From b184964f0fb018acf9e0e404307d095854ab1cd4 Mon Sep 17 00:00:00 2001
From: James Daugherty <jdaugherty@jdresources.net>
Date: Tue, 16 Dec 2025 11:22:34 -0500
Subject: [PATCH] doc - #15293 - add warning about invokedynamic performance

---
 grails-doc/src/en/guide/upgrading/upgrading60x.adoc | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/grails-doc/src/en/guide/upgrading/upgrading60x.adoc b/grails-doc/src/en/guide/upgrading/upgrading60x.adoc
index 3aa2c618f1c..658d4cf5c4a 100644
--- a/grails-doc/src/en/guide/upgrading/upgrading60x.adoc
+++ b/grails-doc/src/en/guide/upgrading/upgrading60x.adoc
@@ -62,6 +62,16 @@ In your gradle file, you can force a dependency upgrade via this code:
   }
 ----
 
+5. By default, Groovy 4 switches away from callsite optimizations and uses invokedynamic instead. This can result in performance regressions compared to Grails 6. Groovy 5 will remove the ability to disable invokedynamic, but to disable it for Groovy 4, modify your `build.gradle` to include the following:
+
+[source,groovy]
+.build.gradle
+----
+  tasks.withType(GroovyCompile).configureEach {
+        groovyOptions.optimizationOptions.indy = false
+  }
+----
+
 ==== 3. Unified Project Version
 
 Grails 7 moved to a mono repository.