Files
xc-llm-ascend/vllm_ascend/quantization/w4a8_dynamic.py
Wang Kunpeng c40d4171bc [main][quantization] Adapt to the new format of ds w4a8 weight (#2392)
### What this PR does / why we need it?

The deepseek w4a8 weights we supported before were in mindie-format
format. It uses int8 to represent int4, so the weight size is similar to
w8a8, and we need to do a few extra steps to make vllm-ascend load it
normally.

Now we can directly use the new weight format, which uses two int4 packs
to save the weight, the weight size is reduced, and there is no need to
do many extra operations to directly use it on vllm-ascend, but we are
also compatible with the weights of the previous mindie format.

The weight changes in the new version: 
1. The weight is packed (2 int4 pack to int8)
2. The bias required in the apply method is directly generated by
modelslim

### Does this PR introduce _any_ user-facing change?
no

### How was this patch tested?

Adding ut case in `tests/ut/quantization/test_w4a8_dynamic.py`

#### 1.How to get weights using Modelslim

##### Installation steps

we can use the branch br_release_MindStudio_8.1.RC2_TR5_20260624
git clone -b br_release_MindStudio_8.1.RC2_TR5_20260624
https://gitee.com/ascend/msit.git
cd msit/msmodelslim
bash install.sh

##### Generate w4a8 weights

cd /example/DeepSeek
Command reference: msmodelslim/example/DeepSeek/README.md Execute the
[pre-check](https://gitee.com/ascend/msit/blob/br_release_MindStudio_8.1.RC2_TR5_20260624/msmodelslim/example/DeepSeek/README.md#%E8%BF%90%E8%A1%8C%E5%89%8D%E5%BF%85%E6%A3%80)
and [DeepSeek-R1 w4a8 mix
quantization](https://gitee.com/ascend/msit/blob/br_release_MindStudio_8.1.RC2_TR5_20260624/msmodelslim/example/DeepSeek/README.md#deepseek-r1-w4a8-%E6%B7%B7%E5%90%88%E9%87%8F%E5%8C%96%E5%89%8D%E4%B8%89%E5%B1%82-mlpw8a8-dynamic-%E9%87%8F%E5%8C%96mla%E5%85%B1%E4%BA%AB%E4%B8%93%E5%AE%B6w8a8%E9%87%8F%E5%8C%96%E8%B7%AF%E7%94%B1%E4%B8%93%E5%AE%B6w4a8-dynamic%E9%87%8F%E5%8C%96)
chapter
Reference command:python3 quant_deepseek_w4a8.py --model_path {Original
weight path} --save_path {Generate weight path}

##### Adapt to vllm-ascend

Modification in `config.json`:`"model_type":deepseekv2` is changed to
`"model_type":deepseek_v3`;

#### 2.How to run w4a8

##### a.How to run eager mode

export VLLM_ASCEND_MLA_PA=1

python -m vllm.entrypoints.openai.api_server --model=$1
--trust-remote-code -tp $2 -dp $3 --enable_expert_parallel
--quantization ascend --port $4 --max-model-len $5 --max-num-seqs $6
--enforce-eager
eg: python -m vllm.entrypoints.openai.api_server
--model=/weightpath/w4a8_4_layer --trust-remote-code -tp 4 -dp 4
--enable_expert_parallel --quantization ascend --port 8002
--max-model-len 5120 --max-num-seqs 128 --enforce-eager

##### b.How to run graph mode

export HCCL_BUFFSIZE=1024

python -m vllm.entrypoints.openai.api_server --model=$1
--trust-remote-code -tp $2 -dp $3 --enable_expert_parallel
--quantization ascend --port $4 --max-model-len $5
--additional_config='{"ascend_scheduler_config":{"enabled":true},"torchair_graph_config":{"enabled":true}}'
eg: python -m vllm.entrypoints.openai.api_server
--model=/weight/dsr1_w4a8_vllm --trust-remote-code -tp 4 -dp 4
--enable_expert_parallel --quantization ascend --port 8002
--max-model-len 5120
--additional_config='{"ascend_scheduler_config":{"enabled":true},"torchair_graph_config":{"enabled":true}}'


