1430451 - CPU-Use nearly tripled on youtube with WebRender

Status: RESOLVED DUPLICATE of bug 1474583

(Core :: Graphics: WebRender, defect, P2)

Description

[Clemens Eisserer]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:59.0) Gecko/20100101 Firefox/59.0
Build ID: 20180113220355

Steps to reproduce:

Compared the following composition modes:
* Basic
* OpenGL (+layers.acceleration.force-enabled;true)
* WebRender  (layers.acceleration.force-enabled;true, gfx.webrender.enabled=true, gfx.webrender.blob-images=2)


Actual results:

Video playback on youtube (https://www.youtube.com/watch?v=3SOd7dEAMNY at 720p, no addons, clean profile )shows serverly increased CPU consumption with WebRender enabled for both the "Web Content" as well as the main Firefox process.

After waiting a little to let the page settle, I got the following CPU consumption values:

WebRender: 50% Web Content + 50% Firefox = 100%
OpenGL: 25% Web Content + 20% Firefox= 40-45%
Basic: 25% Web Content + 10% Firefox = 35-40%


Expected results:

WebRender should cause CPU load compareable to OpenGL compositing.

The tests were performed on an AMD Kaveri based system (AMD APU) with Mesa 17.2.4.
Please note although Mesa drivers are considered low-quality, RadeonSI actually is more mature than the "official" proprietary AMD opengl driver.

Comment 1

[Clemens Eisserer]

Attachment: top output with composition mode "basic"

Comment 2

[Clemens Eisserer]

Attachment: top output with composition mode "opengl"

Comment 3

[Clemens Eisserer]

Attachment: top output with composition mode "WebRender"

Comment 4

[Clemens Eisserer]

Attachment: glxinfo.txt

Comment 5

[Clemens Eisserer]

Follow up: The newly introduced property "gfx.webrender.all" doesn't help, WebRender still consumes 2-3x the CPU time of basic composition.

Comment 6

[Kartikaya Gupta (email:[e-mail])]

Bug 1420430 will probably help here.

Comment 7

[AC]

This may not fall strictly under the scope of this bug, but I see similar results on certain pages that lead to dramatic CPU spikes with webrender enabled. The most simple example is using the Subsonic web player, I've narrowed down the performance hit to a spinning "throbber" CSS animation ("fa-spin" from Font Awesome). This causes the epochs to update very quickly and causes Firefox to use 80% of a CPU core, doubling the usage compared to when that CSS animation is hidden from view.

60.0a1 (2018-02-05) (64-bit) on macOS 10.13.4

Comment 8

[Jeff Muizelaar [:jrmuizel]]

Bug 1419851 will also likely help here.

Comment 9

[Graham Perrin]

1445470 - [tracking] video playback performance
<https://bugzilla.mozilla.org/show_bug.cgi?id=1445470>

Comment 10

[Jeff Muizelaar [:jrmuizel]]

I'm resolving this a dup of bug 1474583. If we declare that fixed and the cpu usage is still no good it's worth opening a new issue.