Merge pull request #13360 from Yancey1989/parallel_bcast

move bcast op into graph passes

Author: Yan Xu

benchmark/fluid/args.py

@@ -140,5 +140,11 @@ def parse_args():
         '--use_lars',
         action='store_true',
         help='If set, use lars for optimizers, ONLY support resnet module.')
+    parser.add_argument(
+        '--reduce_strategy',
+        type=str,
+        choices=['reduce', 'all_reduce'],
+        default='all_reduce',
+        help='Specify the reduce strategy, can be reduce, all_reduce')
     args = parser.parse_args()
     return args

benchmark/fluid/fluid_benchmark.py

@@ -170,6 +170,14 @@ def train_parallel(train_args, test_args, args, train_prog, test_prog,
     strategy = fluid.ExecutionStrategy()
     strategy.num_threads = args.cpus
     strategy.allow_op_delay = False
+    build_strategy = fluid.BuildStrategy()
+    if args.reduce_strategy == "reduce":
+        build_strategy.reduce_strategy = fluid.BuildStrategy(
+        ).ReduceStrategy.Reduce
+    else:
+        build_strategy.reduce_strategy = fluid.BuildStrategy(
+        ).ReduceStrategy.AllReduce
+
     avg_loss = train_args[0]
 
     if args.update_method == "pserver":
@@ -184,6 +192,7 @@ def train_parallel(train_args, test_args, args, train_prog, test_prog,
         avg_loss.name,
         main_program=train_prog,
         exec_strategy=strategy,
+        build_strategy=build_strategy,
         num_trainers=num_trainers,
         trainer_id=trainer_id)
 

benchmark/fluid/models/mnist.py

@@ -67,11 +67,14 @@ def cnn_model(data):
 
 def get_model(args, is_train, main_prog, startup_prog):
     # NOTE: mnist is small, we don't implement data sharding yet.
-    filelist = [
-        os.path.join(args.data_path, f) for f in os.listdir(args.data_path)
-    ]
+    opt = None
+    data_file_handle = None
     with fluid.program_guard(main_prog, startup_prog):
         if args.use_reader_op:
+            filelist = [
+                os.path.join(args.data_path, f)
+                for f in os.listdir(args.data_path)
+            ]
             data_file_handle = fluid.layers.open_files(
                 filenames=filelist,
                 shapes=[[-1, 1, 28, 28], (-1, 1)],
@@ -100,7 +103,7 @@ def get_model(args, is_train, main_prog, startup_prog):
             if is_train:
                 opt = fluid.optimizer.AdamOptimizer(
                     learning_rate=0.001, beta1=0.9, beta2=0.999)
-                opt.minimize()
+                opt.minimize(avg_cost)
                 if args.memory_optimize:
                     fluid.memory_optimize(main_prog)
 

paddle/fluid/framework/details/all_reduce_op_handle.cc

@@ -46,7 +46,8 @@ AllReduceOpHandle::AllReduceOpHandle(ir::Node *node,
 #endif
 
 void AllReduceOpHandle::RunImpl() {
-  platform::RecordEvent r("all_reduce", nullptr);
+  platform::RecordEvent record_event(Name(), dev_ctxes_.begin()->second);
+
   if (NoDummyInputSize() == 1) {
     return;  // No need to all reduce when GPU count = 1;
   } else {

paddle/fluid/framework/details/broadcast_op_handle.cc

@@ -15,12 +15,15 @@
 #include "paddle/fluid/framework/details/broadcast_op_handle.h"
 #include "paddle/fluid/framework/details/container_cast.h"
 #include "paddle/fluid/framework/details/variable_visitor.h"
+#include "paddle/fluid/platform/profiler.h"
 
 namespace paddle {
 namespace framework {
 namespace details {
 
 void BroadcastOpHandle::RunImpl() {
+  platform::RecordEvent record_event(Name(), dev_ctxes_.begin()->second);
+
   if (places_.size() == 1) return;
 
   // The input and output may have dummy vars.

