From 86637704fd01493ddb57e455dbd1e35e4798237d Mon Sep 17 00:00:00 2001
From: Thomas Schatzl <tschatzl@openjdk.org>
Date: Thu, 21 May 2026 07:40:09 +0000
Subject: [PATCH] 8383856: Implement JEP 523: Make G1 the Default Garbage
 Collector in All Environments

Reviewed-by: stefank, phubner, sjohanss
---
 src/hotspot/share/gc/shared/gcConfig.cpp | 10 ++++++----
 1 file changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/hotspot/share/gc/shared/gcConfig.cpp b/src/hotspot/share/gc/shared/gcConfig.cpp
index 402bd0caacd..c31bce35354 100644
--- a/src/hotspot/share/gc/shared/gcConfig.cpp
+++ b/src/hotspot/share/gc/shared/gcConfig.cpp
@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2018, 2025, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2018, 2026, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
@@ -95,10 +95,11 @@ void GCConfig::fail_if_non_included_gc_is_selected() {
 }
 
 void GCConfig::select_gc_ergonomically() {
-  if (os::is_server_class_machine()) {
 #if INCLUDE_G1GC
-    FLAG_SET_ERGO_IF_DEFAULT(UseG1GC, true);
-#elif INCLUDE_PARALLELGC
+  FLAG_SET_ERGO_IF_DEFAULT(UseG1GC, true);
+#else
+  if (os::is_server_class_machine()) {
+#if INCLUDE_PARALLELGC
     FLAG_SET_ERGO_IF_DEFAULT(UseParallelGC, true);
 #elif INCLUDE_SERIALGC
     FLAG_SET_ERGO_IF_DEFAULT(UseSerialGC, true);
@@ -108,6 +109,7 @@ void GCConfig::select_gc_ergonomically() {
     FLAG_SET_ERGO_IF_DEFAULT(UseSerialGC, true);
 #endif
   }
+#endif
 }
 
 bool GCConfig::is_no_gc_selected() {