[runtime] reduce set_input and set_input_zero_copy overhead

Author: hlu1

src/runtime/graph/graph_runtime.cc

@@ -31,11 +31,12 @@
 
 #include <algorithm>
 #include <functional>
+#include <memory>
 #include <numeric>
-#include <vector>
 #include <string>
-#include <memory>
+#include <unordered_set>
 #include <utility>
+#include <vector>
 
 namespace tvm {
 namespace runtime {
@@ -78,18 +79,21 @@ void GraphRuntime::Init(const std::string& graph_json,
   ctxs_ = ctxs;
   this->SetupStorage();
   this->SetupOpExecs();
+  for (size_t i = 0; i < input_nodes_.size(); i++) {
+    uint32_t nid = input_nodes_[i];
+    std::string& name = nodes_[nid].name;
+    input_map_[name] = i;
+  }
 }
 /*!
  * \brief Get the input index given the name of input.
  * \param name The name of the input.
  * \return The index of input.
  */
 int GraphRuntime::GetInputIndex(const std::string& name) {
-  for (size_t i = 0; i< input_nodes_.size(); ++i) {
-    uint32_t nid = input_nodes_[i];
-    if (nodes_[nid].name == name) {
-      return static_cast<int>(i);
-    }
+  auto it = input_map_.find(name);
+  if (it != input_map_.end()) {
+    return it->second;
   }
   LOG(WARNING) << "Warning: cannot find \"" << name << "\" among input";
   return -1;
@@ -125,16 +129,8 @@ void GraphRuntime::SetInputZeroCopy(int index, DLTensor* data_ref) {
   }
 
   // Update the data pointer for each argument of each op
-  for (auto& op_arg : op_args_) {
-    if (op_arg) {
-      const auto it = op_arg->input_entry_ids.find(eid);
-      if (it != op_arg->input_entry_ids.end()) {
-        for (const auto i : it->second) {
-          DLTensor* t = static_cast<DLTensor*>(op_arg->arg_values[i].v_handle);
-          t->data = data_ref->data;
-        }
-      }
-    }
+  for (DLTensor* t : input_dltensors_[eid]) {
+    t->data = data_ref->data;
   }
 }
 /*!
@@ -324,34 +320,38 @@ void GraphRuntime::SetupStorage() {
 
 void GraphRuntime::SetupOpExecs() {
   op_execs_.resize(this->GetNumOfNodes());
-  op_args_.resize(this->GetNumOfNodes());
+  input_dltensors_.resize(num_node_entries());
+  std::unordered_set<uint32_t> input_node_eids;
+  for (size_t i = 0; i < input_nodes_.size(); i++) {
+    uint32_t nid = input_nodes_[i];
+    input_node_eids.insert(entry_id(nid, 0));
+  }
+
   // setup the array and requirements.
   for (uint32_t nid = 0; nid < this->GetNumOfNodes(); ++nid) {
     const auto& inode = nodes_[nid];
     if (inode.op_type == "null") continue;
     std::vector<DLTensor> args;
-    std::vector<uint32_t> input_entry_ids;
     for (const auto& e : inode.inputs) {
       uint32_t eid = this->entry_id(e);
       args.push_back(*(data_entry_[eid].operator->()));
-      input_entry_ids.push_back(eid);
     }
     for (uint32_t index = 0; index < inode.param.num_outputs; ++index) {
       uint32_t eid = this->entry_id(nid, index);
       args.push_back(*(data_entry_[eid].operator->()));
     }
     CHECK(inode.op_type == "tvm_op") << "Can only take tvm_op as op";
 
-    std::tie(op_execs_[nid], op_args_[nid]) =
+    std::shared_ptr<OpArgs> op_args = nullptr;
+    std::tie(op_execs_[nid], op_args) =
         CreateTVMOp(inode.param, args, inode.inputs.size());
-    auto& entry_to_input_pos = op_args_[nid]->input_entry_ids;
-    for (uint32_t i = 0; i < input_entry_ids.size(); ++i) {
-      const auto eid = input_entry_ids[i];
-      auto it = entry_to_input_pos.find(eid);
-      if (it == entry_to_input_pos.end()) {
-        entry_to_input_pos.emplace(eid, std::vector<uint32_t>{i});
-      } else {
-        it->second.push_back(i);
+
+    for (size_t i = 0; i < inode.inputs.size(); i++) {
+      uint32_t eid = this->entry_id(inode.inputs[i]);
+      // check if op input is model input
+      if (input_node_eids.count(eid) > 0) {
+        input_dltensors_[eid].push_back(
+            static_cast<DLTensor*>(op_args->arg_values[i].v_handle));
       }
     }
   }

src/runtime/graph/graph_runtime.h

@@ -70,7 +70,6 @@ struct TVMOpParam {
 class GraphRuntime : public ModuleNode {
   struct OpArgs {
     std::vector<DLTensor> args;
-    std::unordered_map<uint32_t, std::vector<uint32_t> > input_entry_ids;
     std::vector<TVMValue> arg_values;
     std::vector<int> arg_tcodes;
     std::vector<int64_t> shape_data;
@@ -399,6 +398,10 @@ class GraphRuntime : public ModuleNode {
   std::vector<Node> nodes_;
   /*! \brief The argument nodes. */
   std::vector<uint32_t> input_nodes_;
+  /*! \brief Map of input names to input indices. */
+  std::unordered_map<std::string, uint32_t> input_map_;
+  /*! \brief Used for quick node input DLTensor* lookup given an input eid. */
+  std::vector<std::vector<DLTensor*>> input_dltensors_;
   /*! \brief Used for quick entry indexing. */
   std::vector<uint32_t> node_row_ptr_;
   /*! \brief Output entries. */
@@ -417,8 +420,6 @@ class GraphRuntime : public ModuleNode {
   std::vector<size_t> data_alignment_;
   /*! \brief Operator on each node. */
   std::vector<std::function<void()> > op_execs_;
-  /*! \brief Arg info of TVM ops */
-  std::vector<std::shared_ptr<OpArgs> > op_args_;
 };
 
 std::vector<TVMContext> GetAllContext(const TVMArgs& args);