[autoparallel] add experimental permute handler (#2029)

colossalai/tensor/comm_spec.py

@@ -23,6 +23,8 @@ def _all_gather(tensor, comm_spec):
                 torch.zeros(tensor.shape, dtype=tensor.dtype, device=tensor.device)
                 for _ in range(comm_spec.device_mesh.mesh_shape[comm_spec.logical_process_axis])
             ]
+            # without this contiguous operation, the all gather may get some unexpected results.
+            tensor = tensor.contiguous()
             dist.all_gather(tensor_list, tensor, group=process_group)
             output = torch.cat(tuple(tensor_list), comm_spec.gather_dim).contiguous()
             return output