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Posted to commits@tvm.apache.org by GitBox <gi...@apache.org> on 2020/11/08 23:39:50 UTC

[GitHub] [incubator-tvm] comaniac commented on a change in pull request #6882: [AutoScheduler] Tutorial on auto-scheduling a network for GPU

comaniac commented on a change in pull request #6882:
URL: https://github.com/apache/incubator-tvm/pull/6882#discussion_r519491866



##########
File path: src/auto_scheduler/feature.cc
##########
@@ -1345,11 +1345,6 @@ void GetPerStoreFeaturesFromStates(const Array<State>& states, const SearchTask&
                           GetPerStoreFeaturesWorkerFunc(task, states[i], max_n_bufs,
                                                         &(*features)[i], &error_ct);
                         });
-
-  if (error_ct > 0) {
-    std::cerr << "Encountered " << error_ct
-              << " errors during feature extraction, which are safely ignored." << std::endl;
-  }

Review comment:
       Can we keep this message in a lower logging verbose level? If not (which I think might be an issue because DMLC logging system doesn't have DEBUG level), we may need to add a message at the end of the measurement process indicating the case that all states are failed.

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.
+#
+
+
+def get_network(name, batch_size, layout="NHWC", dtype="float32"):
+    """Get the symbol definition and random weight of a network"""
+
+    # auto-scheduler prefers NHWC layout
+    if layout == "NHWC":
+        image_shape = (224, 224, 3)
+    elif layout == "NCHW":
+        image_shape = (3, 224, 224)
+    else:
+        raise ValueError("Invalid layout: " + layout)
+
+    input_shape = (batch_size,) + image_shape
+    output_shape = (batch_size, 1000)
+
+    if name.startswith("resnet-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name.startswith("resnet3d-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "mobilenet":
+        mod, params = relay.testing.mobilenet.get_workload(
+            batch_size=batch_size, layout=layout, dtype=dtype, image_shape=image_shape
+        )
+    elif name == "squeezenet_v1.1":
+        mod, params = relay.testing.squeezenet.get_workload(
+            version="1.1",
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "inception_v3":
+        input_shape = (batch_size, 3, 299, 299) if layout == "NCHW" else (batch_size, 299, 299, 3)
+        mod, params = relay.testing.inception_v3.get_workload(batch_size=batch_size, dtype=dtype)
+    elif name == "mxnet":
+        # an example for mxnet model
+        from mxnet.gluon.model_zoo.vision import get_model
+
+        assert layout == "NCHW"
+
+        block = get_model("resnet18_v1", pretrained=True)
+        mod, params = relay.frontend.from_mxnet(block, shape={"data": input_shape}, dtype=dtype)
+        net = mod["main"]
+        net = relay.Function(
+            net.params, relay.nn.softmax(net.body), None, net.type_params, net.attrs
+        )
+        mod = tvm.IRModule.from_expr(net)
+
+    return mod, params, input_shape, output_shape
+
+
+# Define the neural network and compilation target
+network = "resnet-18"
+batch_size = 1
+layout = "NHWC"
+target = tvm.target.Target("cuda")
+dtype = "float32"
+log_file = "%s-%s-B%d.json" % (network, layout, batch_size)
+
+#################################################################
+# Extract Search Tasks
+# --------------------
+# Next, we extract the search tasks and their weights from a network.
+# The weight of a task is the number of appearances of the task's subgraph
+# in the whole network.
+# By using the weight, we can approximate the end-to-end latency of the network
+# as :code:`sum(latency[t] * weight[t])`, where :code:`latency[t]` is the
+# latency of a task and :code:`weight[t]` is the weight of the task.
+
+# Enable auto-scheduler in relay
+auto_scheduler.enable_relay_integration()
+
+# Extract tasks from the network
+print("Extract tasks...")
+mod, params, input_shape, output_shape = get_network(network, batch_size, layout, dtype=dtype)
+tasks, task_weights = auto_scheduler.extract_tasks(mod["main"], params, target)
+
+# Define the objective as the end-to-end exeuction time of the network
+objective = lambda costs: sum(c * w for c, w in zip(costs, task_weights))
+
+#################################################################
+# Begin Tuning
+# ------------
+# Now, we set some options of tuning and launch the search tasks
+#
+# * :code:`measure_ctx` launches a different process for measurement to
+#   provide isolation. It can protect the master process from GPU crashes
+#   happened during measurement and avoid other runtime conflicts.
+# * :code:`min_repeat_ms` defines the minimum duration of one "repeat" in every measurement.
+#   This can warmup the GPU, which is necessary to get accurate measurement results.
+#   Typically, we recommend a value > 300 ms.
+# * :code:`num_measure_trials` is the number of measurement trials we can use during the tuning.
+#   You can set it to a small number (e.g., 200) for a fast demonstrative run.
+#   In practice, we recommend setting it round :code:`1000 * len(tasks)`,
+#   which is typically enough for the search to converge.
+#   For example, there are 21 tasks in resnet-18, so we can set it as 20000 for renset-18.
+#   You can adjust this parameter according to your time budget.
