Disable thread pool creation when enabled OpenMP (#2485)

Author: fs-eire

onnxruntime/core/framework/session_options.h

@@ -55,6 +55,7 @@ struct SessionOptions {
   TransformerLevel graph_optimization_level = TransformerLevel::Level1;
 
   // controls the size of the thread pool used to parallelize the execution of tasks within individual nodes (ops)
+  // if OpenMP is enabled, this configuration will be ignored
   int intra_op_num_threads = 0;
 
   // controls the size of the thread pool used to parallelize the execution of nodes (ops)

onnxruntime/core/session/inference_session.cc

@@ -102,8 +102,12 @@ InferenceSession::InferenceSession(const SessionOptions& session_options,
     : session_options_(session_options),
       graph_transformation_mgr_(session_options.max_num_graph_transformation_steps),
       logging_manager_(logging_manager),
+#ifndef USE_OPENMP
       thread_pool_(concurrency::CreateThreadPool("intra_op_thread_pool",
                                                  session_options.intra_op_num_threads)),
+#else
+      thread_pool_(nullptr),
+#endif
       inter_op_thread_pool_(session_options.execution_mode == ExecutionMode::ORT_PARALLEL
                                 ? concurrency::CreateThreadPool("inter_op_thread_pool",
                                                                 session_options.inter_op_num_threads)

onnxruntime/test/perftest/README.md

@@ -32,7 +32,7 @@ Options:
         
 	-v: Show verbose information.
         
-	-x: [intra_op_num_threads]: Sets the number of threads used to parallelize the execution within nodes. A value of 0 means the test will auto-select a default. Must >=0.
+	-x: [intra_op_num_threads]: Sets the number of threads used to parallelize the execution within nodes. A value of 0 means the test will auto-select a default. Must >=0. If OpenMP is enabled, this configuration will be ignored.
 
 	-y: [inter_op_num_threads]: Sets the number of threads used to parallelize the execution of the graph (across nodes), A value of 0 means the test will auto-select a default. Must >=0.
 

onnxruntime/test/perftest/command_args_parser.cc

@@ -41,7 +41,7 @@ namespace perftest {
       "\t-p [profile_file]: Specifies the profile name to enable profiling and dump the profile data to the file.\n"
       "\t-s: Show statistics result, like P75, P90.\n"
       "\t-v: Show verbose information.\n"
-      "\t-x [intra_op_num_threads]: Sets the number of threads used to parallelize the execution within nodes, A value of 0 means ORT will pick a default. Must >=0.\n"
+      "\t-x [intra_op_num_threads]: Sets the number of threads used to parallelize the execution within nodes, A value of 0 means ORT will pick a default. Must >=0. If OpenMP is enabled, this configuration will be ignored.\n"
       "\t-y [inter_op_num_threads]: Sets the number of threads used to parallelize the execution of the graph (across nodes), A value of 0 means ORT will pick a default. Must >=0.\n"
       "\t-P: Use parallel executor instead of sequential executor.\n"
       "\t-o [optimization level]: Default is 1. Valid values are 0 (disable), 1 (basic), 2 (extended), 99 (all).\n"
@@ -123,10 +123,15 @@ namespace perftest {
         test_config.run_config.f_verbose = true;
         break;
       case 'x':
+#ifdef USE_OPENMP
+        fprintf(stderr, "cannot use argument '-x' when OpenMP is enabled.\n");
+        return false;
+#else
         test_config.run_config.intra_op_num_threads = static_cast<int>(OrtStrtol<PATH_CHAR_TYPE>(optarg, nullptr));
         if (test_config.run_config.intra_op_num_threads < 0) {
           return false;
         }
+#endif
         break;
       case 'y':
         test_config.run_config.inter_op_num_threads = static_cast<int>(OrtStrtol<PATH_CHAR_TYPE>(optarg, nullptr));

onnxruntime/test/perftest/ort_test_session.cc

@@ -82,7 +82,7 @@ OnnxRuntimeTestSession::OnnxRuntimeTestSession(Ort::Env& env, std::random_device
   } else if (provider_name == onnxruntime::kAclExecutionProvider) {
 #ifdef USE_ACL
     Ort::ThrowOnError(OrtSessionOptionsAppendExecutionProvider_ACL(session_options,
-	performance_test_config.run_config.enable_cpu_mem_arena ? 1 : 0));
+                                                                   performance_test_config.run_config.enable_cpu_mem_arena ? 1 : 0));
 #else
     ORT_THROW("Acl is not supported in this build\n");
 #endif
@@ -100,8 +100,11 @@ OnnxRuntimeTestSession::OnnxRuntimeTestSession(Ort::Env& env, std::random_device
   else
     session_options.DisableMemPattern();
   session_options.SetExecutionMode(performance_test_config.run_config.execution_mode);
+
+#ifndef USE_OPENMP
   fprintf(stdout, "Setting intra_op_num_threads to %d\n", performance_test_config.run_config.intra_op_num_threads);
   session_options.SetIntraOpNumThreads(performance_test_config.run_config.intra_op_num_threads);
+#endif
 
   if (performance_test_config.run_config.execution_mode == ExecutionMode::ORT_PARALLEL) {
     fprintf(stdout, "Setting inter_op_num_threads to %d\n", performance_test_config.run_config.inter_op_num_threads);