ColossalAI/colossalai/tensor/spec.py

99 lines
3.6 KiB
Python

from enum import Enum
from typing import List
from colossalai.context.parallel_mode import ParallelMode
from colossalai.tensor.dist_spec import _DistSpec, DistPlacementPattern
class ComputePattern(Enum):
TP1D = 0
ZeRO = 1
DP = 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.TP1D_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 TP1D_Linear.
# During Linear computation
# Before Linear Op, we gather the tensors according to ZeRO.
# We perform Linear Op according to compute pattern of TP1D_Linear.
# After Linear Op, we split the tensors according to ZeRO.
def __init__(self, dist_spec: _DistSpec, parallel_action_list: List[ParallelAction] = []):
self._parallel_action_list = parallel_action_list
self.dist_spec = dist_spec
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]
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
def get_process_group(self):
return self.dist_spec.process_group
def get_placement(self):
return self.dist_spec.placement
def is_gathered(self):
return self.dist_spec.placement == DistPlacementPattern.REPLICATE \
or (len(self.dist_spec.num_partitions) == 1
and self.dist_spec.num_partitions[0] == 1) \
or (self.dist_spec.process_group.size() == 1)
def is_1D_col(self):
return self.dist_spec.placement == DistPlacementPattern.SHARD \
and len(self.dist_spec.dims) == 1 and self.dist_spec.dims[0] == -1
def is_1D_row(self):
return self.dist_spec.placement == DistPlacementPattern.SHARD \
and len(self.dist_spec.dims) == 1 and self.dist_spec.dims[0] == 0
def has_compute_pattern(self, compute_pattern: ComputePattern):
return self.get_action_by_compute_pattern(compute_pattern) is not None