ColossalAI/colossalai/tensor/spec.py

88 lines
2.9 KiB
Python

from enum import Enum
from typing import Tuple, List
from colossalai.context.parallel_mode import ParallelMode
class ComputePattern(Enum):
TP1DRow_Linear = 1
TP1DCol_Linear = 2
TP1DRow_Embedding = 3
TP1DCol_Embedding = 4
ZeRO = 5
DP = 6
class ShardPattern(Enum):
NA = 0
Row = 1
Col = 2
class ParallelAction(object):
def __init__(self,
priority=0,
compute_pattern=ComputePattern.DP,
parallel_mode=ParallelMode.DATA,
gather_out=True) -> None:
self.priority = priority
self.compute_pattern = compute_pattern
self.parallel_mode = parallel_mode
self.gather_out = gather_out
class TensorSpec(object):
"""
It contains two aspects of information:
First, How are tensors distributed in Heterougenous memory space.
Second, if the tensor is a model parameter, the Spec contains the
parallel computation pattern of the Operator (Layer).
We have to consider the hybrid parallel mode.
"""
# a list of parallel actions.
# For example: On 8 GPUs, a hybrid parallel strategy is applied using
# using ZeRO with DP-degree = 4 and 1DRowTP with TP-degree = 2.
# parallel_action_list = [
# ParallelAction(10, ComputePattern.ZeRO, gpc.get_group(ParallelMode.DATA)),
# ParallelAction(1, ComputePattern.TP1DRow_Linear, gpc.get_group(ParallelMode.PARALLEL_1D))
# ]
# When the ColoTensor is initialized,
# we first splitting tensor according to ParallelAction of ZeRO,
# then splitting tensor according to ParallelAction of TP1DRow_Linear.
# During Linear computation
# Before Linear Op, we gather the tensors according to ZeRO.
# We perform Linear Op according to compute pattern of TP1DRow_Linear.
# After Linear Op, we split the tensors according to ZeRO.
def __init__(self, parallel_action_list: List[ParallelAction] = [], shard_pattern: ShardPattern = ShardPattern.NA):
self._parallel_action_list = parallel_action_list
self._shard_pattern = shard_pattern
self.sort()
@property
def parallel_action_list(self):
return self._parallel_action_list
@property
def num_action(self):
return len(self._parallel_action_list)
@property
def compute_patterns(self):
return [parallel_action.compute_pattern for parallel_action in self._parallel_action_list]
@property
def shard_pattern(self):
return self._shard_pattern
def sort(self):
if len(self._parallel_action_list) > 0:
self._parallel_action_list.sort(key=lambda parallel_action: parallel_action.priority)
def get_action_by_compute_pattern(self, compute_pattern: ComputePattern):
for parallel_action in self._parallel_action_list:
if parallel_action.compute_pattern == compute_pattern:
return parallel_action
return None