+# * In addition, we use :code:`RecordToFile` to dump measurement records into the log file,
+#   The measurement records can be used to query the history best, resume the search,
+#   and do more analyses later.
+# * see :any:`auto_scheduler.TuningOptions`,
+#   :any:`auto_scheduler.LocalRPCMeasureContext` for more parameters.
+#
+
+
+def run_tuning():
+    print("Begin tuning...")
+    measure_ctx = auto_scheduler.LocalRPCMeasureContext(repeat=1, min_repeat_ms=400, timeout=10)
+
+    tuner = auto_scheduler.TaskScheduler(tasks, objective)
+    tune_option = auto_scheduler.TuningOptions(
+        num_measure_trials=200,  # change this to 20000 to achieve the best performance
+        runner=measure_ctx.runner,
+        measure_callbacks=[auto_scheduler.RecordToFile(log_file)],
+    )
+
+    tuner.tune(tune_option)
+
+
+# We do not run the tuning in our webpage server since it takes too long.
+# Uncomment the following line to run it by yourself.
+
+# run_tuning()
+
+
+######################################################################
+# .. note:: Explain the printed information during tuning
+#
+#   During the tuning, a lot of information will be printed on the screen.
+#   They are used for debugging purposes. The most important info is the output
+#   of the task scheduler. The following table is a sample output.
+#
+#   .. code-block:: c
+#
+#     ----------------------------------------------------------------------
+#     ------------------------------  [ Task Scheduler ]
+#     ----------------------------------------------------------------------
+#     |  ID  | Latency (ms) | Speed (GFLOPS) | Trials |
+#     -------------------------------------------------
+#     |    0 |        0.014 |          72.07 |     64 |
+#     |    1 |        0.185 |        1250.68 |    128 |
+#     |    2 |        0.142 |        1626.36 |    192 |
+#     |    3 |        0.137 |        1689.42 |    128 |
+#     |    4 |        0.097 |        1189.75 |    128 |
+#     |    5 |        0.092 |        2505.25 |    128 |
+#     |    6 |        0.080 |        2893.08 |    128 |
+#     |    7 |        0.119 |        1947.84 |    128 |
+#     |    8 |        0.090 |        1292.62 |     64 |
+#     |    9 |        0.107 |        2172.30 |     64 |
+#     |   10 |        0.095 |        2439.36 |     64 |
+#     |   11 |        0.077 |        3003.22 |     64 |
+#     |   12 |        0.068 |        1695.13 |     64 |
+#     |   13 |        0.058 |        3979.29 |     64 |
+#     |   14 |        0.048 |        4859.95 |    128 |
+#     |   15 |        0.073 |        3151.76 |     64 |
+#     |   16 |        0.056 |        4265.94 |     64 |
+#     |   17 |        0.009 |        2754.90 |     64 |
+#     |   18 |        0.011 |        1156.08 |     64 |
+#     |   19 |        0.013 |         955.80 |     64 |
+#     |   20 |        0.029 |         437.71 |     64 |
+#     -------------------------------------------------
+#     Total latency: 1.649 ms  Trials: 1920  Used time : 3598 s  Next ID: 9
+#
+#   This table lists the latency and speed of all tasks.
+#   It also lists the allocation of measurement trials for all tasks.
+#   The last line prints the total weighted latency of these tasks,
+#   which can be a rough estimation of the end-to-end execution time
+#   of the network.
+#   The last line also prints the total number of measurement trials,
+#   total time spent on auto-tuning and the id of the next task to tune.
+#
+#   There will also be some "dmlc::Error"s and CUDA errors. You can safely
+#   ignore them if the tuning can continue.

Review comment:
       Better to add one more sentence to explain the possible reason. Like this is because auto-scheduler tried an invalid schedule, but this can be safely ignore.

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations

Review comment:
       ```suggestion
   schedule templates. In other words, the auto-scheduler only uses the compute declarations
   ```

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================

Review comment:
       ```suggestion
   ===========================================
   ```

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.

Review comment:
       ```suggestion
   execution time and prioritizes the one that can reduce the execution time the most.
   ```

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.

Review comment:
       ```suggestion
   # and we found that the best performance is typically archived with NHWC layout
   # for convolutional neural networks, so we use NHWC layout in this tutorial.
   ```

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.
