462724 - Javascript high CPU usage on walla.co.il

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[yonizaf]

User-Agent:       Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b2pre) Gecko/20081101 Minefield/3.1b2pre
Build Identifier: Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1b2pre) Gecko/20081101 Minefield/3.1b2pre

major hebrew site walla.co.il launched a new design where they replaced marquee tag with js implementation, apparently trying to be more standard support. 
in firefox there's high cpu usage (eg. 80-100% on my 1.8GHz centrino laptop), but in any other major browser it doesn't top 10%. I've tried opera 9.6, MSIE 8b2, Google chrome 0.3.154.9 and safari 4.0a. 
note that flash enabled on that page can use high cpu too, so disabling it would be a good idea.

I've tried 3.0.2 AND 3.1 nightly, even with JIT enabled.

Reproducible: Always

Steps to Reproduce:
1.navigate to http://walla.co.il
2.disable or block flash (good idea)
3.open windows task manager to see cpu usage
Actual Results:  
high cpu usage, might be up to 100% depending on hardware

Expected Results:  
the same level of cpu used as any other browser

Comment 1

[Ria Klaassen (not reading all bugmail)]

You could try filtering the ads out with an extension like Adblock Plus.
https://addons.mozilla.org/en-US/firefox/search?q=adblock%20plus&status=4

Comment 2

[yonizaf]

again, what I'm talking about is not the ads. I've filtered these out already. what causing the problem is the news 'marquee' builtin javascript. 
there are two on that page. one external .js file, and it can be filtered. the other one is inline script tag, and adblock plus can't filter it. even if it could, it will reduce functionality , as the same script tag contain some other functionality in that page.

with that said, that's not the point. we're talking about the most visited local Israeli site, which decided to drop the marquee tag in favor of legitimate javascript code that works fine in every (standard supporting) browser, and only firefox doesn't seem to handle it right. with such attitude they (and others alike) will probably just go back to marquee tag "to support firefox". pretty ironic, i think.

Comment 3

[reelix]

Partially Confirmed.

After loading, Firefox idles at around 30% Processor Usage on an Intel E2160 - 1.8 Dual Core.

Comment 4

[Tyler Downer [He/Him]]

This is a mass search for bugs which are in the Firefox General component, are
UNCO, have not been changed for 500 days and have an unspecified version. 

Reporter, can you please update to Firefox 3.6.10 or later, create a fresh profile, http://support.mozilla.com/en-US/kb/managing+profiles, and test again. If you still see the issue, please update this bug. If the issue is gone, please set the status to RESOLVED > WORKSFORME.

Comment 5

[yonizaf]

The issue still exists.

Comment 6

[Wayne Mery (:wsmwk)]

yonizaf, can you also reproduce with firefox 4 beta?

Comment 7

[Tyler Downer [He/Him]]

Reporter, are you still seeing this issue with Firefox 4.0.1 or later in safe mode or a fresh profile? If not, please close. These links can help you in your testing.
http://support.mozilla.com/kb/Safe+Mode
http://support.mozilla.com/kb/Managing+profiles

Comment 8

[yonizaf]

I don't care about this bug anymore, and it seems nobody else does. As far as I'm concerned it can be closed, as it seems you want to close as many bugs as possible.

I'm not closing this myself, since I'm not sure what status to set.

Comment 9

[Wayne Mery (:wsmwk)]

I think it's more a case of, bugs that can't be reproduce either need to be confirmed by reporter or triagers - and no one else seems to able reproduce. 
WFM with 5.0a2 on win7.