rondogency commented on a change in pull request #17585: Dynamic subgraph property doc URL: https://github.com/apache/incubator-mxnet/pull/17585#discussion_r381475714
########## File path: example/extensions/lib_subgraph/README.md ########## @@ -0,0 +1,192 @@ +<!--- 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. --> + +Custom Partitioner Example and Tutorial +======================================= + +## Introduction + +Adding custom model partitioners in MXNet used to require deep understanding of the MXNet backend, including operator registration and other internal classes, followed by recompiling MXNet from source. This feature allows adding custom partitioners by dynamically loading external libraries at runtime. + +This custom partitioner feature enables users to write custom model partitioning strategies without compiling against all of MXNet header files and dependencies. When a library containing custom partitioners is loaded dynamically, the components found in the library will be re-registered in MXNet so that users can use those natively just like other built-in components. + +## Getting Started + +### Have MXNet Ready + +The custom partitioner feature was merged recently (#15969) and is not available in versions of MXNet prior to v1.7.0. To use the feature now, please install MXNet either by installing the nightly pip wheel or compiling from source. For running the following example, it doesn’t matter if it is a CUDA, MKLDNN or plain MXNet build; the custom partitioner doesn’t interact with the execution of other native MXNet features. Note that if you want to write your custom partitioners running on GPU, you still need an MXNet CUDA build. + +### Run An Example + +You can start getting familiar with custom partitioners by running an example provided in the **example/extensions/lib_subgraph** directory. This example partitions `exp` and `log` operators into subgraphs. Go to the **lib_subgraph** directory and follow these steps: + +1. Run `make`. The Makefile will generate the dynamic library **libsubgraph_lib.so** which is compiled from the `subgraph_lib.cc` file. This is the library you are going to load that contains everything for the custom partitioner. +2. Run `python test_subgraph.py`. It’ll first load the above library, find the components, register them in the MXNet backend, then partition the model and execute the operators like a regular MXNet operator and output the result. Below is the output when running the `python test_subgraph.py` command. Notice that it loads 2 operators: my_gemm and state_gemm. + +``` +[10:38:03] src/c_api/c_api.cc:286: Found 1 operators in library +[10:38:03] src/c_api/c_api.cc:350: Op[0] _custom_subgraph_op +[10:38:03] src/c_api/c_api.cc:785: Found 1 partitioners in library +[10:38:03] src/c_api/c_api.cc:801: Partitioner[0] myProp +[10:38:03] src/c_api/c_api.cc:821: Strategy[0] strategy1 subgraphOp: '_custom_subgraph_op' +``` + +### Basic Files For Custom Partitioner Library + +* **lib_subgraph/subgraph_lib.cc**: This file has a source code implementation of all required components to make a custom partitioner, it also shows registration of them so that they can be loaded by MXNet. + +* **lib_subgraph/Makefile**: This file compiles the source code to a dynamic shared library, with a header file `include/mxnet/lib_api.h` from MXNet source code. Currently the custom operator is compatible with C++11 onwards. + +* **lib_subgraph/test_subgraph.py**: This file calls `mx.library.load(‘libsubgraph_lib.so’)` to load the library containing the custom components, partitions the model using the `optimize_for` API, and prints outputs of the forward passes. The outputs should be the same as the regular MXNet forward pass without partitioning. + Review comment: nit: add lib_api.h intro here like https://github.com/apache/incubator-mxnet/blob/master/example/extensions/lib_custom_op/README.md#basic-files-for-a-gemm-library ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: us...@infra.apache.org With regards, Apache Git Services
