1346032 - Clarify which threads are being profiled

Status: RESOLVED WORKSFORME

(Core :: Gecko Profiler, enhancement)

Description

[Nicholas Nethercote [inactive]]

By default, the Gecko Profiler profilers the "GeckoMain" and "Compositor" threads. You can change this via Settings > Threads. Once you do change it, the profiler seems to remember the change even when you restart the browser. But Settings > Threads still shows "GeckoMain,Compositor" in that case.

This is really confusing, and leads to cases where people think they are running the same workload but they're not, which makes reproduction of bugs confusing. Julian and I have hit such discrepancies multiple times now.

Either the thread selection should be reset on browser restart, or the Settings > Threads box should be accurate. Or both.

I don't know if this problem lies in the C++ code or the extension or a combination.

Comment 1

[Markus Stange [:mstange]]

(In reply to Nicholas Nethercote [:njn] from comment #0)
> But Settings > Threads still shows "GeckoMain,Compositor" in that case.

Yikes. I'm so sorry. I've fixed the add-on. The state was correct internally, it just wasn't reflected in the UI.
https://github.com/devtools-html/Gecko-Profiler-Addon/commit/1209e596c4ca80e30e711041073f824acf07cf60

Comment 2

[Markus Stange [:mstange]]

Bug 1346592 still remains, though, and I suspect that that's a bug in the platform, not in the add-on.

Comment 3

[Nicholas Nethercote [inactive]]

> I've fixed the add-on. The state was correct
> internally, it just wasn't reflected in the UI.
> https://github.com/devtools-html/Gecko-Profiler-Addon/commit/
> 1209e596c4ca80e30e711041073f824acf07cf60

Excellent. Thank you. That might be enough to resolve this bug... I'll look more closely early next week. I'll look at bug 1346592 as well.

Comment 4

[Nicholas Nethercote [inactive]]

I updated to version 2.0.34 of the profiler add-on and things are much better now. Thank you for the fix.