def _test__hvd_dist_model_create_from_backend_dist(backend, true_device):
model = _HorovodDistModel.create_from_backend(backend=backend)
assert hvd.rank() > -1
with pytest.raises(
RuntimeError,
match=r"Can not re-initialize Horovod if it is already initialized"
):
_HorovodDistModel.create_from_backend(backend=backend)
_assert_model(
model,
{
"device": true_device,
"local_rank": hvd.local_rank(),
"rank": hvd.rank(),
"world_size": hvd.size(),
"node_index": 0,
"nnodes": 1,
"nproc_per_node": hvd.local_size(),
},
)
model.finalize()
def _test__hvd_dist_model_create_from_backend_no_dist(backend, true_device):
model = _HorovodDistModel.create_from_backend(backend=backend)
assert hvd.rank() > -1
_assert_model(
model,
{
"device": true_device,
"local_rank": 0,
"rank": 0,
"world_size": 1,
"node_index": 0,
"nnodes": 1,
"nproc_per_node": 1,
},
)
model.finalize()
def test__hvd_dist_model():
with pytest.raises(ValueError, match=r"Backend should be one of"):
_HorovodDistModel.create_from_backend("abc")