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xc-llm-ascend/vllm_ascend/quantization/w8a8_pdmix.py
Slightwind 18eefc23c3 [feature] Support W8A8 PD-Mix Quantization (#4235)
In PD-separated deployment scenarios:

* MoE layers use dynamic quantization exclusively.
* For the Attention module, Prefill (P) nodes use **dynamic**
quantization, while Decode (D) nodes use **static** quantization.

In PD-mixed deployment scenarios:
* **All components fall back to dynamic quantization**, as it is
difficult to distinguish between Prefill and Decode tokens.
___

- vLLM version: v0.11.2
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.2

---------

Signed-off-by: SlightwindSec <slightwindsec@gmail.com>
Signed-off-by: Slightwind <slightwindsec@gmail.com>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>
2025-11-30 11:57:26 +08:00

71 lines
2.7 KiB
Python

from typing import Any, Dict, cast
import torch
from vllm.config import get_current_vllm_config
from .w8a8 import AscendW8A8LinearMethod
from .w8a8_dynamic import (AscendW8A8DynamicFusedMoEMethod,
AscendW8A8DynamicLinearMethod)
class AscendW8A8PDMixLinearMethod(AscendW8A8DynamicLinearMethod):
def __init__(self):
self.kv_transfer_config = get_current_vllm_config().kv_transfer_config
super().__init__()
@staticmethod
def apply(layer, x, bias=None, tp_rank=0):
if layer.is_kv_consumer:
return AscendW8A8LinearMethod.apply(layer, x, bias, tp_rank)
else:
return AscendW8A8DynamicLinearMethod.apply(layer, x, bias, tp_rank)
@staticmethod
def get_pertensor_param(params_dtype: torch.dtype) -> Dict[str, Any]:
return AscendW8A8LinearMethod.get_pertensor_param(params_dtype)
@staticmethod
def get_perchannel_param(
output_size: int,
params_dtype: torch.dtype,
) -> Dict[str, Any]:
return AscendW8A8LinearMethod.get_perchannel_param(
output_size, params_dtype)
def process_weights_after_loading(self, layer):
AscendW8A8LinearMethod.process_weights_after_loading(
cast(AscendW8A8LinearMethod, self), layer)
layer.weight_scale_fp32 = layer.weight_scale.data.to(torch.float32)
layer.is_kv_consumer = self.kv_transfer_config is not None and self.kv_transfer_config.is_kv_consumer
class AscendW8A8PDMixFusedMoeMethod(AscendW8A8DynamicFusedMoEMethod):
def __init__(self):
super().__init__()
@staticmethod
def get_dynamic_quant_param(num_experts: int,
intermediate_size_per_partition: int,
hidden_sizes: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
param_dict = AscendW8A8DynamicFusedMoEMethod.get_dynamic_quant_param(
num_experts, intermediate_size_per_partition, hidden_sizes,
params_dtype)
param_dict["w2_deq_scale"] = torch.empty(num_experts,
hidden_sizes,
dtype=torch.float32)
param_dict["w13_deq_scale"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
dtype=torch.float32)
param_dict["w2_input_offset"] = torch.empty(num_experts,
1,
dtype=torch.int8)
param_dict["w13_input_offset"] = torch.empty(num_experts,
1,
dtype=torch.int8)
return param_dict