1420875 - WebRender Mac: CSS fade animations stress CPU, even after bug 1419079 fixed

Status: RESOLVED INCOMPLETE

(Core :: Graphics: WebRender, defect, P3)

Description

[Mark]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:59.0) Gecko/20100101 Firefox/59.0
Build ID: 20171126220311

Steps to reproduce:

MacOS 10.13.1

I was having trouble with very high CPU loads on attachment 8930451 [details] and I filed bug 1419079.

Hiro and Brian fixed a regression which brought CPU loads down to more sensible levels. 

Hiro gave me a "fixed" version of FF59 in this try:-

https://treeherder.mozilla.org/#/jobs?repo=try&revision=40f630240c1b746325d1062414c2aee988518425&selectedJob=147401571

and I tested it against the fading slideshow animations in attachment 8930451 [details] and also a fade animation in https://codepen.io/davidhc/pen/nLpJk

With WebRender OFF the CPU loads are reasonable for both test pages. With WebRender ON the CPU loads are dramatically higher.

Attachment 8930451 [details]:-
WebRender OFF:-    Web Content ~10% Nightly ~25% 
WebRender ON:-     Web Content ~70% Nightly ~60%

https://codepen.io/davidhc/pen/nLpJk
WebRender OFF:-    Web Content ~10% Nightly ~25%  
WebRender ON:-     Web Content ~40% Nightly ~50%

I turned WebRender ON by setting gfx.webrender.blob-images and gfx.webrender.enabled to TRUE and restarting Nightly.

I have attached performance profiles for attachment 8930451 [details]

WebRender ON:-     https://perfht.ml/2n4TLjn
WebRender OFF:-    https://perfht.ml/2n3FJ1j

Brian mentioned bug 1419851 which from my limited understanding is about throttling. This bug may be different because at least in the https://codepen.io/davidhc/pen/nLpJk case there is only the one animation on screen so throttling is not relevant (I think??)

I can send you any more info you like if you are interested in digging in further.

Mark

Comment 1

[Glenn Watson [:gw]]

There is only WR now.