Closed Bug 1419047 Opened 3 years ago Closed 2 years ago

High CPU usage when playing streaming MP3


(Core :: Web Painting, defect)

57 Branch
Not set





(Reporter: phoffman, Unassigned, NeedInfo)


(Whiteboard: [qf?])


(2 files)

Attached image High-cpu.png
User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.13; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20171112125346

Steps to reproduce:

Go to and play a song using the ">" play button

Actual results:

The CPU level jumps far higher than when playing the same song in Chrome.

Expected results:

Similar low CPU usage
Anthony, can you take a peek at this to see which component should own it, please?
Flags: needinfo?(ajones)
Component: Untriaged → Audio/Video: Playback
Product: Firefox → Core
CPU usage is low in a background tab, i.e. 15% instead of over 50%. Can someone take a look with a profiler to figure out what is using CPU.
Flags: needinfo?(ajones)
Whiteboard: [qf?]
Naveed - does the qf? flag still work?
Flags: needinfo?(nihsanullah)
I can see similar higher CPU use on Windows 8.1 too 4 cores / 8 HT notebook, I see approx. two times more CPU compared to IE 11 and six times more compared to Chromium. I've loaded the page, waited everything to remain quiet, then pressed play, waited, took the screenshot of the Task Manager, then the same with IE 11 and Chromium. I must note, Chromium had display problems for me (blank area over the "sound graph"), Nightly and IE haven't had any visible. All three played the music. Before the play is pressed all 3 browsers don't appear to stress CPU at all, until the mouse is moved.
This page seems to be spending its time doing painting. I'm going to hand it over to layout for further investigation.
Component: Audio/Video: Playback → Layout
(In reply to Anthony Jones (:kentuckyfriedtakahe, :k17e) from comment #5)
> This page seems to be spending its time doing painting. I'm going to hand it
> over to layout for further investigation.

Lots of DisplayList building here, despite not a lot of screen changes. Paint Flashing indicates a lot of invalidation of the elapsed time (despite no actual text changes.) I'd expect RDL to help here. Matt: can you have a look? Thx!
Component: Layout → Layout: Web Painting
Flags: needinfo?(nihsanullah) → needinfo?(matt.woodrow)

Paul, is this still a problem for you? We had tested it and it's not reproducible.

Closed: 2 years ago
Flags: needinfo?(hofmannpaul)
Resolution: --- → INCOMPLETE
You need to log in before you can comment on or make changes to this bug.