- MKLDNN Softmax Grad Op

- Added hash function inside of MKLDNN softmax op to be used as handle for primitives stroing in a
context

- Style fixes to softmax mkldnn op

- Fixes after review

- Coding style

- Fix to style

- style fixes

- style fix

- style fixes

- Fix to cody style check

- Rephrasing a comment

fix t obroken merge

Fixes to rebase

Conflicts:
	benchmark/fluid/models/machine_translation.py
	cmake/external/mkldnn.cmake
	paddle/fluid/operators/softmax_mkldnn_op.cc

- Bumped revision of MKL-DNN up to have softmax backward primitive

- Added choosing MKLDNN softmax grad operator

- First reuse of softmax backward

- Reinvented reusing for softmax

- Fix to crash in reinvented reuse

- Clang format fixes

- Clang format fixes

- Improved softmax mkldnn reuse mechanism

- clang format fixes

- Fix to broken merge

- Fix

cmake/external/mkldnn.cmake

@@ -54,7 +54,7 @@ ExternalProject_Add(
     ${EXTERNAL_PROJECT_LOG_ARGS}
     DEPENDS             ${MKLDNN_DEPENDS}
     GIT_REPOSITORY      "https://github.com/01org/mkl-dnn.git"
-    GIT_TAG             "db3424ad44901513c03a1ea31ccaacdf633fbe9f"
+    GIT_TAG             "a29d8487a63afca3d5b8c5bbdbb473cf8ccc6e51"
     PREFIX              ${MKLDNN_SOURCES_DIR}
     UPDATE_COMMAND      ""
     CMAKE_ARGS          -DCMAKE_INSTALL_PREFIX=${MKLDNN_INSTALL_DIR}

paddle/fluid/operators/softmax_mkldnn_op.cc

@@ -27,8 +27,81 @@ using paddle::platform::MKLDNNMemDesc;
 using mkldnn::memory;  // Note: paddle has also "memory" namespace
 using mkldnn::primitive;
 using mkldnn::softmax_forward;
+using mkldnn::softmax_backward;
 using mkldnn::prop_kind;
 using mkldnn::stream;
+using platform::to_void_cast;
+
+class SoftmaxMKLDNNHandler : public platform::MKLDNNHandler {
+ public:
+  SoftmaxMKLDNNHandler(
+      std::shared_ptr<mkldnn::softmax_forward::primitive_desc> softmax_pd,
+      const platform::MKLDNNDeviceContext& dev_ctx, mkldnn::engine engine,
+      const std::string& base_key)
+      : platform::MKLDNNHandler(dev_ctx, engine, base_key),
+        softmax_pd_(softmax_pd) {}
+
+  SoftmaxMKLDNNHandler(
+      std::shared_ptr<mkldnn::softmax_forward::primitive_desc> softmax_pd,
+      std::shared_ptr<mkldnn::softmax_backward::primitive_desc> softmax_bwd_pd,
+      const platform::MKLDNNDeviceContext& dev_ctx, mkldnn::engine engine,
+      const std::string& base_key)
+      : platform::MKLDNNHandler(dev_ctx, engine, base_key),
+        softmax_pd_(softmax_pd),
+        softmax_bwd_pd_(softmax_bwd_pd) {
+    // If we are in Grad operatgor then update a key with BWD suffix to
+    // distinguish from FWD memory primitives
+    key_ += "-BWD";
+  }
+
+  std::shared_ptr<mkldnn::softmax_forward> AcquireSoftmax(
+      std::shared_ptr<mkldnn::memory> dst_memory_p,
+      std::shared_ptr<mkldnn::memory> src_memory_p) {
+    /*Generate key*/
+    auto prim_key = key_ + "@softmax_p";
+
+    auto softmax_p = std::static_pointer_cast<mkldnn::softmax_forward>(
+        dev_ctx_.GetBlob(prim_key));
+    PADDLE_ENFORCE((softmax_p != nullptr) || (is_reusing_ == false),
+                   "Fail to find softmax primitive in device context");
+    if (softmax_p == nullptr) {
+      softmax_p = std::make_shared<mkldnn::softmax_forward>(
+          *(softmax_pd_.get()),
+          *(static_cast<mkldnn::memory*>(src_memory_p.get())),
+          *(static_cast<mkldnn::memory*>(dst_memory_p.get())));
+      dev_ctx_.SetBlob(prim_key, softmax_p);
+    } else {
+      is_reusing_ = true;
+    }
+
+    return softmax_p;
+  }
+
+  std::shared_ptr<mkldnn::softmax_backward> AcquireSoftmaxBackward(
+      std::shared_ptr<mkldnn::memory> dst_memory_p,
+      std::shared_ptr<mkldnn::memory> diff_dst_memory_p,
+      std::shared_ptr<mkldnn::memory> diff_src_memory_p) {
+    auto prim_key = key_ + "@softmax_bwd_p";
+    auto softmax_bwd_p = std::static_pointer_cast<mkldnn::softmax_backward>(
+        dev_ctx_.GetBlob(prim_key));
+    PADDLE_ENFORCE((softmax_bwd_p != nullptr) || (is_reusing_ == false),
+                   "Fail to find softmax backward primitive in device context");
+    if (softmax_bwd_p == nullptr) {
+      softmax_bwd_p = std::make_shared<mkldnn::softmax_backward>(
+          *softmax_bwd_pd_, *(dst_memory_p.get()), *(diff_dst_memory_p.get()),
+          *(diff_src_memory_p.get()));
+      dev_ctx_.SetBlob(prim_key, softmax_bwd_p);
+    } else {
+      is_reusing_ = true;
+    }
+
+    return softmax_bwd_p;
+  }
+
+ private:
+  std::shared_ptr<mkldnn::softmax_forward::primitive_desc> softmax_pd_;
+  std::shared_ptr<mkldnn::softmax_backward::primitive_desc> softmax_bwd_pd_;
+};
 
