diff --git a/paddle/fluid/inference/analysis/data_flow_graph_tester.cc b/paddle/fluid/inference/analysis/data_flow_graph_tester.cc
index 040ca1951463760b83c30647125d6ea46efc1fb1..1682011c3d8cc9927a4b026b370671798cace625 100644
--- a/paddle/fluid/inference/analysis/data_flow_graph_tester.cc
+++ b/paddle/fluid/inference/analysis/data_flow_graph_tester.cc
@@ -160,77 +160,6 @@ TEST(DataFlowGraph, Build_IR_Graph) {
   ASSERT_EQ(graph.nodes.size(), ir_graph.Nodes().size());
 }
 
-// FlexibleDFS
-/*
- * Graph topology
- * inputs: 0
- * 0 -> 1
- * 1 -> 2
- * 1 -> 3
- * 3 -> 4
- * 4 -> 5
- * 5 -> 2
- */
-TEST(DataFlowGraph, flexibledfs) {
-  DataFlowGraph graph;
-
-  for (int i = 0; i < 6; i++) {
-    auto* node = graph.nodes.Create(Node::Type::kValue);
-    node->SetName("node-" + std::to_string(i));
-  }
-
-  auto add_link = [&](int i, int j) {
-    Node* source = graph.nodes.GetMutable(i);
-    Node* target = graph.nodes.GetMutable(j);
-    target->inlinks.push_back(source);
-    source->outlinks.push_back(target);
-  };
-
-  add_link(0, 1);
-  add_link(1, 2);
-  add_link(1, 3);
-  add_link(3, 4);
-  add_link(4, 5);
-  add_link(5, 2);
-  graph.Build();
-
-  std::vector<const Node*> order;
-  FlexibleDFS(graph.inputs(), false, nullptr, [&order](const Node* n) {
-    order.push_back(n);
-    return true;
-  });
-
-  ASSERT_EQ(order.size(), 6UL);
-
-  order.clear();
-  // reverse dfs
-  FlexibleDFS(graph.outputs(), true, nullptr, [&order](const Node* n) {
-    order.push_back(n);
-    return true;
-  });
-
-  ASSERT_EQ(order.size(), 6UL);
-
-  // If we delete
-  Node* last_node = graph.nodes.GetMutable(2);
-  Node* direct_node = graph.nodes.GetMutable(1);
-  std::vector<Node*> source_nodes;
-  for (Node* node : last_node->inlinks) {
-    if (node != direct_node) source_nodes.push_back(node);
-  }
-
-  bool has_cycle = false;
-  FlexibleDFS(source_nodes, true, nullptr,
-              [&has_cycle, direct_node](const Node* n) {
-                if (n == direct_node) {
-                  has_cycle = true;
-                  return false;
-                }
-                return true;
-              });
-  ASSERT_TRUE(has_cycle);
-}
-
 }  // namespace analysis
 }  // namespace inference
 }  // namespace paddle
diff --git a/paddle/fluid/inference/analysis/subgraph_splitter.cc b/paddle/fluid/inference/analysis/subgraph_splitter.cc
index 857375fc21df0a6d35e94438431160f7bcd20ec0..773fceeeb2e0f353a901eba84e30dc0e6f12fe99 100644
--- a/paddle/fluid/inference/analysis/subgraph_splitter.cc
+++ b/paddle/fluid/inference/analysis/subgraph_splitter.cc
@@ -138,7 +138,7 @@ void UnionContractedNodes(const std::unordered_map<int, BriefNode *> &node_map,
   }
 }
 
-// FlexibleDfS
+// FlexibleDFS
 // If reverse is true, do reverse dfs.
 // If enter func is not nullptr, calls enter(node) before visiting any children
 // of node.