1 /* Copyright 2018 The TensorFlow Authors. All Rights Reserved. 2 3 Licensed under the Apache License, Version 2.0 (the "License"); 4 you may not use this file except in compliance with the License. 5 You may obtain a copy of the License at 6 7 http://www.apache.org/licenses/LICENSE-2.0 8 9 Unless required by applicable law or agreed to in writing, software 10 distributed under the License is distributed on an "AS IS" BASIS, 11 WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 12 See the License for the specific language governing permissions and 13 limitations under the License. 14 ==============================================================================*/ 15 #ifndef TENSORFLOW_CORE_GRAPPLER_OPTIMIZERS_SCOPED_ALLOCATOR_OPTIMIZER_H_ 16 #define TENSORFLOW_CORE_GRAPPLER_OPTIMIZERS_SCOPED_ALLOCATOR_OPTIMIZER_H_ 17 18 #include <atomic> 19 #include <unordered_set> 20 #include <vector> 21 22 #include "absl/container/flat_hash_map.h" 23 #include "absl/container/flat_hash_set.h" 24 #include "tensorflow/core/grappler/optimizers/graph_optimizer.h" 25 #include "tensorflow/core/grappler/utils.h" 26 #include "tensorflow/core/protobuf/rewriter_config.pb.h" 27 28 namespace tensorflow { 29 class Graph; 30 31 namespace grappler { 32 class GraphProperties; 33 class NodeMap; 34 class ScopedAllocatorOptimizer; 35 36 // An Optimizer that introduces ScopedAllocators in order to reduce data 37 // movement and consolidate some kinds of Ops. 38 class ScopedAllocatorOptimizer : public GraphOptimizer { 39 public: 40 ScopedAllocatorOptimizer(RewriterConfig::Toggle opt_level, 41 const ScopedAllocatorOptions& opts); 42 ~ScopedAllocatorOptimizer() override; 43 name()44 string name() const override { return "scoped_allocator_optimizer"; } 45 UsesFunctionLibrary()46 bool UsesFunctionLibrary() const override { return true; } 47 48 Status Optimize(Cluster* cluster, const GrapplerItem& item, 49 GraphDef* optimized_graph) override; 50 51 // Map from an Op name to a vector of Nodes with that Op. 52 typedef absl::flat_hash_map<string, std::vector<NodeDef*>> DevOpOccurrences; 53 // Map from a device name to a DevOpOccurrences map. 54 typedef absl::flat_hash_map<string, DevOpOccurrences> GraphOpOccurrences; 55 typedef absl::flat_hash_set<string> OpNameSet; 56 57 Status ProcessGraphDef(GraphDef* graph, 58 const GraphProperties& graph_properties); 59 60 // Populates *occs by grouping Nodes with common Ops, according to 61 // their assigned devices. 62 void FindOpOccurrences(GraphDef* graph, const OpNameSet& op_names, 63 GraphOpOccurrences* occs); 64 65 // Returns a new, unused scope_id to be assigned to a ScopedAllocator that 66 // will allocate num_fields (> 0) separate tensors. 67 int NewScopedAllocatorId(int num_fields); 68 69 // Returns a new, unused id to be assigned to an IdentityOp used in this graph 70 // rewrite. 71 Status NewIdentityId(int* id); 72 node_map()73 NodeMap* node_map() { return node_map_.get(); } 74 repeated_outputs()75 const absl::flat_hash_set<string>& repeated_outputs() { 76 return repeated_outputs_; 77 } 78 79 // Appends values to the attr value under name in node_def, if present. 80 // If not present does an assignment. 81 static void ExtendNodeAttr(StringPiece name, const std::vector<int32>& values, 82 NodeDef* node_def); 83 84 // Class that knows how to do graph rewriting for a particular kind of Op in 85 // order to take advantage of a ScopedAllocator. 86 class Rewriter { 87 public: ~Rewriter()88 virtual ~Rewriter() {} 89 90 virtual Status Rewrite(ScopedAllocatorOptimizer* paopti, 91 int64_t invocation_count, GraphDef* graph, 92 const string& op_name, 93 const std::vector<NodeDef*>& nodes, 94 bool* applied) = 0; 95 SetGraphProperties(const GraphProperties & graph_properties)96 void SetGraphProperties(const GraphProperties& graph_properties) { 97 graph_properties_ = &graph_properties; 98 CHECK(graph_properties_); 99 } 100 101 protected: 102 const GraphProperties* graph_properties_; 103 }; 104 105 private: 106 Rewriter* GetRewriter(const string& op_name); 107 108 Status OrderNodeSet(std::vector<NodeDef*>* nodes) const; 109 110 RewriterConfig::Toggle opt_level_; 111 std::unordered_set<string> nodes_to_preserve_; 112 OpNameSet op_name_set_; 113 absl::flat_hash_map<string, Rewriter*> rewriters_; 114 std::vector<Rewriter*> to_delete_; 115 int next_sa_id_ = 1; 116 int next_identity_id_ = 1; 117 std::unique_ptr<NodeMap> node_map_; 118 // Keeps track of outputs, i.e. a node and an output index, that are inputs to 119 // more than one op groups that are candidates for scoped allocator 120 // optimization. 121 absl::flat_hash_set<string> repeated_outputs_; 122 }; 123 124 } // namespace grappler 125 } // namespace tensorflow 126 #endif // TENSORFLOW_CORE_GRAPPLER_OPTIMIZERS_SCOPED_ALLOCATOR_OPTIMIZER_H_ 127