1572253 - Console messages are slow to reflow

Status: NEW

(Core :: Layout, defect, P3)

Description

[:Harald Kirschner :digitarald]

Follow up from bug 1571644, see STR for the scenario.

:dholbert recommended to file a bug to investigate the reflow performance for Console in https://bugzilla.mozilla.org/show_bug.cgi?id=1571644#c4

Dan's profile: https://perfht.ml/2TkBrze , reflows taking 100-200ms

Comment 1

[Nicolas Chevobbe [:nchevobbe]]

Note that the reflow on hover was fixed in Bug 1571349

Comment 2

[:Harald Kirschner :digitarald]

The issue can be still triggered by simple switching away and back to the Console

1. open a first tab on https://sugared-oil.glitch.me/ (this page contains ~2000 CSS warnings, CSS warnings seem much heavier to render than normal messages)
2. Switch to Debugger and back to Console …

AR: 500ms+ reflow delay

https://perfht.ml/2M98B3Q

Comment 3

[BugBot [:suhaib / :marco/ :calixte]]

The priority flag is not set for this bug.
:pbro, could you have a look please?

For more information, please visit auto_nag documentation.

Comment 4

[Nicolas Chevobbe [:nchevobbe]]

moving to layout as people in the team might have a better idea what's happening and if this can be fixed

Comment 5

[Nicolas Chevobbe [:nchevobbe]]

Daniel, could you look into this in the coming weeks?
We are getting horrible profiles where our check to scrollHeight takes 800ms (https://profiler.firefox.com/public/cbe4a910ea42399f5feae03667dc03895e1f57ce/stack-chart/?globalTrackOrder=0-1-2-3-4-5-6-7-8-9-10-11&hiddenGlobalTracks=1-2-3-5-6-7-9-10&hiddenLocalTracksByPid=17872-2&localTrackOrderByPid=6584-1-2-0~20192-0~11500-0~4748-0~11976-0-1~10004-0~18752-0~2344-0~17872-3-0-1-2~96-0-1~7324-0-1~1696-0-1~&thread=0&v=4)

Comment 6

[Daniel Holbert [:dholbert]]

Yeah, I'll try. Toggling needinfo to hopefully remind myself.