299727 - Performance of Firefox over X11 remote display, and equivalently under VNC, is unbelievably/unusably slow

Status: RESOLVED INCOMPLETE

(Firefox :: General, defect)

Description

[bgrayson]

User-Agent:       Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.7.5) Gecko/20041125 Firefox/1.0
Build Identifier: Mozilla/5.0 (X11; U; Linux ppc; en-US; rv:1.7.5) Gecko/20041125 Firefox/1.0

If one starts up Firefox on one machine, displaying remotely over X11 to another
machine, even over a 100Mb network, firefox is incredibly slow.  I have a
feeling it has to do with firefox being sloppy with its handling of ExposeNotify
events etc -- are y'all collapsing multiple expose events into a single repaint
request?  Do you do partial-window repaints, or only the whole window at once? 
I tried using xmsgtrace to see what X protocol messages were being sent, but
there were several thousand, more than I can easily examine with the knowledge
of Firefox that I have.

Reproducible: Always

Steps to Reproduce:
1.  From your main workstation, ssh to another machine with Firefox installed.
2.  Using the ssh connection, or directly using DISPLAY=<workstation:0>, start
up a firefox on the remote machine with display on the local machine.
3.  Select some text on the firefox home page.
4.  Now move the mouse out of that window, and back in.  Watch the time lag
between when the selected text becomes gray-selected to when it becomes
blue-selected.
5.  Now move the mouse in and out of the window a few times, then click on a
link.  Watch firefox catch up, over several seconds, until it finally gets
around to following the link.
6.  In general, just use a remote firefox over X11, and feel the pain....
Actual Results:  
It took a very long time for all the repainting to occur.  When using VNC with a
firefox within its display, one can actually see the little blips on the screen
as the window is being redrawn.  Using this, it appears that the entire window
is repainted more than once, to boot.

Expected Results:  
On a mouse-enter kind of event, no repainting should be necessary.

I do not know of any better X protocol tracer than xmsgtrace
(xmsgtrace.sourceforge.net), but there may be some.  I can attach a trace if it
would be more useful than y'all generating your own on your own machines under
controlled circumstances.

Comment 1

[zug_treno]

Related to Core bug 83395?

Comment 2

[Tyler Downer [He/Him]]

This is a mass search for bugs that are in the Firefox General component, are UNCO, and have not been changed for 1000 days and have an unspecified version. 

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

Comment 3

[Tyler Downer [He/Him]]

No reply from reporter, INCOMPLETE. Please retest with Firefox 3.6.12 or later and a new profile (http://support.mozilla.com/kb/Managing+profiles). If you continue to see this issue with the newest firefox and a new profile, then please comment on this bug.