From ffd1c0dfd52e0a021a5b938a3b778594f5c35b33 Mon Sep 17 00:00:00 2001
From: Arseniy Obolenskiy <arseniy.obolenskiy@amd.com>
Date: Sat, 24 Oct 2026 20:24:43 +0200
Subject: [PATCH] [mlir] Skip uniquer locks when a context starts without
 threading (#235294)

---
 mlir/lib/IR/MLIRContext.cpp | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/mlir/lib/IR/MLIRContext.cpp b/mlir/lib/IR/MLIRContext.cpp
index 5c1c3b062f37cc..9eae9676a2b2c3 100644
--- a/mlir/lib/IR/MLIRContext.cpp
+++ b/mlir/lib/IR/MLIRContext.cpp
@@ -287,8 +287,16 @@ class MLIRContextImpl {
     if (threadingIsEnabled) {
       ownedThreadPool = std::make_unique<llvm::DefaultThreadPool>();
       threadPool = ownedThreadPool.get();
+    } else {
+      disableUniquerMultithreading(true);
     }
   }
+  /// Update the threading mode for each of the uniquers.
+  void disableUniquerMultithreading(bool disable) {
+    affineUniquer.disableMultithreading(disable);
+    attributeUniquer.disableMultithreading(disable);
+    typeUniquer.disableMultithreading(disable);
+  }
   ~MLIRContextImpl() {
     for (auto typeMapping : registeredTypes)
       typeMapping.second->~AbstractType();
@@ -625,10 +633,7 @@ void MLIRContext::disableMultithreading(bool disable) {
 
   impl->threadingIsEnabled = !disable;
 
-  // Update the threading mode for each of the uniquers.
-  impl->affineUniquer.disableMultithreading(disable);
-  impl->attributeUniquer.disableMultithreading(disable);
-  impl->typeUniquer.disableMultithreading(disable);
+  impl->disableUniquerMultithreading(disable);
 
   // Destroy thread pool (stop all threads) if it is no longer needed, or create
   // a new one if multithreading was re-enabled.