+#
+
+
+def get_network(name, batch_size, layout="NHWC", dtype="float32"):
+    """Get the symbol definition and random weight of a network"""
+
+    # auto-scheduler prefers NHWC layout
+    if layout == "NHWC":
+        image_shape = (224, 224, 3)
+    elif layout == "NCHW":
+        image_shape = (3, 224, 224)
+    else:
+        raise ValueError("Invalid layout: " + layout)
+
+    input_shape = (batch_size,) + image_shape
+    output_shape = (batch_size, 1000)
+
+    if name.startswith("resnet-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name.startswith("resnet3d-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "mobilenet":
+        mod, params = relay.testing.mobilenet.get_workload(
+            batch_size=batch_size, layout=layout, dtype=dtype, image_shape=image_shape
+        )
+    elif name == "squeezenet_v1.1":
+        mod, params = relay.testing.squeezenet.get_workload(
+            version="1.1",
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "inception_v3":
+        input_shape = (batch_size, 3, 299, 299) if layout == "NCHW" else (batch_size, 299, 299, 3)
+        mod, params = relay.testing.inception_v3.get_workload(batch_size=batch_size, dtype=dtype)
+    elif name == "mxnet":
+        # an example for mxnet model
+        from mxnet.gluon.model_zoo.vision import get_model
+
+        assert layout == "NCHW"
+
+        block = get_model("resnet18_v1", pretrained=True)
+        mod, params = relay.frontend.from_mxnet(block, shape={"data": input_shape}, dtype=dtype)
+        net = mod["main"]
+        net = relay.Function(
+            net.params, relay.nn.softmax(net.body), None, net.type_params, net.attrs
+        )
+        mod = tvm.IRModule.from_expr(net)
+
+    return mod, params, input_shape, output_shape
+
+
+# Define the neural network and compilation target
+network = "resnet-18"
+batch_size = 1
+layout = "NHWC"
+target = tvm.target.Target("cuda")
+dtype = "float32"
+log_file = "%s-%s-B%d.json" % (network, layout, batch_size)
+
+#################################################################
+# Extract Search Tasks
+# --------------------
+# Next, we extract the search tasks and their weights from a network.
+# The weight of a task is the number of appearances of the task's subgraph
+# in the whole network.
+# By using the weight, we can approximate the end-to-end latency of the network
+# as :code:`sum(latency[t] * weight[t])`, where :code:`latency[t]` is the
+# latency of a task and :code:`weight[t]` is the weight of the task.
+
+# Enable auto-scheduler in relay
+auto_scheduler.enable_relay_integration()
+
+# Extract tasks from the network
+print("Extract tasks...")
+mod, params, input_shape, output_shape = get_network(network, batch_size, layout, dtype=dtype)
+tasks, task_weights = auto_scheduler.extract_tasks(mod["main"], params, target)
+
+# Define the objective as the end-to-end exeuction time of the network
+objective = lambda costs: sum(c * w for c, w in zip(costs, task_weights))
+
+#################################################################
+# Begin Tuning
+# ------------
+# Now, we set some options of tuning and launch the search tasks
+#
+# * :code:`measure_ctx` launches a different process for measurement to
+#   provide isolation. It can protect the master process from GPU crashes
+#   happened during measurement and avoid other runtime conflicts.
+# * :code:`min_repeat_ms` defines the minimum duration of one "repeat" in every measurement.
+#   This can warmup the GPU, which is necessary to get accurate measurement results.
+#   Typically, we recommend a value > 300 ms.
+# * :code:`num_measure_trials` is the number of measurement trials we can use during the tuning.
+#   You can set it to a small number (e.g., 200) for a fast demonstrative run.
+#   In practice, we recommend setting it round :code:`1000 * len(tasks)`,
+#   which is typically enough for the search to converge.
+#   For example, there are 21 tasks in resnet-18, so we can set it as 20000 for renset-18.
+#   You can adjust this parameter according to your time budget.
+# * In addition, we use :code:`RecordToFile` to dump measurement records into the log file,
+#   The measurement records can be used to query the history best, resume the search,
+#   and do more analyses later.
+# * see :any:`auto_scheduler.TuningOptions`,
+#   :any:`auto_scheduler.LocalRPCMeasureContext` for more parameters.
+#
+
+
+def run_tuning():
+    print("Begin tuning...")
+    measure_ctx = auto_scheduler.LocalRPCMeasureContext(repeat=1, min_repeat_ms=400, timeout=10)
+
+    tuner = auto_scheduler.TaskScheduler(tasks, objective)
+    tune_option = auto_scheduler.TuningOptions(
+        num_measure_trials=200,  # change this to 20000 to achieve the best performance
+        runner=measure_ctx.runner,
+        measure_callbacks=[auto_scheduler.RecordToFile(log_file)],
+    )
+
+    tuner.tune(tune_option)
+
+
+# We do not run the tuning in our webpage server since it takes too long.
+# Uncomment the following line to run it by yourself.
+
+# run_tuning()
+
+
+######################################################################
+# .. note:: Explain the printed information during tuning
+#
+#   During the tuning, a lot of information will be printed on the screen.
+#   They are used for debugging purposes. The most important info is the output
+#   of the task scheduler. The following table is a sample output.
