1373489 - Main process freezes when many tabs are opened

Status: RESOLVED INCOMPLETE

(Firefox :: Untriaged, defect)

Description

[Nikolay Martynov]

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:54.0) Gecko/20100101 Firefox/54.0
Build ID: 20170612121707

Steps to reproduce:

I have ~50 tabs opened and if firefox has been running for a while main (UI) process starts freezing for prolonged periods of times.

It looks like problem is exacerbated by some websites, especially if they are constantly reloading data. I seem to often see this problem when I leave tab with newrelic graphs (newrelic.com) or graphite dashboard (grahiteapp.com) opened overnight.

It also looks like closing those tabs and then clicking 'minimize memory usage' on 'about:memory' temporarily resolves the problem


Actual results:

firefox freezes


Expected results:

firefox should not freeze.

Comment 1

[Justin [:JW_SoftvisionQA]]

Please follow the steps here "https://developer.mozilla.org/en-US/docs/Mozilla/Performance/Reporting_a_Performance_Problem#Setting_up_the_Gecko_Profiler_extension" to get your performance profile so we can see exactly what is going on.

Comment 2

[Nikolay Martynov]

Justin, does it have to be nightly or can it be release FF version?

It takes some time for a problem to appear which means I would have to 'work' in nightly - I was hoping to avoid it unless nessesary.

Comment 3

[Justin [:JW_SoftvisionQA]]

no you can use release FF.

Comment 4

[Nikolay Martynov]

Here's link for profile: http://bit.ly/2tmvBDc.

It looks like there is this repeating pattern of being stuck in PCookieService::Msg_GetCookieString for a few seconds - which is I guess #1331680. Delays there seem to be about 13 seconds - which is probably not very good.

Main thread seem to be spending a lot of time in nsJSContext::RunCycleCollectorSlice - which I guess would sort of align with the fact that minimizing memory consumption helps. On the related note I should point out that when this profile was collected main process had resident size of ~4G.

Please let me know if I can provide any more information.
Thanks!

Comment 5

[Justin [:JW_SoftvisionQA]]

Hey Mike I know it is a Release profile but could you help here?

Comment 6

[Mike Conley (:mconley) (:⚙️)]

Nikolay Martynov's analysis is spot on - the content processes are blocked on sync messages to get cookies (yes, that's bug 1331680), and the main thread in the parent process is busy doing a very long cycle collection.

Most likely something is leaking - either a page (least likely, since the CC is happening in the parent process), an add-on, or Firefox itself. When in this state, an about:memory report would be most useful, I think.

Comment 7

[Nikolay Martynov]

Attachment: memory-report.json.gz

Attaching memory report when problem exists.

Also, it looks like that opening large google docs slide deck (with lots of images) and leaving it opened makes problem appear sooner.

Comment 8

[Mike Conley (:mconley) (:⚙️)]

There is roughly 2GB in the parent process under "heap unclassified". Smells like a leak.

Are you able to reproduce this with your add-ons disabled?

Comment 9

[Joe Hildebrand [:jhildebrand] (UTC-6)]

mconley, if this is a problem in sync cookies, can we close this now that bug 1331680 landed?

Comment 10

[Joe Hildebrand [:jhildebrand] (UTC-6)]

Sorry, didn't mean to move this one.

Comment 11

[Mike Conley (:mconley) (:⚙️)]

(In reply to Joe Hildebrand  [:hildjj] (UTC-6) from comment #9)
> mconley, if this is a problem in sync cookies, can we close this now that
> bug 1331680 landed?

That, and the fact that we haven't heard back from the reporter, I think we can close this one out as INCOMPLETE.

Comment 12

[Nikolay Martynov]

@Mike, I'm sorry I didn't get back to you.

Unfortunately the bug is reproducible only after a few days of run - and running a few days without plugins is hard.

I was waiting to see if I can still reproduce the problem with only webextentions (and no legacy plugins).

I'll reply (and I guess reopen) this bug if I can reproduce the problem.

Thanks!

Comment 13

[Joe Hildebrand [:jhildebrand] (UTC-6)]

Nikolay, the sync cookies work only landed on nightly a few days ago.  If you can reproduce with a nightly from today forward, NI me or mconley, and we'll reopen this bug - it will be high priority for us!