400230 - simple scrolling takes 100% CPU

Status: RESOLVED WORKSFORME

(Firefox :: General, defect)

Description

[calmar]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a9pre) Gecko/2007101704 Minefield/3.0a9pre
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9a9pre) Gecko/2007101704 Minefield/3.0a9pre

Simple scrolling takes very long and 100% CPU

Reproducible: Always

Steps to Reproduce:
1. try to scroll on the example page mentioned
2.
3.
Actual Results:  
takes 100% cpu and is very slow (therefore)

Expected Results:  
(normal) fast scrolling without 100% CPU usage just for that

Comment 1

[DJiK]

I don't see big problem on the exemple you give. But it seems that position:fixed causes FF3 a lot of troubles! 100% CPU and a big lag. :-(


We discuss it on a french board: http://www.geckozone.org/forum/viewtopic.php?t=65654

Try the given exemples:
http://actu.c4.fr/
http://csszengarden.com/?cssfile=http://www.s427.ch/divers/cssZenGarden/v02/sample.css
http://www.thestyleworks.de/quickref/index.shtml

Comment 2

[calmar]

It seems indeed to be much better now compared to how it was on that narrenschiff page - hardly to detect now even. 

(in fact on http://actu.c4.fr/ the delay is obvious).

Comment 3

[DJiK]

For me the worst is http://www.thestyleworks.de/quickref/index.shtml
Very, very slow!

Comment 4

[Thomas]

Not fixed yet? I only get it with ATI/AMD G-Card 4570 & 9800 pro, with nvidia it runs smooth... Other browsers work fine. See (REALLY WORST with ATI/AMD Graphic Card): http://www.spiegel.de/

scrolling is realy worst! It became really worst with the release of Firefox 3!
Is someone working on this to fix it?

Comment 5

[Tyler Downer [He/Him]]

Reporter, does this still happen in Firefox 3.6.6 or later in a fresh profile?

Comment 6

[calmar]

Yes it does. position:fixed (e.g. a menu) seems to cause quite some delay while scrolling a longer site.

Dunno how exactly how it used to be - possible that it's better or not.

Comment 7

[Tyler Downer [He/Him]]

Can you please give a reduced testcase that shows the issue?

Comment 8

[calmar]

I guess the problem is almost solved and was way worse before.
http://www.calmar.ws/testcase.html (:fixed)
http://www.calmar.ws/testcase2.html (absolute)

you only detect it when you keep the 'arrow' keys pressed that it won't
scroll that smooth - but often jumps. But maybe that's also natural since there is more to calculate.

Here it hangs clearly (here especially when scrolling fast on the mouse-wheel) - http://www.narrenschiff.ch/antiquariat/buecher.php?suche=&gebiet=&untergebiet=&zeig=1000 but all over - I think, it's ok now - as it was way worse I guess.

Comment 9

[Tyler Downer [He/Him]]

This is something that retained layers may fix. It should be landing on trunk in a few days, when it does, we can try to reproduce again.

Comment 10

[Tanner M [:Tannn3r]]

Reporter, can you still reproduce this bug in Firefox 6?

Please update to Firefox 6 or later, update your plugins, and retest in a new profile. If you still see the issue with the updated version of Firefox, please post here. Otherwise, please close as RESOLVED > WORKSFORME.

http://getfirefox.com/

Comment 11

[DJiK]

For me it's OK now. This bug no longer exists since FF4.

On the examples I have given, the scrolling is normal, CPU 30-40% but it's the same in Opera (wich remains a little bit smoother).

I think it's resolved.