SPS Profiler's little popout UI panel causes severe performance degradation, throwing off profiles

RESOLVED FIXED

Status

()

RESOLVED FIXED
7 years ago
6 years ago

People

(Reporter: kael, Unassigned)

Tracking

16 Branch
x86_64
Windows 7
Points:
---

Firefox Tracking Flags

(Not tracked)

Details

(URL)

(Reporter)

Description

7 years ago
The popout panel that appears when you click the 'Profiler: Status' add-on bar panel has severe performance consequences that show up in recorded profiles.

If you make minimum use of the panel (only open it to start/stop profiling) it will only add roughly 0.5-1 seconds worth of noise to your profile, that you can ignore by filtering - if you know to ignore it - but if you leave it open to observe the shiny sparkline, it will absolutely fill your profile with noise generated by rendering gradients, svg filters, etc. See the following for an example:

http://people.mozilla.com/~bgirard/cleopatra/?report=AMIfv96PWpYZMSESBA0h0OD7t6hdxrkfknKVbiwOOmtH-BrNWUU3eMsZeS3LYyHe2Q7-McTFsBFbTJ66Se2-Bw8woMYdWOWL0vvQSYQH52HsM0oeNke8HN9em04SFl4xwcUvUxRT1mvhfBmx4Fdqtah6uKw-koWemw

Turn on 'merge unbranched call paths' and drill down into the obvious hotspot. You can see a bunch of CPU time here is going to rendering the browser and profiler UI.
I've been wondering if that graph was useful at all. It could probably be made optional.
It's not useful, it's mostly 'for show' and make the UI a bit nicer. I wouldn't be terribly sad to see it go. But we will always get some noise when starting/stopping the profile from the panel. I normally use the hotkeys which removes this noise but add key event processing.
The graph has been removed since it wasn't useful at all.
Status: NEW → RESOLVED
Last Resolved: 6 years ago
Resolution: --- → FIXED
You need to log in before you can comment on or make changes to this bug.