Profiling sources of JS garbage no longer works? about profiler

[mstange]

In that profile you also have the nostacksampling feature set. That's probably why the allocations don't have stacks.

The UI could probably do a better job of pointing out conflicting features.

[juj]

Ohhh, thanks! I thought I would disable it since I was not looking to do any time based sampling. I indeed see that it works now with that restored. Got https://share.firefox.dev/3NqXDVK now with stack sampling restored.

Do you know if this mode should capture 100% of all JS allocations, or is it still probabilistic?

[mstange]

I believe it is still probabilistic. @gregtatum might know more.

[juj]

I vaguely remember some years ago my workflow used to be to navigate to about:config, then search for word probability and then change the pref that popped up from 0.05 to 1.0 to make sure I would catch all the allocations. Though now when I try, I don't find any pref that would match with that name. I wonder if the profiler might now be hardcoded to take only a fraction of all allocations...?