Bug 205561 – [GTK][GStreamer] Extremely high CPU usage due to video playback

• Component: WebKitGTK
• Status: RESOLVED WORKSFORME

[Sergio Villar Senin]

Steps to reproduce:

1- Open https://www.nytimes.com/interactive/2019/12/20/opinion/location-tracking-smartphone-marketing.html

The CPU usage rockets to 600% on my laptop and it keeps that way as long as the page is opened. Even if I scroll to a point where only text is shown the CPU usage is super high.

Attaching to the WebProcess with gdb shows tons of GStreamer threads (>60). I've built WebKit with --no-video and the CPU usage goes down to 6-7% as any other web page.

[Sergio Villar Senin]

BTW I had also tried with --no-web-rtc --no-media-stream first before building with --no-video and in that case the CPU usage goes down to 150%. So there is WebRTC stuff going on there too hijacking the CPU.

[Sergio Villar Senin]

Created attachment 386444 [details]
Backtraces

Backtraces of all running threads (88!!!) just after loading the web page. My GStreamer knowledge is pretty limitted but some of the backtraces look really scary, see #74, #65, #63, #54, #47, #38 or #29.

[Sergio Villar Senin]

Hmm after some investigation I am not sure this is a bug on our side, but the natural consecuence of a bad designed bloated webpage. After checking the DOM I see no less than 14 videos with both autoplay and loop enabled.

I'd wait for the multimedia experts but I guess we can close this.

[Philippe Normand]

Could this have been due to AC being disabled in Ephy?

[Milan Crha]

Similar report from Epiphany:
https://gitlab.gnome.org/GNOME/epiphany/-/issues/1572

Using epiphany-40.1-1.fc34.x86_64 with webkit2gtk3-2.32.3-1.fc34.x86_64. It does this even when the video playback is paused in the MiniBrowser (or set as Deny autoplay in Epiphany).

[Philippe Normand]

(In reply to Sergio Villar Senin from comment #3)
> Hmm after some investigation I am not sure this is a bug on our side, but
> the natural consecuence of a bad designed bloated webpage. After checking
> the DOM I see no less than 14 videos with both autoplay and loop enabled.
> 

I don't think we can do much about this... You can disable autoplay with the --media-playback-requires-user-gesture=1 websetting.


(In reply to Milan Crha from comment #5)
> Similar report from Epiphany:
> https://gitlab.gnome.org/GNOME/epiphany/-/issues/1572
> 
> Using epiphany-40.1-1.fc34.x86_64 with webkit2gtk3-2.32.3-1.fc34.x86_64. It
> does this even when the video playback is paused in the MiniBrowser (or set
> as Deny autoplay in Epiphany).

I can't reproduce this issue in MiniBrowser with --media-playback-requires-user-gesture=1 ...