Possible IPC memory leak - how to pinpoint the culprit?
Hey there, I'm having trouble with Firefox. Something inside Firefox is eating up my RAM and CPU. Usually I recognize the problem happening because my laptop fans ramp up. The problem occurs on my laptop as well on my desktop (both on latest stable Firefox[Build ID: 20220513165813] and Windows 11). The workaround is to kill the Firefox subprocess which is using most of the CPU and RAM. Then everything is back to normal for some time, until Firefox starts messing with me again.
While trying to pinpoint the problem I'm stuck. I can't find a culprit other than the fact it has something to do with Firefox. Clean reinstalling did not help. The Firefox Task Manager doesn't know anything about huge amounts of RAM being taken. I searched for solutions on the net and the about:memory indicates the problem is some IPC related stuff:
{ "process": "Main Process (pid 12648)", "path": "queued-ipc-messages/content-parent(Browser, pid=9612, open channel, 0x22e4b33fc30, refcnt=38)", "kind": 2, "units": 1, "amount": 0, "description": "The number of unset IPC messages held in this ContentParent's channel. A large value here might indicate that we're leaking messages. Similarly, a ContentParent object for a process that's no longer running could indicate that we're leaking ContentParents." }
The bug reporting guidelines(https://bugzilla.mozilla.org/page.cgi?id=bug-writing.html) are encouraging me to attach steps to reproduce and try the steps listed on https://support.mozilla.org/en-US/kb/firefox-uses-too-much-memory-or-cpu-resources . But I've exhausted the steps there (Except for upgrading the PC / RAM).
Especially on the go this Firefox-RAM-Party takes quite some battery and right now while writing this Firefox has >100GB virtual RAM reserved for some IPC messages, I personally think this is too much. So I'd like to file a report, but without steps to reproduce I'm afraid the developers are going to say 'well, that's something we are not able to diagnose', because I am unable to explain how to reproduce it. It just happens from time to time.
The anonymized about:memory report: https://bin.disroot.org/?2ba01ef78154cce4#8PLVqLTd9qgaRn2QVX2P17hkbHQyrTDuVAwoykj2cBxg
I left Firefox running like this for about half an hour and at 138GB reserved RAM Windows slaughtered my Firefox. The resulting crash report: https://bin.disroot.org/?0bc57492585dde4b#5YtbWgXcbZSkWYmg2CGkVn9iiipYwfYbxUfCLhmMJh7d
Do you have a clue where I might find out who sends those IPC messages, and therefore who is responsible for this?
All Replies (7)
Well, something shredded the pictures I uploaded. You may find another copy here: https://postimg.cc/gallery/tJDSP3y
Dropa said
reinstall to rebuild the profile again
Thank you for the reply. I have removed everything once already. I am going to do this again and make sure absolutely nothing from the old install remains on the PC. In case this does not help I'll report back..
I really don't want to miss the addons, that's the reason I want to pinpoint the issue to maybe one faulty extension. But removing every extension is not really an option for me, as it would heavily impact my workflow. The AV solution is plain Windows Defender, nothing special there.
The problem has happened once again. This time I disabled one addon after another to find the bad fish in the bowl, but Firefox kept reserving more and more RAM, even with all addons disabled. I then went ahead and used Process Explorer from Sysinternals to get a dump. I might share the minidump, the full dump is 42.2GB. Are there any other steps you recommend or should I go straight ahead to filing a report and, in case the team has no fix, refrain from using Firefox in the future?
Modified
Did another full wipe of my entire profile folder before and copied nothing from the old profile to the new one, just fyi.
Dropa said
So where are you downloading firefox from?
The Mozilla webpage at: https://www.mozilla.org/de/firefox/new/
Start Firefox in Troubleshoot Mode to check if one of the extensions ("3-bar" menu button or Tools -> Add-ons -> Extensions) or if hardware acceleration or userChrome.css is causing the problem.
- switch to the DEFAULT theme: "3-bar" menu button or Tools -> Add-ons -> Themes
- do NOT click the "Refresh Firefox" button on the Troubleshoot Mode start window