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Is it possible to find what exactly is causing Firefox to randomly CPU-spike at 13%, freezing it entirely? And by "exactly", I mean finding what functions/calls/modules/threads/drivers are the direct culprits to the issue (or as closely connected to the issue as possible), rather than pure trial and error of disabling/closing things, to try and estimate what's conflicting with what.

I've spent the last few hours reading about Windows debugging/stack tracing/xperf'ing, trying to hone my skills for some better foundational know-how. As I've been reading, Firefox has been acting up, where it will spike to 13% CPU utilization in Task Manager for 30+ seconds, freezing the entire application. This continues to repeat, cycling at seemingly random intervals.

At some point, the CPU-"scream" will stop, and Firefox will come back to consciousness with an "Unresponsive Script: Stop??" dialog. This dialog references random, seemingly unconnected scripts that are being unresponsive. I can see that at least one of them is an extension I have (Treestyle tabs).

I realize that one could narrow down the "offender" by selectively disabling addons, closing tabs, disabling plugins, killing Flash, etc. And in this case, I'm wagering that there are addons that are clashing. But I'm more interested in learning the method to diagnosing such -- wondering if it's possible for a more "direct" method, such as checking stack traces somewhere, investigating threads, hooked/interfaced modules, driver clashes, etc. ?

I have tools like Process Monitor, Process Explorer, and Process Hacker, but I'm not versed enough to know where exactly to go within them to find the specifics needed as to who the actual culprit is, and how it's "choking" choking firefox (or at least, something as closely connected to the culprit as possible).

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When you observe that behavior, take a look at how much memory is being used. Very likely, it's enormous. In my experience, Firefox leaks memory (perhaps in the plugins) and then begins thrashing. – Nicole Hamilton Dec 15 '12 at 17:19
Anecdotally I have had similar problems to you and I firmly blame Adobe Flash. Since disabling Flash selectively using an add on such as Flashblock all the pointless animated Flash adverts no longer cause Firefox to hang. – Mokubai Dec 15 '12 at 17:42
Try using the Gecko Profiler. – Wk_of_Angmar Dec 15 '12 at 19:58

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