large blank spots while scrolling on mobile.twitter.com

NEW
Unassigned

Status

()

Firefox for Android
Toolbar
P3
normal
5 months ago
5 months ago

People

(Reporter: dietrich, Unassigned)

Tracking

57 Branch
All
Android
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

(Reporter)

Description

5 months ago
57.0a1 2017-08-08
Samsung Galaxy S8

STR:

1. open mobile.twitter.com
2. swipe up or down really quickly

Expected: content scrolls by continuously

Actual: super easy to make large blank white spaces show, for a bit, before the content is painted

I've been testing the PWA on Chrome and Samsung Internet Browser on the same device (since they support manifest=standalone and we don't yet), and have never seen this behavior.
Sounds like checkerboarding. If this is a regression then a regression range would be useful. A gecko profile would probably be useful regardless so we can see what the main thread is spending its time on.
OS: Unspecified → Android
Priority: -- → P3
Hardware: Unspecified → All
Version: unspecified → 57 Branch
(Reporter)

Comment 2

5 months ago
Ok! Any tips on getting a profile on Android?

Don't know about a regression range, just noticed it when I checked to see if our manifest stuff was working yet.
(In reply to Dietrich Ayala (:dietrich) from comment #2)
> Ok! Any tips on getting a profile on Android?

:snorp apparently has an addon that can do it, but it might not work out of the box. The steps are:
1) install addon from https://github.com/snorp/fennec-profiler-addon
2) this will give you start/stop menu items to profile. the profile gets dumped to the sdcard
3) symbolicate the profile using the symbolication script in the addon repo
4) upload it to perf-html.io for visualization

Apparently nobody else has tried it (other than snorp) so if you run into trouble he'd be the best person to ask.
This sounds like bug 1272174 where the problem was that they cause invalidations by changing padding-top.
(Reporter)

Comment 5

5 months ago
Video of what I'm talking about: https://www.youtube.com/watch?v=r3Ak7sk0rZE

Not just large white patches (that's super easy, just scroll hard), but some really bad paint delays and glitches at certain places while just doing normal scrolling up and down. Or is that just artifact of same checkerboarding issue?
(Reporter)

Comment 6

5 months ago
(In reply to Kartikaya Gupta (email:kats@mozilla.com) from comment #3)
> (In reply to Dietrich Ayala (:dietrich) from comment #2)
> > Ok! Any tips on getting a profile on Android?
> 
> :snorp apparently has an addon that can do it, but it might not work out of

I have no ETA for doing this. My new derailer already derailed my other derailings.
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