1488916 - High hangouts related memory usage on gmail with Firefox Nightly 64

Status: RESOLVED INCOMPLETE

(Firefox :: Untriaged, defect)

Description

[volodin.n]

Attachment: baseline.json.gz

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:64.0) Gecko/20100101 Firefox/64.0
Build ID: 20180905123750

Steps to reproduce:

Leaving firefox idle for few hours, with a lot of tabs open and few addons installed.


Actual results:

The firefox ends up using ~7GB of memory. After I restart firefox, it is cleared and after day/two of usage it is again using a lot of memory.
I noticed that it is usually one of the workers that takes all of the memory, while main process and remaining workers use reasonable amount of memory. I also noticed that the same worker uses most of the CPU compared to other workers.

I was able to capture few memory snapshots while it was using a lot of memory, before it became unresponsive and I had to kill it.

I'm not sure where the issue comes from - browser, addon or web-site.


Expected results:

Memory should not have increased so much.

Comment 1

[volodin.n]

I was able to reproduce the same issue to some degree with firefox nightly 64 in clean profile with no addons.

All I did is left logged in gmail and logged in youtube in the background for few hours.
I also captured few more memory snapshots under high memory usage scenario.
Also, I noticed that when I kill the firefox worker process which consumes the most memory, the gmail tab crashes, so I suspect that something suspicious is happening with gmail.

Comment 2

[volodin.n]

Attachment: after-idling-gmail-youtube-open-no-ext.json.gz

Comment 3

[volodin.n]

Attachment: after-idling-more-gmail-youtube-open-no-ext.json.gz

Comment 4

[Kanchan Kumari QA]

Hello Eric, can you please look into attached memory report? Thanks!

Comment 5

[Eric Rahm [:erahm]]

It's definitely gmail that's using a high amount of memory here. Looking at the diff we can see almost all of the memory usage is under toplevel mail.google.com window:

> 681.44 MB (100.0%) -- explicit
> ├──596.13 MB (87.48%) -- window-objects
> │  ├──588.21 MB (86.32%) ++ top(https://mail.google.com/mail/u/0/#inbox, id=NNN)
> │  └────7.92 MB (01.16%) ++ (3 tiny)
> ├───37.12 MB (05.45%) ── heap-unclassified
> ├───33.77 MB (04.96%) ++ js-non-window
> ├───10.00 MB (01.47%) ++ heap-overhead
> └────4.42 MB (00.65%) ++ (11 tiny)

A large portion of that is the js-zone (again this is a diff):

> │  ├──588.21 MB (86.32%) -- top(https://mail.google.com/mail/u/0/#inbox, id=NNN)
> │  │  ├──307.70 MB (45.15%) -- js-zone(0xNNN)
> │  │  │  ├───89.61 MB (13.15%) ++ lazy-scripts
> │  │  │  ├───81.30 MB (11.93%) ++ shapes
> │  │  │  ├───42.21 MB (06.19%) ++ object-groups
> │  │  │  ├───39.98 MB (05.87%) ── type-pool
> │  │  │  ├───21.95 MB (03.22%) ++ (10 tiny)
> │  │  │  ├───20.22 MB (02.97%) ++ scopes
> │  │  │  └───12.42 MB (01.82%) ── unused-gc-things

But also we see a *ton* of hangouts related windows (again this is a diff, there were a ton to start with):

> │  │  └──280.51 MB (41.16%) -- active
> │  │     ├──276.38 MB (40.56%) -- (345 tiny)
> │  │     │  ├────1.94 MB (00.29%) ++ window(https://hangouts.google.com/hangouts/_/hscv?pvt=...snip...https%3A%2F%2Fhangouts.google.com%2Frobots.txt%22%2C%22lpu%22%3A%22https%3A%2F%2Fhangouts.google.com%2Frobots.txt%22%7D)
> ...

So that's 345 instances of that URL, oddly it contains some sort of token referring to https://hangouts.google.com/robots.txt. I would guess that this is the root of the issue, so the question is why gmail is generating tons of hangouts windows, and why are they sticking around.

Comment 6

[Eric Rahm [:erahm]]

This seems like bad behavior on the part of hangouts, it might be good to contact the gmail folks about this.

Comment 7

[Kanchan Kumari QA]

Based on comment 6, closing this bug. Feel free to reopen it if you feel otherwise. Thanks!