1057255 - Inspector performance issue on duckduckgo

Status: RESOLVED WORKSFORME

(DevTools :: Inspector, defect)

Description

[Patrick Brosset <:pbro>]

Here's another inspector performance problem (see bug 976527, bug 1020894, bug 1020438 for other performance-related problems).

- Navigate to http://duckduckgo.com
- Open the webconsole (make sure it is opened first, so that the inspector doesn't load).
- With the devtools either docked to the bottom or to the side, quickly resize the toolbox (like, very quickly)

=> No visible jank, the toolbox is resized pretty smoothly and the site adapts (it has a media query) smoothly too.

- Now, switch to the inspector
- Do the same thing

=> The toolbox gets resized with a noticeable lag, and so does the site.
On my machine it's even worse in vertical mode.

It doesn't make the site or devtools unusable though, it's still just jank when resizing the toolbox, but it's noticeable enough to be worth fixing.

There seems to be a markup mutation on resize of the page, which will trigger a refresh of the markup-view. That's probably one of the reasons it's a bit slow.
I think the rule-view is also refreshed everytime the layout of the toolbox changes, which is, I think, useless.

Comment 1

[Patrick Brosset <:pbro>]

I'm not seeing the jank anymore. Several performance-related fixes have been done recently which may have resolved this problem.