My QOL Scripts uses the GraalJS engine, which can run in two modes: a slower "interpreted" mode and a much faster "JIT-compiled" mode. By default, Minecraft's JVM does not enable the features required for JIT compilation, so you may see a warning in your logs about a "fallback runtime."

For the best performance, especially when running complex scripts, it is highly recommended that you add the following JVM arguments to your Minecraft launch configuration.

Add the following arguments to your JVM configuration for a significant performance boost:

--add-modules=jdk.zipfs --add-exports=java.base/sun.nio.ch=ALL-UNNAMED --add-opens=java.base/java.lang=ALL-UNNAMED --add-opens=java.base/java.nio=ALL-UNNAMED

Note: These are standard arguments for modern Java versions on Fabric and are generally safe and beneficial for other mods as well.

And for MQS specifically:

-XX:+EnableJVMCI -XX:+EnableDynamicAgentLoading

• -XX:+EnableJVMCI: Enables the Java Virtual Machine Compiler Interface. This is the key that allows GraalJS to use its high-performance, just-in-time (JIT) compiler, making scripts run much faster.
• -XX:+EnableDynamicAgentLoading: Required for the advanced HookManager API to function correctly. While you may not write hooks yourself, scripts you download might use this feature.

If you are unable or do not wish to enable JVMCI, you can hide the performance warning message from your logs with this argument:

• -Dpolyglot.engine.WarnInterpreterOnly=false: Disables the console warning about GraalJS running in the slower interpreted mode.

These instructions are for the official Minecraft Launcher. The process is similar for other launchers like Prism or the Modrinth App.

1. Open the Minecraft Launcher.

2. Go to the "Installations" tab.

3. Hover over your Fabric installation and click the three dots (...), then select "Edit".

4. Click "More Options" to reveal the "JVM Arguments" text box.

5. In the text box, add the recommended arguments. It's best to add them to the beginning of the line.

   Example: Before: -Xmx2G ...

   After: -XX:+EnableJVMCI -XX:+EnableDynamicAgentLoading -Xmx2G ...

6. Click "Save" and launch the game. The performance warning should now be gone, and your scripts will run much faster!