+#
+#   .. code-block:: c
+#
+#     ----------------------------------------------------------------------
+#     ------------------------------  [ Task Scheduler ]
+#     ----------------------------------------------------------------------
+#     |  ID  | Latency (ms) | Speed (GFLOPS) | Trials |
+#     -------------------------------------------------
+#     |    0 |        0.014 |          72.07 |     64 |
+#     |    1 |        0.185 |        1250.68 |    128 |
+#     |    2 |        0.142 |        1626.36 |    192 |
+#     |    3 |        0.137 |        1689.42 |    128 |
+#     |    4 |        0.097 |        1189.75 |    128 |
+#     |    5 |        0.092 |        2505.25 |    128 |
+#     |    6 |        0.080 |        2893.08 |    128 |
+#     |    7 |        0.119 |        1947.84 |    128 |
+#     |    8 |        0.090 |        1292.62 |     64 |
+#     |    9 |        0.107 |        2172.30 |     64 |
+#     |   10 |        0.095 |        2439.36 |     64 |
+#     |   11 |        0.077 |        3003.22 |     64 |
+#     |   12 |        0.068 |        1695.13 |     64 |
+#     |   13 |        0.058 |        3979.29 |     64 |
+#     |   14 |        0.048 |        4859.95 |    128 |
+#     |   15 |        0.073 |        3151.76 |     64 |
+#     |   16 |        0.056 |        4265.94 |     64 |
+#     |   17 |        0.009 |        2754.90 |     64 |
+#     |   18 |        0.011 |        1156.08 |     64 |
+#     |   19 |        0.013 |         955.80 |     64 |
+#     |   20 |        0.029 |         437.71 |     64 |
+#     -------------------------------------------------
+#     Total latency: 1.649 ms  Trials: 1920  Used time : 3598 s  Next ID: 9

Review comment:
       Maybe "Estimated total latency" could reduce some confusion. Otherwise I guess some people will directly refer to this number and find that it's inconsistent to the final evaluation.

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.
+#
+
+
+def get_network(name, batch_size, layout="NHWC", dtype="float32"):
+    """Get the symbol definition and random weight of a network"""
+
+    # auto-scheduler prefers NHWC layout
+    if layout == "NHWC":
+        image_shape = (224, 224, 3)
+    elif layout == "NCHW":
+        image_shape = (3, 224, 224)
+    else:
+        raise ValueError("Invalid layout: " + layout)
+
+    input_shape = (batch_size,) + image_shape
+    output_shape = (batch_size, 1000)
+
+    if name.startswith("resnet-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name.startswith("resnet3d-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "mobilenet":
+        mod, params = relay.testing.mobilenet.get_workload(
+            batch_size=batch_size, layout=layout, dtype=dtype, image_shape=image_shape
+        )
+    elif name == "squeezenet_v1.1":
+        mod, params = relay.testing.squeezenet.get_workload(
+            version="1.1",
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "inception_v3":
+        input_shape = (batch_size, 3, 299, 299) if layout == "NCHW" else (batch_size, 299, 299, 3)
+        mod, params = relay.testing.inception_v3.get_workload(batch_size=batch_size, dtype=dtype)
+    elif name == "mxnet":
+        # an example for mxnet model
+        from mxnet.gluon.model_zoo.vision import get_model
+
+        assert layout == "NCHW"
+
+        block = get_model("resnet18_v1", pretrained=True)
+        mod, params = relay.frontend.from_mxnet(block, shape={"data": input_shape}, dtype=dtype)
+        net = mod["main"]
+        net = relay.Function(
+            net.params, relay.nn.softmax(net.body), None, net.type_params, net.attrs
+        )
+        mod = tvm.IRModule.from_expr(net)
+
+    return mod, params, input_shape, output_shape
+
+
+# Define the neural network and compilation target
+network = "resnet-18"
+batch_size = 1
+layout = "NHWC"
+target = tvm.target.Target("cuda")
+dtype = "float32"
+log_file = "%s-%s-B%d.json" % (network, layout, batch_size)
+
+#################################################################
+# Extract Search Tasks
+# --------------------
+# Next, we extract the search tasks and their weights from a network.
+# The weight of a task is the number of appearances of the task's subgraph
+# in the whole network.
+# By using the weight, we can approximate the end-to-end latency of the network
+# as :code:`sum(latency[t] * weight[t])`, where :code:`latency[t]` is the
+# latency of a task and :code:`weight[t]` is the weight of the task.
+
+# Enable auto-scheduler in relay
+auto_scheduler.enable_relay_integration()
+
+# Extract tasks from the network
+print("Extract tasks...")
+mod, params, input_shape, output_shape = get_network(network, batch_size, layout, dtype=dtype)
+tasks, task_weights = auto_scheduler.extract_tasks(mod["main"], params, target)
+
+# Define the objective as the end-to-end exeuction time of the network
+objective = lambda costs: sum(c * w for c, w in zip(costs, task_weights))
+
+#################################################################
+# Begin Tuning
+# ------------
+# Now, we set some options of tuning and launch the search tasks
+#
+# * :code:`measure_ctx` launches a different process for measurement to
+#   provide isolation. It can protect the master process from GPU crashes
+#   happened during measurement and avoid other runtime conflicts.
+# * :code:`min_repeat_ms` defines the minimum duration of one "repeat" in every measurement.
+#   This can warmup the GPU, which is necessary to get accurate measurement results.
+#   Typically, we recommend a value > 300 ms.
+# * :code:`num_measure_trials` is the number of measurement trials we can use during the tuning.
+#   You can set it to a small number (e.g., 200) for a fast demonstrative run.
+#   In practice, we recommend setting it round :code:`1000 * len(tasks)`,
+#   which is typically enough for the search to converge.
+#   For example, there are 21 tasks in resnet-18, so we can set it as 20000 for renset-18.
