444871 - Scrolling some pages is far too slow, takes far too much CPU

Status: RESOLVED DUPLICATE of bug 372039

(Firefox :: General, defect)

Description

[Rene Herman]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008052912 Firefox/3.0
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008052912 Firefox/3.0

The above mentioned site (www.bnrmetal.com) has become unuseable with firefox 3, at least on my hardware.

I'm on a Duron 1300 and while scrolling any page on bnrmetal, X takes some 90+ % CPU with the remaining 10 going to firefox-bin itself. Trying to *stop* scrolling after a good turn of the scrollwheel for example can take up to 10 seconds even...

I just now tried with firefox 2.0.0.15 as well and although that (now that I am paying attention to it) takes quite a bit of CPU as well it's not nearly as bad. The site is still useable with it. I contacted the owner who isn't aware of anything wrong, and Opera 9.50 has no trouble with the site whatsoever it seems. It's lightning fast...

Reproducible: Always

Steps to Reproduce:
1. go to above URL
2. scroll page with scrollwheel or down arrow under right scrollbar
3. see it bring your system to its knees -- probably unless you have a very fast system.
Actual Results:  
A system on its knees

Expected Results:  
A system not on its knees

Verified on various Linux kernels (and browsers as mentioned in the report)

Comment 2

[José Jeria]

Oh, I see now that this is a regression. Reopening.