1684721 - Severely diminished performance loading sessions with extremely large numbers of tabs

Status: RESOLVED WORKSFORME

(Firefox :: Tabbed Browser, defect)

Description

[robert.maxton42]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/87.0.4280.88 Safari/537.36

Steps to reproduce:

Open a very large number of tabs (currently I have ~3.6k across five windows)
Close Firefox.
Attempt to reopen Firefox

Actual results:

Firefox loads extremely sluggishly, eating ~40% of my CPU and ~10GB of RAM while not making much progress. Crashes repeatedly. Seems to make some additional progress on each attempt, somehow?

Expected results:

On previous versions (specifically prior to the 84.0 update), this number of tabs did not cause issues loading. Only if a large number (~100) of tabs were actually loaded in the current session, or if large numbers of images were saved in cache, did issues crop up. As I primarily use Firefox over Chrome because it could handle my tab use, this is a major problem for me.

Comment 1

[Daniel Bodea [:danibodea]]

Setting the Tabbed Browser component since it may be related to it. The Tracking statuses are assumed based on the bug's description, but I can't confirm it.

@robert.maxton42: Creating a user profile with so many different tabs is overkill. I will assume that the profile you are using is personal and private. If it isn't, I would like to ask you to hand it over so I can test the issue mentioned myself. Otherwise, I could guide you through testing your bug yourself using the mozregression tool. Will you help us investigate your issue?

Comment 2

[robert.maxton42]

Well, on the one hand, certainly I can help -- the session indeed has private information I'd rather not share, but I can certainly help track down the bug. However, I should note that since making that post, I found something rather suspicious -- namely, that the problem

a) does not occur if I restart Firefox with add-ons disabled
b) furthermore, continues to not occur if I restart Firefox immediately after (a) with add-ons re-enabled

which makes it sound like there's some error regarding loading tabs due to an add-on interaction, and once I get a 'healthy' session into cache, I can just continue as normal. So I'm not sure the bug actually belongs on this tracker after all; I'll need to go bisect through my addons to figure out which of them is causing the issue.

Comment 3

[Dão Gottwald [:dao]]

Please report back once you've identified the add-on.

Comment 4

[robert.maxton42]

Sorry for the delay -- the bug appears only when Firefox has run long enough to be overloaded, so it's not something I can reproduce immediately.

The add-on culprit appears to be "All Tabs Helper". For now, I've just disabled it, as I've found better tools since.

Comment 5

[Daniel Bodea [:danibodea]]

I continue to be unable to reproduce this issue with the mentioned addon installed, but I did not have a 3.6k tab session to test with, but a few dozen of them.

Furthermore, it appears that the issue is not with Firefox, but the interaction with some addon.
It also appears that the reporter does not reproduce the issue anymore. Robert, is that right?

Comment 6

[Daniel Bodea [:danibodea]]

Considering the fact that it was confirmed that an addon was the cause and not the browser and also that the issue could not be reproduced again, I will resolve this issue as worksforme.