From ee6489fb699a059a802a6ac6aaba560eaa821727 Mon Sep 17 00:00:00 2001
From: embeddedt <42941056+embeddedt@users.noreply.github.com>
Date: Sun, 27 Jul 2025 14:55:34 -0400
Subject: [PATCH] Make mixin.perf.thread_priorities limit background thread
 count as well

---
 .../modernfix/core/ModernFixMixinPlugin.java         | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/common/src/main/java/org/embeddedt/modernfix/core/ModernFixMixinPlugin.java b/common/src/main/java/org/embeddedt/modernfix/core/ModernFixMixinPlugin.java
index 5fbe1c36..73b5eb8d 100644
--- a/common/src/main/java/org/embeddedt/modernfix/core/ModernFixMixinPlugin.java
+++ b/common/src/main/java/org/embeddedt/modernfix/core/ModernFixMixinPlugin.java
@@ -87,9 +87,21 @@ public class ModernFixMixinPlugin implements IMixinConfigPlugin {
                 t.setDaemon(true);
                 t.start();
             }
+
+            if (ModernFixPlatformHooks.INSTANCE.isClient() && ModernFixMixinPlugin.instance.isOptionEnabled("perf.thread_priorities.AdjustThreadCount")) {
+                computeBetterThreadCount();
+            }
         }
     }
 
+    private void computeBetterThreadCount() {
+        // Server thread + client thread + GC thread
+        int reservedCores = 3;
+        int availableBackgroundCores = Math.max(1, Runtime.getRuntime().availableProcessors() - reservedCores);
+        logger.info("Configuring Minecraft's max.bg.threads option with {} threads", availableBackgroundCores);
+        System.setProperty("max.bg.threads", String.valueOf(availableBackgroundCores));
+    }
+
 
     @Override
     public void onLoad(String mixinPackage) {