You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
ColossalAI/colossalai/nn/layer/moe/utils.py

69 lines
2.6 KiB

import torch
import torch.nn.functional as F
from colossalai.utils import get_current_device
from colossalai.context.moe_context import MOE_CONTEXT
from .experts import FFNExperts, TPExperts
class ForceFP32Parameter(torch.nn.Parameter):
def half(self, memory_format=None):
return self.data.clone()
class NormalNoiseGenerator:
"""Generates a random noisy mask for logtis tensor.
All noise is generated from a normal distribution :math:`(0, 1 / E^2)`, where
`E = the number of experts`.
Args:
num_experts (int): The number of experts.
"""
def __init__(self, num_experts: int):
self.normal = torch.distributions.normal.Normal(loc=torch.tensor(0.0, device=get_current_device()),
scale=torch.tensor(1.0 / num_experts**2,
device=get_current_device())).rsample
def __call__(self, inputs: torch.Tensor):
noisy = self.normal(inputs.shape)
return inputs + noisy
class UniformNoiseGenerator:
"""Generates a random noisy mask for logtis tensor.
copied from mesh tensorflow:
Multiply values by a random number between :math:`1-epsilon` and :math:`1+epsilon`.
Makes models more resilient to rounding errors introduced by bfloat16.
This seems particularly important for logits.
Args:
eps (float, optional): Epsilon in generator, defaults 1e-2.
"""
def __init__(self, eps: float = 1e-2):
self.uniform = torch.distributions.uniform.Uniform(low=torch.tensor(1.0 - eps, device=get_current_device()),
high=torch.tensor(1.0 + eps,
device=get_current_device())).rsample
def __call__(self, inputs: torch.Tensor):
noisy = self.uniform(inputs.shape)
return inputs * noisy
def autocast_softmax(logit: torch.Tensor, dim: int):
if logit.dtype != torch.float32:
logit = logit.float()
return F.softmax(logit, dim=dim)
def build_ffn_experts(num_experts: int, d_model: int, d_ff: int, activation=None, drop_rate: float = 0):
mep_size = MOE_CONTEXT.max_ep_size
if num_experts % mep_size == 0 or mep_size % num_experts == 0:
return FFNExperts(num_experts, d_model, d_ff, activation, drop_rate)
elif d_ff % mep_size == 0:
return TPExperts(num_experts, d_model, d_ff, activation, drop_rate)
else:
raise NotImplementedError(f"Can not build {num_experts} experts in {mep_size} GPUS.")