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xc-llm-ascend/vllm_ascend/quantization/w8a8_dynamic.py
Mercykid-bash 29e2f9a43e Bugfix: Align expert map shapes with redundant experts in EPLB adjustment (#5285)
#### Overview
This PR fixes a shape mismatch bug between `expert_placement_map` and
`log2phy_expert_map` when **redundant experts** are enabled in the
vLLM-Ascend platform. The issue occurred during the initialization of
expert maps and their updates via EPLB (Expert Load Balancer)
adjustment, leading to potential tensor shape errors and incorrect
expert routing in distributed MoE deployments.

#### Key Changes
1. **Unify expert map shape calculation logic**
- Ensure the shape of `expert_placement_map` and `log2phy_expert_map`
strictly aligns with the total number of experts (including redundant
experts) during initialization.
- Update the shape adjustment logic in EPLB dynamic update process to
match the initial expert map dimensions.

2. **Add shape consistency checks**
- Add assertion statements to verify the shape consistency of the two
maps after initialization and EPLB adjustment, preventing silent shape
mismatches in subsequent operations.

#### Impact
- Resolves tensor shape errors when using redundant experts with EPLB on
Ascend platform.
- Ensures correct expert routing and load balancing for MoE models with
redundant expert configurations.
- No breaking changes to existing functionality; compatible with
non-redundant expert deployments.

- vLLM version: release/v0.13.0
- vLLM main:
ad32e3e19c

---------

Signed-off-by: Che Ruan <cr623@ic.ac.uk>
Signed-off-by: shenchuxiaofugui <1311027364@qq.com>
Co-authored-by: Che Ruan <cr623@ic.ac.uk>
Co-authored-by: shenchuxiaofugui <1311027364@qq.com>
2026-01-06 17:22:36 +08:00

