1151406 - Waterfall view rendering causes UI jank

Status: RESOLVED WORKSFORME

(DevTools :: Performance Tools (Profiler/Timeline), defect, P2)

Description

[Sami Jaktholm]

Steps to reproduce:
1. Go to https://bug1080884.bugzilla.mozilla.org/attachment.cgi?id=8506982
2. Open the profiler and start recording
3. Let it run for 15-30 seconds (the more markers the more noticeable jank)
4. Stop the recording
5. Select a range of about 80 % the recording.
6. Move the selected range around

Expected results: The selection moves and the waterfall updates smoothly.

Actual results: The selection occasionally stops moving white the waterfall renders itself.

Profiling the profiler reveals that about 50% of the time is spent in _buildOutstandingMarkers.

Comment 2

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

More info in dupe bug 1157914

Comment 3

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

things we can do
1) we could not constantly rerender waterfall when scrubbing selections
2) since we have fixed height rows, we can only render rows in the current view (similar to James' console prototype in pdx/december)
3) ....use the performance tool on it

Comment 4

[Victor Porof [:vporof][:vp]]

(In reply to Jordan Santell [:jsantell] [@jsantell] from comment #3)
> things we can do
> 1) we could not constantly rerender waterfall when scrubbing selections

We already debounce selections I think.

> 2) since we have fixed height rows, we can only render rows in the current
> view (similar to James' console prototype in pdx/december)

We definitely already do this.

Comment 5

[Nick Fitzgerald [:fitzgen] [⏰PST; UTC-8]]

Attachment: profile-waterfall-1.json.gz

Here is a gzipped profile of the waterfall janking for many seconds.

This is so fun that when you import the profile, you can experience it as well.

Comment 6

[Victor Porof [:vporof][:vp]]

Bug 1157914 alleviates this problem a little bit, so things are better now. Marking as P2, but still wanting to fix it.

Comment 7

[Victor Porof [:vporof][:vp]]

perf-perf already blocks perf-tool-v2

Comment 8

[Victor Porof [:vporof][:vp]]

Many pref improvements were made now with bug 1152421. Reopen if this is still a major issue.