Open Bug 1637277 Opened 3 months ago Updated 3 months ago

High CPU usage Firefox 76.01

Categories

(Core :: Graphics, defect, P3)

76 Branch
defect

Tracking

()

UNCONFIRMED

People

(Reporter: andreasberg27, Unassigned)

References

(Blocks 1 open bug)

Details

Attachments

(3 files)

Attached image FirefoxCPUuse.jpg

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

Whenever I enter, for example; PCgamer.com my CPU usage will go over 30% or even up towards 100%. I have a i7 9700K. (also 2080ti and 32 GB RAM) Memory usage is also over 4GB just for firefox alone.
This also happens when viewing a youtube video with chat.
It also happens at alot of other random pages but I cant remember them all.
This happened after I updated to 76.

Actual results:

As stated above high CPU usage to the point of not being able to use firefox because of fan noise.

I tried refreshing firefox. I've disabled and uninstalled all my add-ons and themes and I've tried reinstalling Firefox. Even tried to remove all my settings and favourites. (Clean install) I have not changed anything else with my computer since updating firefox, the problem started with the update.

I have tried everything I can think of so I will stop using Firefox until this is fixed since my GPU will hit 70 degrees C with nothing else open exept Firefox ...

Expected results:

CPU usage should not be this high, and it was'nt until i updated a couple of days ago.

Attached picture of CPU usage just by having PCgamer.com open.

Bugbug thinks this bug should belong to this component, but please revert this change in case of error.

Component: Untriaged → Graphics
Product: Firefox → Core

I've now tried going back to Firefox version 75, but the problem is still there, so maybe its something that has changed with the problem pages.
If I open the page in Edge I get 1% usage after it hits around 20% for a brief moment.
I don't have any other browsers so I can't test any other.

Like I said before; this happened only after I updated.
I am not sure what version I was on before, because I don't usually update straight away. I would guess that I last updated about early April late March ...

Can you use the profiler at https://profiler.firefox.com/ with firefox platform settings when you are experiencing the high cpu and upload a profile and paste the link here?

And since you mentioned high memory use too could you go to about:memory and save a memory report and upload it here?

One more thing, could you upload a copy of your about:support?

Thanks

Flags: needinfo?(andreasberg27)

For the memory usage part, you could enter the address
about:memory?verbose
in the address bar and attach (using the "Attach File" link above) the output here.

Here is my profile: https://perfht.ml/2zxWaK4

Not sure if I did it correctly though ...

I have downgraded to version 75 and the problem is still there. I had about 25% usage now, but it has been a lot higher at other times.
Will try to get the memory log as well.

I also tried using Firefox on my work PC and it was the same problem there.
At work I have a i5-6300U and am on version 75. My work PC have not been updated in quite a while, it was'nt as loud though so maybe this problem have been there a while. I had about 70% CPU usage.

Flags: needinfo?(andreasberg27)
Attached file memory-report.json.gz
Attached file About support.txt

I can't seem to recreate my problem from Youtube that seemed to happen whenever there was a chat window up.
Also my memory seems OK now, also on the report i submitted. I had 7-8% usage on 32GB, about 2,5GB total. I guess that's normal?
This may be because I am now running Firefox version 75 instead of 76.1?

Also in my original report it says GPU temps of 70 degrees C, that should be CPU. GPU use is fine.

Sorry for spamming, but it seems the Youtube problem is only when I have the Add On; Dark Background and Light Text, enabled.

As soon as I got a bit into the video, about 10min, my CPU went to 70%. Closing chat or disabling the Add On made it cool down again.
Memory was still OK.

Made a link to profile while this was happening:
https://perfht.ml/2yTusHt

(In reply to andreasberg27 from comment #9)

Sorry for spamming, but it seems the Youtube problem is only when I have the Add On; Dark Background and Light Text, enabled.

As soon as I got a bit into the video, about 10min, my CPU went to 70%. Closing chat or disabling the Add On made it cool down again.
Memory was still OK.

Made a link to profile while this was happening:
https://perfht.ml/2yTusHt

PS: The PCgamer.com page still uses alot of CPU even without the Add On. At work I do not have this Add On installed.

Could you go to the profiler settings, tick the "custom" option, untick Screenshots and in the "Add custom threads by name" field put the following: "GeckoMain,Compositor,Renderer,RenderBackend,SceneBuilder", and take another profile?

It would be interesting to have a closer look at what the graphics related threads are doing.

Blocks: wr-perf
Flags: needinfo?(andreasberg27)

(In reply to Nicolas Silva [:nical] from comment #11)

Could you go to the profiler settings, tick the "custom" option, untick Screenshots and in the "Add custom threads by name" field put the following: "GeckoMain,Compositor,Renderer,RenderBackend,SceneBuilder", and take another profile?

It would be interesting to have a closer look at what the graphics related threads are doing.

https://perfht.ml/3dP69cP

Let me know if I did'nt do it correctly.

Flags: needinfo?(andreasberg27)

Thanks. This pcgamer page appears to be doing some javascript in the background which is the most visible activity in your profile. Many pages tend to do that in very inefficient ways either for ads related things or to update the content of the page without the user reloading. This unfortunately often translates to significant CPU usage evn though nothing ends up changing on screen. The graphcis threads are mostly idle but there are always improvements that can be made and we have plenty of bugs to track that and ongoing work in the area, although in this particular case I suspect that the ball in the web author's camp.

Severity: -- → S3
Priority: -- → P3

(In reply to Nicolas Silva [:nical] from comment #13)

Thanks. This pcgamer page appears to be doing some javascript in the background which is the most visible activity in your profile. Many pages tend to do that in very inefficient ways either for ads related things or to update the content of the page without the user reloading. This unfortunately often translates to significant CPU usage evn though nothing ends up changing on screen. The graphcis threads are mostly idle but there are always improvements that can be made and we have plenty of bugs to track that and ongoing work in the area, although in this particular case I suspect that the ball in the web author's camp.

Thanks.
I've registered the problem on the forums of this site. It seems there are a lot of people with this problem, not all using Firefox.
I will post back if they find something useful.

So I've been looking into this (I was the one who first noticed and reported on PCGamer forums) and found a bunch of sites which present this unusual behavior and the all look (style wise) the same: pcgamer.com , tomshardware.com , tomsguide.com , gamesradar.com , T3.com. So I guess it's that specific style of website which has this issue.

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