- vLLM version: v0.10.0
- vLLM main:
103f1ec8d3

---------

Signed-off-by: Wang Kunpeng <1289706727@qq.com>
2025-08-20 20:25:18 +08:00

425 lines
19 KiB
Python

#
# 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 typing import Any, Callable, Dict, Optional
import numpy as np
import torch
import torch_npu
from vllm.config import get_current_vllm_config
from vllm.distributed import get_ep_group
from vllm.forward_context import get_forward_context
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.ascend_forward_context import FusedMoEState
from vllm_ascend.distributed.parallel_state import get_mc2_group
from vllm_ascend.ops.layers.experts_selector import select_experts
from vllm_ascend.quantization.w8a8_dynamic import (fused_experts_with_all2all,
fused_experts_with_mc2)
from vllm_ascend.torchair.utils import npu_stream_switch, npu_wait_tensor
class AscendW4A8DynamicLinearMethod:
"""Linear method for Ascend W4A8_DYNAMIC
"""
def __init__(self):
self.transpose_weight = True
try:
self.group_size = get_current_vllm_config(
).quant_config.quant_description.get("group_size", 256)
except AttributeError:
self.group_size = 256
@staticmethod
def get_weight(input_size: int, output_size: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
params_dict = {
"weight": torch.empty(output_size, input_size, dtype=torch.int8)
}
return params_dict
@staticmethod
def get_pertensor_param(params_dtype: torch.dtype) -> Dict[str, Any]:
return {}
@staticmethod
def get_perchannel_param(output_size: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
return {}
def get_pergroup_param(self, input_size: int, output_size: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
params_dict = {}
params_dict["weight_scale"] = torch.empty(output_size,
1,
dtype=params_dtype)
params_dict["weight_offset"] = torch.empty(output_size,
1,
dtype=params_dtype)
params_dict["weight_scale_second"] = torch.empty(output_size,
input_size //
self.group_size,
dtype=params_dtype)
params_dict["weight_offset_second"] = torch.empty(output_size,
input_size //
self.group_size,
dtype=params_dtype)
return params_dict
@staticmethod
def process_scale_second(weight: torch.Tensor, scale: torch.Tensor,
per_group_scale: torch.Tensor):
k, n = weight.shape
group_num, n = per_group_scale.shape
weight_high = weight.to(torch.float32).reshape(
group_num, -1, n) * per_group_scale.reshape(group_num, 1, n)
weight_high = weight_high.reshape(k, n)
bias = 8 * (weight_high.to(torch.float32) * scale).sum(dim=0)
antiquant_scale = (scale * per_group_scale).reshape(group_num, n)
return antiquant_scale.npu(), bias
def apply(
self,
layer: torch.nn.Module,
x: torch.Tensor,
bias: Optional[torch.Tensor] = None,
tp_rank: Optional[int] = None,
) -> torch.Tensor:
return torch_npu.npu_weight_quant_batchmatmul(
x,
layer.weight,
antiquant_scale=layer.weight_scale_second.to(x.dtype),
antiquant_group_size=self.group_size,
)
def process_weights_after_loading(self, layer: torch.nn.Module):
if self.transpose_weight:
layer.weight.data = layer.weight.data.transpose(0, 1).contiguous()
layer.weight_scale.data = layer.weight_scale.data.flatten().to(
torch.float32)
layer.weight_offset.data = layer.weight_offset.data.flatten()
layer.weight_scale_second.data, scale_bias = self.process_scale_second(
layer.weight.data,
layer.weight_scale.data,
layer.weight_scale_second.data.transpose(0, 1).contiguous(),
)