 template <typename T>
 class SoftmaxMKLDNNKernel : public paddle::framework::OpKernel<T> {
@@ -54,56 +127,27 @@ class SoftmaxMKLDNNKernel : public paddle::framework::OpKernel<T> {
     // Same memory descriptor to be used for input and output
     memory::dims softmax_tz = {src_tz[0], src_tz[1]};
     // Generate keys for storing/retriving primitives for this operator
-    // TODO(jczaja): Each MKLDNN operator may have diffrent hashing function
-    auto gethash = [](memory::dims& operand_dims) {
-      return std::string(std::to_string(operand_dims[0]) + "-" +
-                         std::to_string(operand_dims[1]));
-    };
-    const std::string key = gethash(softmax_tz);
-    const std::string key_softmax_p = key + "@softmax_p";
-    const std::string key_softmax_src_mem_p = key + "@softmax_src_mem_p";
-    const std::string key_softmax_dst_mem_p = key + "@softmax_dst_mem_p";
-
-    std::shared_ptr<void> softmax_p = dev_ctx.GetBlob(key_softmax_p);
-    if (softmax_p == nullptr) {
+    const std::string key =
+        platform::MKLDNNHandler::GetHash(softmax_tz, ctx.op().Output("Out"));
+    const std::string key_softmax_pd = key + "@softmax_pd";
+
     // Currently only NC data format is supported
-      auto softmax_md =
-          MKLDNNMemDesc({softmax_tz}, memory::f32, memory::format::nc);
+    auto softmax_md = MKLDNNMemDesc(
+        {softmax_tz}, platform::MKLDNNGetDataType<T>(), memory::format::nc);
     // Normalization is made after innermost dimension eg. C out of NC
     auto softmax_desc = softmax_forward::desc(prop_kind::forward_scoring,
                                               softmax_md, 1 /*dim: C*/);
-      // create memory primitives
-      auto softmax_src_memory_p = std::make_shared<memory>(
-          memory::primitive_desc{softmax_md, mkldnn_engine},
-          static_cast<void*>(const_cast<T*>(input_data)));
-      dev_ctx.SetBlob(key_softmax_src_mem_p, softmax_src_memory_p);
-      auto softmax_dst_memory_p = std::make_shared<memory>(
-          memory::primitive_desc{softmax_md, mkldnn_engine},
-          static_cast<void*>(output_data));
-      dev_ctx.SetBlob(key_softmax_dst_mem_p, softmax_dst_memory_p);
-
-      auto softmax_forward_pd =
-          std::make_shared<softmax_forward::primitive_desc>(softmax_desc,
-                                                            mkldnn_engine);
-      softmax_p = std::make_shared<softmax_forward>(
-          *(softmax_forward_pd.get()),
-          *(static_cast<memory*>(softmax_src_memory_p.get())),
-          *(static_cast<memory*>(softmax_dst_memory_p.get())));
-      dev_ctx.SetBlob(key_softmax_p, softmax_p);
-    } else {
-      // Primitives already exist
-      auto src_memory_p = std::static_pointer_cast<memory>(
-          dev_ctx.GetBlob(key_softmax_src_mem_p));
-      PADDLE_ENFORCE(src_memory_p != nullptr,
-                     "Fail to find softmax src mem_p in device context");
-      auto dst_memory_p = std::static_pointer_cast<memory>(
-          dev_ctx.GetBlob(key_softmax_dst_mem_p));
-      PADDLE_ENFORCE(dst_memory_p != nullptr,
-                     "Fail to find softmax dst mem_p in device context");
-      src_memory_p->set_data_handle(
-          reinterpret_cast<void*>(const_cast<T*>(input_data)));
-      dst_memory_p->set_data_handle(output_data);
-    }
+    auto softmax_pd = std::make_shared<mkldnn::softmax_forward::primitive_desc>(
+        softmax_desc, mkldnn_engine);
+    dev_ctx.SetBlob(key_softmax_pd, softmax_pd);
+
+    SoftmaxMKLDNNHandler handler(softmax_pd, dev_ctx, mkldnn_engine, key);
+    auto softmax_src_memory_p =
+        handler.AcquireSrcMemory(softmax_md, to_void_cast<T>(input_data));
+    auto softmax_dst_memory_p =
+        handler.AcquireDstMemory(softmax_md, to_void_cast<T>(output_data));
+    auto softmax_p =
+        handler.AcquireSoftmax(softmax_dst_memory_p, softmax_src_memory_p);
 
