[tensor]add 1D device mesh (#1492)

pull/1487/head
YuliangLiu0306 2022-08-25 16:48:12 +08:00 committed by GitHub
parent b8d0e39eaf
commit 4b03c25f85
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4 changed files with 66 additions and 13 deletions

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@ -25,7 +25,13 @@ class DeviceMesh:
(default: False)
"""
def __init__(self, physical_mesh_id, mesh_shape, mesh_alpha=None, mesh_beta=None, init_process_group=False):
def __init__(self,
physical_mesh_id,
mesh_shape,
mesh_alpha=None,
mesh_beta=None,
init_process_group=False,
need_flatten=True):
self.physical_mesh_id = physical_mesh_id
self.mesh_shape = mesh_shape
self._logical_mesh_id = self.physical_mesh_id.reshape(self.mesh_shape)
@ -39,8 +45,12 @@ class DeviceMesh:
mesh_beta = [1] * len(self.mesh_shape)
self.mesh_alpha = tuple(mesh_alpha)
self.mesh_beta = tuple(mesh_beta)
if init_process_group:
self.init_process_group = init_process_group
self.need_flatten = need_flatten
if self.init_process_group:
self.process_groups_dict = self.create_process_groups_for_logical_mesh()
if self.need_flatten:
self.flatten_device_mesh = self.flatten()
@property
def shape(self):
@ -54,6 +64,19 @@ class DeviceMesh:
def logical_mesh_id(self):
return self._logical_mesh_id
def flatten(self):
"""
Flatten the logical mesh into an effective 1d logical mesh,
"""
flatten_mesh_shape_size = len(self.mesh_shape)
flatten_mesh_shape = [self.num_devices]
return DeviceMesh(self.physical_mesh_id,
tuple(flatten_mesh_shape),
mesh_alpha=[max(self.mesh_alpha)] * (flatten_mesh_shape_size - 1),
mesh_beta=[min(self.mesh_beta)] * (flatten_mesh_shape_size - 1),
init_process_group=self.init_process_group,
need_flatten=False)
def _global_rank_to_logical_rank_map(self, tensor, index_list):
'''
This method is a helper function to build convert_map recursively.

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@ -3,6 +3,7 @@ from colossalai.tensor.sharding_spec import ShardingSpec, _DimSpec
from colossalai.tensor.utils import all_gather_simulator, all_to_all_simulator, shard_simulator
from enum import Enum
from copy import deepcopy
from typing import Dict, List, Optional, Tuple, Union
import torch.distributed as dist
import math
from functools import reduce
@ -29,9 +30,9 @@ class CommSpec:
Argument:
comm_pattern(CollectiveCommPattern): decribe the communication method used in this spec.
sharding_spec(ShardingSpec): This is sharding spec of the tensor which will join the communication action.
gather_dim(int, optional): The gather_dim of the tensor will be gathered.
shard_dim(int, optional): The shard_dim of the tensor will be sharded.
logical_process_axis(int, optional): The mesh_dim to implement the communication action.
gather_dim(int, Optional): The gather_dim of the tensor will be gathered.
shard_dim(int, Optional): The shard_dim of the tensor will be sharded.
logical_process_axis(Union(int, List[int]), Optional): The mesh_dim to implement the communication action.
'''
def __init__(self, comm_pattern, sharding_spec, gather_dim=None, shard_dim=None, logical_process_axis=None):
@ -40,6 +41,11 @@ class CommSpec:
self.gather_dim = gather_dim
self.shard_dim = shard_dim
self.logical_process_axis = logical_process_axis
if isinstance(self.logical_process_axis, list):
self.device_mesh = self.sharding_spec.device_mesh.flatten_device_mesh
self.logical_process_axis = 0
else:
self.device_mesh = self.sharding_spec.device_mesh
def __repr__(self):
res_list = ["CommSpec:("]
@ -70,11 +76,11 @@ class CommSpec:
'''
comm_size = reduce(operator.mul, self.sharding_spec.get_sharded_shape_per_device(), 1)
if self.comm_pattern == CollectiveCommPattern.ALLGATHER:
return self.sharding_spec.device_mesh.all_gather_cost(comm_size, self.logical_process_axis)
return self.device_mesh.all_gather_cost(comm_size, self.logical_process_axis)
if self.comm_pattern == CollectiveCommPattern.ALLTOALL:
return self.sharding_spec.device_mesh.all_to_all_cost(comm_size, self.logical_process_axis)
return self.device_mesh.all_to_all_cost(comm_size, self.logical_process_axis)
if self.comm_pattern == CollectiveCommPattern.ALLREDUCE:
return self.sharding_spec.device_mesh.all_reduce_cost(comm_size, self.logical_process_axis)
return self.device_mesh.all_reduce_cost(comm_size, self.logical_process_axis)
if self.comm_pattern == CollectiveCommPattern.SHARD:
return 0
raise RuntimeError(f"Could not find a matching CollectiveCommPattern for {self.comm_pattern}.")
@ -87,15 +93,14 @@ class CommSpec:
Argument:
tensor(torch.Tensor): Tensor stored in each device, which could be different in different ranks.
'''
device_mesh = self.sharding_spec.device_mesh
process_groups_list = device_mesh.process_groups_dict[self.logical_process_axis]
process_groups_list = self.device_mesh.process_groups_dict[self.logical_process_axis]
if self.comm_pattern == CollectiveCommPattern.ALLGATHER:
for rank_list, process_group in process_groups_list:
if dist.get_rank() in rank_list:
tensor_list = [
torch.zeros(tensor.shape, dtype=tensor.dtype, device=tensor.device)
for _ in range(self.sharding_spec.device_mesh.mesh_shape[self.logical_process_axis])
for _ in range(self.device_mesh.mesh_shape[self.logical_process_axis])
]
tensor = tensor
group = process_group

