1273132 - The demo is choppy

Status: RESOLVED WONTFIX

(Core :: General, defect)

Description

[Alice0775 White]

Build Identifier:
https://hg.mozilla.org/mozilla-central/rev/4a8ed77f6bb573f20980056bf8c1dadd125c1a85
Mozilla/5.0 (Windows NT 10.0; WOW64; rv:49.0) Gecko/20100101 Firefox/49.0 ID:20160515030241

The problem seems to be existing since Firefox40, but not Firefox39.

Reproducible : always

Steps to reproduce:
1. Open https://videos-real-origin.cdn.mozilla.net/uploads/mozhacks/flight-of-the-navigator/
2. And Click [Start]

Actual Results:
The demo is choppy.
Especially,
at 0:50-1:00
at 1:22-1:31
at 1:40-2:01
at 5:45-6:10

(You can skip the animation by seek bar to save your time)

Expected Results:
No so


Graphics
--------

Features
Compositing: Direct3D 11
Asynchronous Pan/Zoom: wheel input enabled; touch input enabled
WebGL Renderer: Google Inc. -- ANGLE (AMD Radeon HD 6450 Direct3D11 vs_5_0 ps_5_0)
Hardware H264 Decoding: Yes; Using D3D11 API
Direct2D: true
DirectWrite: true (10.0.10586.0)
GPU #1
Active: Yes
Description: AMD Radeon HD 6450
Vendor ID: 0x1002
Device ID: 0x6779
Driver Version: 15.301.1901.0
Driver Date: 2-26-2016
Drivers: aticfx64 aticfx64 aticfx64 amdxc64 aticfx32 aticfx32 aticfx32 amdxc32 atiumd64 atidxx64 atidxx64 atiumdag atidxx32 atidxx32 atiumdva atiumd6a atitmm64
Subsys ID: 23111787
RAM: 1024

Diagnostics
ClearType Parameters: Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 300
AzureCanvasAccelerated: 0
AzureCanvasBackend: direct2d 1.1
AzureContentBackend: direct2d 1.1
AzureFallbackCanvasBackend: cairo
ClearType Parameters: Gamma: 2200 Pixel Structure: R ClearType Level: 100 Enhanced Contrast: 300

Comment 1

[Alice0775 White]

Regression window:
https://hg.mozilla.org/integration/mozilla-inbound/pushloghtml?fromchange=c7720cbbe62e&tochange=c4d1692d88ee

Regressed by: c4d1692d88ee	Jeff Gilbert — Bug 1144906 - Add accel E10S backend for WebGL compositing. - r=jrmuizel,mattwoodrow,nical,sotaro


I do not know why the problem start since Firefox40 in release build, but since Nightly41a1 in nightly m-i build.

Comment 2

[Marcia Knous [:marcia]]

Jeff: Is this something you want to look into? Tracking for 48/49.

Comment 3

[Kelsey Gilbert [:jgilbert]]

I seem to remember that we figured out why this was true last time around.

Based on the reported times, it looks like it's becoming choppy during high-load parts of the demo.

Since the cset is 'e10s for webgl', it's probably just the additional overhead of e10s.

I'm going to WONTFIX this for now, unless this becomes more compelling.

Comment 4

[Firefox Bug Husbandry Bot]

Moving from Core::Untriaged to Core::General https://bugzilla.mozilla.org/show_bug.cgi?id=1407598