1352078 - Odd sliding of potential new LinkedIn connections (doesn't happen in Chrome)

Status: RESOLVED WORKSFORME

(Core :: Layout, defect)

Description

[Andrew Overholt [:overholt]]

Scrolling through the "People you may know" section of https://www.linkedin.com/mynetwork/, people's names and photos seem to slide from the right to the left whereas in Chrome they're pinned to the left (their final position) initially.

Screencast: https://www.dropbox.com/s/n56ozj65fnxpk53/LinkedIn%20-%20Nightly%202017-03-30%209_27_48%20AM.mp4?dl=0

Profile: https://perf-html.io/public/e71b42e9b0cf37dfce77e24177b4f866cfae4cd0/calltree/?range=40.0192_42.3001&thread=2

Comment 1

[Andrew Overholt [:overholt]]

This is on Windows 10 in Nightly, FWIW.

Comment 2

[Desigan Chinniah [:cyberdees] [:dees] [London - GMT]]

(In reply to Andrew Overholt [:overholt] from comment #1)
> This is on Windows 10 in Nightly, FWIW.

It replicates on Mac OSX on Nightly, too.

Comment 3

[Sean Stangl [:sstangl]]

Does not reproduce on Linux Nightly. Very smooth here.

Comment 4

[Sean Stangl [:sstangl]]

Andrew (or Dees), the Cleopatra profile is missing a lot of data.

Would you be able to re-profile by:

1. In the profiler UI, under "Settings," bumping up the buffer size (~200MB?) and decreasing the sampling interval (~0.5ms?).
2. Hitting "Apply (Restart Profiler)".
3. Disabling the profiler.
4. Navigating to https://www.linkedin.com/mynetwork/.
5. Enabling the profiler, then reproducing the bug for a few seconds of scrolling, then collecting the data with Ctrl+Shift+2.

That should hopefully preserve a greater amount of sample data.

Comment 5

[Sean Stangl [:sstangl]]

Andrew pointed out that it does /kind of/ reproduce on my Linux machine -- there's no jank, but at the very bottom of the screen, when names are coming in, the text appears a little on the right and then quickly snaps into position.

Comment 6

[Andrew Overholt [:overholt]]

Better profile: https://perfht.ml/2nzAhQu

Olli looked at my initial profile and saw something taking 400 ms but I forget what it was. Do you remember, Olli?

Comment 7

[Olli Pettay [:smaug][[e-mail]]]

The thing I mentioned was that there was some oddly long painting/rasterization and Matt said something about waiting for GPU synchronization or some such, which definitely shows up in the profile.

That doesn't still explain the behavior though. Is there some similar effect in Chrome, but it is just a lot faster because they paint faster and not block refresh driver

Comment 8

[Olli Pettay [:smaug][[e-mail]]]

See also bug 1349696

Comment 9

[Andrew Overholt [:overholt]]

I used Chrome's devtools' network throttling to see if I could reproduce the effect there and I can't. Maybe they have some sort of CPU-throttling mode that I don't know about?

Comment 10

[Andrew Overholt [:overholt]]

I found Chrome's CPU throttling and it still doesn't reproduce for me in Chrome.

Comment 11

[Andrew Overholt [:overholt]]

LinkedIn seems to have redesigned their site so this is no longer reproducible. The experience seems similar for me in Chrome and in Nightly.