firefox using over 90% of CPU

[Lars Noodén]

Binary package hint: firefox

firefox (2.0.0.1+0dfsg-0u) quickly hogs most of the CPU:

from 'top' :
 PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 6635 user 25 0 198m 74m 29m R 94.5 14.8 38:22.84 firefox-bin

System information:

DISTRIB_ID=Ubuntu
DISTRIB_RELEASE=6.10
DISTRIB_CODENAME=edgy
DISTRIB_DESCRIPTION="Ubuntu 6.10"
Linux host 2.6.17-10-powerpc #2 Fri Oct 13 16:37:41 UTC 2006 ppc GNU/Linux

[Albin Tonnerre (lutin)]

Hello,
could you provide us some piece of information on what actions specifically cause this high cpu usage ?

Thanks for your report:)

ps: bug #38131 is also about high cpu usage, could you have a look at it to check if it's the same ?

[Lars Noodén (larsnooden)]

This is not quite the same as 38131. FF is not slow.

It just burns most of the CPU. I have one window open with tabs. I have extensions noscript and forecastfox. If I have a second window open, even if it's on another virtual desktop the CPU usage is up around 95%

[Chris Burgan (cburgan)]

Could you post a little more info? I am unclear whether you mean to say that this only happens when you open a second window or all the time.

bug 78695 seems to have a similar problem that was eventually attributed to using the forcastfox plugin. Could it possibly be related?

[Lars Noodén (larsnooden)]

Ah. Maybe it could be the forecastfox. I have that and NoScript.

The high load happens pretty much every time. I've disabled it and see what happens today.

I usually have one main window and then a window for downloads. I usually have a few tabs open, between 5 and 15 most of the time, though it can drop to 2 or 3 and briefly peak at 40 or so. As far a I can tell, CPU usage isn't affected by the number of tabs so much as how long FF has been running. After a certain time, it goes from less than 1% of the CPU usage to 90% - 94%

[Lars Noodén (larsnooden)]

ForecastFox is disabled and FF is restarted.

I have one window and four tabs and FF is running round 27% - 29% of the CPU:

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 4521 lars 15 0 204m 83m 30m S 29.5 16.5 7:41.09 firefox-bin
 4161 lars 15 0 63356 26m 20m S 1.7 5.4 1:12.00 ktorrent

[Freddy Martinez (freddymartinez9)]

Try running a new profile. Instuctions can be found https://wiki.ubuntu.com/MozillaTeam/Bugs Recently, users have been complaining about Forecast Fox being a memory hog.

[Chris Burgan (cburgan)]

I am going to reject this as a bug for now as forcastfox is not supported and that seems to be the problem. If you feel that it is something else then feel free to reopen it.

[Lars Noodén (larsnooden)]

I've gotten the same problem without forecastfox being active, so I don't think that's the cause. However, someone with proper access privileges will have to re-open the problem

[Chris Burgan (cburgan)]

Marking it back to unconfirmed if the problem still exists.

[Lars Noodén (larsnooden)]

Here's a cut-n-paste from top:

PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
11024 lars 25 0 219m 99m 29m R 92.0 19.8 47:08.67 firefox-bin

FF is using about 90% of the CPU. I have two windows open and 18 tabs in one and 9 tabs in the other. I completely uninstalled Forecastfox the other day. NoScript is still there.

[John Vivirito (gnomefreak)]

Can you please try running firefox from terminal by typing "firefox --safe-mode" without the " and see if it still uses that much cpu% or if it goes to normal usage. either way can you give us the top readings again with it running in safe-mode.

[Philipp Kohlbecher (xt28)]

I am having the same problem with firefox (1.5.dfsg+1.5.0.11-0ubuntu0.6.06.1) on dapper.
Output of strace is attached. Let me know what other information I can provide.

[Lars Noodén (larsnooden)]

The problem still exists in Kubuntu 7.04 with FF 2.0.0.3

I'm still no closer to figuring out what sets it off.

[Lars Noodén (larsnooden)]

In safe mode seems to be gnash that uses a lot of CPU:

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
10223 lars 15 0 103m 24m 17m R 47.7 4.8 6:31.59 gnash
 5224 lars 15 0 81404 23m 17m R 8.0 4.6 32:32.82 ktorrent
 4575 root 15 0 160m 57m 7576 S 4.6 11.4 25:02.47 Xorg
 5215 lars 15 0 43508 15m 12m S 2.3 3.0 0:59.96 konsole
 5220 lars 15 0 32928 10m 9.8m S 1.0 2.0 1:38.45 kodo

[Alexander Sack (asac)]

we need a step by step instruction on how to reproduce.

[Philipp Kohlbecher (xt28)]

I don't know about the others, but for me this is a little hard to provide, as this problem only happens occasionally. One website that often seems to trigger high CPU usage is www.sueddeutsche.de, a German news site. Opening several tabs often takes up 25%–30% of the clock cycles and some pages on that site take the usage up to about 90%. As soon as that happens again, I will post a URL (hoping that it‘s not a randomly selected ad that causes the problem).

[Giuliastro (gyesspam)]

Same problem here, as reported in bug #66350. It does not depend on extensions, it happens on a fresh install on Gutsy.

[Lars Noodén (larsnooden)]

Firefox in Hardy Heron A2 will often hit 100% of CPU utilization. This often happens when opening a new window (downloads or linking to external app like kpdf)

Linux macbook 2.6.24-3-generic #1 SMP Thu Jan 3 23:30:29 UTC 2008 i686 GNU/Linux

top - 21:38:09 up 26 min, 1 user, load average: 0.71, 0.37, 0.31
Tasks: 126 total, 4 running, 122 sleeping, 0 stopped, 0 zombie
Cpu(s): 52.5%us, 0.5%sy, 0.0%ni, 47.0%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st
Mem: 2058484k total, 712948k used, 1345536k free, 18648k buffers
Swap: 3906240k total, 0k used, 3906240k free, 406888k cached

  PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND
 6269 lars 20 0 176m 86m 21m R 100 4.3 1:55.86 firefox-bin
 5268 root 20 0 294m 16m 5428 R 4 0.8 1:43.88 Xorg

[Alexander Sack (asac)]

firefox 2 wont see any fixes with regards to performance anymore.

[Philipp Kohlbecher (xt28)]

Is that just regarding hardy, or firefox in general?

[John Vivirito (gnomefreak)]

Philipp Kohlbecher wrote:
> Is that just regarding hardy, or firefox in general?
>
Firefox-2 for any version. Mozilla has decided since we are fairly close
to EOLS for f\Firefox-2 so only fixes will be security and extreme bugs
if this is a problem in Firefox-3.0 it will be fixed in 3.0 but not 2.0.

--
Sincerely Yours,
     John Vivirito

https://launchpad.net/~gnomefreak
https://wiki.ubuntu.com/JohnVivirito
Linux User# 414246