     std::vector<primitive> pipeline{
         *(static_cast<softmax_forward::primitive*>(softmax_p.get()))};
@@ -120,6 +164,77 @@ class SoftmaxMKLDNNKernel : public paddle::framework::OpKernel<T> {
   }
 };
 
+template <typename T>
+class SoftmaxMKLDNNGradKernel : public paddle::framework::OpKernel<T> {
+ public:
+  void Compute(const paddle::framework::ExecutionContext& ctx) const override {
+    PADDLE_ENFORCE(paddle::platform::is_cpu_place(ctx.GetPlace()),
+                   "It must use CPUPlace.");
+
+    auto& dev_ctx = ctx.template device_context<MKLDNNDeviceContext>();
+    auto mkldnn_engine = dev_ctx.GetEngine();
+    const Tensor* output = ctx.Input<Tensor>("Out");
+    const T* dst_data = output->data<T>();
+
+    auto* dout = ctx.template Input<Tensor>(framework::GradVarName("Out"));
+    const auto* diff_dst_ptr = dout->template data<T>();
+
+    auto* dx =
+        ctx.template Output<framework::Tensor>(framework::GradVarName("X"));
+    T* diff_src_ptr = dx->template mutable_data<T>(ctx.GetPlace());
+
+    std::vector<int> dst_tz = paddle::framework::vectorize2int(output->dims());
+    std::vector<int> src_tz(dst_tz);
+    PADDLE_ENFORCE(output->dims().size() == 2UL,
+                   "The input of softmax op must be a 2D matrix.");
+    // MKL-DNN does support softmax over selected axis. Having 2D Tensor,
+    // we will make normalization after final eg. axis: 1
+    PADDLE_ENFORCE(((src_tz[0] == dst_tz[0]) && (src_tz[1] == dst_tz[1])),
+                   "Softmax input and output dimensions should match");
+    // Same memory descriptor to be used for input and output
+    memory::dims softmax_tz = {src_tz[0], src_tz[1]};
+    // Currently only supports NC data format
+    // retrieve eltwise primitive desc from device context
+    const std::string key =
+        platform::MKLDNNHandler::GetHash(softmax_tz, ctx.op().Input("Out"));
+    const std::string key_softmax_pd = key + "@softmax_pd";
+
+    auto softmax_pd =
+        std::static_pointer_cast<mkldnn::softmax_forward::primitive_desc>(
+            dev_ctx.GetBlob(key_softmax_pd));
+    PADDLE_ENFORCE(softmax_pd != nullptr,
+                   "Fail to find softmax_pd in device context");
+
+    // TODO(jczaja): Add layouts support when there is a need to do so
+    // Two dimensional softmax does support NC format
+    auto data_softmax_md = MKLDNNMemDesc(
+        {softmax_tz}, platform::MKLDNNGetDataType<T>(), memory::format::nc);
+    auto diff_softmax_md = MKLDNNMemDesc(
+        {softmax_tz}, platform::MKLDNNGetDataType<T>(), memory::format::nc);
+    // Normalization is made after innermost dimension eg. C out of NC
+    auto softmax_bwd_desc =
+        softmax_backward::desc(diff_softmax_md, data_softmax_md, 1 /* dim: C*/);
+    auto softmax_bwd_pd =
+        std::make_shared<mkldnn::softmax_backward::primitive_desc>(
+            softmax_bwd_desc, mkldnn_engine, *softmax_pd);
+
+    SoftmaxMKLDNNHandler handler(softmax_pd, softmax_bwd_pd, dev_ctx,
+                                 mkldnn_engine, key);
+    auto dst_memory_p =
+        handler.AcquireDstMemory(data_softmax_md, to_void_cast<T>(dst_data));
+    auto diff_dst_memory_p = handler.AcquireDiffDstMemory(
+        diff_softmax_md, to_void_cast<T>(diff_dst_ptr));
+    auto diff_src_memory_p = handler.AcquireDiffSrcMemory(
+        diff_softmax_md, to_void_cast<T>(diff_src_ptr));
+
+    // Get primitve from device context
+    auto softmax_bwd_p = handler.AcquireSoftmaxBackward(
+        dst_memory_p, diff_dst_memory_p, diff_src_memory_p);
+
+    std::vector<primitive> pipeline{*softmax_bwd_p};
+    stream(stream::kind::eager).submit(pipeline).wait();
+  }
+};
 }  // namespace operators
 }  // namespace paddle
 