paddle/fluid/framework/details/multi_devices_graph_pass.cc

@@ -348,14 +348,31 @@ std::unique_ptr<ir::Graph> MultiDevSSAGraphBuilder::ApplyImpl(
 
   size_t cur_device_id = 0;
   bool is_forwarding = true;
+  bool is_dist_train = false;
 
   for (ir::Node *node : sorted_ops) {
     if (boost::get<int>(
             node->Op()->GetAttr(OpProtoAndCheckerMaker::OpRoleAttrName())) ==
         static_cast<int>(OpRole::kRPC)) {
-      CreateRPCOp(&result, node);
+      int op_dev_id = CreateRPCOp(&result, node);
+      PADDLE_ENFORCE(op_dev_id != -1,
+                     "Can not schedule the RPC operator to the right place.");
+      if (node->Op()->Type() == "recv") {
+        auto recv_vars_attr =
+            boost::get<std::vector<std::string>>(node->Op()->GetNullableAttr(
+                OpProtoAndCheckerMaker::OpRoleVarAttrName()));
+        PADDLE_ENFORCE(recv_vars_attr.size() == 2UL);  // [parameter, gradient]
+        if (recv_vars_attr[0].find(".block") == std::string::npos) {
+          bcast_var_name_set[op_dev_id].emplace(recv_vars_attr[0]);
+        }
+      }
+      is_dist_train = true;
     } else if (IsDistTrainOp(node, send_vars, recv_vars)) {
-      CreateDistTrainOp(&result, node);
+      int op_dev_id = CreateDistTrainOp(&result, node);
+      if (node->Op()->Type() == "concat") {
+        auto origin_param_name = node->Op()->OutputArgumentNames()[0];
+        bcast_var_name_set[op_dev_id].emplace(origin_param_name);
+      }
     } else if (IsScaleLossOp(node)) {
       // user can customize loss@grad if not use_default_grad_scale_
       if (strategy_.gradient_scale_ !=
@@ -414,7 +431,9 @@ std::unique_ptr<ir::Graph> MultiDevSSAGraphBuilder::ApplyImpl(
                     CreateReduceOp(&result, g_name, cur_device_id);
                     graph->Get<ShardedVarDevice>(kShardedVarDevice)
                         .emplace(g_name, cur_device_id);
-                    bcast_var_name_set[cur_device_id].emplace(p_name);
+                    if (!is_dist_train) {
+                      bcast_var_name_set[cur_device_id].emplace(p_name);
+                    }
                     break;
                   case BuildStrategy::ReduceStrategy::kAllReduce:
                     if (IsSparseGradient(g_name)) {
@@ -436,14 +455,19 @@ std::unique_ptr<ir::Graph> MultiDevSSAGraphBuilder::ApplyImpl(
       }
     }
   }
-
   bool use_gpu = false;
 #ifdef PADDLE_WITH_CUDA
   use_gpu = nccl_ctxs_ != nullptr;
 #endif
 
-  if (use_gpu && strategy_.reduce_ == BuildStrategy::ReduceStrategy::kReduce) {
-    // Insert BCast Ops
+  // Insert broadcast operators principle:
+  // 1. Broadcast optimized parameters in Reduce strategy;
+  // 2. No need broadcast optimized parameters in AllReduce strategy because of
+  //    the optimization sub-graph would be run on every GPU;
+  // 3. Allways broadcast received parameters in Distribute Training.
+  if ((use_gpu &&
+       strategy_.reduce_ == BuildStrategy::ReduceStrategy::kReduce) ||
+      is_dist_train) {
     for (size_t dev_id = 0; dev_id < bcast_var_name_set.size(); ++dev_id) {
       auto &to_bcast_set = bcast_var_name_set[dev_id];
       for (auto &bcast_name : to_bcast_set) {
@@ -675,8 +699,8 @@ VarHandle *MultiDevSSAGraphBuilder::CreateReduceOp(ir::Graph *result,
   return var;
 }
 