+#   You can adjust this parameter according to your time budget.
+# * In addition, we use :code:`RecordToFile` to dump measurement records into the log file,
+#   The measurement records can be used to query the history best, resume the search,
+#   and do more analyses later.
+# * see :any:`auto_scheduler.TuningOptions`,
+#   :any:`auto_scheduler.LocalRPCMeasureContext` for more parameters.
+#
+
+
+def run_tuning():
+    print("Begin tuning...")
+    measure_ctx = auto_scheduler.LocalRPCMeasureContext(repeat=1, min_repeat_ms=400, timeout=10)
+
+    tuner = auto_scheduler.TaskScheduler(tasks, objective)
+    tune_option = auto_scheduler.TuningOptions(
+        num_measure_trials=200,  # change this to 20000 to achieve the best performance
+        runner=measure_ctx.runner,
+        measure_callbacks=[auto_scheduler.RecordToFile(log_file)],
+    )
+
+    tuner.tune(tune_option)
+
+
+# We do not run the tuning in our webpage server since it takes too long.
+# Uncomment the following line to run it by yourself.
+
+# run_tuning()
+
+
+######################################################################
+# .. note:: Explain the printed information during tuning
+#
+#   During the tuning, a lot of information will be printed on the screen.

Review comment:
       ```suggestion
   #   During the tuning, a lot of information will be printed on the console.
   ```

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.
+#
+
+
+def get_network(name, batch_size, layout="NHWC", dtype="float32"):
+    """Get the symbol definition and random weight of a network"""
+
+    # auto-scheduler prefers NHWC layout
+    if layout == "NHWC":
+        image_shape = (224, 224, 3)
+    elif layout == "NCHW":
+        image_shape = (3, 224, 224)
+    else:
+        raise ValueError("Invalid layout: " + layout)
+
+    input_shape = (batch_size,) + image_shape
+    output_shape = (batch_size, 1000)
+
+    if name.startswith("resnet-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name.startswith("resnet3d-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "mobilenet":
+        mod, params = relay.testing.mobilenet.get_workload(
+            batch_size=batch_size, layout=layout, dtype=dtype, image_shape=image_shape
+        )
+    elif name == "squeezenet_v1.1":
+        mod, params = relay.testing.squeezenet.get_workload(
+            version="1.1",
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "inception_v3":
+        input_shape = (batch_size, 3, 299, 299) if layout == "NCHW" else (batch_size, 299, 299, 3)
+        mod, params = relay.testing.inception_v3.get_workload(batch_size=batch_size, dtype=dtype)
+    elif name == "mxnet":
+        # an example for mxnet model
+        from mxnet.gluon.model_zoo.vision import get_model
+
+        assert layout == "NCHW"
+
+        block = get_model("resnet18_v1", pretrained=True)
+        mod, params = relay.frontend.from_mxnet(block, shape={"data": input_shape}, dtype=dtype)
+        net = mod["main"]
+        net = relay.Function(
+            net.params, relay.nn.softmax(net.body), None, net.type_params, net.attrs
+        )
+        mod = tvm.IRModule.from_expr(net)
+
+    return mod, params, input_shape, output_shape
+
+
+# Define the neural network and compilation target
+network = "resnet-18"
+batch_size = 1
+layout = "NHWC"
+target = tvm.target.Target("cuda")
+dtype = "float32"
+log_file = "%s-%s-B%d.json" % (network, layout, batch_size)
+
+#################################################################
+# Extract Search Tasks
+# --------------------
+# Next, we extract the search tasks and their weights from a network.
+# The weight of a task is the number of appearances of the task's subgraph
+# in the whole network.
+# By using the weight, we can approximate the end-to-end latency of the network
+# as :code:`sum(latency[t] * weight[t])`, where :code:`latency[t]` is the
+# latency of a task and :code:`weight[t]` is the weight of the task.
+
+# Enable auto-scheduler in relay
+auto_scheduler.enable_relay_integration()
+
+# Extract tasks from the network
+print("Extract tasks...")
+mod, params, input_shape, output_shape = get_network(network, batch_size, layout, dtype=dtype)
+tasks, task_weights = auto_scheduler.extract_tasks(mod["main"], params, target)
+
+# Define the objective as the end-to-end exeuction time of the network
+objective = lambda costs: sum(c * w for c, w in zip(costs, task_weights))
+
+#################################################################
+# Begin Tuning
+# ------------
+# Now, we set some options of tuning and launch the search tasks
+#
+# * :code:`measure_ctx` launches a different process for measurement to
+#   provide isolation. It can protect the master process from GPU crashes
+#   happened during measurement and avoid other runtime conflicts.
+# * :code:`min_repeat_ms` defines the minimum duration of one "repeat" in every measurement.
+#   This can warmup the GPU, which is necessary to get accurate measurement results.
+#   Typically, we recommend a value > 300 ms.
+# * :code:`num_measure_trials` is the number of measurement trials we can use during the tuning.
+#   You can set it to a small number (e.g., 200) for a fast demonstrative run.
