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sglang/python/sglang/srt/layers/layernorm.py

127 lines
3.6 KiB
Python

"""
Copyright 2023-2024 SGLang Team
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
"""
"""Fused operators for normalization layers."""
import logging
from typing import Optional, Tuple, Union
import torch
import torch.nn as nn
from sglang.srt.utils import is_hip
if not is_hip():
from flashinfer.norm import (
fused_add_rmsnorm,
gemma_fused_add_rmsnorm,
gemma_rmsnorm,
rmsnorm,
)
from vllm.model_executor.custom_op import CustomOp
logger = logging.getLogger(__name__)
class RMSNorm(CustomOp):
def __init__(
self,
hidden_size: int,
eps: float = 1e-6,
) -> None:
super().__init__()
self.weight = nn.Parameter(torch.ones(hidden_size))
self.variance_epsilon = eps
def forward_cuda(
self,
x: torch.Tensor,
residual: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
if residual is not None:
fused_add_rmsnorm(x, residual, self.weight.data, self.variance_epsilon)
return x, residual
out = rmsnorm(x, self.weight.data, self.variance_epsilon)
return out
def forward_native(
self,
x: torch.Tensor,
residual: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
orig_dtype = x.dtype
x = x.to(torch.float32)
if residual is not None:
x = x + residual.to(torch.float32)
residual = x.to(orig_dtype)
variance = x.pow(2).mean(dim=-1, keepdim=True)
x = x * torch.rsqrt(variance + self.variance_epsilon)
x = x.to(orig_dtype) * self.weight
if residual is None:
return x
else:
return x, residual
class GemmaRMSNorm(CustomOp):
def __init__(
self,
hidden_size: int,
eps: float = 1e-6,
) -> None:
super().__init__()
self.weight = nn.Parameter(torch.zeros(hidden_size))
self.variance_epsilon = eps
def forward_native(
self,
x: torch.Tensor,
residual: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
orig_dtype = x.dtype
if residual is not None:
x = x + residual
residual = x
x = x.float()
variance = x.pow(2).mean(dim=-1, keepdim=True)
x = x * torch.rsqrt(variance + self.variance_epsilon)
x = x * (1.0 + self.weight.float())
x = x.to(orig_dtype)
return x if residual is None else (x, residual)
def forward_cuda(
self,
x: torch.Tensor,
residual: Optional[torch.Tensor] = None,
) -> Union[torch.Tensor, Tuple[torch.Tensor, torch.Tensor]]:
if residual is not None:
gemma_fused_add_rmsnorm(
x, residual, self.weight.data, self.variance_epsilon
)
return x, residual
out = gemma_rmsnorm(x, self.weight.data, self.variance_epsilon)
return out
if is_hip():
logger.info(
"FlashInfer is not available on AMD GPUs. Fallback to other kernel libraries."
)
from vllm.model_executor.layers.layernorm import GemmaRMSNorm, RMSNorm