This code performs layer-parallel training of deep neural networks of residual type. It utilizes the parallel-in-time software library XBraid to distribute layers of the network to different compute units. Instead of sequential forward and backward propagation through the network, iterative multigrid udpates are performed in parallel to solve for the network propagation and the training simultaneously. See the paper Guenther et al. for a describtion of the method and all details.
The repository includes XBraid as a submodule. To clone both, use either git clone --recurse-submodules [...] for Git version >= 2.13, or git clone [...] followed by cd xbraid, git submodule init and git submodule update for older Git versions.
Type make in the main directory to build both the code and the XBraid library.
Test cases are located in the 'examples/' subfolder. Each example contains a *.cfg that holds configuration options for the current example dataset, the layer-parallelization with XBraid, and the optimization method and parameters.
Run the test cases by callying './main' with the corresponding configuration file, e.g. ./main examples/peaks/peaks.cfg
An optimization history file 'optim.dat' will be flushed to the examples subfolder.