clarification request for removing android_react_native_perf.use_separate_ui_bg_thread experiment

[hey99xx]

Is this a bug report?

No, but it's a clarification request from FB devs on a recent commit.

Have you read the Contributing Guidelines?

Yes

Environment

Android RN 0.51 above

Steps to Reproduce

Last night this commit 4f886a2 seems to remove UI-Background thread in React Native source code.

This looked like a very beneficial change in the first look, and I was experimenting with it. I understand some changes fail to reach the high-quality bar, or they're difficult to maintain, or there's some other reason that leads to their removal. In this case, I do not know what happened with it. All the commit message says is:

Remove android_react_native_perf.use_separate_ui_bg_thread experiment.

I have an app with infinite scroll views with lots of cards (similar to FB news feed on mobile) and multiple connections opened to fetch more data from the backend. Each card contains quite heavy views such as image carousels. We right now have lots of congestion in the native module thread, so I though this would be a solution to that.

Can I please ask for a clarification for why you did do this change in the first place, and what led you to remove it? If it still aligns with the needs of my app, and if it's not horribly buggy I may revert this commit in my company's RN version (we have capacity to maintain an internal fork, if this will lead to actual performance improvements).

Expected Behavior

I would have liked to this experiment.

Actual Behavior

It seems I won't be able to.

[MacKentoch]

Sad but interesting.

Apart from synchronization issues I don't understand this removal.

[chirag04]

cc @AaaChiuuu @hramos

[hey99xx]

Just commenting so the mods don't close this with the Ice-Box label. It'd be nice to have an answer even it's simply, "it was buggy so now it's gone"

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Maybe the issue has been fixed in a recent release, or perhaps it is not affecting a lot of people. If you think this issue should definitely remain open, please let us know why. Thank you for your contributions.

[hey99xx]

Commenting one more time to make this non-stale. If it gets stale again, I'm just going to let it be closed.