448774 - Scrolling Gmail while a chat is open is extremely slow and jittery

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect, P2)

Description

[Gábor Stefanik]

Just noticed that in Fx3.0.1/WinXP, scrolling the mail list in Gmail (UI 2) with an in-page (non-"popped out") chat window open is extremely slow, and the bottom (or the top when scrolling upwards) of the list looks jittery, it displays what was termed in an earlier bug the "tectonic plate effect". Scrolling the chat window is not affected. This doesn't appear to happen on Linux.

Steps to reproduce:
1. Open Gmail in Firefox 3.0.1 on Windows XP (Vista and Mac not tested, Linux doesn't appear to show the bug).
2. Log in and open a chat window with someone. Don't pop-out the window!
3. Try to scroll the list of e-mails in the background.

Comment 1

[Vladimir Vukicevic [:vlad] [:vladv] (needinfo me, slow to respond)]

This sounds like the usual fixed-position element causes entire page to be repainted on scroll, but we should profile; part of that was fixed in bug 382392, but apparently not enough to handle this case.

Comment 2

[Gábor Stefanik]

(In reply to comment #1)
> This sounds like the usual fixed-position element causes entire page to be
> repainted on scroll

And, it initially gets repainted incorrectly (top and/or bottom of the page flickers - should we use double buffering to fix such cases?)

Comment 3

[Gábor Stefanik]

Also, the flicker is visible on both Windows and Linux, but on Linux, there are no speed issues (on an overclocked Q6600 at least) - on Windows, scrolling is extremely slow even on such a high-performance configuration.

Comment 4

[Gábor Stefanik]

Pulling back from the graveyard, we should not mark NEW bugs as graveyard.

Comment 5

[Gábor Stefanik]

Background-attachment:fixed on the body or html elements also triggers this bug.

Comment 6

[Pushkar]

Problem reoccurred under exactly similar scenario in Linux Ubuntu 8.10. Later realized that problem occurs on pages with running animation using Javascript.

Comment 7

[shift9999]

I am still seeing this with the latest minefield nightly with D2D\DW enabled. I have not tried it without.

Smoothscroll/autoscroll seem to drastically enhance the issue.

Mozilla/5.0 (Windows; U; Windows NT 6.1; en-US; rv:1.9.3a5pre) Gecko/20100412 Minefield/3.7a5pre

with a google chat box open scrolling with the mousewheel and scroll bar is extremely slow.

Comment 8

[Benoit Girard (:BenWa)]

This bug should have been fixed by Layers. If you still see something similar please file a new bug.