1505416 - Tabs hang with 100% CPU for Web Content processes

Status: RESOLVED WORKSFORME

(Firefox :: Untriaged, defect)

Description

[oliver]

Attachment: HungFirefox.png

User Agent: Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:63.0) Gecko/20100101 Firefox/63.0

Steps to reproduce:

Initial discussion here between 2 users experiencing identical symptoms:

https://www.reddit.com/r/firefox/comments/9t0z1w/dae_get_unresponsive_tabs_in_firefox_63_linux/

Using Linux. Note that symptoms only starting occurring after updating to FF63 (same for other user in the above reddit thread).

2 screens with nvidia-driver-390 under Ubuntu 18.04.

$ uname -a Linux oliver 4.15.0-38-generic #41-Ubuntu SMP Wed Oct 10 10:59:38 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux

Open 10 tabs with a mix of "simple" (eg BBC News) and "more complex" (eg Facebook) sites and use Firefox normally. 

( I realise this is not a great reproducible scenario and will try to refine this)


Actual results:

After some time one or more of the tabs become unresponsive. Back/Forward/Reload/Cancel UI becomes unresponsive. Content Area shows throbber/spinner. The only thing that works on those tabs is the "close tab" button. The more tabs are open, the more frequently the issue appears to occur. 

running "top" in a terminal shows 1-4 "Web Content" processes at 100% CPU. 

Progressively closing tabs and watching "top" can help identify which tabs are hogging the Web Content processes. See description here: https://www.reddit.com/r/firefox/comments/9t0z1w/dae_get_unresponsive_tabs_in_firefox_63_linux/e985234/

Screenshot with just 2 tabs and 2x100%WebContent processes attached below

Could possibly be related to https://bugzilla.mozilla.org/show_bug.cgi?id=1499385 (since it occurred about the same time and has similar symptoms)

Although here there is no Chromium running. Could be some other cross-process/gtkWidget locking it up?




Expected results:

tabs don't hang and WebContent CPU usage stays within reasonable limits.

Comment 1

[ovidiu boca[:Ovidiu]]

Hi Oliver, I think this is a duplicate after bug 1499385, the one mentioned by you, I will mark it as a duplicate after that bug based on the fact that there is more info that can help the development team to figure out what's going one. 
Can you also see comment 3 from bug  1499385 https://bugzilla.mozilla.org/show_bug.cgi?id=1499385#c3 and see if you can capture a performance profile. If you can please add it to bug 1499385.

Comment 2

[motleybook]

(In reply to ovidiu boca[:Ovidiu] from comment #1)
> Hi Oliver, I think this is a duplicate after bug 1499385, the one mentioned
> by you, I will mark it as a duplicate after that bug based on the fact that
> there is more info that can help the development team to figure out what's
> going one. 
> Can you also see comment 3 from bug  1499385
> https://bugzilla.mozilla.org/show_bug.cgi?id=1499385#c3 and see if you can
> capture a performance profile. If you can please add it to bug 1499385.

I don't think this is a duplicate as Chrome (or Chromium) isn't running here either.

Comment 3

[Mike Conley (:mconley) (:⚙️)]

I agree that this doesn't sound like a duplicate of bug 1499385.

Comment 4

[oliver]

We have multiple other machines running Ubuntu 16.04 (with nvidia 340.104) and FF63, which do NOT exhibit these problems.

Comment 5

[oliver]

Update!

I can't be 100% sure that I have the cause and effect right here, BUT:

- Yesterday, in frustration at the continuing FF63 lockups, I decided to try to "downgrade" the nvidia drivers to 340.104 (same as our Ubuntu 16.04 machines, which don't exhibit the symptoms, see above)

- This downgrade was actually unsuccessful, ie Ubuntu 18.04 didn't run with 340.104 and defaulted back to the open source nouveau driver. 

- I then reactivated nvidia-driver-390 (which resulted in a recompile of the kernel nvidia module I think)

I have not had any FF63 lockups since then. It's only been less than 24hrs, but normally I would have expected a lockup by now. 

Will monitor and report back.

Comment 6

[oliver]

Still no lockups all day. 

@kurssk since you had the same symptoms, can you test if a de-activate / re-activate with recompile of the nvidia drivers seems to resolve this issue for you?

Comment 7

[kurssk]

@oliver

I believe my issue may have been resolved by moving from the 11/4/18 nightly(FF65.0a1) I was previously on to the 12/2/18 nightly this weekend. But I also upgraded the kernel around that time...

So I'll try FF63 again and see if the issue re-occurs. If it does, I'll recompile the kernel and see what happens.

Comment 8

[oliver]

2 days later I can confirm no lockups for me anymore. 

Looks like an interaction of FF63 and nvdia-drivers may have caused this on my machine. (unless there was another unrelated update which resolved it). 

From my perspective, I am happy for this to be closed?

Comment 9

[kurssk]

I agree. I no longer experienced the issue after reverting back to FF63. It seems plausible to me that my issue was also resolved when my kernel was recompiled this weekend.

Comment 10

[kurssk]

Spoke too soon. Started happening again last night on FF63. I cant point to anything that changed. Running Nightly at the moment to see if it re-occurs.

Comment 11

[motleybook]

I'm also using an nvidia card (GeForce GTX 960). One thing I noticed is that the bug seems to appear most often when opening multiple tabs in a private window (for example by opening all links in a bookmark folder). Then it also happens in the non-private window. That said, it may be just coincidence.

Firefox: 63.0.3 (64-bit)

Comment 12

[motleybook]

(I don't actually remember it happening in a non-private window first, but again this may also be just coincidence.)

Comment 13

[oliver]

Still fine for me. No hangups for days now. 

When it was happening, it was definitely occurring occuring in normal windows (not private). 

What versions of nvidia-drivers are you both using?

Comment 14

[kurssk]

I'm running nvidia 415.18 on a Geforce gtx 660 ti. 

The last time I seen the issue on FF63 was when first navigating to Netflix in a normal window. Probably had greater than 20 tabs open. I believe I may have had a private window open. Not certain.

I've been running the 12/7/18 nightly for the past couple days without closing. Had a private window open and watched Netflix a few times. ~6GB of memory taken up but no lockups.

Comment 15

[motleybook]

@oliver I'm using 410.78 (Current long-lived branch release).

Comment 16

[Hossain Al Ikram [:ikram] (QA Contact)]

Hey oliver,

Can you try and see if you are still having the issue in latest Firefox 64? Let us know if it happens so we can try to reproduce/ find the issue if it still exists. If not, we will be able to resolve the bug as WORKSFORME!

again, I want you to thank for taking your time submitting this bug.

Comment 17

[kurssk]

I've been running 64 for quite a few days now with no issues. So it worksforme!

Comment 18

[oliver]

WORKSFORME with FF63 (since recompiling nvidia drivers) and also with FF64 for the last few days

Comment 19

[ovidiu boca[:Ovidiu]]

Thanks Oliver for your feedback, I will close this as WFM. Please feel free to reopen it if you encounter the same issue in the future.

Comment 20

[Fabrizio Bertoglio]

I read quickly this post. I also have nvidia drivers for my Geforce GTX 950. Is this associated with WebGL? I don't see how opening a tab (which may run js code) will demand so much memory as for example one of the pages is a github page and does not require complex 2d/3d rendering...

seems we are all using the same Geforce series card..

Each tabs opens new process and takes 200mb .. I have 4core8threads so no problems there, even if my laptop 2 fans and cpu goes in overclock.

Thanks