350 lines
15 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 torch
import torch_npu
from vllm.config import CompilationMode, get_current_vllm_config
from vllm.distributed import get_ep_group
from vllm.forward_context import get_forward_context
import vllm_ascend.envs as envs_ascend
from vllm_ascend.ascend_config import get_ascend_config
from vllm_ascend.ascend_forward_context import MoECommType
from vllm_ascend.distributed.parallel_state import get_mc2_group
from vllm_ascend.flash_common3_context import get_flash_common3_context
from vllm_ascend.ops.fused_moe.experts_selector import (select_experts,
zero_experts_compute)
from vllm_ascend.utils import ACL_FORMAT_FRACTAL_NZ, maybe_trans_nz
class AscendW8A8DynamicLinearMethod:
"""Linear method for Ascend W8A8_DYNAMIC.
"""
def __init__(self):
pass
@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]:
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)
return params_dict
def get_pergroup_param(self,
input_size: int,
output_size: int,
params_dtype: torch.dtype,
layer_type: Optional[str] = None) -> Dict[str, Any]:
return {}
@staticmethod
def apply(
layer: torch.nn.Module,
x: torch.Tensor,
bias: Optional[torch.Tensor] = None,
tp_rank: Optional[int] = 0,
) -> torch.Tensor:
quantized_x, pertoken_scale = torch_npu.npu_dynamic_quant(x)
output = torch_npu.npu_quant_matmul(
quantized_x,
layer.weight,
layer.weight_scale,
pertoken_scale=pertoken_scale,
bias=bias,
output_dtype=x.dtype,
)
return output
def process_weights_after_loading(self, layer):
layer.weight.data = layer.weight.data.transpose(0, 1).contiguous()
# cast quantized weight tensors in NZ format for higher inference speed
layer.weight.data = maybe_trans_nz(layer.weight.data)
layer.weight_scale.data = layer.weight_scale.data.flatten()
layer.weight_scale_fp32 = layer.weight_scale.data.to(torch.float32)
layer.weight_offset.data = layer.weight_offset.data.flatten()
class AscendW8A8DynamicFusedMoEMethod:
"""FusedMoe method for Ascend W8A8_DYNAMIC.
"""
def __init__(self):
self.ep_group = get_ep_group()
vllm_config = get_current_vllm_config()
ascend_config = get_ascend_config()
self.use_aclgraph = (vllm_config.compilation_config.mode
== CompilationMode.VLLM_COMPILE
and not vllm_config.model_config.enforce_eager)
self.multistream_overlap_gate = ascend_config.multistream_overlap_gate
self.dynamic_eplb = ascend_config.dynamic_eplb or ascend_config.expert_map_record_path
self.in_dtype = vllm_config.model_config.dtype
self.supports_eplb = True
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 = ""
@staticmethod
def get_weight(num_experts: int, intermediate_size_per_partition: int,
hidden_sizes: int,
params_dtype: torch.dtype) -> Dict[str, Any]:
param_dict = {}
param_dict["w13_weight"] = torch.empty(num_experts,
2 *
intermediate_size_per_partition,
hidden_sizes,
dtype=torch.int8)
param_dict["w2_weight"] = torch.empty(num_experts,
hidden_sizes,
intermediate_size_per_partition,
dtype=torch.int8)
return param_dict
@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 = {}
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["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)
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",
routed_scaling_factor: float = 1.0,
e_score_correction_bias: Optional[torch.Tensor] = None,
is_prefill: bool = True,
enable_force_load_balance: bool = False,
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,
pertoken_scale: Optional[Any] = None,
**kwargs,
) -> torch.Tensor:
zero_expert_num = getattr(layer, "zero_expert_num", 0)
zero_expert_type = getattr(layer, "zero_expert_type", None)
if zero_expert_num == 0 or zero_expert_type is None:
assert router_logits.shape[1] == global_num_experts - global_redundant_expert_num, \
"Number of global experts mismatch (excluding redundancy)"
if self.multistream_overlap_gate:
fc3_context = get_flash_common3_context()
assert fc3_context is not None
topk_weights = fc3_context.topk_weights
topk_ids = fc3_context.topk_ids
else:
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,
routed_scaling_factor=routed_scaling_factor,
e_score_correction_bias=e_score_correction_bias,
global_num_experts=global_num_experts)
assert topk_ids is not None
assert topk_weights is not None
if zero_expert_num > 0 and zero_expert_type is not None:
topk_ids, topk_weights, zero_expert_result = zero_experts_compute(
expert_indices=topk_ids,
expert_scales=topk_weights,
num_experts=global_num_experts,
zero_expert_type=zero_expert_type,
hidden_states=x,
)
# 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:
random_matrix = torch.rand(topk_ids.size(0),
global_num_experts -
global_redundant_expert_num,
device=topk_ids.device)
topk_ids = torch.argsort(
random_matrix, dim=1)[:, :topk_ids.size(1)].to(topk_ids.dtype)
assert topk_weights is not None
topk_weights = topk_weights.to(self.in_dtype)
moe_comm_method = get_forward_context().moe_comm_method
# When VLLM_ASCEND_ENABLE_FUSED_MC2 == 2, use dispatch_gmm_combine_decode, need fp32 scale
w2_weight_scale_fp32_flag = (
get_forward_context().moe_comm_type == MoECommType.FUSED_MC2
and envs_ascend.VLLM_ASCEND_ENABLE_FUSED_MC2 == 2)
if self.dynamic_eplb:
w1 = layer.w13_weight_list
w1_scale = layer.w13_weight_scale_fp32_list
w2 = layer.w2_weight_list
w2_scale = layer.w2_weight_scale_list
else:
w1 = [layer.w13_weight]
w1_scale = [layer.w13_weight_scale_fp32]
w2 = [layer.w2_weight]
w2_scale = [
layer.w2_weight_scale_fp32
if w2_weight_scale_fp32_flag else layer.w2_weight_scale
]
fused_scale_flag = (get_forward_context().moe_comm_type
== MoECommType.FUSED_MC2
and envs_ascend.VLLM_ASCEND_ENABLE_FUSED_MC2 == 1)
final_hidden_states = moe_comm_method.fused_experts(
hidden_states=x,
pertoken_scale=pertoken_scale,
w1=w1,
w1_scale=[layer.fused_w1_scale] if fused_scale_flag else w1_scale,
w2=w2,
w2_scale=[layer.fused_w2_scale] if fused_scale_flag else w2_scale,
topk_weights=topk_weights,
topk_ids=topk_ids,
use_int8_w8a8=True,
expert_map=expert_map,
log2phy=log2phy,
shared_experts=shared_experts,
quantized_x_for_share=quantized_x_for_share,
dynamic_scale_for_share=dynamic_scale_for_share,
dynamic_eplb=self.dynamic_eplb,
mc2_mask=kwargs.get("mc2_mask", None))
if zero_expert_num > 0 and zero_expert_type is not None:
final_hidden_states += zero_expert_result
return final_hidden_states
def process_weights_after_loading(self, layer):
layer.w13_weight.data = layer.w13_weight.data.transpose(
1, 2).contiguous()
layer.w2_weight.data = layer.w2_weight.data.transpose(1,
2).contiguous()
# TODO(zzzzwwjj): Currently, `torch_npu.npu_grouped_matmul_swiglu_quant`
# can only support weight nz.
layer.w13_weight.data = torch_npu.npu_format_cast(
layer.w13_weight.data, ACL_FORMAT_FRACTAL_NZ)
layer.w2_weight.data = torch_npu.npu_format_cast(
layer.w2_weight.data, ACL_FORMAT_FRACTAL_NZ)
layer.w13_weight_scale.data = layer.w13_weight_scale.data.view(
layer.w13_weight_scale.data.shape[0], -1)
layer.w13_weight_scale_fp32 = layer.w13_weight_scale.data.to(
torch.float32)
layer.w13_weight_offset.data = layer.w13_weight_offset.data.view(
layer.w13_weight_offset.data.shape[0], -1)
layer.w2_weight_scale.data = layer.w2_weight_scale.data.view(
layer.w2_weight_scale.data.shape[0], -1)
layer.w2_weight_scale_fp32 = layer.w2_weight_scale.data.to(
torch.float32)
layer.w2_weight_offset.data = layer.w2_weight_offset.data.view(
layer.w2_weight_offset.data.shape[0], -1)
layer.fused_w1_scale = scale_from_float_to_int64(
layer.w13_weight_scale.data)
layer.fused_w2_scale = scale_from_float_to_int64(
layer.w2_weight_scale.data)
if self.dynamic_eplb:
layer.w13_weight_list = [
weight.clone()
for weight in layer.w13_weight.data.unbind(dim=0)
]
layer.w2_weight_list = [
weight.clone() for weight in layer.w2_weight.data.unbind(dim=0)
]
layer.w13_weight_scale_fp32_list = [
weight.clone()
for weight in layer.w13_weight_scale_fp32.data.unbind(dim=0)
]
layer.w2_weight_scale_list = [
weight.clone()
for weight in layer.w2_weight_scale.data.unbind(dim=0)
]
del layer.w13_weight
del layer.w2_weight
del layer.w13_weight_scale
del layer.w13_weight_scale_fp32
del layer.w2_weight_scale
torch.npu.empty_cache()
def scale_from_float_to_int64(scale):
import numpy as np
scale = torch.from_numpy(
np.frombuffer(scale.cpu().to(torch.float32).numpy().tobytes(),
dtype=np.int32).astype(np.int64)).to(scale.device)
return scale