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@ -133,13 +133,36 @@ def check_all_reduce(device_mesh, rank):
# device_mesh_shape: (2, 2)
sharding_spec = ShardingSpec(device_mesh, tensor_to_comm.shape, dim_partition_dict=dim_partition_dict)
# CommSpec:CommSpec:(comm_pattern:all_reduce, logical_process_axis:0)
# CommSpec:(comm_pattern:all_reduce, logical_process_axis:0)
comm_spec = CommSpec(CollectiveCommPattern.ALLREDUCE, sharding_spec, logical_process_axis=0)
comm_spec.covert_spec_to_action(tensor_to_comm)
assert tensor_to_comm.equal(tensor_to_check)
def check_all_reduce_in_flatten_device_mesh(device_mesh, rank):
# tensor to comm
tensor_to_comm = torch.ones(2, 2).cuda() * rank
# reduce through logical process axis 0 at flatten device mesh
# tensor to check
# tensor([[6., 6.],
# [6., 6.]])
tensor_to_check = torch.tensor([[6, 6], [6, 6]], dtype=tensor_to_comm.dtype).cuda()
dim_partition_dict = {}
# DistSpec:
# shard_sequence: R,R
# device_mesh_shape: (2, 2)
sharding_spec = ShardingSpec(device_mesh, tensor_to_comm.shape, dim_partition_dict=dim_partition_dict)
# CommSpec:(comm_pattern:all_reduce, logical_process_axis:[0, 1])
comm_spec = CommSpec(CollectiveCommPattern.ALLREDUCE, sharding_spec, logical_process_axis=[0, 1])
comm_spec.covert_spec_to_action(tensor_to_comm)
assert tensor_to_comm.equal(tensor_to_check)
def check_comm(rank, world_size, port):
disable_existing_loggers()
launch(config={}, rank=rank, world_size=world_size, host='localhost', port=port, backend='nccl')
@ -162,6 +185,9 @@ def check_comm(rank, world_size, port):
# test all reduce
check_all_reduce(device_mesh, rank)
# test all reduce in 1D flatten device mesh
check_all_reduce_in_flatten_device_mesh(device_mesh, rank)
gpc.destroy()

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@ -64,7 +64,6 @@ def check_apply(rank, world_size, port):
tensor_to_comm.sharding_spec = sharding_spec_source
shape_consistency_manager.apply(tensor_to_comm, sharding_spec_target)
print(tensor_to_comm)
assert tensor_to_comm.equal(tensor_to_check)
assert str(tensor_to_comm.sharding_spec.sharding_sequence) == str(sharding_spec_target.sharding_sequence)