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

44 lines
1.7 KiB

import torch
import torch.nn.functional as F
from colossalai.utils import get_current_device
from colossalai.global_variables import moe_env
from .experts import FFNExperts, TPExperts
class NormalNoiseGenerator:
"""Generates a random noisy mask for logtis tensor.
All noise is generated from a normal distribution (0, 1 / E^2), where
E = the number of experts.
:param num_experts: The number of experts
:type num_experts: int
"""
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
def autocast_softmax(inputs: torch.Tensor, dim: int):
assert inputs.dtype in {torch.float16, torch.float32}
fp16_flag = (inputs.dtype == torch.float16)
sm_input = inputs.to(torch.float32) if fp16_flag else inputs
sm_output = F.softmax(sm_input, dim)
return sm_output
def build_ffn_experts(num_experts: int, d_model: int, d_ff: int, activation=None, drop_rate: float = 0):
moe_mp_size = moe_env.model_parallel_size
if num_experts % moe_mp_size == 0:
return FFNExperts(num_experts, d_model, d_ff, activation, drop_rate)
elif d_ff % moe_mp_size == 0:
return TPExperts(num_experts, d_model, d_ff, activation, drop_rate)
else:
raise NotImplementedError(f"Can not build {num_experts} experts in {moe_mp_size} GPUS.")