@@ -127,3 +242,5 @@ namespace ops = paddle::operators;
 
 REGISTER_OP_KERNEL(softmax, MKLDNN, ::paddle::platform::CPUPlace,
                    ops::SoftmaxMKLDNNKernel<float>);
+REGISTER_OP_KERNEL(softmax_grad, MKLDNN, ::paddle::platform::CPUPlace,
+                   ops::SoftmaxMKLDNNGradKernel<float>);

paddle/fluid/operators/softmax_op.cc

@@ -145,16 +145,30 @@ class SoftmaxOpGrad : public framework::OperatorWithKernel {
       const framework::ExecutionContext& ctx) const override {
     // choose cudnn kernel if the runtime supported.
     framework::LibraryType library_{framework::LibraryType::kPlain};
+    std::string data_format = ctx.Attr<std::string>("data_format");
+    framework::DataLayout layout_ = framework::StringToDataLayout(data_format);
 
 #ifdef PADDLE_WITH_CUDA
     if (platform::CanCUDNNBeUsed(ctx)) {
       library_ = framework::LibraryType::kCUDNN;
     }
 #endif
-    std::string data_format = ctx.Attr<std::string>("data_format");
-    return framework::OpKernelType(
-        framework::ToDataType(ctx.Input<Tensor>("X")->type()), ctx.GetPlace(),
-        framework::StringToDataLayout(data_format), library_);
+#ifdef PADDLE_WITH_MKLDNN
+    if (library_ == framework::LibraryType::kPlain &&
+        platform::CanMKLDNNBeUsed(ctx)) {
+      library_ = framework::LibraryType::kMKLDNN;
+      layout_ = framework::DataLayout::kMKLDNN;
+    }
+#endif
+    auto input_data_type =
+        framework::ToDataType(ctx.Input<Tensor>("X")->type());
+    if (input_data_type == framework::proto::VarType::FP16) {
+      PADDLE_ENFORCE(platform::is_gpu_place(ctx.GetPlace()),
+                     "float16 can only be used on GPU place");
+    }
+
+    return framework::OpKernelType(input_data_type, ctx.GetPlace(), layout_,
+                                   library_);
   }
 };
 

paddle/fluid/platform/mkldnn_helper.h

@@ -105,5 +105,137 @@ inline mkldnn::memory::format GetMKLDNNFormat(
       memory.dst_primitive_desc().desc().data.format);
 }
 
