Frequent CPU Spikes to 100%




10 years ago
7 years ago


(Reporter: DC Hart, Unassigned)



3.0 Branch

Firefox Tracking Flags

(Not tracked)


(Whiteboard: [closeme 2011-02-11][dupeme])


(3 attachments)



10 years ago
User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008070912 Fedora/3.0-1.fc8 Firefox/3.0
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9) Gecko/2008070912 Fedora/3.0-1.fc8 Firefox/3.0

3.0 is becoming almost unusable. I also notice considerable CPU consumption when just opened (before a page load). I disabled the memory cache. No joy. I disabled all the language packs and uninstalled forecastfox without improvement.

It can take several minutes to unfreeze. There is no association with the number of tabs open.  

Reproducible: Sometimes

Steps to Reproduce:
Unable to establish a reproduction event chain.

Comment 1

10 years ago
I have the same problem on Windows XP Tablet PC Edition 2005 with Service Pack 2. Firefox 3 (3.0 to 3.0.3) - seemingly at random - starts maxing out one CPU and eating memory. When a certain threshold is reached, memory drops back to the level before the CPU hogging started. This repeats for a few minutes. Eventually memory usage plateaus at the threshold for a bit, then drops again, and Firefox becomes responsive again. While hogging the CPU, it doesn't process any Windows messages either ("program is unresponsive", can't minimize the window, no redraw).

Comment 2

10 years ago
Created attachment 341356 [details]
procexp performance graph of firefox' cpu/mem hogging. the sawtooth wave repeats for a few minutes.

Comment 3

8 years ago
this happens in windows version too. I closed Kaspersky Internet Security, closed my other apps, and firefox somewhat regularly and frequently (every 5-20 seconds) spikes cpu for short spike (up to 100%) from a fraction of a second to up to 5 seconds.


8 years ago
Blocks: 523724

Comment 4

8 years ago
I notice the same behavior, but only after exiting Firefox. As soon as I exit FF, the process remains and then the processor spikes to 100% on one core.

Comment 5

8 years ago
Created attachment 473453 [details]
Firefox .. frequently.

My Firefox 3.6.9 on 32-bit Windows 7 becomes unusable when *click* when i scroll this *refocus* or any page. Maybe setting a skin caused the 25.08 % CPU spikes on this 2.93 GHz quadcore Xeon. Is Firefox waiting for Windows to swap? Why do i lose focus?

Comment 6

8 years ago
Created attachment 473461 [details]
Same session after restart (i'm using BarTab)

Showcase tells me i only have 163 tabs open in 8 windows.

Comment 7

8 years ago
is this reproducible with version 3.6 started in safe mode?

probable dupe to a gc bug (I see this also on windows)
Keywords: perf
Whiteboard: dupme

Comment 8

8 years ago
if you are using kaspersky antivirus, this may be the cause of your cpu spike problems.  I had the same problem, and I can tell you that it was the problem.  it would grab the cpu for 5 minutes and let go of it for about 1/2 second.  that was version 9, which was the stable version.  when I was using it at the time, 10 had just come out and it was pretty much alphaware being released as a final release. subsequent versions of 10 were not much better, so I stayed away from it.  later I dropped kaspersky for mcafee.

Comment 9

8 years ago
I do NOT use Kaspersky, and do have the CPU spikes. If you're technical in nature and understand security, I highly recommend Comodo. It's free, and _by_far_ better than any other free solution for the prevention of infections. In fact, it's more powerful and lighter on system resources than most paid solutions, which means it's great for older PCs!

Comment 10

7 years ago
DC Hart, do you still see this problem?

(In reply to comment #7)
> is this reproducible with version 3.6 started in safe mode?
> probable dupe to a gc bug (I see this also on windows)
Whiteboard: dupme → [closeme 2011-02-11][dupeme]
Version: unspecified → 3.0 Branch
This bug has been marked as CLOSEME for several weeks and the date on the tag is far past. If the reporter is still able to reproduce, Please retest with Firefox 3.6.15 or later and a new profile ( Then remove the CLOSEME tag, mark the proper version and comment on this bug.
Last Resolved: 7 years ago
Resolution: --- → INCOMPLETE
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