475962 - Firefox & Thunderbird cause Xorg to eat CPU cycles drawing window when Internet is slow

Status: RESOLVED WORKSFORME

(Core :: Graphics, defect)

Description

[Michael Doube]

User-Agent:       Mozilla/5.0 (X11; U; Linux x86_64; en-GB; rv:1.9.0.5) Gecko/2008121622 Ubuntu/8.04 (hardy) Firefox/3.0.5
Build Identifier: Mozilla/5.0 (X11; U; Linux x86_64; en-GB; rv:1.9.0.5) Gecko/2008121622 Ubuntu/8.04 (hardy) Firefox/3.0.5

When performing an upload or download, Xorg starts eating 50% or more of my dual core CPU's cycles.  This happens only with Firefox and Thunderbird; no other Internet app causes the same problem.  The Firefox plugin Zotero also causes this problem when synching with the citation server.  Xorg stops eating cycles as soon as Firefox or Thunderbird have finished their file transfer.
This is on 64-bit Ubuntu Hardy with Compiz enabled.

Reproducible: Always

Steps to Reproduce:
1.  Get on a slightly flaky / slow connection
2.  Transfer something of a few hundred kB or more


Actual Results:  
3.  Watch Xorg go mental by running top from the command line
4.  Watch the transfer with iftop and see how as soon as the transfer finishes, Xorg's CPU usage goes back to normal.

Expected Results:  
3.  Xorg uses ~10% of CPU

This bug is being tracked in Launchpad:
https://bugs.launchpad.net/bugs/297143

Comment 1

[Michael Doube]

Xorg's CPU load is only high if some part of the Thunderbird / Firefox window is being drawn; if you run top in a terminal window 'always on top', then minimise and maximise Thunderbird while a big email is downloading you can see Xorg's CPU load going from high (50-70%) to low/normal (10-15%).  You can also observe this behaviour by maximising another window in front of Thunderbird.

Comment 2

[Lars Westergren]

I have it also on
Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.0.10) Gecko/2009042523 Ubuntu/9.04 (jaunty) Firefox/3.0.10

I have a fast connection, but showing Gmail inbox takes a minute for me. There is a 1-2 second pause for rendering every "star" next to a mail, and Xorg CPU load goes up to 85%.

I use a Dell XPC with GeForce 8600M GT if that helps. I can attach lspci -vvnn if you need it.

Comment 3

[mrthefter]

I'm fairly sure that the compositor changes will improve this situation.
However, I don't know if it is the root cause.
Here's the bug: https://bugzilla.mozilla.org/show_bug.cgi?id=374980

Comment 4

[Michael Doube]

Things seem to be improved in Ubuntu Karmic alpha 4, which ships Firefox 3.5.2.

Comment 5

[Robby Pedrica]

I have the same issue with Slackware 13 ( kde 4.2.4 ), Firefox 3.5.2 and Thunderbird 3b4pre ( or and Thunderbird 3 ). If I have either of the two or both running, X will run with high CPU after a few hours from startup ( ie. not immediately ). This in turn slows down any plasma functions in KDE/Plasma. If I close both of FFox and TBird, then X drops to 1-5% after about a minute, which is normal. KDE plasma functions remain slow.

setup:

Slackware 13rc2 32-bit
NVidia 185.14.x
KDE 4.2.4
GSB ( Gnome Slackbuid ) 2.26.3

Comment 6

[Sebastian Krämer]

I'm still seeing it with recent versions of both programs. It's especially noticable with sending emails with large attachments over a slow connection in TB.

Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.2.13) Gecko/20101209 Fedora/3.1.7-0.35.b3pre.fc14 Thunderbird/3.1.7

and Firefox 4.0b11 on the same platform

Comment 7

[Henrik Skupin [:whimboo][⌚️UTC+1]]

Interesting that this bug is still marked as unconfirmed. I can clearly see it myself on my laptop running Ubuntu 14.04. It's not that clear to me yet when it directly starts but it might have something to do with hibernation. When it occurs the CPU load of Xorg and compiz is raising up to 60% and stays at this level until the application gets closed. In my case it is mostly Thunderbird.

I have updated to Ubuntu 14.10 now, and will closely watch this problem over the next couple of days to maybe find a pattern to reproduce.

Comment 8

[Javi Rueda :javirid]

I have been CC'd here. Now I am just wondering why :/ :\

Comment 9

[Wayne Mery (:wsmwk)]

(In reply to Javi Rueda from comment #8)
> I have been CC'd here. Now I am just wondering why :/ :\

I guess ... does this happen with normal speed network?  I.E. does this really only happen with a slow network?

Comment 10

[Wayne Mery (:wsmwk)]

Do you see it with current version 50?


(In reply to mrthefter from comment #3)
> I'm fairly sure that the compositor changes will improve this situation ... bug 374980

This is clearly unlikely to happen.

Comment 11

[Henrik Skupin [:whimboo][⌚️UTC+1]]

I don't use Linux anymore so I cannot respond to the question.

Comment 12

[Adam]

I don't see this issue on FF 51, Linux Mint 18 KDE edition.

Comment 13

[Javi Rueda :javirid]

No longer a Linux user. At least one that could be helpful here, as my one Linux machine is too much old and basic.

Comment 14

[Wayne Mery (:wsmwk)]

WFM per comment 12