Files
vllm-ascend/vllm_ascend/quantization/utils.py
Slightwind 4f6d60eb06 [Feature] Add W4A4 Flat Quantization support (#3427)
Introduce W4A4 Flat Quantization for better model compression and
inference efficiency on Ascend devices.

- vLLM version: v0.11.0rc3
- vLLM main: https://github.com/vllm-project/vllm/commit/v0.11.0

---------

Signed-off-by: SlightwindSec <slightwindsec@gmail.com>
2025-10-13 23:20:16 +08:00

88 lines
3.5 KiB
Python

from typing import Any, Dict, Optional, Type
from vllm.logger import logger
from .w4a4_flatquant_dynamic import AscendW4A4FlatQuantDynamicLinearMethod
from .w4a8_dynamic import (AscendW4A8DynamicFusedMoEMethod,
AscendW4A8DynamicLinearMethod)
from .w8a8 import (AscendC8KVCacheMethod, AscendW8A8FusedMoEMethod,
AscendW8A8LinearMethod)
from .w8a8_dynamic import (AscendW8A8DynamicFusedMoEMethod,
AscendW8A8DynamicLinearMethod)
ASCEND_QUANTIZATION_METHOD_MAP: Dict[str, Dict[str, Type[Any]]] = {
"W4A8_DYNAMIC": {
"linear": AscendW4A8DynamicLinearMethod,
"moe": AscendW4A8DynamicFusedMoEMethod,
},
"W4A4_FLATQUANT_DYNAMIC": {
"linear": AscendW4A4FlatQuantDynamicLinearMethod,
},
"W8A8": {
"linear": AscendW8A8LinearMethod,
"moe": AscendW8A8FusedMoEMethod,
"attention": AscendC8KVCacheMethod,
},
"W8A8_DYNAMIC": {
"linear": AscendW8A8DynamicLinearMethod,
"moe": AscendW8A8DynamicFusedMoEMethod,
},
"C8": {
"attention": AscendC8KVCacheMethod,
},
}
def get_linear_quant_type(quant_description: Dict[str, Any], prefix: str,
packed_modules_mapping: Dict[str, Any]):
proj_name = prefix.split(".")[-1]
if proj_name in packed_modules_mapping:
quant_type = None
shard_prefixes = [
prefix.replace(proj_name, shard_proj_name)
for shard_proj_name in packed_modules_mapping[proj_name]
]
for shard_prefix in shard_prefixes:
shard_quant_type = quant_description[shard_prefix + '.weight']
if quant_type is None:
quant_type = shard_quant_type
elif shard_quant_type != quant_type:
raise ValueError(
f"Not all shards of {prefix} are quantized with same quant type."
f"Shard {proj_name} uses {shard_quant_type}, but another shard"
f"use {quant_type}. Please check quantization config.")
else:
quant_type = quant_description[prefix + '.weight']
return quant_type
def get_quant_method(quant_description: Dict[str, Any],
prefix: str,
layer_type: str,
packed_modules_mapping: Optional[Dict[str, Any]] = None):
logger.info_once("Using the vLLM Ascend Quantization now!")
if packed_modules_mapping is None:
packed_modules_mapping = dict()
# Attention
if '.attn' in prefix and 'fa_quant_type' in quant_description.keys():
quant_type = quant_description['fa_quant_type']
# Use KVCache int8
elif '.attn' in prefix and 'kv_quant_type' in quant_description.keys():
quant_type = quant_description['kv_quant_type']
# Linear
else:
quant_type = get_linear_quant_type(quant_description, prefix,
packed_modules_mapping)
if quant_type in ASCEND_QUANTIZATION_METHOD_MAP.keys():
method_map = ASCEND_QUANTIZATION_METHOD_MAP[quant_type]
if layer_type in method_map.keys():
method_cls = method_map[layer_type]
return method_cls()
else:
raise NotImplementedError(
f"Currently, vLLM Ascend doesn't support {quant_type} for {layer_type}."
)
raise NotImplementedError("Currently, vLLM Ascend only supports following quant types:" \
f"{list(ASCEND_QUANTIZATION_METHOD_MAP.keys())}")