Function allreduce

caffe2/python/data_parallel_model.py:1382–1393

(blobs, **kwargs)

        reduced_blob = str(master_blob) + "_red"

        def allreduce(blobs, **kwargs):
            with core.DeviceScope(reducing_device_opt):
                comm_world, control_input = \
                    context.get_control_and_context(blobs[0])
                net.Allreduce(
                    inputs=[comm_world] + blobs,
                    outputs=blobs,
                    name=blob_name,
                    engine=all_reduce_engine,
                    control_input=control_input,
                    **kwargs
                )

        if rendezvous['engine'] == 'GLOO':
            # With Gloo cross GPU and cross machine allreduce