diff --git a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
--- a/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
+++ b/llvm/tools/llvm-jitlink/llvm-jitlink.cpp
@@ -801,23 +801,24 @@
 }
 
 static std::unique_ptr<JITLinkMemoryManager> createInProcessMemoryManager() {
-  if (!SlabAllocateSizeString.empty()) {
-    auto SlabSize = ExitOnErr(getSlabAllocSize(SlabAllocateSizeString));
 
+#ifdef _WIN32
+  size_t SlabSize = 1024 * 1024;
+#else
+  size_t SlabSize = 1024 * 1024 * 1024;
+#endif
+
+  if (!SlabAllocateSizeString.empty())
+    SlabSize = ExitOnErr(getSlabAllocSize(SlabAllocateSizeString));
+
+  if (NoExec && (SlabAddress || SlabPageSize))
     return ExitOnErr(
         MapperJITLinkMemoryManager::CreateWithMapper<InProcessDeltaMapper>(
             SlabSize));
-  }
 
-#ifdef _WIN32
   return ExitOnErr(
       MapperJITLinkMemoryManager::CreateWithMapper<InProcessMemoryMapper>(
-          1024 * 1024));
-#else
-  return ExitOnErr(
-      MapperJITLinkMemoryManager::CreateWithMapper<InProcessMemoryMapper>(
-          1024 * 1024 * 1024));
-#endif
+          SlabSize));
 }
 
 Expected<std::unique_ptr<jitlink::JITLinkMemoryManager>>