train.py 文件源码

def create_updater(train_iter, optimizer, devices):
    if HAVE_NCCL and len(devices) > 1:
        updater = training.updaters.MultiprocessParallelUpdater(
            train_iter, optimizer, devices=devices)
    elif len(devices) > 1:
        optimizer.lr /= len(devices)
        updater = training.ParallelUpdater(
            train_iter, optimizer, devices=devices)
    else:
        updater = training.StandardUpdater(
            train_iter, optimizer, device=devices['main'])
    return updater