code clean test=develop

paddle/fluid/framework/details/multi_devices_graph_pass.cc

@@ -167,10 +167,6 @@ std::unique_ptr<ir::Graph> MultiDevSSAGraphBuilderBase::ApplyImpl(
 
   bool is_forwarding = true;
   bool insert_collection_ops = NeedCollectiveOps();
-  if (strategy_.async_mode_) {
-    // async mode did not need to merge gradient
-    insert_collection_ops = false;
-  }
 
   for (ir::Node *node : sorted_ops) {
     if (DealWithSpecialOp(&result, node)) {
@@ -749,10 +745,6 @@ bool DistSSAGraphBuilder::DealWithSpecialOp(ir::Graph *result,
                                             ir::Node *node) const {
   bool insert_op = false;
   if (OpHaveRole(*node, OpRole::kRPC)) {
-    // in async_mode, each graph will send it's own gradient.
-    if (strategy_.async_mode_ && node->Op()->Type() == "send") {
-      return false;
-    }
     int op_dev_id = CreateRPCOp(result, node);
     PADDLE_ENFORCE(op_dev_id != -1,
                    "Can not schedule the RPC operator to the right place.");
@@ -768,11 +760,6 @@ bool DistSSAGraphBuilder::DealWithSpecialOp(ir::Graph *result,
     insert_op = true;
     need_broadcast_var_ = true;
   } else if (OpHaveRole(*node, OpRole::kDist)) {
-    // in async_mode, each graph will send it's own gradient, do not need to
-    // merge gradient.
-    if (strategy_.async_mode_ && node->Op()->Type() != "concat") {
-      return false;
-    }
     int op_dev_id = CreateDistTrainOp(result, node);
     if (node->Op()->Type() == "concat") {
       // the input(block of parameter) of concat is on different device,
@@ -844,7 +831,7 @@ int DistSSAGraphBuilder::CreateRPCOp(ir::Graph *result, ir::Node *node) const {
     }
     auto recv_param_grad = boost::get<std::vector<std::string>>(
         node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleVarAttrName()));
-    if (recv_param_grad.size() == 2U && !strategy_.async_mode_) {
+    if (recv_param_grad.size() == 2U) {
       op_dev_id = GetVarDeviceID(recv_param_grad[1]);
       VLOG(10) << "recv param " << recv_param_grad[0]
                << " get grad place: " << recv_param_grad[1]