1393120 - hotmail/outlook.com's mouse-over sluggish

Status: RESOLVED WORKSFORME

(Core :: Layout, defect, P3)

Description

[Clemens Eisserer]

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:56.0) Gecko/20100101 Firefox/56.0
Build ID: 20170821193225

Steps to reproduce:

1. logged into my outlook.com account (ony my quite old Arrandale Laptop)
2. opened a folder / inbox with >50 mails
3. moved the mouse over the mails


Actual results:

the mouse-over hoover only appears with a delay and plays catch-up with the mouse-cursor, resulting in a sluggish user experience.

screencast: https://youtu.be/tRqEFun08wQ

I don't think this has something to do with rendering /compositing - I had enabled OpenGL compositing during the video, but it doesn't make a difference whether OpenGL or Software compositing is enabled.


Expected results:

the mouse-over effect should be as smooth as with chrome.

Comment 1

[Kohei Yoshino [:kohei]]

Please update you graphics driver: https://support.mozilla.org/kb/upgrade-graphics-drivers-use-hardware-acceleration

Comment 2

[Clemens Eisserer]

My graphic driver is up-to-date (Mesa-17.0.5). 
Furthermore, as mentioned previously, the slugishness is also reproduceable with OpenGLÖ acceleration disabled.

I'll give this issue a try on a linux netbook soon and report back.

Comment 3

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

Could you capture a performance profile using the addon from https://perf-html.io/?
The profile does contain some URLs, so if you don't want to share it publicly, perhaps send the url only to me?

I'm creating an account for testing (I assume it is https://outlook.live.com/owa/), but may not be able to reproduce the issue.

Comment 4

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

https://perfht.ml/2eYqBfo

This is layout. Reflow being slow.
Given this is rather popular website, [qf].

Daniel, could you take a look at the profile.

Comment 5

[Daniel Holbert [:dholbert]]

There's some flex reflow at the deepest levels here, so I'd tentatively assume this is related to / dependent on bug 1377253.

Comment 6

[Daniel Holbert [:dholbert]]

Triaging as [qf:investigate] to see if this is better after bug 1377253 is fixed.

Comment 7

[Daniel Holbert [:dholbert]]

Smaug, if you've still got the setup from comment 4, could you see if you can still reproduce? (& if so, could you capture a new profile?) It's possible this has gotten better, per comment 6.

Comment 8

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

I can't see such reflows anymore. Sure there are some, but way way faster.
https://perfht.ml/2DA6Wxs

reporter, please reopen if you still see bad performance.