Description of problem: When the user opens a long gmail thread that pops up the name of the next person who responded to the thread in the bottom right corner, the scrolling of that window is very slow and jerky. When at the last message where that pop-up disappears, the scrolling is smooth again. So whatever CSS element that causes the pop-up is seriously lagging the windows scrolling. This gives a really bad impression of the Linux desktop. Version-Release number of selected component (if applicable): version included in Rawhide 20070502 LiveCD How reproducible: Always Steps to Reproduce: 1. view a long message thread in gmail 2. scroll down using mouse wheel or scroll bar Actual results: The scrolling is not smooth like it is in Firefox running on Windows. Expected results: The scrolling should be smooth.
AJAX apps in general are very slow in Firefox on Linux for some reason. It usually becomes a little faster if you enable Composite on your desktop, but it still does not perform well vs. Windows or MacOS. System > Preferences > Look & Feel > Desktop Effects (This only works on some video drivers.)
Reporter, could you please try to reproduce this problem with Pango disabled? It means running firefox in gnome-terminal/konsole/xterm like this: MOZ_DISABLE_PANGO=1 firefox Does it help?
We found that this bug has been already registered in the upstream database (https://bugzilla.mozilla.org/show_bug.cgi?id=342669) and believe that it is more appropriate to let it be resolved upstream. Red Hat will continue to track the issue in the centralized upstream bug tracker, and will review any bug fixes that become available for consideration in future updates. Thank you for the bug report.
(In reply to comment #2) > Reporter, could you please try to reproduce this problem with Pango disabled? It > means running firefox in gnome-terminal/konsole/xterm like this: > > MOZ_DISABLE_PANGO=1 firefox > > Does it help? No. It is still much less responsive on Fedora Linux than a W2k installation on the same box running the same latest version of Firefox. Disabling smooth scrolling does help a small bit.
(In reply to comment #4) > We found that this bug has been already registered in the upstream database > (https://bugzilla.mozilla.org/show_bug.cgi?id=342669) and believe that it is > more appropriate to let it be resolved upstream. This is not the same problem. This scrolling lag occurs all the time; not just when loading. It also occurs on a Gnome desktop (haven't tried others) on a Fedora systems; not an XP system ... in fact, scrolling is much much better on a W2k system. That is what made me think this is a Firefox/Linux screen rendering issue vs. a general Firefox performance issue. In a nutshell, On a dual-boot box, on the Fedora side, open a webpage with a lot of content (like this bugzilla page) and spin the scroll wheel on your mouse quickly ... it will take about 0.5-1.5 seconds for the page to finally scroll down to where it should be. Now try this on Windows on the same box. It will be at the correct spot nearly instantaneously. It gets a lot worse on a bigger page and when there are elements that float along to stay in the window like the name of the subsequent posters in the gmail example in the original report.
Sounds to me like a configuration problem. Could you compare in about:config all *wheel* and *scroll* configuration settings? See for example http://www.extremetech.com/article2/0,1697,1862333,00.asp for explanations of what could be done with these settings (they even mention an extension which looks nice for changing mouse wheel settings http://www.extremetech.com/article2/0,1697,1862334,00.asp ) Or do we have real problem here?
I took a look at those settings and my system doesn't have enything out of the ordinary. It is all default settings. This window scrolling lag is independent of the mouse-wheel and is even worse when using the cursor key. Hold the cursor down key for a few seconds on a web page on a non-ajax page (like slashdot.org for instance). It won't scroll quickly but will stop instantly when you let go of the key. Do the same thing on a long gmail message thread ... when you let go of the key, it will keep on scrolling for a time but if you are on the last message (where there is no little popup element showing you the next message author) the scrolling is like it is on a non-popup page.
Created attachment 190911 [details] Screenshot of page element causing the lagginess I red circled the floating element that is causing the lag. I am not sure what bit of js causes this but it is present in gmail message threads and a lot of other pages where they want to keep a bit of info on the screen while you scroll down. It kills the page responsiveness in Fedora but not in Windows using the same Firefox version.
Probably https://bugzilla.mozilla.org/show_bug.cgi?id=201307
It sounds a whole lot like that bug and a really ancient one at that. Except that I only really see this in Linux now. In Windows the scrolling performance is acceptable but I haven't looked at CPU usage while scrolling. There may be some odd video driver interaction that makes some people really see this and others give a WFM. Please let me know of any info that I can provide from my system to help with this bug.
Can very well reproduce with Martin's testing firefox-2.0.0.6-12.debug.fc8 on x86_64.
We filed this bug to the upstream database (https://bugzilla.mozilla.org/show_bug.cgi?id=398562) and believe that it is more appropriate to let it be resolved upstream. Red Hat will continue to track the issue in the centralized upstream bug tracker, and will review any bug fixes that become available for consideration in future updates. Thank you for the bug report.