Firefox.exe 15/16 - CPU-Core maxed out 100% after a while

[Gott]

I've got the feeling that Firefox 15+ plugged the add-on memory leaks ... by converting them into a massive CPU leak.
Sadly, using a lot of RAM doesn't increase noise and electric consumption, constantly maxing out one core of my i5-2400 does.

Firefox 15+ (I'm usually on the Aurora branch) does manage to keep its memory consumption around 500-700mb ... but with 8GB of RAM that doesn't really matter much to me.

However, firefox.exe uses 10% of one core upon launch and slowly creeps up during usage, after a while and heavily depending on usage it ends up at 100% CPU for that core and stays there until the browser is restarted.

I was not able to reproduce this issue in safe mode, either it is only related to add-ons or occurs a lot slower. But even trying to painstakingly disable most add-ons and plugins and then trying to find the potential culprit was futile, I was unable to find one specific add-on that could be causing this - it looks like a change in Firefox 15 caused this behavior and I would guess it has to do with this: http://blog.mozilla.org/nnethercote/201 ... -on-leaks/

Sadly I do rely on a couple of add-ons with known memory leaks. Up until now that meant restarting the browser every day or two, not a big deal, I have enough RAM to compensate easily ... the massive increase of CPU time consumed by my browser however is a serious problem.

Firefox 16.0a2
Mozilla/5.0 (Windows NT 6.1; WOW64; rv:16.0) Gecko/16.0 Firefox/16.0

My current add-ons:

Adblock Plus
2.1.1

Autofill Forms
0.9.8.3

Deutsches Wörterbuch
2.0.2

Dictionary Switcher
1.3.2

Element Hiding Helper für Adblock Plus
1.2.3

Firebug
1.10.0

Flash Video Downloader Youtube Downloader
3.6.6

Fox To Phone
1.2.2

Greasemonkey
1.0beta5

Image Zoom
0.4.6

OpenDownload²
3.2.1

Organize Search Engines
1.7

Pocket
3.0.0

ProxTube
1.4.2

Reddit Enhancement Suite
4.1.2

Search By Image (by Google)
1.0.6

Show my Password
2.0

StumbleUpon
4.13

United States English Spellchecker
6.0

Update Scanner
3.1.8

Web Developer
1.1.9

WebMail Notifier
2.9.8

P.S.: Just during the course of creating this post my CPU consumption crept up from 10% to 20% of the core.

Any help would be appreciated.

[Dingler]

I was not able to reproduce this issue in safe mode, either it is only related to add-ons or occurs a lot slower. But even trying to painstakingly disable most add-ons and plugins and then trying to find the potential culprit was futile, I was unable to find one specific add-on that could be causing this -

It's not the add-ons, the culprit is the hardware acceleration.
Disable HWA in advanced options, restart FF and make a try.

[Gott]

I was not able to reproduce this issue in safe mode, either it is only related to add-ons or occurs a lot slower. But even trying to painstakingly disable most add-ons and plugins and then trying to find the potential culprit was futile, I was unable to find one specific add-on that could be causing this -

It's not the add-ons, the culprit is the hardware acceleration.
Disable HWA in advanced options, restart FF and make a try.

I'll give it a shot, any reason why this is only happening in Firefox 15+ and everything up to 14 was fine? I didn't read about any recent changes to HWA in Firefox 15/16.

[Omega X]

Do you disable Firebug when you're not using it?

[kilara1988]

Am i wrong or HWA is supposed to offload some of the calculations to the GPU and thus reducing CPU usage?How is disabling HWA going to reduce CPU?I think it will increase it.

PS:Btw i have no such issue wit latest nightly and im pretty sure its and addon issue.

[_Alexander]

Am i wrong or HWA is supposed to offload some of the calculations to the GPU and thus reducing CPU usage?How is disabling HWA going to reduce CPU?I think it will increase it.

PS:Btw i have no such issue wit latest nightly and im pretty sure its and addon issue.

How is disabling poorly coded unoptimized slow-progressing GPU acceleration code going to to help performance?

[Omega X]

The same way it gets Hera to post his traditional ridiculous flamefest.

[Gott]

Disabling HWA doesn't help, it's back maxing out my core.

Firebug is generally disabled (as in the bug is grey and not used, not as in the add on is entirely disabled). Disabling the add-on entirely doesn't fix the problem either, it looks like the problem is caused by more than one add-on, if those are the - admittedly likely - culprit. I still think that this may be a problem triggered by the new add-on memory management which would explain why this started happening with 15+.

[Omega X]

Disable them all and turn them on one by one to see which one is the culprit.

[megamanx]

Same thing happened on my laptop AMD Dual core.

I thought it was the computer, but it turned out to happen on my desktop i3 Dualcore

It was Adblock+ that was spking up the memory, so I went with the Developer add-on of Ablock Plus and happy camper.

This might not help you, though, but a tip is worth anything at this point.

[Gott]

Disable them all and turn them on one by one to see which one is the culprit.

That is much easier said than done considering that it takes up to several hours for the CPU load to creep all the way up to 100%. What experimentation I have done so far with disabling add-ons seems to suggest that it isn't a single add-on causing it, but a change in Firefox that causes more than one of them to misbehave like this.

It was Adblock+ that was spking up the memory, so I went with the Developer add-on of Ablock Plus and happy camper.

Thank you so much, I will certainly take your advice and try this.

Adblock Plus is one of the memory leak culprits listed in this article:
http://blog.mozilla.org/nnethercote/201 ... -on-leaks/

I'm using others listed in there, where it becomes much harderto find a solution. ImageZoom for example has become somewhat indispensable for me, but it looks like the original developer simply stopped supporting it (he acknowledged the memory leak but never did anything about it, the add-on has since been downgraded to "preliminary approval" because of it: https://bugzilla.mozilla.org/show_bug.cgi?id=691102

I'm guessing that the code responsible for plugging the memory leaks in Firefox 15+ is responsible for the now observed CPU leak - which, at least for me, is a much more problematic leak to deal with.

Does anyone know of an alternative to ImageZoom for example?

[Gott]

Upgrading to Adblock Plus Dev builds sadly didn't fix it.

There is one more curious observation:

Whenever a dialog box is open, CPU load drops to zero. Like when trying to close the browser: "There are 5 Tabs open, are you sure you want to proceed?" = 0% CPU, closing this box (and not the browser) and the CPU load goes back to max.

[greenknight]

Sometimes problems can be caused by extensions conflicting with each other, rather than any single extension. Can make diagnosis tricky.

Anyway, a more efficient method than enabling one at a time is to do half of them at once. Eliminate half as suspects, then test half of those remaining; repeat until you zero in on the culprit. Much faster.

[shadowsteve]

Just had this high cpu usage problem, and the guilty was Search By Image (by Google) 1.0.6. And i see op use it too.
I think some recent changes broke this add-on.

[Gott]

Just had this high cpu usage problem, and the guilty was Search By Image (by Google) 1.0.6. And i see op use it too.
I think some recent changes broke this add-on.

Thanks, would have never guessed that one as a potential culprit, it's such a simple add-on. Disabled it now, let's see what happens.

@greenknight

I fully agree with you and that may be possible, however: these extensions worked perfectly fine together in all Firefox builds up to 14.x - in fact, they still do, downgrading fixes the problem. So it must have been a recent change in Firefox that triggered this issue.