+#   In practice, we recommend setting it round :code:`1000 * len(tasks)`,
+#   which is typically enough for the search to converge.
+#   For example, there are 21 tasks in resnet-18, so we can set it as 20000 for renset-18.
+#   You can adjust this parameter according to your time budget.
+# * In addition, we use :code:`RecordToFile` to dump measurement records into the log file,
+#   The measurement records can be used to query the history best, resume the search,
+#   and do more analyses later.
+# * see :any:`auto_scheduler.TuningOptions`,
+#   :any:`auto_scheduler.LocalRPCMeasureContext` for more parameters.
+#
+
+
+def run_tuning():
+    print("Begin tuning...")
+    measure_ctx = auto_scheduler.LocalRPCMeasureContext(repeat=1, min_repeat_ms=400, timeout=10)
+
+    tuner = auto_scheduler.TaskScheduler(tasks, objective)
+    tune_option = auto_scheduler.TuningOptions(
+        num_measure_trials=200,  # change this to 20000 to achieve the best performance
+        runner=measure_ctx.runner,
+        measure_callbacks=[auto_scheduler.RecordToFile(log_file)],
+    )
+
+    tuner.tune(tune_option)
+
+
+# We do not run the tuning in our webpage server since it takes too long.
+# Uncomment the following line to run it by yourself.
+
+# run_tuning()
+
+
+######################################################################
+# .. note:: Explain the printed information during tuning
+#
+#   During the tuning, a lot of information will be printed on the screen.
+#   They are used for debugging purposes. The most important info is the output
+#   of the task scheduler. The following table is a sample output.
+#
+#   .. code-block:: c
+#
+#     ----------------------------------------------------------------------
+#     ------------------------------  [ Task Scheduler ]
+#     ----------------------------------------------------------------------
+#     |  ID  | Latency (ms) | Speed (GFLOPS) | Trials |
+#     -------------------------------------------------
+#     |    0 |        0.014 |          72.07 |     64 |
+#     |    1 |        0.185 |        1250.68 |    128 |
+#     |    2 |        0.142 |        1626.36 |    192 |
+#     |    3 |        0.137 |        1689.42 |    128 |
+#     |    4 |        0.097 |        1189.75 |    128 |
+#     |    5 |        0.092 |        2505.25 |    128 |
+#     |    6 |        0.080 |        2893.08 |    128 |
+#     |    7 |        0.119 |        1947.84 |    128 |
+#     |    8 |        0.090 |        1292.62 |     64 |
+#     |    9 |        0.107 |        2172.30 |     64 |
+#     |   10 |        0.095 |        2439.36 |     64 |
+#     |   11 |        0.077 |        3003.22 |     64 |
+#     |   12 |        0.068 |        1695.13 |     64 |
+#     |   13 |        0.058 |        3979.29 |     64 |
+#     |   14 |        0.048 |        4859.95 |    128 |
+#     |   15 |        0.073 |        3151.76 |     64 |
+#     |   16 |        0.056 |        4265.94 |     64 |
+#     |   17 |        0.009 |        2754.90 |     64 |
+#     |   18 |        0.011 |        1156.08 |     64 |
+#     |   19 |        0.013 |         955.80 |     64 |
+#     |   20 |        0.029 |         437.71 |     64 |
+#     -------------------------------------------------
+#     Total latency: 1.649 ms  Trials: 1920  Used time : 3598 s  Next ID: 9
+#
+#   This table lists the latency and speed of all tasks.
+#   It also lists the allocation of measurement trials for all tasks.
+#   The last line prints the total weighted latency of these tasks,
+#   which can be a rough estimation of the end-to-end execution time
+#   of the network.
+#   The last line also prints the total number of measurement trials,
+#   total time spent on auto-tuning and the id of the next task to tune.
+#
+#   There will also be some "dmlc::Error"s and CUDA errors. You can safely
+#   ignore them if the tuning can continue.
+
+######################################################################
+# .. note:: Terminate the tuning earlier
+#
+#   You can terminate the tuning earlier by forcely killing this process.
+#   As long as you get at least one valid schedule for each task in the log file,
+#   you should be able to do the compilation (the secion below).
+#
+
+#################################################################
+# Compile and Evaluate
+# --------------------
+# After auto-tuning, we can compile the network with the best schedules we found.
+# All measurement records are dumpled into the log file during auto-tuning,
+# so we can read the log file and load the best schedules.

Review comment:
       Better to also mention what happen and what messages you will see if there is no valid schedules in the log file.

##########
File path: tutorials/auto_scheduler/tune_network_cuda.py
##########
@@ -0,0 +1,286 @@
+# Licensed to the Apache Software Foundation (ASF) under one
+# or more contributor license agreements.  See the NOTICE file
+# distributed with this work for additional information
+# regarding copyright ownership.  The ASF licenses this file
+# to you under the Apache License, Version 2.0 (the
+# "License"); you may not use this file except in compliance
+# with the License.  You may obtain a copy of the License at
+#
+#   http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing,
+# software distributed under the License is distributed on an
+# "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
+# KIND, either express or implied.  See the License for the
+# specific language governing permissions and limitations
+# under the License.
