115 lines
3.4 KiB
Python
115 lines
3.4 KiB
Python
"""Provide utils for distributed sparse optimizers
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"""
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import torch as th
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import torch.distributed as dist
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def alltoall_cpu(rank, world_size, output_tensor_list, input_tensor_list):
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"""Each process scatters list of input tensors to all processes in a cluster
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and return gathered list of tensors in output list. The tensors should have the same shape.
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Parameters
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----------
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rank : int
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The rank of current worker
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world_size : int
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The size of the entire communicator
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output_tensor_list : List of tensor
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The received tensors
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input_tensor_list : List of tensor
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The tensors to exchange
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"""
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input_tensor_list = [
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tensor.to(th.device("cpu")) for tensor in input_tensor_list
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]
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for i in range(world_size):
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dist.scatter(
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output_tensor_list[i], input_tensor_list if i == rank else [], src=i
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)
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def alltoallv_cpu(rank, world_size, output_tensor_list, input_tensor_list):
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"""Each process scatters list of input tensors to all processes in a cluster
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and return gathered list of tensors in output list.
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Parameters
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----------
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rank : int
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The rank of current worker
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world_size : int
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The size of the entire communicator
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output_tensor_list : List of tensor
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The received tensors
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input_tensor_list : List of tensor
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The tensors to exchange
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"""
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# send tensor to each target trainer using torch.distributed.isend
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# isend is async
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senders = []
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for i in range(world_size):
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if i == rank:
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output_tensor_list[i] = input_tensor_list[i].to(th.device("cpu"))
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else:
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sender = dist.isend(
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input_tensor_list[i].to(th.device("cpu")), dst=i
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)
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senders.append(sender)
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for i in range(world_size):
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if i != rank:
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dist.recv(output_tensor_list[i], src=i)
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th.distributed.barrier()
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def alltoall(rank, world_size, output_tensor_list, input_tensor_list):
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"""Each process scatters list of input tensors to all processes in a cluster
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and return gathered list of tensors in output list. The tensors should have the same shape.
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Parameters
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----------
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rank : int
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The rank of current worker
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world_size : int
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The size of the entire communicator
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output_tensor_list : List of tensor
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The received tensors
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input_tensor_list : List of tensor
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The tensors to exchange
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"""
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if th.distributed.get_backend() == "nccl":
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th.distributed.all_to_all(output_tensor_list, input_tensor_list)
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else:
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alltoall_cpu(
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rank,
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world_size,
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output_tensor_list,
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input_tensor_list,
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)
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def alltoallv(rank, world_size, output_tensor_list, input_tensor_list):
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"""Each process scatters list of input tensors to all processes in a cluster
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and return gathered list of tensors in output list.
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Parameters
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----------
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rank : int
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The rank of current worker
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world_size : int
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The size of the entire communicator
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output_tensor_list : List of tensor
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The received tensors
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input_tensor_list : List of tensor
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The tensors to exchange
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"""
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if th.distributed.get_backend() == "nccl":
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th.distributed.all_to_all(output_tensor_list, input_tensor_list)
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else:
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alltoallv_cpu(
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rank,
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world_size,
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output_tensor_list,
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input_tensor_list,
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)
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