288472 - High CPU load after a few hours

Status: RESOLVED DUPLICATE of bug 273310

(Firefox :: General, defect)

Description

[Martin Otten]

User-Agent:       Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.6) Gecko/20050326 Firefox/1.0.2 (PowerBook)
Build Identifier: Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.7.6) Gecko/20050326 Firefox/1.0.2 (PowerBook)

After a few hours sometimes firefox uses up to 80% of the CPU-power (even if
firfox should have nothing to do). As I do not restart my powerbook for weeks I
know that it seems to happen every time running firefox and using it for a few
hours.
Closing windows and tabs does not help

Reproducible: Always

Steps to Reproduce:
1. Start Firefox on MacOSX 10.3.8
2. Open some windows and tabs
3. wait some hours (maybe more than 24)
4. open the terminal
5. execute "top"
Actual Results:  
top shows me up to 70% of cpu load

Expected Results:  
cpu useage near 0%

Comment 1

[L. H.]

Please attach output of sample when Firefox is using cpu

Comment 2

[Martin Otten]

Attachment: This shows the firefox-cpu load. currently it is between 30 and 50 %

Before I mage this screenshot I ran some java-applets. The tabs containing this
applets are closed now. currently firefox has nothing else to do than
displaying 12 pages opened in tabs in one window. The pages only contain
animated gifs. But currently none of them are visible while I am writing this
comment.

Comment 3

[Bart van Bragt]

Related to or duplicate of bug 254884 ?

Comment 4

[Yosh Mantinband]

I am using FireFox on a Win XP Pro machine & getting similar results. I tend to
keep many tabs open in many windows. I also tend to shut down with "hibernate"
to save my state, including where I've been browsing. At first, CPU usage seems
normal, but after a day or two, FireFox is pegging 97-99% of CPU.

I shut down tabs one at a time trying to find a "guilty page", but it doesn't
seem to matter what the content is: static html or anything else. After each
closure there's a slight reduction for a a second or two to 70-80%, then it
springs right back up to 99. Finally I get it down to a single tab with static
content and the Task Manager still shows FireFox consuming 98-99% CPU.

This impacts my usage primarily when starting new processes. When they start
taking forever to start up, I check & see FireFox is busy doing nothing with 99%
of the CPU. Interestingly, other interactive stuff usually seems to be
unaffected (perhaps because other interactive stuff is so lightweight it can get
by with the remaining CPU power?).

Comment 5

[Jim Tuttle]

I've been using Firefox since "back in the day".  Ever since 0.9 or so, I'm been
seeing CPU hogging (in Windows 2000).  At first, Firefox just used to be slow to
open a window that had been minimized - almost like Firefox had gone to sleep
and was having trouble "waking" up.

Now, I get this a LOT, even while typing this.  Firefox uses almost 100% of the
CPU and appears to just lock up.  It usually recovers in 10-30 seconds, but I
find myself opnening up IE (gasp!) while it's hung just so I can keep working.

If you search for "CPU" in the open bugs list
(https://bugzilla.mozilla.org/buglist.cgi?query_format=specific&order=relevance+desc&bug_status=__open__&product=Firefox&content=cpu)
you will see a LOT of bugs that appear similar in nature.

Sounds like something being seen by enough users under enough different
situations to warrant a serious investigation!

Comment 6

[Martin Otten]

Attachment: This shows the hight cpu usage of camino after several hours running. The only page I was browsing is www.deviantart.com. 3 Windows with only a few tabs opened where in use

I checked if camino has got the same bug, and well it has. Take a look at the
attatchment.

Comment 7

[M S]

* Firefox 1.0.4 on XP pro SP1, ie. not Mac only, 
also earlier versions and Mozilla

After several hours of use with many tabs, Firefox starts to consume 
all available CPU time. At the same time, Windows Task manager shows 
"I/O Other" to increase by some 100000 requests per second and 
"I/O Other Bytes" by some 1 MB per second. (see talkback TB6717605X,
Firefox actually crashed then but it is rare)

Prior to the steady 100% load there may be brief periods of 100 % load 
when starting a download, sometimes throughout an entire download. 
Sometimes the condition is triggered upon resume from hibernation, and 
then it can almost freeze the entire system for several minutes (any 
operation in windows taking several seconds). 

In one form or another, similar CPU hogging has occurred in most Mozilla and
Firefox versions. Even Mozilla email client alone may start it. 

Comment 8

[Hermann Schaefer]

Firefox is getting slower on every little release since several months. No idea,
if this is due to any changes in OS X, but on my machine, Firefox is almost
unusable now (well, I started with Mosaic on a SE and it was faster..).
Opening pages, clicking links, typing here on bugzilla - everything is very
slooow. I have so many beachballs here - I could open a shop :/
I tried to alter the setting in many ways, removed/added fonts, tried everything
I could but no luck. Safari is about 500% faster or even more, esp. after some
hours. I rarely restart my machine, but only Firefox shows this behaviour. After
these few lines of text, Firefox draws 1 char/s and I have to wait several
seconds just to see what I wrote. This happens on all websites. Typing here
highers the cpu-time up to 84% (1GHz G4, 1,5GB RAM) with only one window open
containing 6 tabs from bugzilla. Copy from top:
  PID COMMAND      %CPU   TIME   #TH #PRTS #MREGS RPRVT  RSHRD  RSIZE  VSIZE
23584 firefox-bi  59.5% 13:16:52   3   100  1370   213M  60.9M-  128M   611M 
All version I tried show this slowness, DeerPark is even worse. Sad to say, but
I have to say goodbye to Firefox and start to use Safari :( Even the old IE is
*way* faster for me. I read several comments like mine on several pages, so I am
not alone. *sigh* This is really a critical bug(?), because it renders Firefox
unusable on many machines I know of/use.