param = torch.nn.Parameter(scale_bias, requires_grad=False)
layer.register_parameter("weight_scale_bias", param)
layer.weight.data = torch_npu.npu_convert_weight_to_int4pack(
layer.weight.data.to(torch.int32))
class AscendW4A8DynamicFusedMoEMethod:
"""FusedMoe method for Ascend W4A8_DYNAMIC.
"""
def __init__(self):
self.transpose_weight = True
self.ep_group = get_ep_group()
ascend_config = get_ascend_config()
self.torchair_graph_enabled = ascend_config.torchair_graph_config.enabled
vllm_config = get_current_vllm_config()
self.group_size = vllm_config.quant_config.quant_description.get(
"group_size", 256)
quant_version = vllm_config.quant_config.quant_description.get(
"version", "0")
# NOTE: new quantize weights: 2 int4 pack into int8
self.new_quant_version = quant_version == "1.0.0"
self.tp_size = 1 if vllm_config.parallel_config.enable_expert_parallel else self.ep_group.world_size
if self.new_quant_version and self.tp_size > 16:
raise ValueError(
"The current weight does not support moe part tp>16.")
try:
device_group = get_mc2_group().device_group
# TODO: Try local_rank = ep_group.rank_in_group
local_rank = torch.distributed.get_rank(group=device_group)
backend = device_group._get_backend(torch.device("npu"))
self.moe_all_to_all_group_name = backend.get_hccl_comm_name(
local_rank)
except AttributeError:
self.moe_all_to_all_group_name = ""
def get_weight(self, num_experts: int,
intermediate_size_per_partition: int, hidden_sizes: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
param_dict = {}
if self.new_quant_version:
w13_output_size = intermediate_size_per_partition
w2_output_size = hidden_sizes // 2
else:
w13_output_size = 2 * intermediate_size_per_partition
w2_output_size = hidden_sizes
param_dict["w13_weight"] = torch.empty(num_experts,
w13_output_size,
hidden_sizes,
dtype=torch.int8)
param_dict["w2_weight"] = torch.empty(num_experts,
w2_output_size,
intermediate_size_per_partition,
dtype=torch.int8)
return param_dict
def get_dynamic_quant_param(self, num_experts: int,
intermediate_size_per_partition: int,
hidden_sizes: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
param_dict = {}
param_dict["w13_weight_scale"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
1,
dtype=params_dtype)
param_dict["w13_weight_offset"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
1,
dtype=params_dtype)
param_dict["w13_weight_scale_second"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
hidden_sizes // self.group_size,
dtype=params_dtype)
param_dict["w13_weight_offset_second"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
hidden_sizes // self.group_size,
dtype=params_dtype)
param_dict["w2_weight_scale"] = torch.empty(num_experts,
hidden_sizes,
1,
dtype=params_dtype)
param_dict["w2_weight_offset"] = torch.empty(num_experts,
hidden_sizes,
1,
dtype=params_dtype)
param_dict["w2_weight_scale_second"] = torch.empty(
num_experts,
hidden_sizes,
intermediate_size_per_partition // self.group_size,
dtype=params_dtype)
param_dict["w2_weight_offset_second"] = torch.empty(
num_experts,
hidden_sizes,
intermediate_size_per_partition // self.group_size,
dtype=params_dtype)
if self.new_quant_version:
param_dict["w13_scale_bias"] = torch.empty(
num_experts,
2 * intermediate_size_per_partition,
1,
dtype=torch.float32)
param_dict["w2_scale_bias"] = torch.empty(num_experts,
hidden_sizes,
16 // self.tp_size,
dtype=torch.float32)
