) Open any long enough web site in another tab (which requires scrolling)
5) Go to offline mode
6) Return to 1) and Hit Packages
7) Firefox will stall and even if you managed to return to 4) tab, Firefox will become unusable.

I can upload a video clip if you want to see how this bug affects me.

Comment 18

[Brian Carpenter [:geeknik]]

Go ahead and upload a video clip for those of us not on Linux can see what is happening. I'll go ahead and mark this NEW and get some more eyes on it.

Comment 19

[Artem S. Tashkinov]

In the beginning of the video I actively try to switch to another tab and I cannot (only at 00:00:15 firefox does that), then I try to smooth scroll, firefox does nothing, then I try to scroll using the right scrollbar, firefox doesn't allow me to scroll (only around 00:00:30 firefox gains consciousness).

URL: http://www.mediafire.com/?z2iyufrhlv5y48l

Comment 20

[Artem S. Tashkinov]

Attachment: Video demonstration

Hopefully Electrolysis will solve this issue