1246306 - Codemirror in debugger very janky

Status: RESOLVED DUPLICATE of bug 1243554

(DevTools :: Debugger, defect, P2)

Description

[Jordan Santell [:jsantell] [@jsantell]]

Attachment: worker-debug-jank.gif

When scrolling through the codemirror worker debugger, I'm getting a lot of jank. Attached is a gif of the jank -- looks like the browser toolbox isn't picking this up, not sure how this window is related to that, so couldn't figure out if it was reflow or GC or what.

The chopiness in the gif is mostly from jank (although framerate of gif is still 10fps or so)

Comment 1

[Brian Grinstead [:bgrins]]

(In reply to Jordan Santell [:jsantell] [@jsantell] (Please needinfo) from comment #0)
> When scrolling through the codemirror worker debugger, I'm getting a lot of
> jank. Attached is a gif of the jank -- looks like the browser toolbox isn't
> picking this up, not sure how this window is related to that, so couldn't
> figure out if it was reflow or GC or what.

Can you use the frame-picker dropdown feature in the browser toolbox to select the worker debugger toolbox?

Comment 2

[Jordan Santell [:jsantell] [@jsantell]]

Attachment: worker-debug-jank.json

I think I got the right debugger.xul window (based off of the inspector picker), and I captured framerate drops, but no markers or frames that give any indication that something's up.

Comment 3

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

Do you see the same scrolling jank in the regular page debugger?  Does about:support say APZ is enabled?

If yes, then could be same as bug 1239615.

Comment 4

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

(In reply to J. Ryan Stinnett [:jryans] (use ni?) from comment #3)
> Do you see the same scrolling jank in the regular page debugger?  Does
> about:support say APZ is enabled?

You should also confirm that it *only* happens with APZ on by disabling "layers.async-pan-zoom.enabled", restarting Firefox, and repeating your test.  If that fixes the issue, then that is likely the right bug for you.

Comment 5

[Jordan Santell [:jsantell] [@jsantell]]

It happens regardless of APZ settings after trying it on and off. It looks it also is in the normal debugger when scrolling fast, so not worker debugger specific.

Comment 6

[J. Ryan Stinnett [:jryans] (Use needinfo, replies may be slow)]

(In reply to Jordan Santell [:jsantell] [@jsantell] (Please needinfo) from comment #5)
> It happens regardless of APZ settings after trying it on and off. It looks
> it also is in the normal debugger when scrolling fast, so not worker
> debugger specific.

Okay, in that case, what about bug 1243554?

It claims issues with both APZ on and off.

Comment 7

[Jordan Santell [:jsantell] [@jsantell]]

That looks like it might be it. Scrolling with the scrollbars doesn't seem to incur the same amount of jank compared to the trackpad. Thanks for the help in diagnosing -- feel free to close, but might be good to track in debugger too so others can see to not duplicate more bugs

Comment 8

[Eddy Bruel [:ejpbruel]]

Bug 1243554 has since been fixed. Jordan, did this resolve the issue, or should I leave the bug open for now?

Comment 9

[Jordan Santell [:jsantell] [@jsantell]]

Looks good to me! Thanks all!