return param_dict
def apply(
self,
layer: torch.nn.Module,
x: torch.Tensor,
router_logits: torch.Tensor,
top_k: int,
renormalize: bool,
use_grouped_topk: bool = False,
global_num_experts: int = -1,
expert_map: Optional[torch.Tensor] = None,
topk_group: Optional[int] = None,
num_expert_group: Optional[int] = None,
custom_routing_function: Optional[Callable] = None,
scoring_func: str = "softmax",
e_score_correction_bias: Optional[torch.Tensor] = None,
is_prefill: bool = True,
enable_force_load_balance: bool = True,
log2phy: torch.Tensor = None,
global_redundant_expert_num: int = 0,
shared_experts: Optional[Any] = None,
quantized_x_for_share: Optional[Any] = None,
dynamic_scale_for_share: Optional[Any] = None,
**kwargs,
) -> torch.Tensor:
assert router_logits.shape[
1] == global_num_experts, "Number of global experts mismatch"
# NOTE: now npu_moe_gating_top_k can only support `group_count=256` pattern
topk_weights, topk_ids = select_experts(
hidden_states=x,
router_logits=router_logits,
top_k=top_k,
use_grouped_topk=use_grouped_topk,
renormalize=renormalize,
topk_group=topk_group,
num_expert_group=num_expert_group,
custom_routing_function=custom_routing_function,
scoring_func=scoring_func,
e_score_correction_bias=e_score_correction_bias,
global_num_experts=global_num_experts)
fused_moe_state = get_forward_context().fused_moe_state
shared_gate_up, shared_dequant_scale = None, None
if shared_experts is not None and fused_moe_state == FusedMoEState.MC2:
with npu_stream_switch("moe_secondary", 0):
npu_wait_tensor(quantized_x_for_share, router_logits)
share_up_out, _ = shared_experts.gate_up_proj(
(quantized_x_for_share, dynamic_scale_for_share))
shared_gate_up, shared_dequant_scale = share_up_out[
0], share_up_out[1]
# this is a naive implementation for experts load balance so as
# to avoid accumulating too much tokens on a single rank.
# currently it is only activated when doing profile runs.
if enable_force_load_balance:
topk_ids = torch.randint_like(topk_ids, 0, global_num_experts)
topk_weights = topk_weights.to(x.dtype)
if fused_moe_state == FusedMoEState.MC2:
return fused_experts_with_mc2(
hidden_states=x,
w1=layer.w13_weight,
w2=layer.w2_weight,
w1_scale=layer.w13_weight_scale_second,
w2_scale=layer.w2_weight_scale_second,
w1_scale_bias=layer.w13_scale_bias,
w2_scale_bias=layer.w2_scale_bias,
topk_weights=topk_weights,
topk_ids=topk_ids,
top_k=top_k,
expert_map=expert_map,
moe_all_to_all_group_name=self.moe_all_to_all_group_name,
log2phy=log2phy,
global_redundant_expert_num=global_redundant_expert_num,
shared_experts=shared_experts,
is_torchair=self.torchair_graph_enabled,
quantized_x_for_share=shared_gate_up,
dynamic_scale_for_share=shared_dequant_scale,
mc2_mask=kwargs.get("mc2_mask", None))
else:
# The current implementation of deepseek moe splits hidden_states
# according to tp_size before they are feed into layers module.
# Therefore, all2all is needed no matter how dp/tp is set so as to
# dispatch/combine tokens.
return fused_experts_with_all2all(
hidden_states=x,
w1=layer.w13_weight,
w2=layer.w2_weight,
w1_scale=layer.w13_weight_scale_second,
w2_scale=layer.w2_weight_scale_second,
w1_scale_bias=layer.w13_scale_bias,
w2_scale_bias=layer.w2_scale_bias,
topk_weights=topk_weights,
topk_ids=topk_ids,
top_k=top_k,
expert_map=expert_map,
ep_group=self.ep_group,
log2phy=log2phy,
