1393090 - On a long page with embedded Youtube videos, and with ABP with lots of filters added, scrolling gets janky

Status: RESOLVED WONTFIX

(Core :: General, defect, P5)

Description

[Mayank Bansal]

User Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:57.0) Gecko/20100101 Firefox/57.0
Build ID: 20170822171841

Steps to reproduce:

1. Use my normal profile. It has ABP webext version installed, with some filter lists.
2. Go to http://www.rollingstone.com/tv/lists/100-greatest-tv-shows-of-all-time-w439520?index=61&limit=1
3. Scroll down slowly using a touchpad


Actual results:

As you scroll, the embedded videos are loaded. The videos probably have some sort of ads/cookies/tracking mechanisms that ABP blocks (if you install specific filter lists).
You will see that when the videos loads, and ABP blocks ads, the number is shown in the ABP icon. When the numbers increase, there is a jank.

I am not sure whether the jank is due to ABP blocking the ads, or the videos getting loaded.

Profile: https://perfht.ml/2voFooK


Expected results:

not so. Silky smooth scrolling.

Comment 1

[Mayank Bansal]

Profile on a new profile, with ABP+filters. Stylo off.

https://perfht.ml/2vplPwI

Comment 2

[Mayank Bansal]

ni? as you regularly analyze user perf profiles.

Comment 3

[Mayank Bansal]

Attachment: aboutsupport.txt

about:support of regular profile

Comment 4

[Mayank Bansal]

my general idea is that this page is janky in general, which is exacerbated by ABP and Stylo

Comment 5

[Mike Conley (:mconley) (:⚙️)]

Hey Mayank, sorry for the delay here.

We analyzed this profile during the most recent episode of The Joy of Profiling: https://air.mozilla.org/the-joy-of-profiling-episode-10/

Our findings are as follows:

* ABP is still using a lot of sync IPC traffic which will bog things down. The ABP devs are hoping to release a pure WebExtension version of ABP before 57 ships to release. That should help a great deal with this problem, since we're seeing quite a bit of sync IPC caused by ABP in this profile.
* mstange noticed that we're re-compiling some very similar JS for each embedded YouTube video inside the Rollingstone document. We filed bug 1393977 for that. Thanks for bringing that to our attention!

Comment 6

[Mayank Bansal]

thanks for looking at this. I am glad that something actionable came out of the profile.

Comment 7

[Selena Deckelmann :selenamarie :selena]

Resolving this WONTFIX in recognition of the sync IPC issue in ABP causing this, rather than Firefox itself. Added the JS bug to "see also".  

Thanks again for the profile and report!