+class MKLDNNHandler {
+ public:
+  MKLDNNHandler(const MKLDNNDeviceContext& dev_ctx, mkldnn::engine engine,
+                const std::string& base_key)
+      : dev_ctx_(dev_ctx),
+        engine_(engine),
+        key_(base_key),
+        is_reusing_(false) {}
+
+  std::shared_ptr<mkldnn::memory> AcquireSrcMemory(
+      const mkldnn::memory::desc& md, void* ptr) {
+    return this->AcquireMemory(md, ptr, "@user_src_mem_p");
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireWeightsMemory(
+      const mkldnn::memory::desc& md, void* ptr) {
+    return this->AcquireMemory(md, ptr, "@user_weights_mem_p");
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireDstMemory(
+      const mkldnn::memory::desc& md, void* ptr) {
+    return this->AcquireMemory(md, ptr, "@user_dst_mem_p");
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireDiffDstMemory(
+      const mkldnn::memory::desc& md, void* ptr) {
+    return this->AcquireMemory(md, ptr, "@user_diff_dst_mem_p");
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireDiffSrcMemory(
+      const mkldnn::memory::desc& md, void* ptr) {
+    return this->AcquireMemory(md, ptr, "@user_diff_src_mem_p");
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireMemoryFromPrimitive(
+      mkldnn::memory::primitive_desc mdp, void* ptr,
+      const std::string& suffix) {
+    auto local_key = key_ + suffix;
+    auto mem_p =
+        std::static_pointer_cast<mkldnn::memory>(dev_ctx_.GetBlob(local_key));
+    PADDLE_ENFORCE((mem_p != nullptr) || (is_reusing_ == false),
+                   "Fail to find mem primitive in device context");
+    if (mem_p == nullptr) {
+      mem_p = std::make_shared<mkldnn::memory>(mdp, ptr);
+      dev_ctx_.SetBlob(local_key, mem_p);
+    } else {
+      mem_p->set_data_handle(ptr);
+      // Mark that reusing happenned. All primitives from operator instance
+      // should be reused or none of them. So we check consistency
+      is_reusing_ = true;
+    }
+    return mem_p;
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireMemory(const mkldnn::memory::desc& md,
+                                                void* ptr,
+                                                const std::string& suffix) {
+    /*Generate key*/
+    auto local_key = key_ + suffix;
+    auto mem_p =
+        std::static_pointer_cast<mkldnn::memory>(dev_ctx_.GetBlob(local_key));
+    PADDLE_ENFORCE((mem_p != nullptr) || (is_reusing_ == false),
+                   "Fail to find mem primitive in device context");
+    if (mem_p == nullptr) {
+      mem_p = std::make_shared<mkldnn::memory>(
+          mkldnn::memory::primitive_desc{md, engine_}, ptr);
+      dev_ctx_.SetBlob(local_key, mem_p);
+    } else {
+      mem_p->set_data_handle(ptr);
+      // Mark that reusing happenned. All primitives from operator instance
+      // should be reused or none of them. So we check consistency
+      is_reusing_ = true;
+    }
+    return mem_p;
+  }
+
+  std::shared_ptr<mkldnn::memory> AcquireMemory(
+      mkldnn::memory::primitive_desc& mpd,
+      mkldnn::memory::primitive_desc& user_mpd,
+      const std::shared_ptr<mkldnn::memory> user_memory_p,
+      const std::string& suffix, std::vector<mkldnn::primitive>& pipeline) {
+    // create reorder primitive if the input format is not the preferred one
+    auto local_key = key_ + suffix;
+    auto key_reorder_p = key_ + suffix + "reorder_p";
+
+    auto target_memory_p =
+        std::static_pointer_cast<mkldnn::memory>(dev_ctx_.GetBlob(local_key));
+    PADDLE_ENFORCE((target_memory_p != nullptr) || (is_reusing_ == false),
+                   "Fail to find mem primitive in device context");
+    if (target_memory_p == nullptr) {
+      target_memory_p = user_memory_p;
+      std::shared_ptr<mkldnn::primitive> reorder_p;
+      if (mpd != user_mpd) {
+        target_memory_p = std::make_shared<mkldnn::memory>(mpd);
+
+        auto reorder_p =
+            std::make_shared<mkldnn::reorder>(*user_memory_p, *target_memory_p);
+        dev_ctx_.SetBlob(key_reorder_p, reorder_p);
+        pipeline.push_back(*reorder_p);
+      }
+      dev_ctx_.SetBlob(local_key, target_memory_p);
+    } else {
+      // Make reorder if needed
+      auto reorder_p = std::static_pointer_cast<mkldnn::reorder>(
+          dev_ctx_.GetBlob(key_reorder_p));
+      if (reorder_p != nullptr) {
+        pipeline.push_back(*reorder_p);
+      }
+      is_reusing_ = true;
+    }
+    return target_memory_p;
+  }
+
+  static std::string GetHash(mkldnn::memory::dims& operand_dims,
+                             const std::string& suffix) {
+    auto dims2str = [](const mkldnn::memory::dims& operand_dims) {
+      std::string dstr = "";
+      for (size_t i = 0; i < operand_dims.size(); ++i) {
+        dstr += std::to_string(operand_dims[i]) + "-";
+      }
+      return dstr;
+    };
+    return dims2str(operand_dims) + suffix;
+  };
+
+ protected:
+  const MKLDNNDeviceContext& dev_ctx_;
+  mkldnn::engine engine_;
+  std::string key_;
+  bool is_reusing_;
+};
+
 }  // namespace platform
 }  // namespace paddle