Firefox is laggy when wiping the background on




6 years ago
6 months ago


(Reporter: beta, Unassigned)



22 Branch

Firefox Tracking Flags

(Not tracked)



(1 attachment)



6 years ago
User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:22.0) Gecko/20130322 Firefox/22.0
Build ID: 20130322031028

Steps to reproduce:

Visit the site for the reveal of Battlefield 4.
They have an interesting background which is a window above an image, the user swipes the cursor across the page to reveal whats behind, for the condensation to return after a time…
The animation isn’t as smooth as it could be, with Chromium 25 performing better.

Need to investigate if this is a Firefox issue or how they have coded the behaviour to prefer webkit/v8.


6 years ago
Keywords: perf

Comment 1

6 years ago
Created attachment 729623 [details]
‘minimal’ testcase

Site is closing soon, so keep a pared* down version as a test case.
Depends on jQuery from and two images on

*for whatever minimal is accepted, HTML is bare-bones, JS is scarily wasteful but likely a chunk of the perf issue.


6 years ago
Attachment #729623 - Attachment mime type: text/plain → text/html

Comment 2

6 years ago
Captured a profile of this lulls in graph is where I am pausing the mouse cursor for a few seconds to allow the swipe to fade and just to make the sampling clearer. Is this capturing useful info?

Comment 3

6 years ago
Mixed content blocking breaks this testcase... do you know if this is still an issue?
Flags: needinfo?(john)

Comment 4

6 years ago
On the most recent Nightly, yes, it still has jank. should have all the files to run locally
Flags: needinfo?(john)
Component: Untriaged → DOM
Product: Firefox → Core
I can't reproduce using 64-linux-nightly

Comment 6

5 years ago
Still there for me in Nightly 2013-08-26; Chrome still performs better in responsiveness and smoothness of drawing. Tried with OMTC about:config flags which improves the smoothness of animation and doesnt have the sudden pauses but latency is much worse - mouse cursor can be ahead by ~100 pixels

Adapter Description	NVIDIA Corporation -- GeForce GT 630/PCIe/SSE2
Device ID	GeForce GT 630/PCIe/SSE2
Driver Version	4.3.0 NVIDIA 325.08
GPU Accelerated Windows	0/1 Basic
windowLayerManagerRemote	false
AzureCanvasBackend	cairo
AzureContentBackend	none
AzureFallbackCanvasBackend	none
AzureSkiaAccelerated	0

Move all DOM bugs that haven’t been updated in more than 3 years and has no one currently assigned to P5.

If you have questions, please contact :mdaly.
Priority: -- → P5
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