Slowness on the UI after using react-native-v8

[kelvinsantos]

Hello,

I tried to integrate react-native-v8 into our react native expo application, details as follows:

• react:18.2.0
• react-native:0.71.3
• react-native-v8:2.0.0
• v8-android-jit:11.110.1
• expo:48.0.4

But after the build and confirmed that our app is running v8. The UI/UX got so laggy.
But the performance of the app has been significantly better. Please let me know if there is anything that we can do.

Screen_Recording_20230228_153949_CRDZ.mp4

[Kudo]

hi there! could you create a repro for me to further investigate? i was thinking whether this comes from react-native upgrade, or v8 upgrade.

[kelvinsantos]

hi @Kudo, I found out the issue already! With my project I have the "react-native-reanimated": "~2.14.4", which caused the slowness to the application.

[affansk]

Hi @Kudo its very slow i have the latest version of reanimated "^3.0.2" and react native 0.71.5

[sunnylqm]

same issue. working fine if switch back to "jsc-android": "^294992.0.0"

[Kudo]

is that reanimated 3 + v8 only? would be good if someone could share a repro project.

[sunnylqm]

@Kudo

v8 + reanimated2:
https://github.com/OneKeyHQ/app-monorepo/tree/feat/rn71-expo48-v8

hermes + reanimated2:
https://github.com/OneKeyHQ/app-monorepo/tree/feat/rn71-expo48

the diff:
OneKeyHQ/app-monorepo@feat/rn71-expo48...feat/rn71-expo48-v8

it's a complicated monorepo and there are some issues with the new metro, so please run yarn native first in workspace root folder and open a new terminal to run yarn android. And you may need to uninstall the app before switching to another engine (guess maybe related to realm database?)

[Kudo]

great repro, thanks @sunnylqm!
it turns out the performance regression is coming from v8 upgrade and i've tried to address on Kudo/v8-android-buildscripts#36. could you try to upgrade v8-android-jit@^11.110.3 and check whether it improves the performance for you?

[sunnylqm]

@Kudo Thanks for looking into this. I just tried v8-android-jit@^11.110.3 but unfortunately it seems even worse (took minutes to boot and got lots of unresponsive warnings)

[Kudo]

having no idea in the meantime but only to downgrade v8 for original version 10.0.139.9.
published v8-android-jit@11.1000.3 and that requires a patch to react-native-v8.
not get a chance to test on @sunnylqm's repo but updates here. hopes someone could help to verify this.

--- a/node_modules/react-native-v8/src/v8runtime/V8Inspector.cpp
+++ b/node_modules/react-native-v8/src/v8runtime/V8Inspector.cpp
@@ -150,8 +150,7 @@ InspectorClient::InspectorClient(
   session_ = inspector_->connect(
       contextGroupId,
       channel_.get(),
-      inspectorNameStringView,
-      v8_inspector::V8Inspector::kFullyTrusted);
+      inspectorNameStringView);
   context_.Reset(isolate_, context);

   inspector_->contextCreated(v8_inspector::V8ContextInfo(

[kylecesmat]

@Kudo this change works great! No more performance issues noted after applyingv8-android-jit@11.1000.3

[sunnylqm]

@Kudo I can confirm v8-android-jit@11.1000.3 is working again 🎉