+"""
+Auto-tuning a Neural Network for NVIDIA GPU
+==================================================
+**Author**: `Lianmin Zheng <https://github.com/merrymercy>`_
+
+Auto-tuning for specific devices and workloads is critical for getting the
+best performance. This is a tutorial on how to tune a whole neural
+network for NVIDIA GPU with the auto-scheduler.
+
+To auto-tune a neural network, we partition the network into small subgraphs and 
+tune them independently. Each subgraph is treated as one search task.
+A task scheduler slices the time and dynamically allocates time resources to
+these tasks. The task scheduler predicts the impact of each task on the end-to-end
+execution time and prioritizes the one that can reduce the execution time fastest.
+
+For each subgraph, we use the compute declaration in :code:`tvm/python/topi` to
+get the computational DAG in the tensor expression form.
+We then use the auto-scheduler to construct a search space of this DAG and search
+for good schedules (low-level optimizations).
+
+Different from the template-based :ref:`autotvm <tutorials-autotvm-sec>` which relies on
+manual templates to define the search space, the auto-scheduler does not require any
+schedule templates. So the auto-scheduler only uses the compute declarations
+in :code:`tvm/python/topi` while does not use existing schedule templates.
+
+Note that this tutorial will not run on Windows or recent versions of macOS. To
+get it to run, you will need to wrap the body of this tutorial in a :code:`if
+__name__ == "__main__":` block.
+"""
+
+import numpy as np
+
+import tvm
+from tvm import relay, auto_scheduler
+import tvm.relay.testing
+from tvm.contrib import graph_runtime
+
+#################################################################
+# Define a Network
+# ----------------
+# First, we need to define the network in relay frontend API.
+# We can load some pre-defined network from :code:`tvm.relay.testing`.
+# We can also load models from MXNet, ONNX, PyTorch, and TensorFlow
+# (see :ref:`front end tutorials<tutorial-frontend>`).
+#
+# Note that although auto-scheduler can work with any layouts,
+# we found that the best performance is typically archived with NHWC layout
+# for convolutional neural networks.
+#
+
+
+def get_network(name, batch_size, layout="NHWC", dtype="float32"):
+    """Get the symbol definition and random weight of a network"""
+
+    # auto-scheduler prefers NHWC layout
+    if layout == "NHWC":
+        image_shape = (224, 224, 3)
+    elif layout == "NCHW":
+        image_shape = (3, 224, 224)
+    else:
+        raise ValueError("Invalid layout: " + layout)
+
+    input_shape = (batch_size,) + image_shape
+    output_shape = (batch_size, 1000)
+
+    if name.startswith("resnet-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name.startswith("resnet3d-"):
+        n_layer = int(name.split("-")[1])
+        mod, params = relay.testing.resnet.get_workload(
+            num_layers=n_layer,
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "mobilenet":
+        mod, params = relay.testing.mobilenet.get_workload(
+            batch_size=batch_size, layout=layout, dtype=dtype, image_shape=image_shape
+        )
+    elif name == "squeezenet_v1.1":
+        mod, params = relay.testing.squeezenet.get_workload(
+            version="1.1",
+            batch_size=batch_size,
+            layout=layout,
+            dtype=dtype,
+            image_shape=image_shape,
+        )
+    elif name == "inception_v3":
+        input_shape = (batch_size, 3, 299, 299) if layout == "NCHW" else (batch_size, 299, 299, 3)
+        mod, params = relay.testing.inception_v3.get_workload(batch_size=batch_size, dtype=dtype)
+    elif name == "mxnet":
+        # an example for mxnet model
+        from mxnet.gluon.model_zoo.vision import get_model
+
+        assert layout == "NCHW"
+
+        block = get_model("resnet18_v1", pretrained=True)
+        mod, params = relay.frontend.from_mxnet(block, shape={"data": input_shape}, dtype=dtype)
+        net = mod["main"]
+        net = relay.Function(
+            net.params, relay.nn.softmax(net.body), None, net.type_params, net.attrs
+        )
+        mod = tvm.IRModule.from_expr(net)
+
+    return mod, params, input_shape, output_shape
+
+
+# Define the neural network and compilation target
+network = "resnet-18"
+batch_size = 1
+layout = "NHWC"
+target = tvm.target.Target("cuda")
+dtype = "float32"
+log_file = "%s-%s-B%d.json" % (network, layout, batch_size)
+
+#################################################################
+# Extract Search Tasks
+# --------------------
+# Next, we extract the search tasks and their weights from a network.
+# The weight of a task is the number of appearances of the task's subgraph
+# in the whole network.
+# By using the weight, we can approximate the end-to-end latency of the network
+# as :code:`sum(latency[t] * weight[t])`, where :code:`latency[t]` is the
+# latency of a task and :code:`weight[t]` is the weight of the task.
+
+# Enable auto-scheduler in relay
+auto_scheduler.enable_relay_integration()
+
+# Extract tasks from the network
+print("Extract tasks...")