Comment 9

[Jon Baumgartner]

Attachment: Output from sample every 100 msec for 5 seconds

I've been seeing this too, on OS X 10.4.2. This sample output was taken right
after I had clicked on a link in bloglines. If Firefox has been started
recently, this link will load very quickly (a few seconds at most) and the CPU
is usually around 12% for firefox-bin. When this sample was taken, it took
almost two minutes for the page to load. CPU load for firefox-bin was between
32% and 60%.

Comment 10

[Marco De Vitis]

I'm using Firefox 1.5 beta 2 on Mac OS 10.4.2, on an iBook G4 (1 GHz, 768 MB RAM).
Although I never noticed any particular high CPU usage (apart from pages with
Flash content, but that's why I have the Flashblock extension installed), I can
tell you that, after long browsing sessions, Firefox surely starts becoming
slower: scrolling, page loading, tab handling... everything becomes slower and
slower as the sessions continues; when opening the preferences window I can even
see the buttons in the window fade in.

Quitting Firefox and launching it again fixes the problem, so it does not seem
to be related to particular web pages, or to the amount of history items.

Also 1.5 beta 1 had the same problem, and I REALLY hope it can be fixed before
the release, as it is a real showstopper for me. I sometimes have to launch
Safari to decently browse a web site when Firefox has slowed down and I have
other open tabs that I do not want to lose (or I sometimes save all of them as a
bookmark folder and quit the browser).

As far as I can tell, versions 1.0.x didn't have this problem.

Comment 11

[Martin Otten]

As Cammino got the same problem I am sure that this is a problem of the gecko-engine. I hope that it will 
be fixed in the new vectorgraphics version. 

Comment 12

[bugzilla]

Mozilla/5.0 (Macintosh; U; PPC Mac OS X Mach-O; en-US; rv:1.9a1) Gecko/20051118 Firefox/1.6a1

I have gotten the same problem running Firefox 1.5 through Deer Park 1.6a1 on Mac OS 10.3.8, 600 Mhz iBook.

1. STATIC PAGES
After 1-2 day's work on the machine (no restarts), Firefox uses 15-60% of CPU cycles, sometimes more -- even if Firefox is hidden, and even if all open pages are plain HTML with no moving images. Closing tabs or windows will not free up the CPU cycles; I must restart the program.

2. ANIMATED PAGES
If Firefox is displaying pages with animated GIFs or other moving images, it can chew up ALL CPU cycles left available by other programs, even if:

  (a) the animated images are in hidden tabs (that is, the top tab on all animated windows is a static page), or
  (b) Firefox is hidden, and shouldn't be processing anything.

In this case, closing the tabs with animated images will free up some CPU cycles, BUT the program will continue to use too many CPU cycles a la #1, depending on how long I left it running.

CPU cycle usage does not increase during time the machine is in Sleep mode.


Reproducible: Always

Steps to Reproduce #1:
1.  Start Firefox/Deer Park on Mac OS 10.3.8
2.  Open at least one window, with several tabs (more windows and more tabs seems to make the problem worse)
3.  Leave Firefox/Deer Park open for some hours -- doesn't matter if you Hide it, stick the windows in the Dock, or leave them visible, and doesn't matter if you use or don't use the program
4.  Check CPU usage using Activity Monitor (I usually do this when I notice a program -- not necessarily Firefox -- responding slowly)
5.  CPU usage will be at 12% even if the program is hidden, more usually 15-60%, and is more (a) the longer the program runs and (b) the more windows and tabs are open while it runs
6.  Closing tabs and windows will not free up the CPU cycles; restart is necessary.

Steps to reproduce #2:
Same as above, but open some windows with animations. The effect is greater with more animation windows open, even if all are hidden. Closing tabs and windows will free up some CPU cycles, but not those consumed by Problem #1.

Expected results: CPU usage in the 1-2% range when the program is inactive and hidden.

A slew of other bug reports seem to point to the same problem:
312048 (Mac)
311242 (Windows)
293689 (Windows)
313751 (Solaris)

Comment 13

[Marco De Vitis]

I think this has been fixed in Firefox 1.5 final, I did not experience this problem anymore, although Firefox still "feels somewhat heavy" on my iBook G4 1GHz, but there's not much that can be done about it at the moment, I'm afraid.

Comment 14

[Jose Cruz]

Several times when opening the bookmarks list and no other programs running, Direfox takes 100% control of the CPU and becomes unresponsive. The only way to close it is by going to the task bar and issuing a close comand.

Comment 15

[Hiro]

The same problem occurs in Camino. 

Mac OS X 10.3.9
Camino trunk NB 2006041619 (v1.2+)

Comment 16

[Hiro]

Attachment: Sample of Camino

When the problem occurred, the sample was taken from the activity monitor.

Comment 17

[Ryuichi KUBUKI]

*** This bug has been marked as a duplicate of 273310 ***