global_redundant_expert_num=global_redundant_expert_num,
)
def process_scale(self, weight: torch.Tensor, scale, per_group_scale):
group_num, k, n = weight.shape
# the weight of the new version is reduced by half by pack n, so it needs to be restored
if self.new_quant_version:
n = n * 2
per_group_scale = per_group_scale.reshape(group_num, -1, n)
group_num, quantgroup_num, n = per_group_scale.shape
bias = None
if not self.new_quant_version:
weight_high = weight.to(torch.float32).reshape([group_num, quantgroup_num, -1, n]) * \
per_group_scale.reshape([group_num, quantgroup_num, 1, n])
weight_high = weight_high.reshape([group_num, k, n])
bias = 8 * (weight_high.to(torch.float32) * scale).sum(axis=1)
scale_fp32 = (scale * per_group_scale).to(torch.float16).to(
torch.float32)
scale_fp32_np = scale_fp32.cpu().numpy()
scale_fp32_np.dtype = np.uint32
sscale_uint64 = np.zeros((group_num, quantgroup_num, n * 2),
dtype=np.uint32)
sscale_uint64[..., ::2] = scale_fp32_np
sscale_uint64_buffer = np.frombuffer(sscale_uint64.tobytes(),
dtype=np.int64).copy()
sscale_uint64_tensor = torch.from_numpy(sscale_uint64_buffer).reshape(
group_num, quantgroup_num, n)
sscale_uint64_tensor = sscale_uint64_tensor.npu()
return sscale_uint64_tensor, bias
def update_bias(self, layer, w13_bias, w2_bias):
if self.new_quant_version:
layer.w13_scale_bias.data = layer.w13_scale_bias.data.transpose(
1, 2).contiguous().sum(axis=1)
layer.w2_scale_bias.data = layer.w2_scale_bias.data.transpose(
1, 2).contiguous().sum(axis=1)
else:
w13_scale_bias = torch.nn.Parameter(w13_bias, requires_grad=False)
layer.register_parameter("w13_scale_bias", w13_scale_bias)
w2_scale_bias = torch.nn.Parameter(w2_bias, requires_grad=False)
layer.register_parameter("w2_scale_bias", w2_scale_bias)
def pack_to_int32(self, weight: torch.Tensor):
if self.new_quant_version:
group_num, k, n = weight.shape
assert n % 4 == 0, "the last dim of weight needs to be divided by 4"
packed_n = n // 4
# pack 4 int8(int4*2) to int32, because in pytorch, we need to use int32 to represent int4
packed_weight = torch.from_numpy(
np.frombuffer(weight.cpu().numpy().tobytes(), dtype=np.int32))
return packed_weight.reshape(group_num, k, packed_n).npu()
else:
return torch_npu.npu_quantize(weight.to(torch.float32),
torch.tensor([1.]).npu(), None,
torch.quint4x2, -1, False)
def process_weights_after_loading(self, layer):
if self.transpose_weight:
layer.w13_weight.data = layer.w13_weight.data.transpose(
1, 2).contiguous()
layer.w2_weight.data = layer.w2_weight.data.transpose(
1, 2).contiguous()
layer.w13_weight_scale.data = layer.w13_weight_scale.data.transpose(
1, 2).contiguous()
layer.w2_weight_scale.data = layer.w2_weight_scale.data.transpose(
1, 2).contiguous()
layer.w13_weight_scale_second.data = layer.w13_weight_scale_second.data.transpose(
1, 2).contiguous()
layer.w2_weight_scale_second.data = layer.w2_weight_scale_second.data.transpose(
1, 2).contiguous()
layer.w13_weight_scale_second.data, w13_bias = self.process_scale(
layer.w13_weight, layer.w13_weight_scale.data,
layer.w13_weight_scale_second.data)
layer.w2_weight_scale_second.data, w2_bias = self.process_scale(
layer.w2_weight, layer.w2_weight_scale.data,
layer.w2_weight_scale_second.data)
self.update_bias(layer, w13_bias, w2_bias)
layer.w13_weight.data = self.pack_to_int32(layer.w13_weight.data)
layer.w2_weight.data = self.pack_to_int32(layer.w2_weight.data)