+mod, params, input_shape, output_shape = get_network(network, batch_size, layout, dtype=dtype)
+tasks, task_weights = auto_scheduler.extract_tasks(mod["main"], params, target)
+
+# Define the objective as the end-to-end exeuction time of the network
+objective = lambda costs: sum(c * w for c, w in zip(costs, task_weights))
+
+#################################################################
+# Begin Tuning
+# ------------
+# Now, we set some options of tuning and launch the search tasks
+#
+# * :code:`measure_ctx` launches a different process for measurement to
+#   provide isolation. It can protect the master process from GPU crashes
+#   happened during measurement and avoid other runtime conflicts.
+# * :code:`min_repeat_ms` defines the minimum duration of one "repeat" in every measurement.
+#   This can warmup the GPU, which is necessary to get accurate measurement results.
+#   Typically, we recommend a value > 300 ms.
+# * :code:`num_measure_trials` is the number of measurement trials we can use during the tuning.
+#   You can set it to a small number (e.g., 200) for a fast demonstrative run.
+#   In practice, we recommend setting it round :code:`1000 * len(tasks)`,
+#   which is typically enough for the search to converge.
+#   For example, there are 21 tasks in resnet-18, so we can set it as 20000 for renset-18.
+#   You can adjust this parameter according to your time budget.
+# * In addition, we use :code:`RecordToFile` to dump measurement records into the log file,
+#   The measurement records can be used to query the history best, resume the search,
+#   and do more analyses later.
+# * see :any:`auto_scheduler.TuningOptions`,
+#   :any:`auto_scheduler.LocalRPCMeasureContext` for more parameters.
+#
+
+
+def run_tuning():
+    print("Begin tuning...")
+    measure_ctx = auto_scheduler.LocalRPCMeasureContext(repeat=1, min_repeat_ms=400, timeout=10)
+
+    tuner = auto_scheduler.TaskScheduler(tasks, objective)
+    tune_option = auto_scheduler.TuningOptions(
+        num_measure_trials=200,  # change this to 20000 to achieve the best performance
+        runner=measure_ctx.runner,
+        measure_callbacks=[auto_scheduler.RecordToFile(log_file)],
+    )
+
+    tuner.tune(tune_option)
+
+
+# We do not run the tuning in our webpage server since it takes too long.
+# Uncomment the following line to run it by yourself.
+
+# run_tuning()
+
+
+######################################################################
+# .. note:: Explain the printed information during tuning
+#
+#   During the tuning, a lot of information will be printed on the screen.
+#   They are used for debugging purposes. The most important info is the output
+#   of the task scheduler. The following table is a sample output.
+#
+#   .. code-block:: c
+#
+#     ----------------------------------------------------------------------
+#     ------------------------------  [ Task Scheduler ]
+#     ----------------------------------------------------------------------
+#     |  ID  | Latency (ms) | Speed (GFLOPS) | Trials |
+#     -------------------------------------------------
+#     |    0 |        0.014 |          72.07 |     64 |
+#     |    1 |        0.185 |        1250.68 |    128 |
+#     |    2 |        0.142 |        1626.36 |    192 |
+#     |    3 |        0.137 |        1689.42 |    128 |
+#     |    4 |        0.097 |        1189.75 |    128 |
+#     |    5 |        0.092 |        2505.25 |    128 |
+#     |    6 |        0.080 |        2893.08 |    128 |
+#     |    7 |        0.119 |        1947.84 |    128 |
+#     |    8 |        0.090 |        1292.62 |     64 |
+#     |    9 |        0.107 |        2172.30 |     64 |
+#     |   10 |        0.095 |        2439.36 |     64 |
+#     |   11 |        0.077 |        3003.22 |     64 |
+#     |   12 |        0.068 |        1695.13 |     64 |
+#     |   13 |        0.058 |        3979.29 |     64 |
+#     |   14 |        0.048 |        4859.95 |    128 |
+#     |   15 |        0.073 |        3151.76 |     64 |
+#     |   16 |        0.056 |        4265.94 |     64 |
+#     |   17 |        0.009 |        2754.90 |     64 |
+#     |   18 |        0.011 |        1156.08 |     64 |
+#     |   19 |        0.013 |         955.80 |     64 |
+#     |   20 |        0.029 |         437.71 |     64 |
+#     -------------------------------------------------
+#     Total latency: 1.649 ms  Trials: 1920  Used time : 3598 s  Next ID: 9
+#
+#   This table lists the latency and speed of all tasks.
+#   It also lists the allocation of measurement trials for all tasks.
+#   The last line prints the total weighted latency of these tasks,
+#   which can be a rough estimation of the end-to-end execution time
+#   of the network.
+#   The last line also prints the total number of measurement trials,
+#   total time spent on auto-tuning and the id of the next task to tune.
+#
+#   There will also be some "dmlc::Error"s and CUDA errors. You can safely
+#   ignore them if the tuning can continue.
+
+######################################################################
+# .. note:: Terminate the tuning earlier
+#
+#   You can terminate the tuning earlier by forcely killing this process.

Review comment:
       Since we use fork and RPC mechanism during tuning, simply ctrl+c may cause zombie processes remaining. Maybe we should suggest a way to  terminate the process as a good practice.




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