pytorch

43fb0015 - custom build script (#30144)

custom build script (#30144) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/30144 Create script to produce libtorch that only contains ops needed by specific models. Developers can use this workflow to further optimize mobile build size. Need keep a dummy stub for unused (stripped) ops because some JIT side logic requires certain function schemas to be existed in the JIT op registry. Test Steps: 1. Build "dump_operator_names" binary and use it to dump root ops needed by a specific model: ``` build/bin/dump_operator_names --model=mobilenetv2.pk --output=mobilenetv2.yaml ``` 2. The MobileNetV2 model should use the following ops: ``` - aten::t - aten::dropout - aten::mean.dim - aten::add.Tensor - prim::ListConstruct - aten::addmm - aten::_convolution - aten::batch_norm - aten::hardtanh_ - aten::mm ``` NOTE that for some reason it outputs "aten::addmm" but actually uses "aten::mm". You need fix it manually for now. 3. Run custom build script locally (use Android as an example): ``` SELECTED_OP_LIST=mobilenetv2.yaml scripts/build_pytorch_android.sh armeabi-v7a ``` 4. Checkout demo app that uses locally built library instead of downloading from jcenter repo: ``` git clone --single-branch --branch custom_build git@github.com:ljk53/android-demo-app.git ``` 5. Copy locally built libraries to demo app folder: ``` find ${HOME}/src/pytorch/android -name '*.aar' -exec cp {} ${HOME}/src/android-demo-app/HelloWorldApp/app/libs/ \; ``` 6. Build demo app with locally built libtorch: ``` cd ${HOME}/src/android-demo-app/HelloWorldApp ./gradlew clean && ./gradlew assembleDebug ``` 7. Install and run the demo app. In-APK arm-v7 libpytorch_jni.so build size reduced from 5.5M to 2.9M. Test Plan: Imported from OSS Differential Revision: D18612127 Pulled By: ljk53 fbshipit-source-id: fa8d5e1d3259143c7346abd1c862773be8c7e29a