Probable 'deadly embrace' memory allocation issue between Firefox and Microsoft Update
I had my usual "several" (probably 3 to 5) Firefox windows/tabs open ... and Microsoft decided to send an update to my Windows 7 box.
I observed Firefox memory use rise rapidly to nearly 800MB ... while netsvcs.exe did approximately the same thing. (This machine has 2GB of RAM.)
Fortunately I had Windows Performance Monitor running, and was able to determine that Windows Update was the competing activity ... and after-the-fact, determined that it had been installing an update to MS Security Essentials (basically a malware signature update - and I have the ID of the specific update, but since it is a security update, I'm hesitant to post that detail in a quasi-public forum). Usually, such updates install quickly and transparently. I also cannot tell, with confidence, whether the memory consumption was from the process of installing the signature - or the process of scanning for malware presence after the sig was installed (although I'd *guess* the latter). I believe both of those aspects execute within netsvcs.exe.
This happened over a period of approximately an hour, during which about all I could do was "sniff around" to identify the culprits; eventually I killed the Firefox process (hoping that its History feature would allow me to return to my open tabs... which was not quite true).
I have reported the event to Microsoft as well, as it could equally be their problem.
Suggestion: Add instrumentation to Firefox to capture data on sudden increases in RAM use - paying particular attention to outside-the-norm values, in relatively short time periods (minutes, not hours) that do not self-resolve ... and consider whether Firefox can be more aggressive at releasing memory it has "claimed," when things go bad.
(Perhaps collect high-level "physical memory available" data when things begin to "go bad," and capture the "footprint" of Firefox memory use... And perhaps add intelligence to log memory allocation failures somewhere. I don't know with certainty if the issue was fragmentation, or the sheer amount requested, but experience and grey-hair lead me to suspect the former. The only Firefox window/tab that I know might have been a high-memory-consumer was a moderate-sized Google Map covering an urban area of several dozen square miles, so it was a complex image.)
Not suggesting this is Firefox's "fault" -- clearly, both processes were "to blame" in the sense that they didn't handle the situation well... but Firefox might handle it better.
I've seen (and reported) quite a series of memory-utilization issues since 28.0 ... perhaps it's time for a "tiger team" to look into these.
AH - one other detail: I keep Firefox pinned to the Windows task bar, and when it starts, it asks me which profile I want to use (of about 5 choices). When restarting Firefox after identifying all the above... I found that it no longer asked me to choose a profile, and the profile it opened was clearly NOT my most-common profile, which includes (e.g.) all my most-common, site-specific login information. I had to mess around for several minutes to get this profile "back" up and running, and I did not make note of what I tried during that effort.
Additional System Details
- User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:33.0) Gecko/20100101 Firefox/33.0
(Not bothering with this, because it was a different, long-deceased Firefox instance that exhibited the problem.)
I've called the big guys to help you. Good luck.
As to Security Essentials, Open the computers Control Panel. Go to Uninstall Programs. Right click on Essentials and select Repair.
There is no 'Repair' option on Microsoft Security Essentials (MSE).
Windows Update is one of the delivery vehicles for daily MSE malware signature updates. In practice, with Windows 7, this means that the entire Windows 7 SP1 update catalog (currently multiple 100s of MB) will be downloaded every day... even if the only thing that's changed is the relatively-small MSE signature update (typically less than 1MB of the total).
Firefox (or presumably any browser) is mostly a victim of this design, competing for network bandwidth with a massive daily download (which unfortunately is not easily re-scheduled by the customer for a "convenient" time).
Not totally clear to me why Firefox memory use was skyrocketing, unless it was just backlog of browser traffic that got stuck in the pipe.
The solution is for Microsoft to release an SP2 for Win7 - at which point the daily update would be much smaller. Does the Mozilla community have any contacts who can nudge MS in this direction?
Try Microsoft Essentials