-void MultiDevSSAGraphBuilder::CreateDistTrainOp(ir::Graph *result,
-                                                ir::Node *node) const {
+int MultiDevSSAGraphBuilder::CreateDistTrainOp(ir::Graph *result,
+                                               ir::Node *node) const {
   int op_dev_id = -1;
   std::vector<std::string> input_var_names;
   std::vector<std::string> output_var_names;
@@ -719,6 +743,7 @@ void MultiDevSSAGraphBuilder::CreateDistTrainOp(ir::Graph *result,
                  node->Op()->Type());
 
   CreateComputationalOp(result, node, op_dev_id);
+  return op_dev_id;
 }
 
 void SetOpInputsAllPlaces(ir::Graph *result, ir::Node *node, int num_places) {
@@ -737,8 +762,8 @@ void SetOpInputsAllPlaces(ir::Graph *result, ir::Node *node, int num_places) {
 }
 
 // Create RPC related op handles that connects its in ops and out ops.
-void MultiDevSSAGraphBuilder::CreateRPCOp(ir::Graph *result,
-                                          ir::Node *node) const {
+int MultiDevSSAGraphBuilder::CreateRPCOp(ir::Graph *result,
+                                         ir::Node *node) const {
   int op_dev_id = -1;
   if (node->Op()->Type() == "send") {
     // TODO(paddle-dev): getting the first var is not safe.
@@ -824,6 +849,7 @@ void MultiDevSSAGraphBuilder::CreateRPCOp(ir::Graph *result,
       CreateOpOutput(result, op_handle, new_node, p, outvar_dev_id);
     }
   }
+  return op_dev_id;
 }
 
 bool MultiDevSSAGraphBuilder::IsScaleLossOp(ir::Node *node) const {

paddle/fluid/framework/details/multi_devices_graph_pass.h

@@ -54,8 +54,8 @@ class MultiDevSSAGraphBuilder : public ir::Pass {
 
   bool IsScaleLossOp(ir::Node *node) const;
 
-  void CreateRPCOp(ir::Graph *result, ir::Node *node) const;
-  void CreateDistTrainOp(ir::Graph *result, ir::Node *node) const;
+  int CreateRPCOp(ir::Graph *result, ir::Node *node) const;
+  int CreateDistTrainOp(ir::Graph *result, ir::Node *node) const;
 
   /**
    * Is this operator as the end-point operator before/after send operator.

paddle/fluid/framework/details/reduce_op_handle.cc

@@ -27,7 +27,8 @@ namespace framework {
 namespace details {
 
 void ReduceOpHandle::RunImpl() {
-  platform::RecordEvent r("reduce", nullptr);
+  platform::RecordEvent record_event(Name(), dev_ctxes_.begin()->second);
+
   if (places_.size() == 1) return;
   // the input and output may have dummy var.
   auto in_var_handles = DynamicCast<VarHandle>(inputs_);

paddle/fluid/framework/details/scale_loss_grad_op_handle.cc

@@ -51,7 +51,7 @@ void ScaleLossGradOpHandle::RunImpl() {
               ->stream();
       memory::Copy(boost::get<platform::CUDAPlace>(place_), tmp,
                    platform::CPUPlace(), &coeff_, sizeof(float), stream);
-      VLOG(1) << place_ << "RUN Scale loss grad op";
+      VLOG(10) << place_ << "RUN Scale loss grad op";
     });
 #endif
   }

paddle/fluid/pybind/pybind.cc

@@ -683,7 +683,6 @@ All parameter, weight, gradient are variables in Paddle.
                   const std::string &, Scope *, std::vector<Scope *> &,
                   const ExecutionStrategy &, const BuildStrategy &, size_t,
                   size_t>())
-      .def("_bcast_params", &ParallelExecutor::BCastParamsToDevices)
       // NOTE: even we return a vec<Scope*>* to Python use reference policy.
       // We still cannot get local_scope from this vector, since the element
       // of vec<Scope*> will be freed by Python GC. We can only return Scope*