63
vllm_ascend/ops/fused_moe/gate_linear.py
Normal file
63
vllm_ascend/ops/fused_moe/gate_linear.py
Normal file
@@ -0,0 +1,63 @@
|
||||
#
|
||||
# Copyright (c) 2025 Huawei Technologies Co., Ltd. All Rights Reserved.
|
||||
# This file is a part of the vllm-ascend project.
|
||||
#
|
||||
# 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.
|
||||
#
|
||||
|
||||
from __future__ import annotations
|
||||
|
||||
import torch
|
||||
from vllm.model_executor.layers.fused_moe.router.gate_linear import GateLinear
|
||||
from vllm.model_executor.layers.linear import ReplicatedLinear
|
||||
|
||||
|
||||
class AscendGateLinear(GateLinear):
|
||||
"""Ascend replacement for vLLM GateLinear.
|
||||
Router logits are sensitive to numerical precision because they directly
|
||||
affect expert selection in MoE models. On NPU, computing the router gate in
|
||||
lower precision may lead to accuracy issues in some agent workloads.
|
||||
Therefore, this layer forces the gate input and weights to fp32 for the
|
||||
router linear computation, and keeps the router logits in fp32.
|
||||
"""
|
||||
|
||||
def __init__(
|
||||
self,
|
||||
input_size: int,
|
||||
output_size: int,
|
||||
bias: bool = False,
|
||||
out_dtype: torch.dtype | None = None,
|
||||
params_dtype: torch.dtype | None = None,
|
||||
force_fp32_compute: bool = False,
|
||||
prefix: str = "",
|
||||
):
|
||||
super().__init__(
|
||||
input_size=input_size,
|
||||
output_size=output_size,
|
||||
bias=bias,
|
||||
params_dtype=torch.float32,
|
||||
out_dtype=out_dtype,
|
||||
force_fp32_compute=True,
|
||||
prefix=prefix,
|
||||
)
|
||||
|
||||
def forward(self, x: torch.Tensor):
|
||||
# TODO: Remove this workaround after upgrading to a vLLM version that
|
||||
# no longer forces router logits to bf16 via
|
||||
# self.gate.set_out_dtype(torch.bfloat16).
|
||||
if x.dtype != torch.float32:
|
||||
x = x.to(torch.float32)
|
||||
|
||||
output, output_bias = ReplicatedLinear.forward(self, x)
|
||||
|
||||
return output, output_bias
|
||||
Reference in New Issue
Block a user